Merge commit 'v2.6.38-rc1' into kbuild/packaging

This commit is contained in:
Michal Marek 2011-03-09 16:15:44 +01:00
commit 2d8ad87195
23412 changed files with 3067224 additions and 1776882 deletions

19
.gitignore vendored
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@ -35,13 +35,18 @@ modules.builtin
#
# Top-level generic files
#
tags
TAGS
vmlinux
vmlinuz
System.map
Module.markers
Module.symvers
/tags
/TAGS
/linux
/vmlinux
/vmlinuz
/System.map
/Module.markers
/Module.symvers
#
# git files that we don't want to ignore even it they are dot-files
#
!.gitignore
!.mailmap

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@ -105,3 +105,4 @@ Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Uwe Kleine-König <ukl@pengutronix.de>
Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Takashi YOSHII <takashi.yoshii.zj@renesas.com>

14
CREDITS
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@ -2365,8 +2365,6 @@ E: acme@redhat.com
W: http://oops.ghostprotocols.net:81/blog/
P: 1024D/9224DF01 D5DF E3BB E3C8 BCBB F8AD 841A B6AB 4681 9224 DF01
D: IPX, LLC, DCCP, cyc2x, wl3501_cs, net/ hacks
S: R. Brasílio Itiberê, 4270/1010 - Água Verde
S: 80240-060 - Curitiba - Paraná
S: Brazil
N: Karsten Merker
@ -2813,8 +2811,8 @@ D: CDROM driver "sonycd535" (Sony CDU-535/531)
N: Stelian Pop
E: stelian@popies.net
P: 1024D/EDBB6147 7B36 0E07 04BC 11DC A7A0 D3F7 7185 9E7A EDBB 6147
D: sonypi, meye drivers, mct_u232 usb serial hacks
S: Paris, France
D: random kernel hacks
S: Paimpont, France
N: Pete Popov
E: pete_popov@yahoo.com
@ -3554,12 +3552,12 @@ E: cvance@nai.com
D: portions of the Linux Security Module (LSM) framework and security modules
N: Petr Vandrovec
E: vandrove@vc.cvut.cz
E: petr@vandrovec.name
D: Small contributions to ncpfs
D: Matrox framebuffer driver
S: Chudenicka 8
S: 10200 Prague 10, Hostivar
S: Czech Republic
S: 21513 Conradia Ct
S: Cupertino, CA 95014
S: USA
N: Thibaut Varene
E: T-Bone@parisc-linux.org

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@ -32,8 +32,6 @@ DocBook/
- directory with DocBook templates etc. for kernel documentation.
HOWTO
- the process and procedures of how to do Linux kernel development.
IO-mapping.txt
- how to access I/O mapped memory from within device drivers.
IPMI.txt
- info on Linux Intelligent Platform Management Interface (IPMI) Driver.
IRQ-affinity.txt
@ -84,6 +82,8 @@ blockdev/
- info on block devices & drivers
btmrvl.txt
- info on Marvell Bluetooth driver usage.
bus-virt-phys-mapping.txt
- how to access I/O mapped memory from within device drivers.
cachetlb.txt
- describes the cache/TLB flushing interfaces Linux uses.
cdrom/
@ -130,8 +130,6 @@ edac.txt
- information on EDAC - Error Detection And Correction
eisa.txt
- info on EISA bus support.
exception.txt
- how Linux v2.2 handles exceptions without verify_area etc.
fault-injection/
- dir with docs about the fault injection capabilities infrastructure.
fb/
@ -168,6 +166,8 @@ initrd.txt
- how to use the RAM disk as an initial/temporary root filesystem.
input/
- info on Linux input device support.
io-mapping.txt
- description of io_mapping functions in linux/io-mapping.h
io_ordering.txt
- info on ordering I/O writes to memory-mapped addresses.
ioctl/
@ -232,6 +232,8 @@ memory.txt
- info on typical Linux memory problems.
mips/
- directory with info about Linux on MIPS architecture.
mmc/
- directory with info about the MMC subsystem
mono.txt
- how to execute Mono-based .NET binaries with the help of BINFMT_MISC.
mutex-design.txt
@ -250,6 +252,8 @@ numastat.txt
- info on how to read Numa policy hit/miss statistics in sysfs.
oops-tracing.txt
- how to decode those nasty internal kernel error dump messages.
padata.txt
- An introduction to the "padata" parallel execution API
parisc/
- directory with info on using Linux on PA-RISC architecture.
parport.txt

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@ -1,9 +0,0 @@
What: dv1394 (a.k.a. "OHCI-DV I/O support" for FireWire)
Contact: linux1394-devel@lists.sourceforge.net
Description:
New application development should use raw1394 + userspace libraries
instead, notably libiec61883 which is functionally equivalent.
Users:
ffmpeg/libavformat (used by a variety of media players)
dvgrab v1.x (replaced by dvgrab2 on top of raw1394 and resp. libraries)

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@ -0,0 +1,22 @@
What: /proc/<pid>/oom_adj
When: August 2012
Why: /proc/<pid>/oom_adj allows userspace to influence the oom killer's
badness heuristic used to determine which task to kill when the kernel
is out of memory.
The badness heuristic has since been rewritten since the introduction of
this tunable such that its meaning is deprecated. The value was
implemented as a bitshift on a score generated by the badness()
function that did not have any precise units of measure. With the
rewrite, the score is given as a proportion of available memory to the
task allocating pages, so using a bitshift which grows the score
exponentially is, thus, impossible to tune with fine granularity.
A much more powerful interface, /proc/<pid>/oom_score_adj, was
introduced with the oom killer rewrite that allows users to increase or
decrease the badness() score linearly. This interface will replace
/proc/<pid>/oom_adj.
A warning will be emitted to the kernel log if an application uses this
deprecated interface. After it is printed once, future warnings will be
suppressed until the kernel is rebooted.

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@ -0,0 +1,31 @@
What: /sys/bus/usb/devices/.../power/level
Date: March 2007
KernelVersion: 2.6.21
Contact: Alan Stern <stern@rowland.harvard.edu>
Description:
Each USB device directory will contain a file named
power/level. This file holds a power-level setting for
the device, either "on" or "auto".
"on" means that the device is not allowed to autosuspend,
although normal suspends for system sleep will still
be honored. "auto" means the device will autosuspend
and autoresume in the usual manner, according to the
capabilities of its driver.
During normal use, devices should be left in the "auto"
level. The "on" level is meant for administrative uses.
If you want to suspend a device immediately but leave it
free to wake up in response to I/O requests, you should
write "0" to power/autosuspend.
Device not capable of proper suspend and resume should be
left in the "on" level. Although the USB spec requires
devices to support suspend/resume, many of them do not.
In fact so many don't that by default, the USB core
initializes all non-hub devices in the "on" level. Some
drivers may change this setting when they are bound.
This file is deprecated and will be removed after 2010.
Use the power/control file instead; it does exactly the
same thing.

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@ -0,0 +1,29 @@
rfkill - radio frequency (RF) connector kill switch support
For details to this subsystem look at Documentation/rfkill.txt.
What: /sys/class/rfkill/rfkill[0-9]+/state
Date: 09-Jul-2007
KernelVersion v2.6.22
Contact: linux-wireless@vger.kernel.org
Description: Current state of the transmitter.
This file is deprecated and sheduled to be removed in 2014,
because its not possible to express the 'soft and hard block'
state of the rfkill driver.
Values: A numeric value.
0: RFKILL_STATE_SOFT_BLOCKED
transmitter is turned off by software
1: RFKILL_STATE_UNBLOCKED
transmitter is (potentially) active
2: RFKILL_STATE_HARD_BLOCKED
transmitter is forced off by something outside of
the driver's control.
What: /sys/class/rfkill/rfkill[0-9]+/claim
Date: 09-Jul-2007
KernelVersion v2.6.22
Contact: linux-wireless@vger.kernel.org
Description: This file is deprecated because there no longer is a way to
claim just control over a single rfkill instance.
This file is scheduled to be removed in 2012.
Values: 0: Kernel handles events

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@ -0,0 +1,14 @@
What: dv1394 (a.k.a. "OHCI-DV I/O support" for FireWire)
Date: May 2010 (scheduled), finally removed in kernel v2.6.37
Contact: linux1394-devel@lists.sourceforge.net
Description:
/dev/dv1394/* were character device files, one for each FireWire
controller and for NTSC and PAL respectively, from which DV data
could be received by read() or transmitted by write(). A few
ioctl()s allowed limited control.
This special-purpose interface has been superseded by libraw1394 +
libiec61883 which are functionally equivalent, support HDV, and
transparently work on top of the newer firewire kernel drivers.
Users:
ffmpeg/libavformat (if configured for DV1394)

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@ -0,0 +1,15 @@
What: raw1394 (a.k.a. "Raw IEEE1394 I/O support" for FireWire)
Date: May 2010 (scheduled), finally removed in kernel v2.6.37
Contact: linux1394-devel@lists.sourceforge.net
Description:
/dev/raw1394 was a character device file that allowed low-level
access to FireWire buses. Its major drawbacks were its inability
to implement sensible device security policies, and its low level
of abstraction that required userspace clients do duplicate much
of the kernel's ieee1394 core functionality.
Replaced by /dev/fw*, i.e. the <linux/firewire-cdev.h> ABI of
firewire-core.
Users:
libraw1394 (works with firewire-cdev too, transparent to library ABI
users)

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@ -1,16 +0,0 @@
What: legacy isochronous ABI of raw1394 (1st generation iso ABI)
Date: June 2007 (scheduled), removed in kernel v2.6.23
Contact: linux1394-devel@lists.sourceforge.net
Description:
The two request types RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN have
been deprecated for quite some time. They are very inefficient as they
come with high interrupt load and several layers of callbacks for each
packet. Because of these deficiencies, the video1394 and dv1394 drivers
and the 3rd-generation isochronous ABI in raw1394 (rawiso) were created.
Users:
libraw1394 users via the long deprecated API raw1394_iso_write,
raw1394_start_iso_write, raw1394_start_iso_rcv, raw1394_stop_iso_rcv
libdc1394, which optionally uses these old libraw1394 calls
alternatively to the more efficient video1394 ABI

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@ -0,0 +1,16 @@
What: video1394 (a.k.a. "OHCI-1394 Video support" for FireWire)
Date: May 2010 (scheduled), finally removed in kernel v2.6.37
Contact: linux1394-devel@lists.sourceforge.net
Description:
/dev/video1394/* were character device files, one for each FireWire
controller, which were used for isochronous I/O. It was added as an
alternative to raw1394's isochronous I/O functionality which had
performance issues in its first generation. Any video1394 user had
to use raw1394 + libraw1394 too because video1394 did not provide
asynchronous I/O for device discovery and configuration.
Replaced by /dev/fw*, i.e. the <linux/firewire-cdev.h> ABI of
firewire-core.
Users:
libdc1394 (works with firewire-cdev too, transparent to library ABI
users)

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@ -0,0 +1,67 @@
rfkill - radio frequency (RF) connector kill switch support
For details to this subsystem look at Documentation/rfkill.txt.
For the deprecated /sys/class/rfkill/*/state and
/sys/class/rfkill/*/claim knobs of this interface look in
Documentation/ABI/obsolete/sysfs-class-rfkill.
What: /sys/class/rfkill
Date: 09-Jul-2007
KernelVersion: v2.6.22
Contact: linux-wireless@vger.kernel.org,
Description: The rfkill class subsystem folder.
Each registered rfkill driver is represented by an rfkillX
subfolder (X being an integer > 0).
What: /sys/class/rfkill/rfkill[0-9]+/name
Date: 09-Jul-2007
KernelVersion v2.6.22
Contact: linux-wireless@vger.kernel.org
Description: Name assigned by driver to this key (interface or driver name).
Values: arbitrary string.
What: /sys/class/rfkill/rfkill[0-9]+/type
Date: 09-Jul-2007
KernelVersion v2.6.22
Contact: linux-wireless@vger.kernel.org
Description: Driver type string ("wlan", "bluetooth", etc).
Values: See include/linux/rfkill.h.
What: /sys/class/rfkill/rfkill[0-9]+/persistent
Date: 09-Jul-2007
KernelVersion v2.6.22
Contact: linux-wireless@vger.kernel.org
Description: Whether the soft blocked state is initialised from non-volatile
storage at startup.
Values: A numeric value.
0: false
1: true
What: /sys/class/rfkill/rfkill[0-9]+/hard
Date: 12-March-2010
KernelVersion v2.6.34
Contact: linux-wireless@vger.kernel.org
Description: Current hardblock state. This file is read only.
Values: A numeric value.
0: inactive
The transmitter is (potentially) active.
1: active
The transmitter is forced off by something outside of
the driver's control.
What: /sys/class/rfkill/rfkill[0-9]+/soft
Date: 12-March-2010
KernelVersion v2.6.34
Contact: linux-wireless@vger.kernel.org
Description: Current softblock state. This file is read and write.
Values: A numeric value.
0: inactive
The transmitter is (potentially) active.
1: active
The transmitter is turned off by software.

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@ -0,0 +1,7 @@
What: /sys/devices/system/node/nodeX
Date: October 2002
Contact: Linux Memory Management list <linux-mm@kvack.org>
Description:
When CONFIG_NUMA is enabled, this is a directory containing
information on node X such as what CPUs are local to the
node.

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@ -0,0 +1,4 @@
What: A notification mechanism for thermal related events
Description:
This interface enables notification for thermal related events.
The notification is in the form of a netlink event.

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@ -0,0 +1,20 @@
What: /sys/kernel/debug/ec/*/{gpe,use_global_lock,io}
Date: July 2010
Contact: Thomas Renninger <trenn@suse.de>
Description:
General information like which GPE is assigned to the EC and whether
the global lock should get used.
Knowing the EC GPE one can watch the amount of HW events related to
the EC here (XY -> GPE number from /sys/kernel/debug/ec/*/gpe):
/sys/firmware/acpi/interrupts/gpeXY
The io file is binary and a userspace tool located here:
ftp://ftp.suse.com/pub/people/trenn/sources/ec/
should get used to read out the 256 Embedded Controller registers
or writing to them.
CAUTION: Do not write to the Embedded Controller if you don't know
what you are doing! Rebooting afterwards also is a good idea.
This can influence the way your machine is cooled and fans may
not get switched on again after you did a wrong write.

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@ -1,71 +0,0 @@
What: /sys/kernel/debug/kmemtrace/
Date: July 2008
Contact: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Description:
In kmemtrace-enabled kernels, the following files are created:
/sys/kernel/debug/kmemtrace/
cpu<n> (0400) Per-CPU tracing data, see below. (binary)
total_overruns (0400) Total number of bytes which were dropped from
cpu<n> files because of full buffer condition,
non-binary. (text)
abi_version (0400) Kernel's kmemtrace ABI version. (text)
Each per-CPU file should be read according to the relay interface. That is,
the reader should set affinity to that specific CPU and, as currently done by
the userspace application (though there are other methods), use poll() with
an infinite timeout before every read(). Otherwise, erroneous data may be
read. The binary data has the following _core_ format:
Event ID (1 byte) Unsigned integer, one of:
0 - represents an allocation (KMEMTRACE_EVENT_ALLOC)
1 - represents a freeing of previously allocated memory
(KMEMTRACE_EVENT_FREE)
Type ID (1 byte) Unsigned integer, one of:
0 - this is a kmalloc() / kfree()
1 - this is a kmem_cache_alloc() / kmem_cache_free()
2 - this is a __get_free_pages() et al.
Event size (2 bytes) Unsigned integer representing the
size of this event. Used to extend
kmemtrace. Discard the bytes you
don't know about.
Sequence number (4 bytes) Signed integer used to reorder data
logged on SMP machines. Wraparound
must be taken into account, although
it is unlikely.
Caller address (8 bytes) Return address to the caller.
Pointer to mem (8 bytes) Pointer to target memory area. Can be
NULL, but not all such calls might be
recorded.
In case of KMEMTRACE_EVENT_ALLOC events, the next fields follow:
Requested bytes (8 bytes) Total number of requested bytes,
unsigned, must not be zero.
Allocated bytes (8 bytes) Total number of actually allocated
bytes, unsigned, must not be lower
than requested bytes.
Requested flags (4 bytes) GFP flags supplied by the caller.
Target CPU (4 bytes) Signed integer, valid for event id 1.
If equal to -1, target CPU is the same
as origin CPU, but the reverse might
not be true.
The data is made available in the same endianness the machine has.
Other event ids and type ids may be defined and added. Other fields may be
added by increasing event size, but see below for details.
Every modification to the ABI, including new id definitions, are followed
by bumping the ABI version by one.
Adding new data to the packet (features) is done at the end of the mandatory
data:
Feature size (2 byte)
Feature ID (1 byte)
Feature data (Feature size - 3 bytes)
Users:
kmemtrace-user - git://repo.or.cz/kmemtrace-user.git

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@ -20,7 +20,7 @@ Description:
lsm: [[subj_user=] [subj_role=] [subj_type=]
[obj_user=] [obj_role=] [obj_type=]]
base: func:= [BPRM_CHECK][FILE_MMAP][INODE_PERMISSION]
base: func:= [BPRM_CHECK][FILE_MMAP][FILE_CHECK]
mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC]
fsmagic:= hex value
uid:= decimal value
@ -40,11 +40,11 @@ Description:
measure func=BPRM_CHECK
measure func=FILE_MMAP mask=MAY_EXEC
measure func=INODE_PERM mask=MAY_READ uid=0
measure func=FILE_CHECK mask=MAY_READ uid=0
The default policy measures all executables in bprm_check,
all files mmapped executable in file_mmap, and all files
open for read by root in inode_permission.
open for read by root in do_filp_open.
Examples of LSM specific definitions:
@ -54,8 +54,8 @@ Description:
dont_measure obj_type=var_log_t
dont_measure obj_type=auditd_log_t
measure subj_user=system_u func=INODE_PERM mask=MAY_READ
measure subj_role=system_r func=INODE_PERM mask=MAY_READ
measure subj_user=system_u func=FILE_CHECK mask=MAY_READ
measure subj_role=system_r func=FILE_CHECK mask=MAY_READ
Smack:
measure subj_user=_ func=INODE_PERM mask=MAY_READ
measure subj_user=_ func=FILE_CHECK mask=MAY_READ

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@ -0,0 +1,99 @@
What: /sys/class/ata_...
Date: August 2008
Contact: Gwendal Grignou<gwendal@google.com>
Description:
Provide a place in sysfs for storing the ATA topology of the system. This allows
retrieving various information about ATA objects.
Files under /sys/class/ata_port
-------------------------------
For each port, a directory ataX is created where X is the ata_port_id of
the port. The device parent is the ata host device.
idle_irq (read)
Number of IRQ received by the port while idle [some ata HBA only].
nr_pmp_links (read)
If a SATA Port Multiplier (PM) is connected, number of link behind it.
Files under /sys/class/ata_link
-------------------------------
Behind each port, there is a ata_link. If there is a SATA PM in the
topology, 15 ata_link objects are created.
If a link is behind a port, the directory name is linkX, where X is
ata_port_id of the port.
If a link is behind a PM, its name is linkX.Y where X is ata_port_id
of the parent port and Y the PM port.
hw_sata_spd_limit
Maximum speed supported by the connected SATA device.
sata_spd_limit
Maximum speed imposed by libata.
sata_spd
Current speed of the link [1.5, 3Gps,...].
Files under /sys/class/ata_device
---------------------------------
Behind each link, up to two ata device are created.
The name of the directory is devX[.Y].Z where:
- X is ata_port_id of the port where the device is connected,
- Y the port of the PM if any, and
- Z the device id: for PATA, there is usually 2 devices [0,1],
only 1 for SATA.
class
Device class. Can be "ata" for disk, "atapi" for packet device,
"pmp" for PM, or "none" if no device was found behind the link.
dma_mode
Transfer modes supported by the device when in DMA mode.
Mostly used by PATA device.
pio_mode
Transfer modes supported by the device when in PIO mode.
Mostly used by PATA device.
xfer_mode
Current transfer mode.
id
Cached result of IDENTIFY command, as described in ATA8 7.16 and 7.17.
Only valid if the device is not a PM.
gscr
Cached result of the dump of PM GSCR register.
Valid registers are:
0: SATA_PMP_GSCR_PROD_ID,
1: SATA_PMP_GSCR_REV,
2: SATA_PMP_GSCR_PORT_INFO,
32: SATA_PMP_GSCR_ERROR,
33: SATA_PMP_GSCR_ERROR_EN,
64: SATA_PMP_GSCR_FEAT,
96: SATA_PMP_GSCR_FEAT_EN,
130: SATA_PMP_GSCR_SII_GPIO
Only valid if the device is a PM.
spdn_cnt
Number of time libata decided to lower the speed of link due to errors.
ering
Formatted output of the error ring of the device.

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@ -128,3 +128,17 @@ Description:
preferred request size for workloads where sustained
throughput is desired. If no optimal I/O size is
reported this file contains 0.
What: /sys/block/<disk>/queue/nomerges
Date: January 2010
Contact:
Description:
Standard I/O elevator operations include attempts to
merge contiguous I/Os. For known random I/O loads these
attempts will always fail and result in extra cycles
being spent in the kernel. This allows one to turn off
this behavior on one of two ways: When set to 1, complex
merge checks are disabled, but the simple one-shot merges
with the previous I/O request are enabled. When set to 2,
all merge tries are disabled. The default value is 0 -
which enables all types of merge tries.

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@ -0,0 +1,99 @@
What: /sys/block/zram<id>/disksize
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The disksize file is read-write and specifies the disk size
which represents the limit on the *uncompressed* worth of data
that can be stored in this disk.
What: /sys/block/zram<id>/initstate
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The disksize file is read-only and shows the initialization
state of the device.
What: /sys/block/zram<id>/reset
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The disksize file is write-only and allows resetting the
device. The reset operation frees all the memory assocaited
with this device.
What: /sys/block/zram<id>/num_reads
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The num_reads file is read-only and specifies the number of
reads (failed or successful) done on this device.
What: /sys/block/zram<id>/num_writes
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The num_writes file is read-only and specifies the number of
writes (failed or successful) done on this device.
What: /sys/block/zram<id>/invalid_io
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The invalid_io file is read-only and specifies the number of
non-page-size-aligned I/O requests issued to this device.
What: /sys/block/zram<id>/notify_free
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The notify_free file is read-only and specifies the number of
swap slot free notifications received by this device. These
notifications are send to a swap block device when a swap slot
is freed. This statistic is applicable only when this disk is
being used as a swap disk.
What: /sys/block/zram<id>/discard
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The discard file is read-only and specifies the number of
discard requests received by this device. These requests
provide information to block device regarding blocks which are
no longer used by filesystem.
What: /sys/block/zram<id>/zero_pages
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The zero_pages file is read-only and specifies number of zero
filled pages written to this disk. No memory is allocated for
such pages.
What: /sys/block/zram<id>/orig_data_size
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The orig_data_size file is read-only and specifies uncompressed
size of data stored in this disk. This excludes zero-filled
pages (zero_pages) since no memory is allocated for them.
Unit: bytes
What: /sys/block/zram<id>/compr_data_size
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The compr_data_size file is read-only and specifies compressed
size of data stored in this disk. So, compression ratio can be
calculated using orig_data_size and this statistic.
Unit: bytes
What: /sys/block/zram<id>/mem_used_total
Date: August 2010
Contact: Nitin Gupta <ngupta@vflare.org>
Description:
The mem_used_total file is read-only and specifies the amount
of memory, including allocator fragmentation and metadata
overhead, allocated for this disk. So, allocator space
efficiency can be calculated using compr_data_size and this
statistic.
Unit: bytes

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@ -0,0 +1,21 @@
Where: /sys/bus/i2c/devices/.../heading0_input
Date: April 2010
Kernel Version: 2.6.36?
Contact: alan.cox@intel.com
Description: Reports the current heading from the compass as a floating
point value in degrees.
Where: /sys/bus/i2c/devices/.../power_state
Date: April 2010
Kernel Version: 2.6.36?
Contact: alan.cox@intel.com
Description: Sets the power state of the device. 0 sets the device into
sleep mode, 1 wakes it up.
Where: /sys/bus/i2c/devices/.../calibration
Date: April 2010
Kernel Version: 2.6.36?
Contact: alan.cox@intel.com
Description: Sets the calibration on or off (1 = on, 0 = off). See the
chip data sheet.

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@ -139,3 +139,30 @@ Contact: linux-pci@vger.kernel.org
Description:
This symbolic link points to the PCI hotplug controller driver
module that manages the hotplug slot.
What: /sys/bus/pci/devices/.../label
Date: July 2010
Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
Description:
Reading this attribute will provide the firmware
given name(SMBIOS type 41 string) of the PCI device.
The attribute will be created only if the firmware
has given a name to the PCI device.
Users:
Userspace applications interested in knowing the
firmware assigned name of the PCI device.
What: /sys/bus/pci/devices/.../index
Date: July 2010
Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
Description:
Reading this attribute will provide the firmware
given instance(SMBIOS type 41 device type instance)
of the PCI device. The attribute will be created
only if the firmware has given a device type instance
to the PCI device.
Users:
Userspace applications interested in knowing the
firmware assigned device type instance of the PCI
device that can help in understanding the firmware
intended order of the PCI device.

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@ -0,0 +1,83 @@
What: /sys/bus/rbd/
Date: November 2010
Contact: Yehuda Sadeh <yehuda@hq.newdream.net>,
Sage Weil <sage@newdream.net>
Description:
Being used for adding and removing rbd block devices.
Usage: <mon ip addr> <options> <pool name> <rbd image name> [snap name]
$ echo "192.168.0.1 name=admin rbd foo" > /sys/bus/rbd/add
The snapshot name can be "-" or omitted to map the image read/write. A <dev-id>
will be assigned for any registered block device. If snapshot is used, it will
be mapped read-only.
Removal of a device:
$ echo <dev-id> > /sys/bus/rbd/remove
Entries under /sys/bus/rbd/devices/<dev-id>/
--------------------------------------------
client_id
The ceph unique client id that was assigned for this specific session.
major
The block device major number.
name
The name of the rbd image.
pool
The pool where this rbd image resides. The pool-name pair is unique
per rados system.
size
The size (in bytes) of the mapped block device.
refresh
Writing to this file will reread the image header data and set
all relevant datastructures accordingly.
current_snap
The current snapshot for which the device is mapped.
create_snap
Create a snapshot:
$ echo <snap-name> > /sys/bus/rbd/devices/<dev-id>/snap_create
rollback_snap
Rolls back data to the specified snapshot. This goes over the entire
list of rados blocks and sends a rollback command to each.
$ echo <snap-name> > /sys/bus/rbd/devices/<dev-id>/snap_rollback
snap_*
A directory per each snapshot
Entries under /sys/bus/rbd/devices/<dev-id>/snap_<snap-name>
-------------------------------------------------------------
id
The rados internal snapshot id assigned for this snapshot
size
The size of the image when this snapshot was taken.

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@ -14,34 +14,6 @@ Description:
The autosuspend delay for newly-created devices is set to
the value of the usbcore.autosuspend module parameter.
What: /sys/bus/usb/devices/.../power/level
Date: March 2007
KernelVersion: 2.6.21
Contact: Alan Stern <stern@rowland.harvard.edu>
Description:
Each USB device directory will contain a file named
power/level. This file holds a power-level setting for
the device, either "on" or "auto".
"on" means that the device is not allowed to autosuspend,
although normal suspends for system sleep will still
be honored. "auto" means the device will autosuspend
and autoresume in the usual manner, according to the
capabilities of its driver.
During normal use, devices should be left in the "auto"
level. The "on" level is meant for administrative uses.
If you want to suspend a device immediately but leave it
free to wake up in response to I/O requests, you should
write "0" to power/autosuspend.
Device not capable of proper suspend and resume should be
left in the "on" level. Although the USB spec requires
devices to support suspend/resume, many of them do not.
In fact so many don't that by default, the USB core
initializes all non-hub devices in the "on" level. Some
drivers may change this setting when they are bound.
What: /sys/bus/usb/devices/.../power/persist
Date: May 2007
KernelVersion: 2.6.23
@ -159,3 +131,14 @@ Description:
device. This is useful to ensure auto probing won't
match the driver to the device. For example:
# echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
What: /sys/bus/usb/device/.../avoid_reset_quirk
Date: December 2009
Contact: Oliver Neukum <oliver@neukum.org>
Description:
Writing 1 to this file tells the kernel that this
device will morph into another mode when it is reset.
Drivers will not use reset for error handling for
such devices.
Users:
usb_modeswitch

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@ -26,3 +26,12 @@ Description:
scheduler is chosen. Trigger specific parameters can appear in
/sys/class/leds/<led> once a given trigger is selected.
What: /sys/class/leds/<led>/inverted
Date: January 2011
KernelVersion: 2.6.38
Contact: Richard Purdie <rpurdie@rpsys.net>
Description:
Invert the LED on/off state. This parameter is specific to
gpio and backlight triggers. In case of the backlight trigger,
it is usefull when driving a LED which is intended to indicate
a device in a standby like state.

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@ -0,0 +1,14 @@
What: /sys/class/net/<iface>/batman-adv/mesh_iface
Date: May 2010
Contact: Marek Lindner <lindner_marek@yahoo.de>
Description:
The /sys/class/net/<iface>/batman-adv/mesh_iface file
displays the batman mesh interface this <iface>
currently is associated with.
What: /sys/class/net/<iface>/batman-adv/iface_status
Date: May 2010
Contact: Marek Lindner <lindner_marek@yahoo.de>
Description:
Indicates the status of <iface> as it is seen by batman.

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@ -0,0 +1,69 @@
What: /sys/class/net/<mesh_iface>/mesh/aggregated_ogms
Date: May 2010
Contact: Marek Lindner <lindner_marek@yahoo.de>
Description:
Indicates whether the batman protocol messages of the
mesh <mesh_iface> shall be aggregated or not.
What: /sys/class/net/<mesh_iface>/mesh/bonding
Date: June 2010
Contact: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Description:
Indicates whether the data traffic going through the
mesh will be sent using multiple interfaces at the
same time (if available).
What: /sys/class/net/<mesh_iface>/mesh/fragmentation
Date: October 2010
Contact: Andreas Langer <an.langer@gmx.de>
Description:
Indicates whether the data traffic going through the
mesh will be fragmented or silently discarded if the
packet size exceeds the outgoing interface MTU.
What: /sys/class/net/<mesh_iface>/mesh/gw_bandwidth
Date: October 2010
Contact: Marek Lindner <lindner_marek@yahoo.de>
Description:
Defines the bandwidth which is propagated by this
node if gw_mode was set to 'server'.
What: /sys/class/net/<mesh_iface>/mesh/gw_mode
Date: October 2010
Contact: Marek Lindner <lindner_marek@yahoo.de>
Description:
Defines the state of the gateway features. Can be
either 'off', 'client' or 'server'.
What: /sys/class/net/<mesh_iface>/mesh/gw_sel_class
Date: October 2010
Contact: Marek Lindner <lindner_marek@yahoo.de>
Description:
Defines the selection criteria this node will use
to choose a gateway if gw_mode was set to 'client'.
What: /sys/class/net/<mesh_iface>/mesh/orig_interval
Date: May 2010
Contact: Marek Lindner <lindner_marek@yahoo.de>
Description:
Defines the interval in milliseconds in which batman
sends its protocol messages.
What: /sys/class/net/<mesh_iface>/mesh/hop_penalty
Date: Oct 2010
Contact: Linus Lüssing <linus.luessing@web.de>
Description:
Defines the penalty which will be applied to an
originator message's tq-field on every hop.
What: /sys/class/net/<mesh_iface>/mesh/vis_mode
Date: May 2010
Contact: Marek Lindner <lindner_marek@yahoo.de>
Description:
Each batman node only maintains information about its
own local neighborhood, therefore generating graphs
showing the topology of the entire mesh is not easily
feasible without having a central instance to collect
the local topologies from all nodes. This file allows
to activate the collecting (server) mode.

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@ -0,0 +1,20 @@
What: /sys/class/power/ds2760-battery.*/charge_now
Date: May 2010
KernelVersion: 2.6.35
Contact: Daniel Mack <daniel@caiaq.de>
Description:
This file is writeable and can be used to set the current
coloumb counter value inside the battery monitor chip. This
is needed for unavoidable corrections of aging batteries.
A userspace daemon can monitor the battery charging logic
and once the counter drops out of considerable bounds, take
appropriate action.
What: /sys/class/power/ds2760-battery.*/charge_full
Date: May 2010
KernelVersion: 2.6.35
Contact: Daniel Mack <daniel@caiaq.de>
Description:
This file is writeable and can be used to set the assumed
battery 'full level'. As batteries age, this value has to be
amended over time.

View File

@ -7,7 +7,7 @@ Description:
added or removed dynamically to represent hot-add/remove
operations.
Users: hotplug memory add/remove tools
https://w3.opensource.ibm.com/projects/powerpc-utils/
http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
What: /sys/devices/system/memory/memoryX/removable
Date: June 2008
@ -19,7 +19,7 @@ Description:
identify removable sections of the memory before attempting
potentially expensive hot-remove memory operation
Users: hotplug memory remove tools
https://w3.opensource.ibm.com/projects/powerpc-utils/
http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
What: /sys/devices/system/memory/memoryX/phys_device
Date: September 2008
@ -43,7 +43,7 @@ Date: September 2008
Contact: Badari Pulavarty <pbadari@us.ibm.com>
Description:
The file /sys/devices/system/memory/memoryX/state
is read-write. When read, it's contents show the
is read-write. When read, its contents show the
online/offline state of the memory section. When written,
root can toggle the the online/offline state of a removable
memory section (see removable file description above)
@ -58,7 +58,7 @@ Description:
by root to offline that section.
# echo offline > /sys/devices/system/memory/memory22/state
Users: hotplug memory remove tools
https://w3.opensource.ibm.com/projects/powerpc-utils/
http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
What: /sys/devices/system/memoryX/nodeY

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@ -0,0 +1,7 @@
What: /sys/devices/system/node/nodeX/compact
Date: February 2010
Contact: Mel Gorman <mel@csn.ul.ie>
Description:
When this file is written to, all memory within that node
will be compacted. When it completes, memory will be freed
into blocks which have as many contiguous pages as possible

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@ -0,0 +1,21 @@
What: /sys/devices/platform/_UDC_/gadget/suspended
Date: April 2010
Contact: Fabien Chouteau <fabien.chouteau@barco.com>
Description:
Show the suspend state of an USB composite gadget.
1 -> suspended
0 -> resumed
(_UDC_ is the name of the USB Device Controller driver)
What: /sys/devices/platform/_UDC_/gadget/gadget-lunX/nofua
Date: July 2010
Contact: Andy Shevchenko <andy.shevchenko@gmail.com>
Description:
Show or set the reaction on the FUA (Force Unit Access) bit in
the SCSI WRITE(10,12) commands when a gadget in USB Mass
Storage mode.
Possible values are:
1 -> ignore the FUA flag
0 -> obey the FUA flag

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@ -0,0 +1,167 @@
What: /sys/devices/.../power/
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../power directory contains attributes
allowing the user space to check and modify some power
management related properties of given device.
What: /sys/devices/.../power/wakeup
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../power/wakeup attribute allows the user
space to check if the device is enabled to wake up the system
from sleep states, such as the memory sleep state (suspend to
RAM) and hibernation (suspend to disk), and to enable or disable
it to do that as desired.
Some devices support "wakeup" events, which are hardware signals
used to activate the system from a sleep state. Such devices
have one of the following two values for the sysfs power/wakeup
file:
+ "enabled\n" to issue the events;
+ "disabled\n" not to do so;
In that cases the user space can change the setting represented
by the contents of this file by writing either "enabled", or
"disabled" to it.
For the devices that are not capable of generating system wakeup
events this file contains "\n". In that cases the user space
cannot modify the contents of this file and the device cannot be
enabled to wake up the system.
What: /sys/devices/.../power/control
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../power/control attribute allows the user
space to control the run-time power management of the device.
All devices have one of the following two values for the
power/control file:
+ "auto\n" to allow the device to be power managed at run time;
+ "on\n" to prevent the device from being power managed;
The default for all devices is "auto", which means that they may
be subject to automatic power management, depending on their
drivers. Changing this attribute to "on" prevents the driver
from power managing the device at run time. Doing that while
the device is suspended causes it to be woken up.
What: /sys/devices/.../power/async
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../async attribute allows the user space to
enable or diasble the device's suspend and resume callbacks to
be executed asynchronously (ie. in separate threads, in parallel
with the main suspend/resume thread) during system-wide power
transitions (eg. suspend to RAM, hibernation).
All devices have one of the following two values for the
power/async file:
+ "enabled\n" to permit the asynchronous suspend/resume;
+ "disabled\n" to forbid it;
The value of this attribute may be changed by writing either
"enabled", or "disabled" to it.
It generally is unsafe to permit the asynchronous suspend/resume
of a device unless it is certain that all of the PM dependencies
of the device are known to the PM core. However, for some
devices this attribute is set to "enabled" by bus type code or
device drivers and in that cases it should be safe to leave the
default value.
What: /sys/devices/.../power/wakeup_count
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_count attribute contains the number
of signaled wakeup events associated with the device. This
attribute is read-only. If the device is not enabled to wake up
the system from sleep states, this attribute is empty.
What: /sys/devices/.../power/wakeup_active_count
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_active_count attribute contains the
number of times the processing of wakeup events associated with
the device was completed (at the kernel level). This attribute
is read-only. If the device is not enabled to wake up the
system from sleep states, this attribute is empty.
What: /sys/devices/.../power/wakeup_hit_count
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_hit_count attribute contains the
number of times the processing of a wakeup event associated with
the device might prevent the system from entering a sleep state.
This attribute is read-only. If the device is not enabled to
wake up the system from sleep states, this attribute is empty.
What: /sys/devices/.../power/wakeup_active
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_active attribute contains either 1,
or 0, depending on whether or not a wakeup event associated with
the device is being processed (1). This attribute is read-only.
If the device is not enabled to wake up the system from sleep
states, this attribute is empty.
What: /sys/devices/.../power/wakeup_total_time_ms
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_total_time_ms attribute contains
the total time of processing wakeup events associated with the
device, in milliseconds. This attribute is read-only. If the
device is not enabled to wake up the system from sleep states,
this attribute is empty.
What: /sys/devices/.../power/wakeup_max_time_ms
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_max_time_ms attribute contains
the maximum time of processing a single wakeup event associated
with the device, in milliseconds. This attribute is read-only.
If the device is not enabled to wake up the system from sleep
states, this attribute is empty.
What: /sys/devices/.../power/wakeup_last_time_ms
Date: September 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../wakeup_last_time_ms attribute contains
the value of the monotonic clock corresponding to the time of
signaling the last wakeup event associated with the device, in
milliseconds. This attribute is read-only. If the device is
not enabled to wake up the system from sleep states, this
attribute is empty.
What: /sys/devices/.../power/autosuspend_delay_ms
Date: September 2010
Contact: Alan Stern <stern@rowland.harvard.edu>
Description:
The /sys/devices/.../power/autosuspend_delay_ms attribute
contains the autosuspend delay value (in milliseconds). Some
drivers do not want their device to suspend as soon as it
becomes idle at run time; they want the device to remain
inactive for a certain minimum period of time first. That
period is called the autosuspend delay. Negative values will
prevent the device from being suspended at run time (similar
to writing "on" to the power/control attribute). Values >=
1000 will cause the autosuspend timer expiration to be rounded
up to the nearest second.
Not all drivers support this attribute. If it isn't supported,
attempts to read or write it will yield I/O errors.

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@ -197,7 +197,7 @@ Description: These files exist in every cpu's cache index directories.
Currently, only AMD Family 10h Processors support cache index
disable, and only for their L3 caches. See the BIOS and
Kernel Developer's Guide at
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116-Public-GH-BKDG_3.20_2-4-09.pdf
http://support.amd.com/us/Embedded_TechDocs/31116-Public-GH-BKDG_3-28_5-28-09.pdf
for formatting information and other details on the
cache index disable.
Users: joachim.deguara@amd.com

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@ -0,0 +1,22 @@
What: state
Date: Sep 2010
KernelVersion: 2.6.37
Contact: Vernon Mauery <vernux@us.ibm.com>
Description: The state file allows a means by which to change in and
out of Premium Real-Time Mode (PRTM), as well as the
ability to query the current state.
0 => PRTM off
1 => PRTM enabled
Users: The ibm-prtm userspace daemon uses this interface.
What: version
Date: Sep 2010
KernelVersion: 2.6.37
Contact: Vernon Mauery <vernux@us.ibm.com>
Description: The version file provides a means by which to query
the RTL table version that lives in the Extended
BIOS Data Area (EBDA).
Users: The ibm-prtm userspace daemon uses this interface.

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@ -0,0 +1,43 @@
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/operation_mode
Date: March 2010
Contact: Bruno Prémont <bonbons@linux-vserver.org>
Description: Make it possible to switch the PicoLCD device between LCD
(firmware) and bootloader (flasher) operation modes.
Reading: returns list of available modes, the active mode being
enclosed in brackets ('[' and ']')
Writing: causes operation mode switch. Permitted values are
the non-active mode names listed when read.
Note: when switching mode the current PicoLCD HID device gets
disconnected and reconnects after above delay (see attribute
operation_mode_delay for its value).
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/operation_mode_delay
Date: April 2010
Contact: Bruno Prémont <bonbons@linux-vserver.org>
Description: Delay PicoLCD waits before restarting in new mode when
operation_mode has changed.
Reading/Writing: It is expressed in ms and permitted range is
0..30000ms.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/fb_update_rate
Date: March 2010
Contact: Bruno Prémont <bonbons@linux-vserver.org>
Description: Make it possible to adjust defio refresh rate.
Reading: returns list of available refresh rates (expressed in Hz),
the active refresh rate being enclosed in brackets ('[' and ']')
Writing: accepts new refresh rate expressed in integer Hz
within permitted rates.
Note: As device can barely do 2 complete refreshes a second
it only makes sense to adjust this value if only one or two
tiles get changed and it's not appropriate to expect the application
to flush it's tiny changes explicitely at higher than default rate.

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@ -0,0 +1,29 @@
What: /sys/bus/hid/drivers/prodikeys/.../channel
Date: April 2010
KernelVersion: 2.6.34
Contact: Don Prince <dhprince.devel@yahoo.co.uk>
Description:
Allows control (via software) the midi channel to which
that the pc-midi keyboard will output.midi data.
Range: 0..15
Type: Read/write
What: /sys/bus/hid/drivers/prodikeys/.../sustain
Date: April 2010
KernelVersion: 2.6.34
Contact: Don Prince <dhprince.devel@yahoo.co.uk>
Description:
Allows control (via software) the sustain duration of a
note held by the pc-midi driver.
0 means sustain mode is disabled.
Range: 0..5000 (milliseconds)
Type: Read/write
What: /sys/bus/hid/drivers/prodikeys/.../octave
Date: April 2010
KernelVersion: 2.6.34
Contact: Don Prince <dhprince.devel@yahoo.co.uk>
Description:
Controls the octave shift modifier in the pc-midi driver.
The octave can be shifted via software up/down 2 octaves.
0 means the no ocatve shift.
Range: -2..2 (minus 2 to plus 2)
Type: Read/Write

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@ -0,0 +1,98 @@
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/kone/roccatkone<minor>/actual_dpi
Date: March 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: It is possible to switch the dpi setting of the mouse with the
press of a button.
When read, this file returns the raw number of the actual dpi
setting reported by the mouse. This number has to be further
processed to receive the real dpi value.
VALUE DPI
1 800
2 1200
3 1600
4 2000
5 2400
6 3200
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/kone/roccatkone<minor>/actual_profile
Date: March 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read, this file returns the number of the actual profile.
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/kone/roccatkone<minor>/firmware_version
Date: March 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read, this file returns the raw integer version number of the
firmware reported by the mouse. Using the integer value eases
further usage in other programs. To receive the real version
number the decimal point has to be shifted 2 positions to the
left. E.g. a returned value of 138 means 1.38
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/kone/roccatkone<minor>/profile[1-5]
Date: March 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile holds informations like button
mappings, sensitivity, the colors of the 5 leds and light
effects.
When read, these files return the respective profile. The
returned data is 975 bytes in size.
When written, this file lets one write the respective profile
data back to the mouse. The data has to be 975 bytes long.
The mouse will reject invalid data, whereas the profile number
stored in the profile doesn't need to fit the number of the
store.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/kone/roccatkone<minor>/settings
Date: March 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read, this file returns the settings stored in the mouse.
The size of the data is 36 bytes and holds information like the
startup_profile, tcu state and calibration_data.
When written, this file lets write settings back to the mouse.
The data has to be 36 bytes long. The mouse will reject invalid
data.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/kone/roccatkone<minor>/startup_profile
Date: March 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The integer value of this attribute ranges from 1 to 5.
When read, this attribute returns the number of the profile
that's active when the mouse is powered on.
When written, this file sets the number of the startup profile
and the mouse activates this profile immediately.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/kone/roccatkone<minor>/tcu
Date: March 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse has a "Tracking Control Unit" which lets the user
calibrate the laser power to fit the mousepad surface.
When read, this file returns the current state of the TCU,
where 0 means off and 1 means on.
Writing 0 in this file will switch the TCU off.
Writing 1 in this file will start the calibration which takes
around 6 seconds to complete and activates the TCU.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/kone/roccatkone<minor>/weight
Date: March 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can be equipped with one of four supplied weights
ranging from 5 to 20 grams which are recognized by the mouse
and its value can be read out. When read, this file returns the
raw value returned by the mouse which eases further processing
in other software.
The values map to the weights as follows:
VALUE WEIGHT
0 none
1 5g
2 10g
3 15g
4 20g
This file is readonly.

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@ -0,0 +1,108 @@
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/actual_profile
Date: October 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read, this file returns the number of the actual profile in
range 0-4.
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/firmware_version
Date: October 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read, this file returns the raw integer version number of the
firmware reported by the mouse. Using the integer value eases
further usage in other programs. To receive the real version
number the decimal point has to be shifted 2 positions to the
left. E.g. a returned value of 121 means 1.21
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/macro
Date: October 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store a macro with max 500 key/button strokes
internally.
When written, this file lets one set the sequence for a specific
button for a specific profile. Button and profile numbers are
included in written data. The data has to be 2082 bytes long.
This file is writeonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/profile_buttons
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile is split in settings and buttons.
profile_buttons holds informations about button layout.
When written, this file lets one write the respective profile
buttons back to the mouse. The data has to be 77 bytes long.
The mouse will reject invalid data.
Which profile to write is determined by the profile number
contained in the data.
This file is writeonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/profile[1-5]_buttons
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile is split in settings and buttons.
profile_buttons holds informations about button layout.
When read, these files return the respective profile buttons.
The returned data is 77 bytes in size.
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/profile_settings
Date: October 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile is split in settings and buttons.
profile_settings holds informations like resolution, sensitivity
and light effects.
When written, this file lets one write the respective profile
settings back to the mouse. The data has to be 43 bytes long.
The mouse will reject invalid data.
Which profile to write is determined by the profile number
contained in the data.
This file is writeonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/profile[1-5]_settings
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile is split in settings and buttons.
profile_settings holds informations like resolution, sensitivity
and light effects.
When read, these files return the respective profile settings.
The returned data is 43 bytes in size.
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/sensor
Date: October 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse has a tracking- and a distance-control-unit. These
can be activated/deactivated and the lift-off distance can be
set. The data has to be 6 bytes long.
This file is writeonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/startup_profile
Date: October 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The integer value of this attribute ranges from 0-4.
When read, this attribute returns the number of the profile
that's active when the mouse is powered on.
When written, this file sets the number of the startup profile
and the mouse activates this profile immediately.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/tcu
Date: October 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When written a calibration process for the tracking control unit
can be initiated/cancelled.
The data has to be 3 bytes long.
This file is writeonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/koneplus/roccatkoneplus<minor>/tcu_image
Date: October 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read the mouse returns a 30x30 pixel image of the
sampled underground. This works only in the course of a
calibration process initiated with tcu.
The returned data is 1028 bytes in size.
This file is readonly.

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@ -0,0 +1,98 @@
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/actual_cpi
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: It is possible to switch the cpi setting of the mouse with the
press of a button.
When read, this file returns the raw number of the actual cpi
setting reported by the mouse. This number has to be further
processed to receive the real dpi value.
VALUE DPI
1 400
2 800
4 1600
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/actual_profile
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read, this file returns the number of the actual profile in
range 0-4.
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/firmware_version
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read, this file returns the raw integer version number of the
firmware reported by the mouse. Using the integer value eases
further usage in other programs. To receive the real version
number the decimal point has to be shifted 2 positions to the
left. E.g. a returned value of 138 means 1.38
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/profile_settings
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile is split in settings and buttons.
profile_settings holds informations like resolution, sensitivity
and light effects.
When written, this file lets one write the respective profile
settings back to the mouse. The data has to be 13 bytes long.
The mouse will reject invalid data.
Which profile to write is determined by the profile number
contained in the data.
This file is writeonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/profile[1-5]_settings
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile is split in settings and buttons.
profile_settings holds informations like resolution, sensitivity
and light effects.
When read, these files return the respective profile settings.
The returned data is 13 bytes in size.
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/profile_buttons
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile is split in settings and buttons.
profile_buttons holds informations about button layout.
When written, this file lets one write the respective profile
buttons back to the mouse. The data has to be 19 bytes long.
The mouse will reject invalid data.
Which profile to write is determined by the profile number
contained in the data.
This file is writeonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/profile[1-5]_buttons
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The mouse can store 5 profiles which can be switched by the
press of a button. A profile is split in settings and buttons.
profile_buttons holds informations about button layout.
When read, these files return the respective profile buttons.
The returned data is 19 bytes in size.
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/startup_profile
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: The integer value of this attribute ranges from 0-4.
When read, this attribute returns the number of the profile
that's active when the mouse is powered on.
This file is readonly.
What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/pyra/roccatpyra<minor>/settings
Date: August 2010
Contact: Stefan Achatz <erazor_de@users.sourceforge.net>
Description: When read, this file returns the settings stored in the mouse.
The size of the data is 3 bytes and holds information on the
startup_profile.
When written, this file lets write settings back to the mouse.
The data has to be 3 bytes long. The mouse will reject invalid
data.

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@ -0,0 +1,15 @@
What: /sys/firmware/sfi/tables/
Date: May 2010
Contact: Len Brown <lenb@kernel.org>
Description:
SFI defines a number of small static memory tables
so the kernel can get platform information from firmware.
The tables are defined in the latest SFI specification:
http://simplefirmware.org/documentation
While the tables are used by the kernel, user-space
can observe them this way:
# cd /sys/firmware/sfi/tables
# cat $TABLENAME > $TABLENAME.bin

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@ -0,0 +1,31 @@
What: /sys/bus/i2c/devices/<busnum>-<devaddr>/pressure0_input
Date: June 2010
Contact: Christoph Mair <christoph.mair@gmail.com>
Description: Start a pressure measurement and read the result. Values
represent the ambient air pressure in pascal (0.01 millibar).
Reading: returns the current air pressure.
What: /sys/bus/i2c/devices/<busnum>-<devaddr>/temp0_input
Date: June 2010
Contact: Christoph Mair <christoph.mair@gmail.com>
Description: Measure the ambient temperature. The returned value represents
the ambient temperature in units of 0.1 degree celsius.
Reading: returns the current temperature.
What: /sys/bus/i2c/devices/<busnum>-<devaddr>/oversampling
Date: June 2010
Contact: Christoph Mair <christoph.mair@gmail.com>
Description: Tell the bmp085 to use more samples to calculate a pressure
value. When writing to this file the chip will use 2^x samples
to calculate the next pressure value with x being the value
written. Using this feature will decrease RMS noise and
increase the measurement time.
Reading: returns the current oversampling setting.
Writing: sets a new oversampling setting.
Accepted values: 0..3.

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@ -0,0 +1,12 @@
What: /sys/module/pch_phub/drivers/.../pch_mac
Date: August 2010
KernelVersion: 2.6.35
Contact: masa-korg@dsn.okisemi.com
Description: Write/read GbE MAC address.
What: /sys/module/pch_phub/drivers/.../pch_firmware
Date: August 2010
KernelVersion: 2.6.35
Contact: masa-korg@dsn.okisemi.com
Description: Write/read Option ROM data.

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@ -1,4 +1,4 @@
What: /sys/devices/platform/asus-laptop/display
What: /sys/devices/platform/asus_laptop/display
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
@ -13,7 +13,7 @@ Description:
Ex: - 0 (0000b) means no display
- 3 (0011b) CRT+LCD.
What: /sys/devices/platform/asus-laptop/gps
What: /sys/devices/platform/asus_laptop/gps
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
@ -21,7 +21,7 @@ Description:
Control the gps device. 1 means on, 0 means off.
Users: Lapsus
What: /sys/devices/platform/asus-laptop/ledd
What: /sys/devices/platform/asus_laptop/ledd
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
@ -29,11 +29,11 @@ Description:
Some models like the W1N have a LED display that can be
used to display several informations.
To control the LED display, use the following :
echo 0x0T000DDD > /sys/devices/platform/asus-laptop/
echo 0x0T000DDD > /sys/devices/platform/asus_laptop/
where T control the 3 letters display, and DDD the 3 digits display.
The DDD table can be found in Documentation/laptops/asus-laptop.txt
What: /sys/devices/platform/asus-laptop/bluetooth
What: /sys/devices/platform/asus_laptop/bluetooth
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
@ -42,11 +42,25 @@ Description:
This may control the led, the device or both.
Users: Lapsus
What: /sys/devices/platform/asus-laptop/wlan
What: /sys/devices/platform/asus_laptop/wlan
Date: January 2007
KernelVersion: 2.6.20
Contact: "Corentin Chary" <corentincj@iksaif.net>
Description:
Control the bluetooth device. 1 means on, 0 means off.
Control the wlan device. 1 means on, 0 means off.
This may control the led, the device or both.
Users: Lapsus
What: /sys/devices/platform/asus_laptop/wimax
Date: October 2010
KernelVersion: 2.6.37
Contact: "Corentin Chary" <corentincj@iksaif.net>
Description:
Control the wimax device. 1 means on, 0 means off.
What: /sys/devices/platform/asus_laptop/wwan
Date: October 2010
KernelVersion: 2.6.37
Contact: "Corentin Chary" <corentincj@iksaif.net>
Description:
Control the wwan (3G) device. 1 means on, 0 means off.

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@ -1,4 +1,4 @@
What: /sys/devices/platform/eeepc-laptop/disp
What: /sys/devices/platform/eeepc/disp
Date: May 2008
KernelVersion: 2.6.26
Contact: "Corentin Chary" <corentincj@iksaif.net>
@ -9,21 +9,21 @@ Description:
- 3 = LCD+CRT
If you run X11, you should use xrandr instead.
What: /sys/devices/platform/eeepc-laptop/camera
What: /sys/devices/platform/eeepc/camera
Date: May 2008
KernelVersion: 2.6.26
Contact: "Corentin Chary" <corentincj@iksaif.net>
Description:
Control the camera. 1 means on, 0 means off.
What: /sys/devices/platform/eeepc-laptop/cardr
What: /sys/devices/platform/eeepc/cardr
Date: May 2008
KernelVersion: 2.6.26
Contact: "Corentin Chary" <corentincj@iksaif.net>
Description:
Control the card reader. 1 means on, 0 means off.
What: /sys/devices/platform/eeepc-laptop/cpufv
What: /sys/devices/platform/eeepc/cpufv
Date: Jun 2009
KernelVersion: 2.6.31
Contact: "Corentin Chary" <corentincj@iksaif.net>
@ -42,7 +42,7 @@ Description:
`------------ Availables modes
For example, 0x301 means: mode 1 selected, 3 available modes.
What: /sys/devices/platform/eeepc-laptop/available_cpufv
What: /sys/devices/platform/eeepc/available_cpufv
Date: Jun 2009
KernelVersion: 2.6.31
Contact: "Corentin Chary" <corentincj@iksaif.net>

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@ -0,0 +1,10 @@
What: /sys/devices/platform/eeepc-wmi/cpufv
Date: Oct 2010
KernelVersion: 2.6.37
Contact: "Corentin Chary" <corentincj@iksaif.net>
Description:
Change CPU clock configuration (write-only).
There are three available clock configuration:
* 0 -> Super Performance Mode
* 1 -> High Performance Mode
* 2 -> Power Saving Mode

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@ -0,0 +1,6 @@
What: /sys/devices/platform/ideapad/camera_power
Date: Dec 2010
KernelVersion: 2.6.37
Contact: "Ike Panhc <ike.pan@canonical.com>"
Description:
Control the power of camera module. 1 means on, 0 means off.

View File

@ -99,5 +99,62 @@ Description:
dmesg -s 1000000 | grep 'hash matches'
If you do not get any matches (or they appear to be false
positives), it is possible that the last PM event point
referred to a device created by a loadable kernel module. In
this case cat /sys/power/pm_trace_dev_match (see below) after
your system is started up and the kernel modules are loaded.
CAUTION: Using it will cause your machine's real-time (CMOS)
clock to be set to a random invalid time after a resume.
What; /sys/power/pm_trace_dev_match
Date: October 2010
Contact: James Hogan <james@albanarts.com>
Description:
The /sys/power/pm_trace_dev_match file contains the name of the
device associated with the last PM event point saved in the RTC
across reboots when pm_trace has been used. More precisely it
contains the list of current devices (including those
registered by loadable kernel modules since boot) which match
the device hash in the RTC at boot, with a newline after each
one.
The advantage of this file over the hash matches printed to the
kernel log (see /sys/power/pm_trace), is that it includes
devices created after boot by loadable kernel modules.
Due to the small hash size necessary to fit in the RTC, it is
possible that more than one device matches the hash, in which
case further investigation is required to determine which
device is causing the problem. Note that genuine RTC clock
values (such as when pm_trace has not been used), can still
match a device and output it's name here.
What: /sys/power/pm_async
Date: January 2009
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/power/pm_async file controls the switch allowing the
user space to enable or disable asynchronous suspend and resume
of devices. If enabled, this feature will cause some device
drivers' suspend and resume callbacks to be executed in parallel
with each other and with the main suspend thread. It is enabled
if this file contains "1", which is the default. It may be
disabled by writing "0" to this file, in which case all devices
will be suspended and resumed synchronously.
What: /sys/power/wakeup_count
Date: July 2010
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/power/wakeup_count file allows user space to put the
system into a sleep state while taking into account the
concurrent arrival of wakeup events. Reading from it returns
the current number of registered wakeup events and it blocks if
some wakeup events are being processed at the time the file is
read from. Writing to it will only succeed if the current
number of wakeup events is equal to the written value and, if
successful, will make the kernel abort a subsequent transition
to a sleep state if any wakeup events are reported after the
write has returned.

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@ -0,0 +1,19 @@
What: /sys/class/tty/console/active
Date: Nov 2010
Contact: Kay Sievers <kay.sievers@vrfy.org>
Description:
Shows the list of currently configured
console devices, like 'tty1 ttyS0'.
The last entry in the file is the active
device connected to /dev/console.
The file supports poll() to detect virtual
console switches.
What: /sys/class/tty/tty0/active
Date: Nov 2010
Contact: Kay Sievers <kay.sievers@vrfy.org>
Description:
Shows the currently active virtual console
device, like 'tty1'.
The file supports poll() to detect virtual
console switches.

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@ -0,0 +1,10 @@
What: /sys/class/hidraw/hidraw*/device/speed
Date: April 2010
Kernel Version: 2.6.35
Contact: linux-bluetooth@vger.kernel.org
Description:
The /sys/class/hidraw/hidraw*/device/speed file controls
reporting speed of wacom bluetooth tablet. Reading from
this file returns 1 if tablet reports in high speed mode
or 0 otherwise. Writing to this file one of these values
switches reporting speed.

View File

@ -49,7 +49,7 @@ o oprofile 0.9 # oprofiled --version
o udev 081 # udevinfo -V
o grub 0.93 # grub --version
o mcelog 0.6
o iptables 1.4.1 # iptables -V
o iptables 1.4.2 # iptables -V
Kernel compilation
@ -331,7 +331,7 @@ o <ftp://ftp.kernel.org/pub/linux/kernel/people/rusty/modules/>
Mkinitrd
--------
o <ftp://rawhide.redhat.com/pub/rawhide/SRPMS/SRPMS/>
o <https://code.launchpad.net/initrd-tools/main>
E2fsprogs
---------
@ -343,11 +343,11 @@ o <http://jfs.sourceforge.net/>
Reiserfsprogs
-------------
o <http://www.namesys.com/pub/reiserfsprogs/reiserfsprogs-3.6.3.tar.gz>
o <http://www.kernel.org/pub/linux/utils/fs/reiserfs/>
Xfsprogs
--------
o <ftp://oss.sgi.com/projects/xfs/download/>
o <ftp://oss.sgi.com/projects/xfs/>
Pcmciautils
-----------
@ -387,18 +387,18 @@ o <http://sourceforge.net/projects/fuse>
mcelog
------
o <ftp://ftp.kernel.org/pub/linux/utils/cpu/mce/mcelog/>
o <ftp://ftp.kernel.org/pub/linux/utils/cpu/mce/>
Networking
**********
PPP
---
o <ftp://ftp.samba.org/pub/ppp/ppp-2.4.0.tar.gz>
o <ftp://ftp.samba.org/pub/ppp/>
Isdn4k-utils
------------
o <ftp://ftp.isdn4linux.de/pub/isdn4linux/utils/isdn4k-utils.v3.1pre1.tar.gz>
o <ftp://ftp.isdn4linux.de/pub/isdn4linux/utils/>
NFS-utils
---------

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@ -0,0 +1,781 @@
Dynamic DMA mapping Guide
=========================
David S. Miller <davem@redhat.com>
Richard Henderson <rth@cygnus.com>
Jakub Jelinek <jakub@redhat.com>
This is a guide to device driver writers on how to use the DMA API
with example pseudo-code. For a concise description of the API, see
DMA-API.txt.
Most of the 64bit platforms have special hardware that translates bus
addresses (DMA addresses) into physical addresses. This is similar to
how page tables and/or a TLB translates virtual addresses to physical
addresses on a CPU. This is needed so that e.g. PCI devices can
access with a Single Address Cycle (32bit DMA address) any page in the
64bit physical address space. Previously in Linux those 64bit
platforms had to set artificial limits on the maximum RAM size in the
system, so that the virt_to_bus() static scheme works (the DMA address
translation tables were simply filled on bootup to map each bus
address to the physical page __pa(bus_to_virt())).
So that Linux can use the dynamic DMA mapping, it needs some help from the
drivers, namely it has to take into account that DMA addresses should be
mapped only for the time they are actually used and unmapped after the DMA
transfer.
The following API will work of course even on platforms where no such
hardware exists.
Note that the DMA API works with any bus independent of the underlying
microprocessor architecture. You should use the DMA API rather than
the bus specific DMA API (e.g. pci_dma_*).
First of all, you should make sure
#include <linux/dma-mapping.h>
is in your driver. This file will obtain for you the definition of the
dma_addr_t (which can hold any valid DMA address for the platform)
type which should be used everywhere you hold a DMA (bus) address
returned from the DMA mapping functions.
What memory is DMA'able?
The first piece of information you must know is what kernel memory can
be used with the DMA mapping facilities. There has been an unwritten
set of rules regarding this, and this text is an attempt to finally
write them down.
If you acquired your memory via the page allocator
(i.e. __get_free_page*()) or the generic memory allocators
(i.e. kmalloc() or kmem_cache_alloc()) then you may DMA to/from
that memory using the addresses returned from those routines.
This means specifically that you may _not_ use the memory/addresses
returned from vmalloc() for DMA. It is possible to DMA to the
_underlying_ memory mapped into a vmalloc() area, but this requires
walking page tables to get the physical addresses, and then
translating each of those pages back to a kernel address using
something like __va(). [ EDIT: Update this when we integrate
Gerd Knorr's generic code which does this. ]
This rule also means that you may use neither kernel image addresses
(items in data/text/bss segments), nor module image addresses, nor
stack addresses for DMA. These could all be mapped somewhere entirely
different than the rest of physical memory. Even if those classes of
memory could physically work with DMA, you'd need to ensure the I/O
buffers were cacheline-aligned. Without that, you'd see cacheline
sharing problems (data corruption) on CPUs with DMA-incoherent caches.
(The CPU could write to one word, DMA would write to a different one
in the same cache line, and one of them could be overwritten.)
Also, this means that you cannot take the return of a kmap()
call and DMA to/from that. This is similar to vmalloc().
What about block I/O and networking buffers? The block I/O and
networking subsystems make sure that the buffers they use are valid
for you to DMA from/to.
DMA addressing limitations
Does your device have any DMA addressing limitations? For example, is
your device only capable of driving the low order 24-bits of address?
If so, you need to inform the kernel of this fact.
By default, the kernel assumes that your device can address the full
32-bits. For a 64-bit capable device, this needs to be increased.
And for a device with limitations, as discussed in the previous
paragraph, it needs to be decreased.
Special note about PCI: PCI-X specification requires PCI-X devices to
support 64-bit addressing (DAC) for all transactions. And at least
one platform (SGI SN2) requires 64-bit consistent allocations to
operate correctly when the IO bus is in PCI-X mode.
For correct operation, you must interrogate the kernel in your device
probe routine to see if the DMA controller on the machine can properly
support the DMA addressing limitation your device has. It is good
style to do this even if your device holds the default setting,
because this shows that you did think about these issues wrt. your
device.
The query is performed via a call to dma_set_mask():
int dma_set_mask(struct device *dev, u64 mask);
The query for consistent allocations is performed via a call to
dma_set_coherent_mask():
int dma_set_coherent_mask(struct device *dev, u64 mask);
Here, dev is a pointer to the device struct of your device, and mask
is a bit mask describing which bits of an address your device
supports. It returns zero if your card can perform DMA properly on
the machine given the address mask you provided. In general, the
device struct of your device is embedded in the bus specific device
struct of your device. For example, a pointer to the device struct of
your PCI device is pdev->dev (pdev is a pointer to the PCI device
struct of your device).
If it returns non-zero, your device cannot perform DMA properly on
this platform, and attempting to do so will result in undefined
behavior. You must either use a different mask, or not use DMA.
This means that in the failure case, you have three options:
1) Use another DMA mask, if possible (see below).
2) Use some non-DMA mode for data transfer, if possible.
3) Ignore this device and do not initialize it.
It is recommended that your driver print a kernel KERN_WARNING message
when you end up performing either #2 or #3. In this manner, if a user
of your driver reports that performance is bad or that the device is not
even detected, you can ask them for the kernel messages to find out
exactly why.
The standard 32-bit addressing device would do something like this:
if (dma_set_mask(dev, DMA_BIT_MASK(32))) {
printk(KERN_WARNING
"mydev: No suitable DMA available.\n");
goto ignore_this_device;
}
Another common scenario is a 64-bit capable device. The approach here
is to try for 64-bit addressing, but back down to a 32-bit mask that
should not fail. The kernel may fail the 64-bit mask not because the
platform is not capable of 64-bit addressing. Rather, it may fail in
this case simply because 32-bit addressing is done more efficiently
than 64-bit addressing. For example, Sparc64 PCI SAC addressing is
more efficient than DAC addressing.
Here is how you would handle a 64-bit capable device which can drive
all 64-bits when accessing streaming DMA:
int using_dac;
if (!dma_set_mask(dev, DMA_BIT_MASK(64))) {
using_dac = 1;
} else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) {
using_dac = 0;
} else {
printk(KERN_WARNING
"mydev: No suitable DMA available.\n");
goto ignore_this_device;
}
If a card is capable of using 64-bit consistent allocations as well,
the case would look like this:
int using_dac, consistent_using_dac;
if (!dma_set_mask(dev, DMA_BIT_MASK(64))) {
using_dac = 1;
consistent_using_dac = 1;
dma_set_coherent_mask(dev, DMA_BIT_MASK(64));
} else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) {
using_dac = 0;
consistent_using_dac = 0;
dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
} else {
printk(KERN_WARNING
"mydev: No suitable DMA available.\n");
goto ignore_this_device;
}
dma_set_coherent_mask() will always be able to set the same or a
smaller mask as dma_set_mask(). However for the rare case that a
device driver only uses consistent allocations, one would have to
check the return value from dma_set_coherent_mask().
Finally, if your device can only drive the low 24-bits of
address you might do something like:
if (dma_set_mask(dev, DMA_BIT_MASK(24))) {
printk(KERN_WARNING
"mydev: 24-bit DMA addressing not available.\n");
goto ignore_this_device;
}
When dma_set_mask() is successful, and returns zero, the kernel saves
away this mask you have provided. The kernel will use this
information later when you make DMA mappings.
There is a case which we are aware of at this time, which is worth
mentioning in this documentation. If your device supports multiple
functions (for example a sound card provides playback and record
functions) and the various different functions have _different_
DMA addressing limitations, you may wish to probe each mask and
only provide the functionality which the machine can handle. It
is important that the last call to dma_set_mask() be for the
most specific mask.
Here is pseudo-code showing how this might be done:
#define PLAYBACK_ADDRESS_BITS DMA_BIT_MASK(32)
#define RECORD_ADDRESS_BITS DMA_BIT_MASK(24)
struct my_sound_card *card;
struct device *dev;
...
if (!dma_set_mask(dev, PLAYBACK_ADDRESS_BITS)) {
card->playback_enabled = 1;
} else {
card->playback_enabled = 0;
printk(KERN_WARNING "%s: Playback disabled due to DMA limitations.\n",
card->name);
}
if (!dma_set_mask(dev, RECORD_ADDRESS_BITS)) {
card->record_enabled = 1;
} else {
card->record_enabled = 0;
printk(KERN_WARNING "%s: Record disabled due to DMA limitations.\n",
card->name);
}
A sound card was used as an example here because this genre of PCI
devices seems to be littered with ISA chips given a PCI front end,
and thus retaining the 16MB DMA addressing limitations of ISA.
Types of DMA mappings
There are two types of DMA mappings:
- Consistent DMA mappings which are usually mapped at driver
initialization, unmapped at the end and for which the hardware should
guarantee that the device and the CPU can access the data
in parallel and will see updates made by each other without any
explicit software flushing.
Think of "consistent" as "synchronous" or "coherent".
The current default is to return consistent memory in the low 32
bits of the bus space. However, for future compatibility you should
set the consistent mask even if this default is fine for your
driver.
Good examples of what to use consistent mappings for are:
- Network card DMA ring descriptors.
- SCSI adapter mailbox command data structures.
- Device firmware microcode executed out of
main memory.
The invariant these examples all require is that any CPU store
to memory is immediately visible to the device, and vice
versa. Consistent mappings guarantee this.
IMPORTANT: Consistent DMA memory does not preclude the usage of
proper memory barriers. The CPU may reorder stores to
consistent memory just as it may normal memory. Example:
if it is important for the device to see the first word
of a descriptor updated before the second, you must do
something like:
desc->word0 = address;
wmb();
desc->word1 = DESC_VALID;
in order to get correct behavior on all platforms.
Also, on some platforms your driver may need to flush CPU write
buffers in much the same way as it needs to flush write buffers
found in PCI bridges (such as by reading a register's value
after writing it).
- Streaming DMA mappings which are usually mapped for one DMA
transfer, unmapped right after it (unless you use dma_sync_* below)
and for which hardware can optimize for sequential accesses.
This of "streaming" as "asynchronous" or "outside the coherency
domain".
Good examples of what to use streaming mappings for are:
- Networking buffers transmitted/received by a device.
- Filesystem buffers written/read by a SCSI device.
The interfaces for using this type of mapping were designed in
such a way that an implementation can make whatever performance
optimizations the hardware allows. To this end, when using
such mappings you must be explicit about what you want to happen.
Neither type of DMA mapping has alignment restrictions that come from
the underlying bus, although some devices may have such restrictions.
Also, systems with caches that aren't DMA-coherent will work better
when the underlying buffers don't share cache lines with other data.
Using Consistent DMA mappings.
To allocate and map large (PAGE_SIZE or so) consistent DMA regions,
you should do:
dma_addr_t dma_handle;
cpu_addr = dma_alloc_coherent(dev, size, &dma_handle, gfp);
where device is a struct device *. This may be called in interrupt
context with the GFP_ATOMIC flag.
Size is the length of the region you want to allocate, in bytes.
This routine will allocate RAM for that region, so it acts similarly to
__get_free_pages (but takes size instead of a page order). If your
driver needs regions sized smaller than a page, you may prefer using
the dma_pool interface, described below.
The consistent DMA mapping interfaces, for non-NULL dev, will by
default return a DMA address which is 32-bit addressable. Even if the
device indicates (via DMA mask) that it may address the upper 32-bits,
consistent allocation will only return > 32-bit addresses for DMA if
the consistent DMA mask has been explicitly changed via
dma_set_coherent_mask(). This is true of the dma_pool interface as
well.
dma_alloc_coherent returns two values: the virtual address which you
can use to access it from the CPU and dma_handle which you pass to the
card.
The cpu return address and the DMA bus master address are both
guaranteed to be aligned to the smallest PAGE_SIZE order which
is greater than or equal to the requested size. This invariant
exists (for example) to guarantee that if you allocate a chunk
which is smaller than or equal to 64 kilobytes, the extent of the
buffer you receive will not cross a 64K boundary.
To unmap and free such a DMA region, you call:
dma_free_coherent(dev, size, cpu_addr, dma_handle);
where dev, size are the same as in the above call and cpu_addr and
dma_handle are the values dma_alloc_coherent returned to you.
This function may not be called in interrupt context.
If your driver needs lots of smaller memory regions, you can write
custom code to subdivide pages returned by dma_alloc_coherent,
or you can use the dma_pool API to do that. A dma_pool is like
a kmem_cache, but it uses dma_alloc_coherent not __get_free_pages.
Also, it understands common hardware constraints for alignment,
like queue heads needing to be aligned on N byte boundaries.
Create a dma_pool like this:
struct dma_pool *pool;
pool = dma_pool_create(name, dev, size, align, alloc);
The "name" is for diagnostics (like a kmem_cache name); dev and size
are as above. The device's hardware alignment requirement for this
type of data is "align" (which is expressed in bytes, and must be a
power of two). If your device has no boundary crossing restrictions,
pass 0 for alloc; passing 4096 says memory allocated from this pool
must not cross 4KByte boundaries (but at that time it may be better to
go for dma_alloc_coherent directly instead).
Allocate memory from a dma pool like this:
cpu_addr = dma_pool_alloc(pool, flags, &dma_handle);
flags are SLAB_KERNEL if blocking is permitted (not in_interrupt nor
holding SMP locks), SLAB_ATOMIC otherwise. Like dma_alloc_coherent,
this returns two values, cpu_addr and dma_handle.
Free memory that was allocated from a dma_pool like this:
dma_pool_free(pool, cpu_addr, dma_handle);
where pool is what you passed to dma_pool_alloc, and cpu_addr and
dma_handle are the values dma_pool_alloc returned. This function
may be called in interrupt context.
Destroy a dma_pool by calling:
dma_pool_destroy(pool);
Make sure you've called dma_pool_free for all memory allocated
from a pool before you destroy the pool. This function may not
be called in interrupt context.
DMA Direction
The interfaces described in subsequent portions of this document
take a DMA direction argument, which is an integer and takes on
one of the following values:
DMA_BIDIRECTIONAL
DMA_TO_DEVICE
DMA_FROM_DEVICE
DMA_NONE
One should provide the exact DMA direction if you know it.
DMA_TO_DEVICE means "from main memory to the device"
DMA_FROM_DEVICE means "from the device to main memory"
It is the direction in which the data moves during the DMA
transfer.
You are _strongly_ encouraged to specify this as precisely
as you possibly can.
If you absolutely cannot know the direction of the DMA transfer,
specify DMA_BIDIRECTIONAL. It means that the DMA can go in
either direction. The platform guarantees that you may legally
specify this, and that it will work, but this may be at the
cost of performance for example.
The value DMA_NONE is to be used for debugging. One can
hold this in a data structure before you come to know the
precise direction, and this will help catch cases where your
direction tracking logic has failed to set things up properly.
Another advantage of specifying this value precisely (outside of
potential platform-specific optimizations of such) is for debugging.
Some platforms actually have a write permission boolean which DMA
mappings can be marked with, much like page protections in the user
program address space. Such platforms can and do report errors in the
kernel logs when the DMA controller hardware detects violation of the
permission setting.
Only streaming mappings specify a direction, consistent mappings
implicitly have a direction attribute setting of
DMA_BIDIRECTIONAL.
The SCSI subsystem tells you the direction to use in the
'sc_data_direction' member of the SCSI command your driver is
working on.
For Networking drivers, it's a rather simple affair. For transmit
packets, map/unmap them with the DMA_TO_DEVICE direction
specifier. For receive packets, just the opposite, map/unmap them
with the DMA_FROM_DEVICE direction specifier.
Using Streaming DMA mappings
The streaming DMA mapping routines can be called from interrupt
context. There are two versions of each map/unmap, one which will
map/unmap a single memory region, and one which will map/unmap a
scatterlist.
To map a single region, you do:
struct device *dev = &my_dev->dev;
dma_addr_t dma_handle;
void *addr = buffer->ptr;
size_t size = buffer->len;
dma_handle = dma_map_single(dev, addr, size, direction);
and to unmap it:
dma_unmap_single(dev, dma_handle, size, direction);
You should call dma_unmap_single when the DMA activity is finished, e.g.
from the interrupt which told you that the DMA transfer is done.
Using cpu pointers like this for single mappings has a disadvantage,
you cannot reference HIGHMEM memory in this way. Thus, there is a
map/unmap interface pair akin to dma_{map,unmap}_single. These
interfaces deal with page/offset pairs instead of cpu pointers.
Specifically:
struct device *dev = &my_dev->dev;
dma_addr_t dma_handle;
struct page *page = buffer->page;
unsigned long offset = buffer->offset;
size_t size = buffer->len;
dma_handle = dma_map_page(dev, page, offset, size, direction);
...
dma_unmap_page(dev, dma_handle, size, direction);
Here, "offset" means byte offset within the given page.
With scatterlists, you map a region gathered from several regions by:
int i, count = dma_map_sg(dev, sglist, nents, direction);
struct scatterlist *sg;
for_each_sg(sglist, sg, count, i) {
hw_address[i] = sg_dma_address(sg);
hw_len[i] = sg_dma_len(sg);
}
where nents is the number of entries in the sglist.
The implementation is free to merge several consecutive sglist entries
into one (e.g. if DMA mapping is done with PAGE_SIZE granularity, any
consecutive sglist entries can be merged into one provided the first one
ends and the second one starts on a page boundary - in fact this is a huge
advantage for cards which either cannot do scatter-gather or have very
limited number of scatter-gather entries) and returns the actual number
of sg entries it mapped them to. On failure 0 is returned.
Then you should loop count times (note: this can be less than nents times)
and use sg_dma_address() and sg_dma_len() macros where you previously
accessed sg->address and sg->length as shown above.
To unmap a scatterlist, just call:
dma_unmap_sg(dev, sglist, nents, direction);
Again, make sure DMA activity has already finished.
PLEASE NOTE: The 'nents' argument to the dma_unmap_sg call must be
the _same_ one you passed into the dma_map_sg call,
it should _NOT_ be the 'count' value _returned_ from the
dma_map_sg call.
Every dma_map_{single,sg} call should have its dma_unmap_{single,sg}
counterpart, because the bus address space is a shared resource (although
in some ports the mapping is per each BUS so less devices contend for the
same bus address space) and you could render the machine unusable by eating
all bus addresses.
If you need to use the same streaming DMA region multiple times and touch
the data in between the DMA transfers, the buffer needs to be synced
properly in order for the cpu and device to see the most uptodate and
correct copy of the DMA buffer.
So, firstly, just map it with dma_map_{single,sg}, and after each DMA
transfer call either:
dma_sync_single_for_cpu(dev, dma_handle, size, direction);
or:
dma_sync_sg_for_cpu(dev, sglist, nents, direction);
as appropriate.
Then, if you wish to let the device get at the DMA area again,
finish accessing the data with the cpu, and then before actually
giving the buffer to the hardware call either:
dma_sync_single_for_device(dev, dma_handle, size, direction);
or:
dma_sync_sg_for_device(dev, sglist, nents, direction);
as appropriate.
After the last DMA transfer call one of the DMA unmap routines
dma_unmap_{single,sg}. If you don't touch the data from the first dma_map_*
call till dma_unmap_*, then you don't have to call the dma_sync_*
routines at all.
Here is pseudo code which shows a situation in which you would need
to use the dma_sync_*() interfaces.
my_card_setup_receive_buffer(struct my_card *cp, char *buffer, int len)
{
dma_addr_t mapping;
mapping = dma_map_single(cp->dev, buffer, len, DMA_FROM_DEVICE);
cp->rx_buf = buffer;
cp->rx_len = len;
cp->rx_dma = mapping;
give_rx_buf_to_card(cp);
}
...
my_card_interrupt_handler(int irq, void *devid, struct pt_regs *regs)
{
struct my_card *cp = devid;
...
if (read_card_status(cp) == RX_BUF_TRANSFERRED) {
struct my_card_header *hp;
/* Examine the header to see if we wish
* to accept the data. But synchronize
* the DMA transfer with the CPU first
* so that we see updated contents.
*/
dma_sync_single_for_cpu(&cp->dev, cp->rx_dma,
cp->rx_len,
DMA_FROM_DEVICE);
/* Now it is safe to examine the buffer. */
hp = (struct my_card_header *) cp->rx_buf;
if (header_is_ok(hp)) {
dma_unmap_single(&cp->dev, cp->rx_dma, cp->rx_len,
DMA_FROM_DEVICE);
pass_to_upper_layers(cp->rx_buf);
make_and_setup_new_rx_buf(cp);
} else {
/* Just sync the buffer and give it back
* to the card.
*/
dma_sync_single_for_device(&cp->dev,
cp->rx_dma,
cp->rx_len,
DMA_FROM_DEVICE);
give_rx_buf_to_card(cp);
}
}
}
Drivers converted fully to this interface should not use virt_to_bus any
longer, nor should they use bus_to_virt. Some drivers have to be changed a
little bit, because there is no longer an equivalent to bus_to_virt in the
dynamic DMA mapping scheme - you have to always store the DMA addresses
returned by the dma_alloc_coherent, dma_pool_alloc, and dma_map_single
calls (dma_map_sg stores them in the scatterlist itself if the platform
supports dynamic DMA mapping in hardware) in your driver structures and/or
in the card registers.
All drivers should be using these interfaces with no exceptions. It
is planned to completely remove virt_to_bus() and bus_to_virt() as
they are entirely deprecated. Some ports already do not provide these
as it is impossible to correctly support them.
Handling Errors
DMA address space is limited on some architectures and an allocation
failure can be determined by:
- checking if dma_alloc_coherent returns NULL or dma_map_sg returns 0
- checking the returned dma_addr_t of dma_map_single and dma_map_page
by using dma_mapping_error():
dma_addr_t dma_handle;
dma_handle = dma_map_single(dev, addr, size, direction);
if (dma_mapping_error(dev, dma_handle)) {
/*
* reduce current DMA mapping usage,
* delay and try again later or
* reset driver.
*/
}
Networking drivers must call dev_kfree_skb to free the socket buffer
and return NETDEV_TX_OK if the DMA mapping fails on the transmit hook
(ndo_start_xmit). This means that the socket buffer is just dropped in
the failure case.
SCSI drivers must return SCSI_MLQUEUE_HOST_BUSY if the DMA mapping
fails in the queuecommand hook. This means that the SCSI subsystem
passes the command to the driver again later.
Optimizing Unmap State Space Consumption
On many platforms, dma_unmap_{single,page}() is simply a nop.
Therefore, keeping track of the mapping address and length is a waste
of space. Instead of filling your drivers up with ifdefs and the like
to "work around" this (which would defeat the whole purpose of a
portable API) the following facilities are provided.
Actually, instead of describing the macros one by one, we'll
transform some example code.
1) Use DEFINE_DMA_UNMAP_{ADDR,LEN} in state saving structures.
Example, before:
struct ring_state {
struct sk_buff *skb;
dma_addr_t mapping;
__u32 len;
};
after:
struct ring_state {
struct sk_buff *skb;
DEFINE_DMA_UNMAP_ADDR(mapping);
DEFINE_DMA_UNMAP_LEN(len);
};
2) Use dma_unmap_{addr,len}_set to set these values.
Example, before:
ringp->mapping = FOO;
ringp->len = BAR;
after:
dma_unmap_addr_set(ringp, mapping, FOO);
dma_unmap_len_set(ringp, len, BAR);
3) Use dma_unmap_{addr,len} to access these values.
Example, before:
dma_unmap_single(dev, ringp->mapping, ringp->len,
DMA_FROM_DEVICE);
after:
dma_unmap_single(dev,
dma_unmap_addr(ringp, mapping),
dma_unmap_len(ringp, len),
DMA_FROM_DEVICE);
It really should be self-explanatory. We treat the ADDR and LEN
separately, because it is possible for an implementation to only
need the address in order to perform the unmap operation.
Platform Issues
If you are just writing drivers for Linux and do not maintain
an architecture port for the kernel, you can safely skip down
to "Closing".
1) Struct scatterlist requirements.
Don't invent the architecture specific struct scatterlist; just use
<asm-generic/scatterlist.h>. You need to enable
CONFIG_NEED_SG_DMA_LENGTH if the architecture supports IOMMUs
(including software IOMMU).
2) ARCH_DMA_MINALIGN
Architectures must ensure that kmalloc'ed buffer is
DMA-safe. Drivers and subsystems depend on it. If an architecture
isn't fully DMA-coherent (i.e. hardware doesn't ensure that data in
the CPU cache is identical to data in main memory),
ARCH_DMA_MINALIGN must be set so that the memory allocator
makes sure that kmalloc'ed buffer doesn't share a cache line with
the others. See arch/arm/include/asm/cache.h as an example.
Note that ARCH_DMA_MINALIGN is about DMA memory alignment
constraints. You don't need to worry about the architecture data
alignment constraints (e.g. the alignment constraints about 64-bit
objects).
3) Supporting multiple types of IOMMUs
If your architecture needs to support multiple types of IOMMUs, you
can use include/linux/asm-generic/dma-mapping-common.h. It's a
library to support the DMA API with multiple types of IOMMUs. Lots
of architectures (x86, powerpc, sh, alpha, ia64, microblaze and
sparc) use it. Choose one to see how it can be used. If you need to
support multiple types of IOMMUs in a single system, the example of
x86 or powerpc helps.
Closing
This document, and the API itself, would not be in its current
form without the feedback and suggestions from numerous individuals.
We would like to specifically mention, in no particular order, the
following people:
Russell King <rmk@arm.linux.org.uk>
Leo Dagum <dagum@barrel.engr.sgi.com>
Ralf Baechle <ralf@oss.sgi.com>
Grant Grundler <grundler@cup.hp.com>
Jay Estabrook <Jay.Estabrook@compaq.com>
Thomas Sailer <sailer@ife.ee.ethz.ch>
Andrea Arcangeli <andrea@suse.de>
Jens Axboe <jens.axboe@oracle.com>
David Mosberger-Tang <davidm@hpl.hp.com>

View File

@ -4,20 +4,18 @@
James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
This document describes the DMA API. For a more gentle introduction
phrased in terms of the pci_ equivalents (and actual examples) see
Documentation/PCI/PCI-DMA-mapping.txt.
of the API (and actual examples) see
Documentation/DMA-API-HOWTO.txt.
This API is split into two pieces. Part I describes the API and the
corresponding pci_ API. Part II describes the extensions to the API
for supporting non-consistent memory machines. Unless you know that
your driver absolutely has to support non-consistent platforms (this
is usually only legacy platforms) you should only use the API
described in part I.
This API is split into two pieces. Part I describes the API. Part II
describes the extensions to the API for supporting non-consistent
memory machines. Unless you know that your driver absolutely has to
support non-consistent platforms (this is usually only legacy
platforms) you should only use the API described in part I.
Part I - pci_ and dma_ Equivalent API
Part I - dma_ API
-------------------------------------
To get the pci_ API, you must #include <linux/pci.h>
To get the dma_ API, you must #include <linux/dma-mapping.h>
@ -27,9 +25,6 @@ Part Ia - Using large dma-coherent buffers
void *
dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
void *
pci_alloc_consistent(struct pci_dev *dev, size_t size,
dma_addr_t *dma_handle)
Consistent memory is memory for which a write by either the device or
the processor can immediately be read by the processor or device
@ -53,15 +48,11 @@ The simplest way to do that is to use the dma_pool calls (see below).
The flag parameter (dma_alloc_coherent only) allows the caller to
specify the GFP_ flags (see kmalloc) for the allocation (the
implementation may choose to ignore flags that affect the location of
the returned memory, like GFP_DMA). For pci_alloc_consistent, you
must assume GFP_ATOMIC behaviour.
the returned memory, like GFP_DMA).
void
dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_handle)
void
pci_free_consistent(struct pci_dev *dev, size_t size, void *cpu_addr,
dma_addr_t dma_handle)
Free the region of consistent memory you previously allocated. dev,
size and dma_handle must all be the same as those passed into the
@ -89,10 +80,6 @@ for alignment, like queue heads needing to be aligned on N-byte boundaries.
dma_pool_create(const char *name, struct device *dev,
size_t size, size_t align, size_t alloc);
struct pci_pool *
pci_pool_create(const char *name, struct pci_device *dev,
size_t size, size_t align, size_t alloc);
The pool create() routines initialize a pool of dma-coherent buffers
for use with a given device. It must be called in a context which
can sleep.
@ -108,9 +95,6 @@ from this pool must not cross 4KByte boundaries.
void *dma_pool_alloc(struct dma_pool *pool, gfp_t gfp_flags,
dma_addr_t *dma_handle);
void *pci_pool_alloc(struct pci_pool *pool, gfp_t gfp_flags,
dma_addr_t *dma_handle);
This allocates memory from the pool; the returned memory will meet the size
and alignment requirements specified at creation time. Pass GFP_ATOMIC to
prevent blocking, or if it's permitted (not in_interrupt, not holding SMP locks),
@ -122,9 +106,6 @@ pool's device.
void dma_pool_free(struct dma_pool *pool, void *vaddr,
dma_addr_t addr);
void pci_pool_free(struct pci_pool *pool, void *vaddr,
dma_addr_t addr);
This puts memory back into the pool. The pool is what was passed to
the pool allocation routine; the cpu (vaddr) and dma addresses are what
were returned when that routine allocated the memory being freed.
@ -132,8 +113,6 @@ were returned when that routine allocated the memory being freed.
void dma_pool_destroy(struct dma_pool *pool);
void pci_pool_destroy(struct pci_pool *pool);
The pool destroy() routines free the resources of the pool. They must be
called in a context which can sleep. Make sure you've freed all allocated
memory back to the pool before you destroy it.
@ -144,8 +123,6 @@ Part Ic - DMA addressing limitations
int
dma_supported(struct device *dev, u64 mask)
int
pci_dma_supported(struct pci_dev *hwdev, u64 mask)
Checks to see if the device can support DMA to the memory described by
mask.
@ -159,8 +136,14 @@ driver writers.
int
dma_set_mask(struct device *dev, u64 mask)
Checks to see if the mask is possible and updates the device
parameters if it is.
Returns: 0 if successful and a negative error if not.
int
pci_set_dma_mask(struct pci_device *dev, u64 mask)
dma_set_coherent_mask(struct device *dev, u64 mask)
Checks to see if the mask is possible and updates the device
parameters if it is.
@ -187,9 +170,6 @@ Part Id - Streaming DMA mappings
dma_addr_t
dma_map_single(struct device *dev, void *cpu_addr, size_t size,
enum dma_data_direction direction)
dma_addr_t
pci_map_single(struct pci_dev *hwdev, void *cpu_addr, size_t size,
int direction)
Maps a piece of processor virtual memory so it can be accessed by the
device and returns the physical handle of the memory.
@ -198,14 +178,10 @@ The direction for both api's may be converted freely by casting.
However the dma_ API uses a strongly typed enumerator for its
direction:
DMA_NONE = PCI_DMA_NONE no direction (used for
debugging)
DMA_TO_DEVICE = PCI_DMA_TODEVICE data is going from the
memory to the device
DMA_FROM_DEVICE = PCI_DMA_FROMDEVICE data is coming from
the device to the
memory
DMA_BIDIRECTIONAL = PCI_DMA_BIDIRECTIONAL direction isn't known
DMA_NONE no direction (used for debugging)
DMA_TO_DEVICE data is going from the memory to the device
DMA_FROM_DEVICE data is coming from the device to the memory
DMA_BIDIRECTIONAL direction isn't known
Notes: Not all memory regions in a machine can be mapped by this
API. Further, regions that appear to be physically contiguous in
@ -268,9 +244,6 @@ cache lines are updated with data that the device may have changed).
void
dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction direction)
void
pci_unmap_single(struct pci_dev *hwdev, dma_addr_t dma_addr,
size_t size, int direction)
Unmaps the region previously mapped. All the parameters passed in
must be identical to those passed in (and returned) by the mapping
@ -280,15 +253,9 @@ dma_addr_t
dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction)
dma_addr_t
pci_map_page(struct pci_dev *hwdev, struct page *page,
unsigned long offset, size_t size, int direction)
void
dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
enum dma_data_direction direction)
void
pci_unmap_page(struct pci_dev *hwdev, dma_addr_t dma_address,
size_t size, int direction)
API for mapping and unmapping for pages. All the notes and warnings
for the other mapping APIs apply here. Also, although the <offset>
@ -299,9 +266,6 @@ cache width is.
int
dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
int
pci_dma_mapping_error(struct pci_dev *hwdev, dma_addr_t dma_addr)
In some circumstances dma_map_single and dma_map_page will fail to create
a mapping. A driver can check for these errors by testing the returned
dma address with dma_mapping_error(). A non-zero return value means the mapping
@ -311,9 +275,6 @@ reduce current DMA mapping usage or delay and try again later).
int
dma_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction)
int
pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg,
int nents, int direction)
Returns: the number of physical segments mapped (this may be shorter
than <nents> passed in if some elements of the scatter/gather list are
@ -353,9 +314,6 @@ accessed sg->address and sg->length as shown above.
void
dma_unmap_sg(struct device *dev, struct scatterlist *sg,
int nhwentries, enum dma_data_direction direction)
void
pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sg,
int nents, int direction)
Unmap the previously mapped scatter/gather list. All the parameters
must be the same as those and passed in to the scatter/gather mapping
@ -365,21 +323,23 @@ Note: <nents> must be the number you passed in, *not* the number of
physical entries returned.
void
dma_sync_single(struct device *dev, dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
void
pci_dma_sync_single(struct pci_dev *hwdev, dma_addr_t dma_handle,
size_t size, int direction)
dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
void
dma_sync_sg(struct device *dev, struct scatterlist *sg, int nelems,
enum dma_data_direction direction)
dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
enum dma_data_direction direction)
void
pci_dma_sync_sg(struct pci_dev *hwdev, struct scatterlist *sg,
int nelems, int direction)
dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
enum dma_data_direction direction)
Synchronise a single contiguous or scatter/gather mapping. All the
parameters must be the same as those passed into the single mapping
API.
Synchronise a single contiguous or scatter/gather mapping for the cpu
and device. With the sync_sg API, all the parameters must be the same
as those passed into the single mapping API. With the sync_single API,
you can use dma_handle and size parameters that aren't identical to
those passed into the single mapping API to do a partial sync.
Notes: You must do this:
@ -461,9 +421,9 @@ void whizco_dma_map_sg_attrs(struct device *dev, dma_addr_t dma_addr,
Part II - Advanced dma_ usage
-----------------------------
Warning: These pieces of the DMA API have no PCI equivalent. They
should also not be used in the majority of cases, since they cater for
unlikely corner cases that don't belong in usual drivers.
Warning: These pieces of the DMA API should not be used in the
majority of cases, since they cater for unlikely corner cases that
don't belong in usual drivers.
If you don't understand how cache line coherency works between a
processor and an I/O device, you should not be using this part of the
@ -495,12 +455,6 @@ Free memory allocated by the nonconsistent API. All parameters must
be identical to those passed in (and returned by
dma_alloc_noncoherent()).
int
dma_is_consistent(struct device *dev, dma_addr_t dma_handle)
Returns true if the device dev is performing consistent DMA on the memory
area pointed to by the dma_handle.
int
dma_get_cache_alignment(void)
@ -513,16 +467,6 @@ line, but it will guarantee that one or more cache lines fit exactly
into the width returned by this call. It will also always be a power
of two for easy alignment.
void
dma_sync_single_range(struct device *dev, dma_addr_t dma_handle,
unsigned long offset, size_t size,
enum dma_data_direction direction)
Does a partial sync, starting at offset and continuing for size. You
must be careful to observe the cache alignment and width when doing
anything like this. You must also be extra careful about accessing
memory you intend to sync partially.
void
dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction)

View File

@ -0,0 +1,574 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE set PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
<set>
<setinfo>
<title>The 802.11 subsystems &ndash; for kernel developers</title>
<subtitle>
Explaining wireless 802.11 networking in the Linux kernel
</subtitle>
<copyright>
<year>2007-2009</year>
<holder>Johannes Berg</holder>
</copyright>
<authorgroup>
<author>
<firstname>Johannes</firstname>
<surname>Berg</surname>
<affiliation>
<address><email>johannes@sipsolutions.net</email></address>
</affiliation>
</author>
</authorgroup>
<legalnotice>
<para>
This documentation is free software; you can redistribute
it and/or modify it under the terms of the GNU General Public
License version 2 as published by the Free Software Foundation.
</para>
<para>
This documentation is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
</para>
<para>
You should have received a copy of the GNU General Public
License along with this documentation; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
</para>
<para>
For more details see the file COPYING in the source
distribution of Linux.
</para>
</legalnotice>
<abstract>
<para>
These books attempt to give a description of the
various subsystems that play a role in 802.11 wireless
networking in Linux. Since these books are for kernel
developers they attempts to document the structures
and functions used in the kernel as well as giving a
higher-level overview.
</para>
<para>
The reader is expected to be familiar with the 802.11
standard as published by the IEEE in 802.11-2007 (or
possibly later versions). References to this standard
will be given as "802.11-2007 8.1.5".
</para>
</abstract>
</setinfo>
<book id="cfg80211-developers-guide">
<bookinfo>
<title>The cfg80211 subsystem</title>
<abstract>
!Pinclude/net/cfg80211.h Introduction
</abstract>
</bookinfo>
<chapter>
<title>Device registration</title>
!Pinclude/net/cfg80211.h Device registration
!Finclude/net/cfg80211.h ieee80211_band
!Finclude/net/cfg80211.h ieee80211_channel_flags
!Finclude/net/cfg80211.h ieee80211_channel
!Finclude/net/cfg80211.h ieee80211_rate_flags
!Finclude/net/cfg80211.h ieee80211_rate
!Finclude/net/cfg80211.h ieee80211_sta_ht_cap
!Finclude/net/cfg80211.h ieee80211_supported_band
!Finclude/net/cfg80211.h cfg80211_signal_type
!Finclude/net/cfg80211.h wiphy_params_flags
!Finclude/net/cfg80211.h wiphy_flags
!Finclude/net/cfg80211.h wiphy
!Finclude/net/cfg80211.h wireless_dev
!Finclude/net/cfg80211.h wiphy_new
!Finclude/net/cfg80211.h wiphy_register
!Finclude/net/cfg80211.h wiphy_unregister
!Finclude/net/cfg80211.h wiphy_free
!Finclude/net/cfg80211.h wiphy_name
!Finclude/net/cfg80211.h wiphy_dev
!Finclude/net/cfg80211.h wiphy_priv
!Finclude/net/cfg80211.h priv_to_wiphy
!Finclude/net/cfg80211.h set_wiphy_dev
!Finclude/net/cfg80211.h wdev_priv
</chapter>
<chapter>
<title>Actions and configuration</title>
!Pinclude/net/cfg80211.h Actions and configuration
!Finclude/net/cfg80211.h cfg80211_ops
!Finclude/net/cfg80211.h vif_params
!Finclude/net/cfg80211.h key_params
!Finclude/net/cfg80211.h survey_info_flags
!Finclude/net/cfg80211.h survey_info
!Finclude/net/cfg80211.h beacon_parameters
!Finclude/net/cfg80211.h plink_actions
!Finclude/net/cfg80211.h station_parameters
!Finclude/net/cfg80211.h station_info_flags
!Finclude/net/cfg80211.h rate_info_flags
!Finclude/net/cfg80211.h rate_info
!Finclude/net/cfg80211.h station_info
!Finclude/net/cfg80211.h monitor_flags
!Finclude/net/cfg80211.h mpath_info_flags
!Finclude/net/cfg80211.h mpath_info
!Finclude/net/cfg80211.h bss_parameters
!Finclude/net/cfg80211.h ieee80211_txq_params
!Finclude/net/cfg80211.h cfg80211_crypto_settings
!Finclude/net/cfg80211.h cfg80211_auth_request
!Finclude/net/cfg80211.h cfg80211_assoc_request
!Finclude/net/cfg80211.h cfg80211_deauth_request
!Finclude/net/cfg80211.h cfg80211_disassoc_request
!Finclude/net/cfg80211.h cfg80211_ibss_params
!Finclude/net/cfg80211.h cfg80211_connect_params
!Finclude/net/cfg80211.h cfg80211_pmksa
!Finclude/net/cfg80211.h cfg80211_send_rx_auth
!Finclude/net/cfg80211.h cfg80211_send_auth_timeout
!Finclude/net/cfg80211.h __cfg80211_auth_canceled
!Finclude/net/cfg80211.h cfg80211_send_rx_assoc
!Finclude/net/cfg80211.h cfg80211_send_assoc_timeout
!Finclude/net/cfg80211.h cfg80211_send_deauth
!Finclude/net/cfg80211.h __cfg80211_send_deauth
!Finclude/net/cfg80211.h cfg80211_send_disassoc
!Finclude/net/cfg80211.h __cfg80211_send_disassoc
!Finclude/net/cfg80211.h cfg80211_ibss_joined
!Finclude/net/cfg80211.h cfg80211_connect_result
!Finclude/net/cfg80211.h cfg80211_roamed
!Finclude/net/cfg80211.h cfg80211_disconnected
!Finclude/net/cfg80211.h cfg80211_ready_on_channel
!Finclude/net/cfg80211.h cfg80211_remain_on_channel_expired
!Finclude/net/cfg80211.h cfg80211_new_sta
!Finclude/net/cfg80211.h cfg80211_rx_mgmt
!Finclude/net/cfg80211.h cfg80211_mgmt_tx_status
!Finclude/net/cfg80211.h cfg80211_cqm_rssi_notify
!Finclude/net/cfg80211.h cfg80211_cqm_pktloss_notify
!Finclude/net/cfg80211.h cfg80211_michael_mic_failure
</chapter>
<chapter>
<title>Scanning and BSS list handling</title>
!Pinclude/net/cfg80211.h Scanning and BSS list handling
!Finclude/net/cfg80211.h cfg80211_ssid
!Finclude/net/cfg80211.h cfg80211_scan_request
!Finclude/net/cfg80211.h cfg80211_scan_done
!Finclude/net/cfg80211.h cfg80211_bss
!Finclude/net/cfg80211.h cfg80211_inform_bss_frame
!Finclude/net/cfg80211.h cfg80211_inform_bss
!Finclude/net/cfg80211.h cfg80211_unlink_bss
!Finclude/net/cfg80211.h cfg80211_find_ie
!Finclude/net/cfg80211.h ieee80211_bss_get_ie
</chapter>
<chapter>
<title>Utility functions</title>
!Pinclude/net/cfg80211.h Utility functions
!Finclude/net/cfg80211.h ieee80211_channel_to_frequency
!Finclude/net/cfg80211.h ieee80211_frequency_to_channel
!Finclude/net/cfg80211.h ieee80211_get_channel
!Finclude/net/cfg80211.h ieee80211_get_response_rate
!Finclude/net/cfg80211.h ieee80211_hdrlen
!Finclude/net/cfg80211.h ieee80211_get_hdrlen_from_skb
!Finclude/net/cfg80211.h ieee80211_radiotap_iterator
</chapter>
<chapter>
<title>Data path helpers</title>
!Pinclude/net/cfg80211.h Data path helpers
!Finclude/net/cfg80211.h ieee80211_data_to_8023
!Finclude/net/cfg80211.h ieee80211_data_from_8023
!Finclude/net/cfg80211.h ieee80211_amsdu_to_8023s
!Finclude/net/cfg80211.h cfg80211_classify8021d
</chapter>
<chapter>
<title>Regulatory enforcement infrastructure</title>
!Pinclude/net/cfg80211.h Regulatory enforcement infrastructure
!Finclude/net/cfg80211.h regulatory_hint
!Finclude/net/cfg80211.h wiphy_apply_custom_regulatory
!Finclude/net/cfg80211.h freq_reg_info
</chapter>
<chapter>
<title>RFkill integration</title>
!Pinclude/net/cfg80211.h RFkill integration
!Finclude/net/cfg80211.h wiphy_rfkill_set_hw_state
!Finclude/net/cfg80211.h wiphy_rfkill_start_polling
!Finclude/net/cfg80211.h wiphy_rfkill_stop_polling
</chapter>
<chapter>
<title>Test mode</title>
!Pinclude/net/cfg80211.h Test mode
!Finclude/net/cfg80211.h cfg80211_testmode_alloc_reply_skb
!Finclude/net/cfg80211.h cfg80211_testmode_reply
!Finclude/net/cfg80211.h cfg80211_testmode_alloc_event_skb
!Finclude/net/cfg80211.h cfg80211_testmode_event
</chapter>
</book>
<book id="mac80211-developers-guide">
<bookinfo>
<title>The mac80211 subsystem</title>
<abstract>
!Pinclude/net/mac80211.h Introduction
!Pinclude/net/mac80211.h Warning
</abstract>
</bookinfo>
<toc></toc>
<!--
Generally, this document shall be ordered by increasing complexity.
It is important to note that readers should be able to read only
the first few sections to get a working driver and only advanced
usage should require reading the full document.
-->
<part>
<title>The basic mac80211 driver interface</title>
<partintro>
<para>
You should read and understand the information contained
within this part of the book while implementing a driver.
In some chapters, advanced usage is noted, that may be
skipped at first.
</para>
<para>
This part of the book only covers station and monitor mode
functionality, additional information required to implement
the other modes is covered in the second part of the book.
</para>
</partintro>
<chapter id="basics">
<title>Basic hardware handling</title>
<para>TBD</para>
<para>
This chapter shall contain information on getting a hw
struct allocated and registered with mac80211.
</para>
<para>
Since it is required to allocate rates/modes before registering
a hw struct, this chapter shall also contain information on setting
up the rate/mode structs.
</para>
<para>
Additionally, some discussion about the callbacks and
the general programming model should be in here, including
the definition of ieee80211_ops which will be referred to
a lot.
</para>
<para>
Finally, a discussion of hardware capabilities should be done
with references to other parts of the book.
</para>
<!-- intentionally multiple !F lines to get proper order -->
!Finclude/net/mac80211.h ieee80211_hw
!Finclude/net/mac80211.h ieee80211_hw_flags
!Finclude/net/mac80211.h SET_IEEE80211_DEV
!Finclude/net/mac80211.h SET_IEEE80211_PERM_ADDR
!Finclude/net/mac80211.h ieee80211_ops
!Finclude/net/mac80211.h ieee80211_alloc_hw
!Finclude/net/mac80211.h ieee80211_register_hw
!Finclude/net/mac80211.h ieee80211_unregister_hw
!Finclude/net/mac80211.h ieee80211_free_hw
</chapter>
<chapter id="phy-handling">
<title>PHY configuration</title>
<para>TBD</para>
<para>
This chapter should describe PHY handling including
start/stop callbacks and the various structures used.
</para>
!Finclude/net/mac80211.h ieee80211_conf
!Finclude/net/mac80211.h ieee80211_conf_flags
</chapter>
<chapter id="iface-handling">
<title>Virtual interfaces</title>
<para>TBD</para>
<para>
This chapter should describe virtual interface basics
that are relevant to the driver (VLANs, MGMT etc are not.)
It should explain the use of the add_iface/remove_iface
callbacks as well as the interface configuration callbacks.
</para>
<para>Things related to AP mode should be discussed there.</para>
<para>
Things related to supporting multiple interfaces should be
in the appropriate chapter, a BIG FAT note should be here about
this though and the recommendation to allow only a single
interface in STA mode at first!
</para>
!Finclude/net/mac80211.h ieee80211_vif
</chapter>
<chapter id="rx-tx">
<title>Receive and transmit processing</title>
<sect1>
<title>what should be here</title>
<para>TBD</para>
<para>
This should describe the receive and transmit
paths in mac80211/the drivers as well as
transmit status handling.
</para>
</sect1>
<sect1>
<title>Frame format</title>
!Pinclude/net/mac80211.h Frame format
</sect1>
<sect1>
<title>Packet alignment</title>
!Pnet/mac80211/rx.c Packet alignment
</sect1>
<sect1>
<title>Calling into mac80211 from interrupts</title>
!Pinclude/net/mac80211.h Calling mac80211 from interrupts
</sect1>
<sect1>
<title>functions/definitions</title>
!Finclude/net/mac80211.h ieee80211_rx_status
!Finclude/net/mac80211.h mac80211_rx_flags
!Finclude/net/mac80211.h mac80211_tx_control_flags
!Finclude/net/mac80211.h mac80211_rate_control_flags
!Finclude/net/mac80211.h ieee80211_tx_rate
!Finclude/net/mac80211.h ieee80211_tx_info
!Finclude/net/mac80211.h ieee80211_tx_info_clear_status
!Finclude/net/mac80211.h ieee80211_rx
!Finclude/net/mac80211.h ieee80211_rx_ni
!Finclude/net/mac80211.h ieee80211_rx_irqsafe
!Finclude/net/mac80211.h ieee80211_tx_status
!Finclude/net/mac80211.h ieee80211_tx_status_ni
!Finclude/net/mac80211.h ieee80211_tx_status_irqsafe
!Finclude/net/mac80211.h ieee80211_rts_get
!Finclude/net/mac80211.h ieee80211_rts_duration
!Finclude/net/mac80211.h ieee80211_ctstoself_get
!Finclude/net/mac80211.h ieee80211_ctstoself_duration
!Finclude/net/mac80211.h ieee80211_generic_frame_duration
!Finclude/net/mac80211.h ieee80211_wake_queue
!Finclude/net/mac80211.h ieee80211_stop_queue
!Finclude/net/mac80211.h ieee80211_wake_queues
!Finclude/net/mac80211.h ieee80211_stop_queues
!Finclude/net/mac80211.h ieee80211_queue_stopped
</sect1>
</chapter>
<chapter id="filters">
<title>Frame filtering</title>
!Pinclude/net/mac80211.h Frame filtering
!Finclude/net/mac80211.h ieee80211_filter_flags
</chapter>
<chapter id="workqueue">
<title>The mac80211 workqueue</title>
!Pinclude/net/mac80211.h mac80211 workqueue
!Finclude/net/mac80211.h ieee80211_queue_work
!Finclude/net/mac80211.h ieee80211_queue_delayed_work
</chapter>
</part>
<part id="advanced">
<title>Advanced driver interface</title>
<partintro>
<para>
Information contained within this part of the book is
of interest only for advanced interaction of mac80211
with drivers to exploit more hardware capabilities and
improve performance.
</para>
</partintro>
<chapter id="led-support">
<title>LED support</title>
<para>
Mac80211 supports various ways of blinking LEDs. Wherever possible,
device LEDs should be exposed as LED class devices and hooked up to
the appropriate trigger, which will then be triggered appropriately
by mac80211.
</para>
!Finclude/net/mac80211.h ieee80211_get_tx_led_name
!Finclude/net/mac80211.h ieee80211_get_rx_led_name
!Finclude/net/mac80211.h ieee80211_get_assoc_led_name
!Finclude/net/mac80211.h ieee80211_get_radio_led_name
!Finclude/net/mac80211.h ieee80211_tpt_blink
!Finclude/net/mac80211.h ieee80211_tpt_led_trigger_flags
!Finclude/net/mac80211.h ieee80211_create_tpt_led_trigger
</chapter>
<chapter id="hardware-crypto-offload">
<title>Hardware crypto acceleration</title>
!Pinclude/net/mac80211.h Hardware crypto acceleration
<!-- intentionally multiple !F lines to get proper order -->
!Finclude/net/mac80211.h set_key_cmd
!Finclude/net/mac80211.h ieee80211_key_conf
!Finclude/net/mac80211.h ieee80211_key_flags
!Finclude/net/mac80211.h ieee80211_tkip_key_type
!Finclude/net/mac80211.h ieee80211_get_tkip_key
!Finclude/net/mac80211.h ieee80211_key_removed
</chapter>
<chapter id="powersave">
<title>Powersave support</title>
!Pinclude/net/mac80211.h Powersave support
</chapter>
<chapter id="beacon-filter">
<title>Beacon filter support</title>
!Pinclude/net/mac80211.h Beacon filter support
!Finclude/net/mac80211.h ieee80211_beacon_loss
</chapter>
<chapter id="qos">
<title>Multiple queues and QoS support</title>
<para>TBD</para>
!Finclude/net/mac80211.h ieee80211_tx_queue_params
</chapter>
<chapter id="AP">
<title>Access point mode support</title>
<para>TBD</para>
<para>Some parts of the if_conf should be discussed here instead</para>
<para>
Insert notes about VLAN interfaces with hw crypto here or
in the hw crypto chapter.
</para>
!Finclude/net/mac80211.h ieee80211_get_buffered_bc
!Finclude/net/mac80211.h ieee80211_beacon_get
</chapter>
<chapter id="multi-iface">
<title>Supporting multiple virtual interfaces</title>
<para>TBD</para>
<para>
Note: WDS with identical MAC address should almost always be OK
</para>
<para>
Insert notes about having multiple virtual interfaces with
different MAC addresses here, note which configurations are
supported by mac80211, add notes about supporting hw crypto
with it.
</para>
!Finclude/net/mac80211.h ieee80211_iterate_active_interfaces
!Finclude/net/mac80211.h ieee80211_iterate_active_interfaces_atomic
</chapter>
<chapter id="station-handling">
<title>Station handling</title>
<para>TODO</para>
!Finclude/net/mac80211.h ieee80211_sta
!Finclude/net/mac80211.h sta_notify_cmd
!Finclude/net/mac80211.h ieee80211_find_sta
!Finclude/net/mac80211.h ieee80211_find_sta_by_ifaddr
!Finclude/net/mac80211.h ieee80211_sta_block_awake
</chapter>
<chapter id="hardware-scan-offload">
<title>Hardware scan offload</title>
<para>TBD</para>
!Finclude/net/mac80211.h ieee80211_scan_completed
</chapter>
<chapter id="aggregation">
<title>Aggregation</title>
<sect1>
<title>TX A-MPDU aggregation</title>
!Pnet/mac80211/agg-tx.c TX A-MPDU aggregation
!Cnet/mac80211/agg-tx.c
</sect1>
<sect1>
<title>RX A-MPDU aggregation</title>
!Pnet/mac80211/agg-rx.c RX A-MPDU aggregation
!Cnet/mac80211/agg-rx.c
</sect1>
!Finclude/net/mac80211.h ieee80211_ampdu_mlme_action
</chapter>
<chapter id="smps">
<title>Spatial Multiplexing Powersave (SMPS)</title>
!Pinclude/net/mac80211.h Spatial multiplexing power save
!Finclude/net/mac80211.h ieee80211_request_smps
!Finclude/net/mac80211.h ieee80211_smps_mode
</chapter>
</part>
<part id="rate-control">
<title>Rate control interface</title>
<partintro>
<para>TBD</para>
<para>
This part of the book describes the rate control algorithm
interface and how it relates to mac80211 and drivers.
</para>
</partintro>
<chapter id="ratecontrol-api">
<title>Rate Control API</title>
<para>TBD</para>
!Finclude/net/mac80211.h ieee80211_start_tx_ba_session
!Finclude/net/mac80211.h ieee80211_start_tx_ba_cb_irqsafe
!Finclude/net/mac80211.h ieee80211_stop_tx_ba_session
!Finclude/net/mac80211.h ieee80211_stop_tx_ba_cb_irqsafe
!Finclude/net/mac80211.h rate_control_changed
!Finclude/net/mac80211.h ieee80211_tx_rate_control
!Finclude/net/mac80211.h rate_control_send_low
</chapter>
</part>
<part id="internal">
<title>Internals</title>
<partintro>
<para>TBD</para>
<para>
This part of the book describes mac80211 internals.
</para>
</partintro>
<chapter id="key-handling">
<title>Key handling</title>
<sect1>
<title>Key handling basics</title>
!Pnet/mac80211/key.c Key handling basics
</sect1>
<sect1>
<title>MORE TBD</title>
<para>TBD</para>
</sect1>
</chapter>
<chapter id="rx-processing">
<title>Receive processing</title>
<para>TBD</para>
</chapter>
<chapter id="tx-processing">
<title>Transmit processing</title>
<para>TBD</para>
</chapter>
<chapter id="sta-info">
<title>Station info handling</title>
<sect1>
<title>Programming information</title>
!Fnet/mac80211/sta_info.h sta_info
!Fnet/mac80211/sta_info.h ieee80211_sta_info_flags
</sect1>
<sect1>
<title>STA information lifetime rules</title>
!Pnet/mac80211/sta_info.c STA information lifetime rules
</sect1>
</chapter>
<chapter id="aggregation-internals">
<title>Aggregation</title>
!Fnet/mac80211/sta_info.h sta_ampdu_mlme
!Fnet/mac80211/sta_info.h tid_ampdu_tx
!Fnet/mac80211/sta_info.h tid_ampdu_rx
</chapter>
<chapter id="synchronisation">
<title>Synchronisation</title>
<para>TBD</para>
<para>Locking, lots of RCU</para>
</chapter>
</part>
</book>
</set>

View File

@ -12,9 +12,9 @@ DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \
kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \
mac80211.xml debugobjects.xml sh.xml regulator.xml \
80211.xml debugobjects.xml sh.xml regulator.xml \
alsa-driver-api.xml writing-an-alsa-driver.xml \
tracepoint.xml media.xml
tracepoint.xml media.xml drm.xml
###
# The build process is as follows (targets):
@ -35,7 +35,7 @@ PS_METHOD = $(prefer-db2x)
PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs xmldoclinks
BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))
xmldocs: $(BOOKS) xmldoclinks
xmldocs: $(BOOKS)
sgmldocs: xmldocs
PS := $(patsubst %.xml, %.ps, $(BOOKS))
@ -45,7 +45,7 @@ PDF := $(patsubst %.xml, %.pdf, $(BOOKS))
pdfdocs: $(PDF)
HTML := $(sort $(patsubst %.xml, %.html, $(BOOKS)))
htmldocs: $(HTML)
htmldocs: $(HTML) xmldoclinks
$(call build_main_index)
$(call build_images)
@ -95,7 +95,7 @@ define rule_docproc
) > $(dir $@).$(notdir $@).cmd
endef
%.xml: %.tmpl FORCE
%.xml: %.tmpl xmldoclinks FORCE
$(call if_changed_rule,docproc)
###

View File

@ -45,14 +45,18 @@
</sect1>
<sect1><title>Atomic and pointer manipulation</title>
!Iarch/x86/include/asm/atomic_32.h
!Iarch/x86/include/asm/unaligned.h
!Iarch/x86/include/asm/atomic.h
</sect1>
<sect1><title>Delaying, scheduling, and timer routines</title>
!Iinclude/linux/sched.h
!Ekernel/sched.c
!Iinclude/linux/completion.h
!Ekernel/timer.c
</sect1>
<sect1><title>Wait queues and Wake events</title>
!Iinclude/linux/wait.h
!Ekernel/wait.c
</sect1>
<sect1><title>High-resolution timers</title>
!Iinclude/linux/ktime.h
@ -111,6 +115,7 @@ X!Edrivers/base/attribute_container.c
<!--
X!Edrivers/base/interface.c
-->
!Iinclude/linux/platform_device.h
!Edrivers/base/platform.c
!Edrivers/base/bus.c
</sect1>
@ -298,6 +303,10 @@ X!Idrivers/video/console/fonts.c
!Edrivers/input/input.c
!Edrivers/input/ff-core.c
!Edrivers/input/ff-memless.c
</sect1>
<sect1><title>Multitouch Library</title>
!Iinclude/linux/input/mt.h
!Edrivers/input/input-mt.c
</sect1>
<sect1><title>Polled input devices</title>
!Iinclude/linux/input-polldev.h

View File

@ -316,7 +316,7 @@ CPU B: spin_unlock_irqrestore(&amp;dev_lock, flags)
<chapter id="pubfunctions">
<title>Public Functions Provided</title>
!Iarch/x86/include/asm/io_32.h
!Iarch/x86/include/asm/io.h
!Elib/iomap.c
</chapter>

View File

@ -0,0 +1,840 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
<book id="drmDevelopersGuide">
<bookinfo>
<title>Linux DRM Developer's Guide</title>
<copyright>
<year>2008-2009</year>
<holder>
Intel Corporation (Jesse Barnes &lt;jesse.barnes@intel.com&gt;)
</holder>
</copyright>
<legalnotice>
<para>
The contents of this file may be used under the terms of the GNU
General Public License version 2 (the "GPL") as distributed in
the kernel source COPYING file.
</para>
</legalnotice>
</bookinfo>
<toc></toc>
<!-- Introduction -->
<chapter id="drmIntroduction">
<title>Introduction</title>
<para>
The Linux DRM layer contains code intended to support the needs
of complex graphics devices, usually containing programmable
pipelines well suited to 3D graphics acceleration. Graphics
drivers in the kernel can make use of DRM functions to make
tasks like memory management, interrupt handling and DMA easier,
and provide a uniform interface to applications.
</para>
<para>
A note on versions: this guide covers features found in the DRM
tree, including the TTM memory manager, output configuration and
mode setting, and the new vblank internals, in addition to all
the regular features found in current kernels.
</para>
<para>
[Insert diagram of typical DRM stack here]
</para>
</chapter>
<!-- Internals -->
<chapter id="drmInternals">
<title>DRM Internals</title>
<para>
This chapter documents DRM internals relevant to driver authors
and developers working to add support for the latest features to
existing drivers.
</para>
<para>
First, we'll go over some typical driver initialization
requirements, like setting up command buffers, creating an
initial output configuration, and initializing core services.
Subsequent sections will cover core internals in more detail,
providing implementation notes and examples.
</para>
<para>
The DRM layer provides several services to graphics drivers,
many of them driven by the application interfaces it provides
through libdrm, the library that wraps most of the DRM ioctls.
These include vblank event handling, memory
management, output management, framebuffer management, command
submission &amp; fencing, suspend/resume support, and DMA
services.
</para>
<para>
The core of every DRM driver is struct drm_device. Drivers
will typically statically initialize a drm_device structure,
then pass it to drm_init() at load time.
</para>
<!-- Internals: driver init -->
<sect1>
<title>Driver initialization</title>
<para>
Before calling the DRM initialization routines, the driver must
first create and fill out a struct drm_device structure.
</para>
<programlisting>
static struct drm_driver driver = {
/* don't use mtrr's here, the Xserver or user space app should
* deal with them for intel hardware.
*/
.driver_features =
DRIVER_USE_AGP | DRIVER_REQUIRE_AGP |
DRIVER_HAVE_IRQ | DRIVER_IRQ_SHARED | DRIVER_MODESET,
.load = i915_driver_load,
.unload = i915_driver_unload,
.firstopen = i915_driver_firstopen,
.lastclose = i915_driver_lastclose,
.preclose = i915_driver_preclose,
.save = i915_save,
.restore = i915_restore,
.device_is_agp = i915_driver_device_is_agp,
.get_vblank_counter = i915_get_vblank_counter,
.enable_vblank = i915_enable_vblank,
.disable_vblank = i915_disable_vblank,
.irq_preinstall = i915_driver_irq_preinstall,
.irq_postinstall = i915_driver_irq_postinstall,
.irq_uninstall = i915_driver_irq_uninstall,
.irq_handler = i915_driver_irq_handler,
.reclaim_buffers = drm_core_reclaim_buffers,
.get_map_ofs = drm_core_get_map_ofs,
.get_reg_ofs = drm_core_get_reg_ofs,
.fb_probe = intelfb_probe,
.fb_remove = intelfb_remove,
.fb_resize = intelfb_resize,
.master_create = i915_master_create,
.master_destroy = i915_master_destroy,
#if defined(CONFIG_DEBUG_FS)
.debugfs_init = i915_debugfs_init,
.debugfs_cleanup = i915_debugfs_cleanup,
#endif
.gem_init_object = i915_gem_init_object,
.gem_free_object = i915_gem_free_object,
.gem_vm_ops = &amp;i915_gem_vm_ops,
.ioctls = i915_ioctls,
.fops = {
.owner = THIS_MODULE,
.open = drm_open,
.release = drm_release,
.ioctl = drm_ioctl,
.mmap = drm_mmap,
.poll = drm_poll,
.fasync = drm_fasync,
#ifdef CONFIG_COMPAT
.compat_ioctl = i915_compat_ioctl,
#endif
.llseek = noop_llseek,
},
.pci_driver = {
.name = DRIVER_NAME,
.id_table = pciidlist,
.probe = probe,
.remove = __devexit_p(drm_cleanup_pci),
},
.name = DRIVER_NAME,
.desc = DRIVER_DESC,
.date = DRIVER_DATE,
.major = DRIVER_MAJOR,
.minor = DRIVER_MINOR,
.patchlevel = DRIVER_PATCHLEVEL,
};
</programlisting>
<para>
In the example above, taken from the i915 DRM driver, the driver
sets several flags indicating what core features it supports.
We'll go over the individual callbacks in later sections. Since
flags indicate which features your driver supports to the DRM
core, you need to set most of them prior to calling drm_init(). Some,
like DRIVER_MODESET can be set later based on user supplied parameters,
but that's the exception rather than the rule.
</para>
<variablelist>
<title>Driver flags</title>
<varlistentry>
<term>DRIVER_USE_AGP</term>
<listitem><para>
Driver uses AGP interface
</para></listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_REQUIRE_AGP</term>
<listitem><para>
Driver needs AGP interface to function.
</para></listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_USE_MTRR</term>
<listitem>
<para>
Driver uses MTRR interface for mapping memory. Deprecated.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_PCI_DMA</term>
<listitem><para>
Driver is capable of PCI DMA. Deprecated.
</para></listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_SG</term>
<listitem><para>
Driver can perform scatter/gather DMA. Deprecated.
</para></listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_HAVE_DMA</term>
<listitem><para>Driver supports DMA. Deprecated.</para></listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_HAVE_IRQ</term><term>DRIVER_IRQ_SHARED</term>
<listitem>
<para>
DRIVER_HAVE_IRQ indicates whether the driver has a IRQ
handler, DRIVER_IRQ_SHARED indicates whether the device &amp;
handler support shared IRQs (note that this is required of
PCI drivers).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_DMA_QUEUE</term>
<listitem>
<para>
If the driver queues DMA requests and completes them
asynchronously, this flag should be set. Deprecated.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_FB_DMA</term>
<listitem>
<para>
Driver supports DMA to/from the framebuffer. Deprecated.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>DRIVER_MODESET</term>
<listitem>
<para>
Driver supports mode setting interfaces.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
In this specific case, the driver requires AGP and supports
IRQs. DMA, as we'll see, is handled by device specific ioctls
in this case. It also supports the kernel mode setting APIs, though
unlike in the actual i915 driver source, this example unconditionally
exports KMS capability.
</para>
</sect1>
<!-- Internals: driver load -->
<sect1>
<title>Driver load</title>
<para>
In the previous section, we saw what a typical drm_driver
structure might look like. One of the more important fields in
the structure is the hook for the load function.
</para>
<programlisting>
static struct drm_driver driver = {
...
.load = i915_driver_load,
...
};
</programlisting>
<para>
The load function has many responsibilities: allocating a driver
private structure, specifying supported performance counters,
configuring the device (e.g. mapping registers &amp; command
buffers), initializing the memory manager, and setting up the
initial output configuration.
</para>
<para>
Note that the tasks performed at driver load time must not
conflict with DRM client requirements. For instance, if user
level mode setting drivers are in use, it would be problematic
to perform output discovery &amp; configuration at load time.
Likewise, if pre-memory management aware user level drivers are
in use, memory management and command buffer setup may need to
be omitted. These requirements are driver specific, and care
needs to be taken to keep both old and new applications and
libraries working. The i915 driver supports the "modeset"
module parameter to control whether advanced features are
enabled at load time or in legacy fashion. If compatibility is
a concern (e.g. with drivers converted over to the new interfaces
from the old ones), care must be taken to prevent incompatible
device initialization and control with the currently active
userspace drivers.
</para>
<sect2>
<title>Driver private &amp; performance counters</title>
<para>
The driver private hangs off the main drm_device structure and
can be used for tracking various device specific bits of
information, like register offsets, command buffer status,
register state for suspend/resume, etc. At load time, a
driver can simply allocate one and set drm_device.dev_priv
appropriately; at unload the driver can free it and set
drm_device.dev_priv to NULL.
</para>
<para>
The DRM supports several counters which can be used for rough
performance characterization. Note that the DRM stat counter
system is not often used by applications, and supporting
additional counters is completely optional.
</para>
<para>
These interfaces are deprecated and should not be used. If performance
monitoring is desired, the developer should investigate and
potentially enhance the kernel perf and tracing infrastructure to export
GPU related performance information to performance monitoring
tools and applications.
</para>
</sect2>
<sect2>
<title>Configuring the device</title>
<para>
Obviously, device configuration will be device specific.
However, there are several common operations: finding a
device's PCI resources, mapping them, and potentially setting
up an IRQ handler.
</para>
<para>
Finding &amp; mapping resources is fairly straightforward. The
DRM wrapper functions, drm_get_resource_start() and
drm_get_resource_len() can be used to find BARs on the given
drm_device struct. Once those values have been retrieved, the
driver load function can call drm_addmap() to create a new
mapping for the BAR in question. Note you'll probably want a
drm_local_map_t in your driver private structure to track any
mappings you create.
<!-- !Fdrivers/gpu/drm/drm_bufs.c drm_get_resource_* -->
<!-- !Finclude/drm/drmP.h drm_local_map_t -->
</para>
<para>
if compatibility with other operating systems isn't a concern
(DRM drivers can run under various BSD variants and OpenSolaris),
native Linux calls can be used for the above, e.g. pci_resource_*
and iomap*/iounmap. See the Linux device driver book for more
info.
</para>
<para>
Once you have a register map, you can use the DRM_READn() and
DRM_WRITEn() macros to access the registers on your device, or
use driver specific versions to offset into your MMIO space
relative to a driver specific base pointer (see I915_READ for
example).
</para>
<para>
If your device supports interrupt generation, you may want to
setup an interrupt handler at driver load time as well. This
is done using the drm_irq_install() function. If your device
supports vertical blank interrupts, it should call
drm_vblank_init() to initialize the core vblank handling code before
enabling interrupts on your device. This ensures the vblank related
structures are allocated and allows the core to handle vblank events.
</para>
<!--!Fdrivers/char/drm/drm_irq.c drm_irq_install-->
<para>
Once your interrupt handler is registered (it'll use your
drm_driver.irq_handler as the actual interrupt handling
function), you can safely enable interrupts on your device,
assuming any other state your interrupt handler uses is also
initialized.
</para>
<para>
Another task that may be necessary during configuration is
mapping the video BIOS. On many devices, the VBIOS describes
device configuration, LCD panel timings (if any), and contains
flags indicating device state. Mapping the BIOS can be done
using the pci_map_rom() call, a convenience function that
takes care of mapping the actual ROM, whether it has been
shadowed into memory (typically at address 0xc0000) or exists
on the PCI device in the ROM BAR. Note that once you've
mapped the ROM and extracted any necessary information, be
sure to unmap it; on many devices the ROM address decoder is
shared with other BARs, so leaving it mapped can cause
undesired behavior like hangs or memory corruption.
<!--!Fdrivers/pci/rom.c pci_map_rom-->
</para>
</sect2>
<sect2>
<title>Memory manager initialization</title>
<para>
In order to allocate command buffers, cursor memory, scanout
buffers, etc., as well as support the latest features provided
by packages like Mesa and the X.Org X server, your driver
should support a memory manager.
</para>
<para>
If your driver supports memory management (it should!), you'll
need to set that up at load time as well. How you initialize
it depends on which memory manager you're using, TTM or GEM.
</para>
<sect3>
<title>TTM initialization</title>
<para>
TTM (for Translation Table Manager) manages video memory and
aperture space for graphics devices. TTM supports both UMA devices
and devices with dedicated video RAM (VRAM), i.e. most discrete
graphics devices. If your device has dedicated RAM, supporting
TTM is desirable. TTM also integrates tightly with your
driver specific buffer execution function. See the radeon
driver for examples.
</para>
<para>
The core TTM structure is the ttm_bo_driver struct. It contains
several fields with function pointers for initializing the TTM,
allocating and freeing memory, waiting for command completion
and fence synchronization, and memory migration. See the
radeon_ttm.c file for an example of usage.
</para>
<para>
The ttm_global_reference structure is made up of several fields:
</para>
<programlisting>
struct ttm_global_reference {
enum ttm_global_types global_type;
size_t size;
void *object;
int (*init) (struct ttm_global_reference *);
void (*release) (struct ttm_global_reference *);
};
</programlisting>
<para>
There should be one global reference structure for your memory
manager as a whole, and there will be others for each object
created by the memory manager at runtime. Your global TTM should
have a type of TTM_GLOBAL_TTM_MEM. The size field for the global
object should be sizeof(struct ttm_mem_global), and the init and
release hooks should point at your driver specific init and
release routines, which will probably eventually call
ttm_mem_global_init and ttm_mem_global_release respectively.
</para>
<para>
Once your global TTM accounting structure is set up and initialized
(done by calling ttm_global_item_ref on the global object you
just created), you'll need to create a buffer object TTM to
provide a pool for buffer object allocation by clients and the
kernel itself. The type of this object should be TTM_GLOBAL_TTM_BO,
and its size should be sizeof(struct ttm_bo_global). Again,
driver specific init and release functions can be provided,
likely eventually calling ttm_bo_global_init and
ttm_bo_global_release, respectively. Also like the previous
object, ttm_global_item_ref is used to create an initial reference
count for the TTM, which will call your initialization function.
</para>
</sect3>
<sect3>
<title>GEM initialization</title>
<para>
GEM is an alternative to TTM, designed specifically for UMA
devices. It has simpler initialization and execution requirements
than TTM, but has no VRAM management capability. Core GEM
initialization is comprised of a basic drm_mm_init call to create
a GTT DRM MM object, which provides an address space pool for
object allocation. In a KMS configuration, the driver will
need to allocate and initialize a command ring buffer following
basic GEM initialization. Most UMA devices have a so-called
"stolen" memory region, which provides space for the initial
framebuffer and large, contiguous memory regions required by the
device. This space is not typically managed by GEM, and must
be initialized separately into its own DRM MM object.
</para>
<para>
Initialization will be driver specific, and will depend on
the architecture of the device. In the case of Intel
integrated graphics chips like 965GM, GEM initialization can
be done by calling the internal GEM init function,
i915_gem_do_init(). Since the 965GM is a UMA device
(i.e. it doesn't have dedicated VRAM), GEM will manage
making regular RAM available for GPU operations. Memory set
aside by the BIOS (called "stolen" memory by the i915
driver) will be managed by the DRM memrange allocator; the
rest of the aperture will be managed by GEM.
<programlisting>
/* Basic memrange allocator for stolen space (aka vram) */
drm_memrange_init(&amp;dev_priv->vram, 0, prealloc_size);
/* Let GEM Manage from end of prealloc space to end of aperture */
i915_gem_do_init(dev, prealloc_size, agp_size);
</programlisting>
<!--!Edrivers/char/drm/drm_memrange.c-->
</para>
<para>
Once the memory manager has been set up, we can allocate the
command buffer. In the i915 case, this is also done with a
GEM function, i915_gem_init_ringbuffer().
</para>
</sect3>
</sect2>
<sect2>
<title>Output configuration</title>
<para>
The final initialization task is output configuration. This involves
finding and initializing the CRTCs, encoders and connectors
for your device, creating an initial configuration and
registering a framebuffer console driver.
</para>
<sect3>
<title>Output discovery and initialization</title>
<para>
Several core functions exist to create CRTCs, encoders and
connectors, namely drm_crtc_init(), drm_connector_init() and
drm_encoder_init(), along with several "helper" functions to
perform common tasks.
</para>
<para>
Connectors should be registered with sysfs once they've been
detected and initialized, using the
drm_sysfs_connector_add() function. Likewise, when they're
removed from the system, they should be destroyed with
drm_sysfs_connector_remove().
</para>
<programlisting>
<![CDATA[
void intel_crt_init(struct drm_device *dev)
{
struct drm_connector *connector;
struct intel_output *intel_output;
intel_output = kzalloc(sizeof(struct intel_output), GFP_KERNEL);
if (!intel_output)
return;
connector = &intel_output->base;
drm_connector_init(dev, &intel_output->base,
&intel_crt_connector_funcs, DRM_MODE_CONNECTOR_VGA);
drm_encoder_init(dev, &intel_output->enc, &intel_crt_enc_funcs,
DRM_MODE_ENCODER_DAC);
drm_mode_connector_attach_encoder(&intel_output->base,
&intel_output->enc);
/* Set up the DDC bus. */
intel_output->ddc_bus = intel_i2c_create(dev, GPIOA, "CRTDDC_A");
if (!intel_output->ddc_bus) {
dev_printk(KERN_ERR, &dev->pdev->dev, "DDC bus registration "
"failed.\n");
return;
}
intel_output->type = INTEL_OUTPUT_ANALOG;
connector->interlace_allowed = 0;
connector->doublescan_allowed = 0;
drm_encoder_helper_add(&intel_output->enc, &intel_crt_helper_funcs);
drm_connector_helper_add(connector, &intel_crt_connector_helper_funcs);
drm_sysfs_connector_add(connector);
}
]]>
</programlisting>
<para>
In the example above (again, taken from the i915 driver), a
CRT connector and encoder combination is created. A device
specific i2c bus is also created, for fetching EDID data and
performing monitor detection. Once the process is complete,
the new connector is registered with sysfs, to make its
properties available to applications.
</para>
<sect4>
<title>Helper functions and core functions</title>
<para>
Since many PC-class graphics devices have similar display output
designs, the DRM provides a set of helper functions to make
output management easier. The core helper routines handle
encoder re-routing and disabling of unused functions following
mode set. Using the helpers is optional, but recommended for
devices with PC-style architectures (i.e. a set of display planes
for feeding pixels to encoders which are in turn routed to
connectors). Devices with more complex requirements needing
finer grained management can opt to use the core callbacks
directly.
</para>
<para>
[Insert typical diagram here.] [Insert OMAP style config here.]
</para>
</sect4>
<para>
For each encoder, CRTC and connector, several functions must
be provided, depending on the object type. Encoder objects
need to provide a DPMS (basically on/off) function, mode fixup
(for converting requested modes into native hardware timings),
and prepare, set and commit functions for use by the core DRM
helper functions. Connector helpers need to provide mode fetch and
validity functions as well as an encoder matching function for
returning an ideal encoder for a given connector. The core
connector functions include a DPMS callback, (deprecated)
save/restore routines, detection, mode probing, property handling,
and cleanup functions.
</para>
<!--!Edrivers/char/drm/drm_crtc.h-->
<!--!Edrivers/char/drm/drm_crtc.c-->
<!--!Edrivers/char/drm/drm_crtc_helper.c-->
</sect3>
</sect2>
</sect1>
<!-- Internals: vblank handling -->
<sect1>
<title>VBlank event handling</title>
<para>
The DRM core exposes two vertical blank related ioctls:
DRM_IOCTL_WAIT_VBLANK and DRM_IOCTL_MODESET_CTL.
<!--!Edrivers/char/drm/drm_irq.c-->
</para>
<para>
DRM_IOCTL_WAIT_VBLANK takes a struct drm_wait_vblank structure
as its argument, and is used to block or request a signal when a
specified vblank event occurs.
</para>
<para>
DRM_IOCTL_MODESET_CTL should be called by application level
drivers before and after mode setting, since on many devices the
vertical blank counter will be reset at that time. Internally,
the DRM snapshots the last vblank count when the ioctl is called
with the _DRM_PRE_MODESET command so that the counter won't go
backwards (which is dealt with when _DRM_POST_MODESET is used).
</para>
<para>
To support the functions above, the DRM core provides several
helper functions for tracking vertical blank counters, and
requires drivers to provide several callbacks:
get_vblank_counter(), enable_vblank() and disable_vblank(). The
core uses get_vblank_counter() to keep the counter accurate
across interrupt disable periods. It should return the current
vertical blank event count, which is often tracked in a device
register. The enable and disable vblank callbacks should enable
and disable vertical blank interrupts, respectively. In the
absence of DRM clients waiting on vblank events, the core DRM
code will use the disable_vblank() function to disable
interrupts, which saves power. They'll be re-enabled again when
a client calls the vblank wait ioctl above.
</para>
<para>
Devices that don't provide a count register can simply use an
internal atomic counter incremented on every vertical blank
interrupt, and can make their enable and disable vblank
functions into no-ops.
</para>
</sect1>
<sect1>
<title>Memory management</title>
<para>
The memory manager lies at the heart of many DRM operations, and
is also required to support advanced client features like OpenGL
pbuffers. The DRM currently contains two memory managers, TTM
and GEM.
</para>
<sect2>
<title>The Translation Table Manager (TTM)</title>
<para>
TTM was developed by Tungsten Graphics, primarily by Thomas
Hellström, and is intended to be a flexible, high performance
graphics memory manager.
</para>
<para>
Drivers wishing to support TTM must fill out a drm_bo_driver
structure.
</para>
<para>
TTM design background and information belongs here.
</para>
</sect2>
<sect2>
<title>The Graphics Execution Manager (GEM)</title>
<para>
GEM is an Intel project, authored by Eric Anholt and Keith
Packard. It provides simpler interfaces than TTM, and is well
suited for UMA devices.
</para>
<para>
GEM-enabled drivers must provide gem_init_object() and
gem_free_object() callbacks to support the core memory
allocation routines. They should also provide several driver
specific ioctls to support command execution, pinning, buffer
read &amp; write, mapping, and domain ownership transfers.
</para>
<para>
On a fundamental level, GEM involves several operations: memory
allocation and freeing, command execution, and aperture management
at command execution time. Buffer object allocation is relatively
straightforward and largely provided by Linux's shmem layer, which
provides memory to back each object. When mapped into the GTT
or used in a command buffer, the backing pages for an object are
flushed to memory and marked write combined so as to be coherent
with the GPU. Likewise, when the GPU finishes rendering to an object,
if the CPU accesses it, it must be made coherent with the CPU's view
of memory, usually involving GPU cache flushing of various kinds.
This core CPU&lt;-&gt;GPU coherency management is provided by the GEM
set domain function, which evaluates an object's current domain and
performs any necessary flushing or synchronization to put the object
into the desired coherency domain (note that the object may be busy,
i.e. an active render target; in that case the set domain function
will block the client and wait for rendering to complete before
performing any necessary flushing operations).
</para>
<para>
Perhaps the most important GEM function is providing a command
execution interface to clients. Client programs construct command
buffers containing references to previously allocated memory objects
and submit them to GEM. At that point, GEM will take care to bind
all the objects into the GTT, execute the buffer, and provide
necessary synchronization between clients accessing the same buffers.
This often involves evicting some objects from the GTT and re-binding
others (a fairly expensive operation), and providing relocation
support which hides fixed GTT offsets from clients. Clients must
take care not to submit command buffers that reference more objects
than can fit in the GTT or GEM will reject them and no rendering
will occur. Similarly, if several objects in the buffer require
fence registers to be allocated for correct rendering (e.g. 2D blits
on pre-965 chips), care must be taken not to require more fence
registers than are available to the client. Such resource management
should be abstracted from the client in libdrm.
</para>
</sect2>
</sect1>
<!-- Output management -->
<sect1>
<title>Output management</title>
<para>
At the core of the DRM output management code is a set of
structures representing CRTCs, encoders and connectors.
</para>
<para>
A CRTC is an abstraction representing a part of the chip that
contains a pointer to a scanout buffer. Therefore, the number
of CRTCs available determines how many independent scanout
buffers can be active at any given time. The CRTC structure
contains several fields to support this: a pointer to some video
memory, a display mode, and an (x, y) offset into the video
memory to support panning or configurations where one piece of
video memory spans multiple CRTCs.
</para>
<para>
An encoder takes pixel data from a CRTC and converts it to a
format suitable for any attached connectors. On some devices,
it may be possible to have a CRTC send data to more than one
encoder. In that case, both encoders would receive data from
the same scanout buffer, resulting in a "cloned" display
configuration across the connectors attached to each encoder.
</para>
<para>
A connector is the final destination for pixel data on a device,
and usually connects directly to an external display device like
a monitor or laptop panel. A connector can only be attached to
one encoder at a time. The connector is also the structure
where information about the attached display is kept, so it
contains fields for display data, EDID data, DPMS &amp;
connection status, and information about modes supported on the
attached displays.
</para>
<!--!Edrivers/char/drm/drm_crtc.c-->
</sect1>
<sect1>
<title>Framebuffer management</title>
<para>
In order to set a mode on a given CRTC, encoder and connector
configuration, clients need to provide a framebuffer object which
will provide a source of pixels for the CRTC to deliver to the encoder(s)
and ultimately the connector(s) in the configuration. A framebuffer
is fundamentally a driver specific memory object, made into an opaque
handle by the DRM addfb function. Once an fb has been created this
way it can be passed to the KMS mode setting routines for use in
a configuration.
</para>
</sect1>
<sect1>
<title>Command submission &amp; fencing</title>
<para>
This should cover a few device specific command submission
implementations.
</para>
</sect1>
<sect1>
<title>Suspend/resume</title>
<para>
The DRM core provides some suspend/resume code, but drivers
wanting full suspend/resume support should provide save() and
restore() functions. These will be called at suspend,
hibernate, or resume time, and should perform any state save or
restore required by your device across suspend or hibernate
states.
</para>
</sect1>
<sect1>
<title>DMA services</title>
<para>
This should cover how DMA mapping etc. is supported by the core.
These functions are deprecated and should not be used.
</para>
</sect1>
</chapter>
<!-- External interfaces -->
<chapter id="drmExternals">
<title>Userland interfaces</title>
<para>
The DRM core exports several interfaces to applications,
generally intended to be used through corresponding libdrm
wrapper functions. In addition, drivers export device specific
interfaces for use by userspace drivers &amp; device aware
applications through ioctls and sysfs files.
</para>
<para>
External interfaces include: memory mapping, context management,
DMA operations, AGP management, vblank control, fence
management, memory management, and output management.
</para>
<para>
Cover generic ioctls and sysfs layout here. Only need high
level info, since man pages will cover the rest.
</para>
</chapter>
<!-- API reference -->
<appendix id="drmDriverApi">
<title>DRM Driver API</title>
<para>
Include auto-generated API reference here (need to reference it
from paragraphs above too).
</para>
</appendix>
</book>

View File

@ -12,10 +12,12 @@
<othername role="mi">O. C.</othername>
<affiliation><address><email>rjkm@metzlerbros.de</email></address></affiliation>
</author>
</authorgroup>
<authorgroup>
<author>
<firstname>Mauro</firstname>
<surname>Chehab</surname>
<othername role="mi">Carvalho</othername>
<surname>Chehab</surname>
<affiliation><address><email>mchehab@redhat.com</email></address></affiliation>
<contrib>Ported document to Docbook XML.</contrib>
</author>
@ -23,12 +25,23 @@
<copyright>
<year>2002</year>
<year>2003</year>
<year>2009</year>
<holder>Convergence GmbH</holder>
</copyright>
<copyright>
<year>2009-2010</year>
<holder>Mauro Carvalho Chehab</holder>
</copyright>
<revhistory>
<!-- Put document revisions here, newest first. -->
<revision>
<revnumber>2.0.3</revnumber>
<date>2010-07-03</date>
<authorinitials>mcc</authorinitials>
<revremark>
Add some frontend capabilities flags, present on kernel, but missing at the specs.
</revremark>
</revision>
<revision>
<revnumber>2.0.2</revnumber>
<date>2009-10-25</date>
@ -63,7 +76,7 @@ Added ISDB-T test originally written by Patrick Boettcher
<title>LINUX DVB API</title>
<subtitle>Version 3</subtitle>
<subtitle>Version 5.2</subtitle>
<!-- ADD THE CHAPTERS HERE -->
<chapter id="dvb_introdution">
&sub-intro;

View File

@ -63,6 +63,7 @@ typedef enum fe_caps {
FE_CAN_8VSB = 0x200000,
FE_CAN_16VSB = 0x400000,
FE_HAS_EXTENDED_CAPS = 0x800000, /* We need more bitspace for newer APIs, indicate this. */
FE_CAN_TURBO_FEC = 0x8000000, /* frontend supports "turbo fec modulation" */
FE_CAN_2G_MODULATION = 0x10000000, /* frontend supports "2nd generation modulation" (DVB-S2) */
FE_NEEDS_BENDING = 0x20000000, /* not supported anymore, don't use (frontend requires frequency bending) */
FE_CAN_RECOVER = 0x40000000, /* frontend can recover from a cable unplug automatically */

View File

@ -64,8 +64,14 @@ a specific frontend type.</para>
FE_CAN_BANDWIDTH_AUTO = 0x40000,
FE_CAN_GUARD_INTERVAL_AUTO = 0x80000,
FE_CAN_HIERARCHY_AUTO = 0x100000,
FE_CAN_MUTE_TS = 0x80000000,
FE_CAN_CLEAN_SETUP = 0x40000000
FE_CAN_8VSB = 0x200000,
FE_CAN_16VSB = 0x400000,
FE_HAS_EXTENDED_CAPS = 0x800000,
FE_CAN_TURBO_FEC = 0x8000000,
FE_CAN_2G_MODULATION = 0x10000000,
FE_NEEDS_BENDING = 0x20000000,
FE_CAN_RECOVER = 0x40000000,
FE_CAN_MUTE_TS = 0x80000000
} fe_caps_t;
</programlisting>
</section>

View File

@ -28,7 +28,7 @@
</authorgroup>
<copyright>
<year>2005-2006</year>
<year>2005-2010</year>
<holder>Thomas Gleixner</holder>
</copyright>
<copyright>
@ -100,6 +100,10 @@
<listitem><para>Edge type</para></listitem>
<listitem><para>Simple type</para></listitem>
</itemizedlist>
During the implementation we identified another type:
<itemizedlist>
<listitem><para>Fast EOI type</para></listitem>
</itemizedlist>
In the SMP world of the __do_IRQ() super-handler another type
was identified:
<itemizedlist>
@ -153,6 +157,7 @@
is still available. This leads to a kind of duality for the time
being. Over time the new model should be used in more and more
architectures, as it enables smaller and cleaner IRQ subsystems.
It's deprecated for three years now and about to be removed.
</para>
</chapter>
<chapter id="bugs">
@ -217,6 +222,7 @@
<itemizedlist>
<listitem><para>handle_level_irq</para></listitem>
<listitem><para>handle_edge_irq</para></listitem>
<listitem><para>handle_fasteoi_irq</para></listitem>
<listitem><para>handle_simple_irq</para></listitem>
<listitem><para>handle_percpu_irq</para></listitem>
</itemizedlist>
@ -233,33 +239,33 @@
are used by the default flow implementations.
The following helper functions are implemented (simplified excerpt):
<programlisting>
default_enable(irq)
default_enable(struct irq_data *data)
{
desc->chip->unmask(irq);
desc->chip->irq_unmask(data);
}
default_disable(irq)
default_disable(struct irq_data *data)
{
if (!delay_disable(irq))
desc->chip->mask(irq);
if (!delay_disable(data))
desc->chip->irq_mask(data);
}
default_ack(irq)
default_ack(struct irq_data *data)
{
chip->ack(irq);
chip->irq_ack(data);
}
default_mask_ack(irq)
default_mask_ack(struct irq_data *data)
{
if (chip->mask_ack) {
chip->mask_ack(irq);
if (chip->irq_mask_ack) {
chip->irq_mask_ack(data);
} else {
chip->mask(irq);
chip->ack(irq);
chip->irq_mask(data);
chip->irq_ack(data);
}
}
noop(irq)
noop(struct irq_data *data))
{
}
@ -278,12 +284,27 @@ noop(irq)
<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
desc->chip->start();
desc->chip->irq_mask();
handle_IRQ_event(desc->action);
desc->chip->end();
desc->chip->irq_unmask();
</programlisting>
</para>
</sect3>
</sect3>
<sect3 id="Default_FASTEOI_IRQ_flow_handler">
<title>Default Fast EOI IRQ flow handler</title>
<para>
handle_fasteoi_irq provides a generic implementation
for interrupts, which only need an EOI at the end of
the handler
</para>
<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
handle_IRQ_event(desc->action);
desc->chip->irq_eoi();
</programlisting>
</para>
</sect3>
<sect3 id="Default_Edge_IRQ_flow_handler">
<title>Default Edge IRQ flow handler</title>
<para>
@ -294,20 +315,19 @@ desc->chip->end();
The following control flow is implemented (simplified excerpt):
<programlisting>
if (desc->status &amp; running) {
desc->chip->hold();
desc->chip->irq_mask();
desc->status |= pending | masked;
return;
}
desc->chip->start();
desc->chip->irq_ack();
desc->status |= running;
do {
if (desc->status &amp; masked)
desc->chip->enable();
desc->chip->irq_unmask();
desc->status &amp;= ~pending;
handle_IRQ_event(desc->action);
} while (status &amp; pending);
desc->status &amp;= ~running;
desc->chip->end();
</programlisting>
</para>
</sect3>
@ -342,9 +362,9 @@ handle_IRQ_event(desc->action);
<para>
The following control flow is implemented (simplified excerpt):
<programlisting>
desc->chip->start();
handle_IRQ_event(desc->action);
desc->chip->end();
if (desc->chip->irq_eoi)
desc->chip->irq_eoi();
</programlisting>
</para>
</sect3>
@ -375,8 +395,7 @@ desc->chip->end();
mechanism. (It's necessary to enable CONFIG_HARDIRQS_SW_RESEND when
you want to use the delayed interrupt disable feature and your
hardware is not capable of retriggering an interrupt.)
The delayed interrupt disable can be runtime enabled, per interrupt,
by setting the IRQ_DELAYED_DISABLE flag in the irq_desc status field.
The delayed interrupt disable is not configurable.
</para>
</sect2>
</sect1>
@ -387,13 +406,13 @@ desc->chip->end();
contains all the direct chip relevant functions, which
can be utilized by the irq flow implementations.
<itemizedlist>
<listitem><para>ack()</para></listitem>
<listitem><para>mask_ack() - Optional, recommended for performance</para></listitem>
<listitem><para>mask()</para></listitem>
<listitem><para>unmask()</para></listitem>
<listitem><para>retrigger() - Optional</para></listitem>
<listitem><para>set_type() - Optional</para></listitem>
<listitem><para>set_wake() - Optional</para></listitem>
<listitem><para>irq_ack()</para></listitem>
<listitem><para>irq_mask_ack() - Optional, recommended for performance</para></listitem>
<listitem><para>irq_mask()</para></listitem>
<listitem><para>irq_unmask()</para></listitem>
<listitem><para>irq_retrigger() - Optional</para></listitem>
<listitem><para>irq_set_type() - Optional</para></listitem>
<listitem><para>irq_set_wake() - Optional</para></listitem>
</itemizedlist>
These primitives are strictly intended to mean what they say: ack means
ACK, masking means masking of an IRQ line, etc. It is up to the flow
@ -458,6 +477,7 @@ desc->chip->end();
<para>
This chapter contains the autogenerated documentation of the internal functions.
</para>
!Ikernel/irq/irqdesc.c
!Ikernel/irq/handle.c
!Ikernel/irq/chip.c
</chapter>

View File

@ -57,7 +57,6 @@
</para>
<sect1><title>String Conversions</title>
!Ilib/vsprintf.c
!Elib/vsprintf.c
</sect1>
<sect1><title>String Manipulation</title>
@ -94,6 +93,12 @@ X!Ilib/string.c
!Elib/crc32.c
!Elib/crc-ccitt.c
</sect1>
<sect1 id="idr"><title>idr/ida Functions</title>
!Pinclude/linux/idr.h idr sync
!Plib/idr.c IDA description
!Elib/idr.c
</sect1>
</chapter>
<chapter id="mm">
@ -132,7 +137,6 @@ X!Ilib/string.c
<title>FIFO Buffer</title>
<sect1><title>kfifo interface</title>
!Iinclude/linux/kfifo.h
!Ekernel/kfifo.c
</sect1>
</chapter>
@ -259,7 +263,8 @@ X!Earch/x86/kernel/mca_32.c
!Iblock/blk-sysfs.c
!Eblock/blk-settings.c
!Eblock/blk-exec.c
!Eblock/blk-barrier.c
!Eblock/blk-flush.c
!Eblock/blk-lib.c
!Eblock/blk-tag.c
!Iblock/blk-tag.c
!Eblock/blk-integrity.c

View File

@ -1645,7 +1645,9 @@ the amount of locking which needs to be done.
all the readers who were traversing the list when we deleted the
element are finished. We use <function>call_rcu()</function> to
register a callback which will actually destroy the object once
the readers are finished.
all pre-existing readers are finished. Alternatively,
<function>synchronize_rcu()</function> may be used to block until
all pre-existing are finished.
</para>
<para>
But how does Read Copy Update know when the readers are
@ -1714,7 +1716,7 @@ the amount of locking which needs to be done.
- object_put(obj);
+ list_del_rcu(&amp;obj-&gt;list);
cache_num--;
+ call_rcu(&amp;obj-&gt;rcu, cache_delete_rcu, obj);
+ call_rcu(&amp;obj-&gt;rcu, cache_delete_rcu);
}
/* Must be holding cache_lock */
@ -1725,14 +1727,6 @@ the amount of locking which needs to be done.
if (++cache_num > MAX_CACHE_SIZE) {
struct object *i, *outcast = NULL;
list_for_each_entry(i, &amp;cache, list) {
@@ -85,6 +94,7 @@
obj-&gt;popularity = 0;
atomic_set(&amp;obj-&gt;refcnt, 1); /* The cache holds a reference */
spin_lock_init(&amp;obj-&gt;lock);
+ INIT_RCU_HEAD(&amp;obj-&gt;rcu);
spin_lock_irqsave(&amp;cache_lock, flags);
__cache_add(obj);
@@ -104,12 +114,11 @@
struct object *cache_find(int id)
{
@ -1922,9 +1916,12 @@ machines due to caching.
<function>mutex_lock()</function>
</para>
<para>
There is a <function>mutex_trylock()</function> which can be
used inside interrupt context, as it will not sleep.
There is a <function>mutex_trylock()</function> which does not
sleep. Still, it must not be used inside interrupt context since
its implementation is not safe for that.
<function>mutex_unlock()</function> will also never sleep.
It cannot be used in interrupt context either since a mutex
must be released by the same task that acquired it.
</para>
</listitem>
</itemizedlist>
@ -1958,6 +1955,12 @@ machines due to caching.
</sect1>
</chapter>
<chapter id="apiref">
<title>Mutex API reference</title>
!Iinclude/linux/mutex.h
!Ekernel/mutex.c
</chapter>
<chapter id="references">
<title>Further reading</title>

View File

@ -4,7 +4,7 @@
<book id="kgdbOnLinux">
<bookinfo>
<title>Using kgdb and the kgdb Internals</title>
<title>Using kgdb, kdb and the kernel debugger internals</title>
<authorgroup>
<author>
@ -17,33 +17,8 @@
</affiliation>
</author>
</authorgroup>
<authorgroup>
<author>
<firstname>Tom</firstname>
<surname>Rini</surname>
<affiliation>
<address>
<email>trini@kernel.crashing.org</email>
</address>
</affiliation>
</author>
</authorgroup>
<authorgroup>
<author>
<firstname>Amit S.</firstname>
<surname>Kale</surname>
<affiliation>
<address>
<email>amitkale@linsyssoft.com</email>
</address>
</affiliation>
</author>
</authorgroup>
<copyright>
<year>2008</year>
<year>2008,2010</year>
<holder>Wind River Systems, Inc.</holder>
</copyright>
<copyright>
@ -69,41 +44,76 @@
<chapter id="Introduction">
<title>Introduction</title>
<para>
kgdb is a source level debugger for linux kernel. It is used along
with gdb to debug a linux kernel. The expectation is that gdb can
be used to "break in" to the kernel to inspect memory, variables
and look through call stack information similar to what an
application developer would use gdb for. It is possible to place
breakpoints in kernel code and perform some limited execution
stepping.
The kernel has two different debugger front ends (kdb and kgdb)
which interface to the debug core. It is possible to use either
of the debugger front ends and dynamically transition between them
if you configure the kernel properly at compile and runtime.
</para>
<para>
Two machines are required for using kgdb. One of these machines is a
development machine and the other is a test machine. The kernel
to be debugged runs on the test machine. The development machine
runs an instance of gdb against the vmlinux file which contains
the symbols (not boot image such as bzImage, zImage, uImage...).
In gdb the developer specifies the connection parameters and
connects to kgdb. The type of connection a developer makes with
gdb depends on the availability of kgdb I/O modules compiled as
builtin's or kernel modules in the test machine's kernel.
Kdb is simplistic shell-style interface which you can use on a
system console with a keyboard or serial console. You can use it
to inspect memory, registers, process lists, dmesg, and even set
breakpoints to stop in a certain location. Kdb is not a source
level debugger, although you can set breakpoints and execute some
basic kernel run control. Kdb is mainly aimed at doing some
analysis to aid in development or diagnosing kernel problems. You
can access some symbols by name in kernel built-ins or in kernel
modules if the code was built
with <symbol>CONFIG_KALLSYMS</symbol>.
</para>
<para>
Kgdb is intended to be used as a source level debugger for the
Linux kernel. It is used along with gdb to debug a Linux kernel.
The expectation is that gdb can be used to "break in" to the
kernel to inspect memory, variables and look through call stack
information similar to the way an application developer would use
gdb to debug an application. It is possible to place breakpoints
in kernel code and perform some limited execution stepping.
</para>
<para>
Two machines are required for using kgdb. One of these machines is
a development machine and the other is the target machine. The
kernel to be debugged runs on the target machine. The development
machine runs an instance of gdb against the vmlinux file which
contains the symbols (not boot image such as bzImage, zImage,
uImage...). In gdb the developer specifies the connection
parameters and connects to kgdb. The type of connection a
developer makes with gdb depends on the availability of kgdb I/O
modules compiled as built-ins or loadable kernel modules in the test
machine's kernel.
</para>
</chapter>
<chapter id="CompilingAKernel">
<title>Compiling a kernel</title>
<title>Compiling a kernel</title>
<para>
<itemizedlist>
<listitem><para>In order to enable compilation of kdb, you must first enable kgdb.</para></listitem>
<listitem><para>The kgdb test compile options are described in the kgdb test suite chapter.</para></listitem>
</itemizedlist>
</para>
<sect1 id="CompileKGDB">
<title>Kernel config options for kgdb</title>
<para>
To enable <symbol>CONFIG_KGDB</symbol> you should first turn on
"Prompt for development and/or incomplete code/drivers"
(CONFIG_EXPERIMENTAL) in "General setup", then under the
"Kernel debugging" select "KGDB: kernel debugging with remote gdb".
"Kernel debugging" select "KGDB: kernel debugger".
</para>
<para>
While it is not a hard requirement that you have symbols in your
vmlinux file, gdb tends not to be very useful without the symbolic
data, so you will want to turn
on <symbol>CONFIG_DEBUG_INFO</symbol> which is called "Compile the
kernel with debug info" in the config menu.
</para>
<para>
It is advised, but not required that you turn on the
CONFIG_FRAME_POINTER kernel option. This option inserts code to
into the compiled executable which saves the frame information in
registers or on the stack at different points which will allow a
debugger such as gdb to more accurately construct stack back traces
while debugging the kernel.
<symbol>CONFIG_FRAME_POINTER</symbol> kernel option which is called "Compile the
kernel with frame pointers" in the config menu. This option
inserts code to into the compiled executable which saves the frame
information in registers or on the stack at different points which
allows a debugger such as gdb to more accurately construct
stack back traces while debugging the kernel.
</para>
<para>
If the architecture that you are using supports the kernel option
@ -116,38 +126,192 @@
this option.
</para>
<para>
Next you should choose one of more I/O drivers to interconnect debugging
host and debugged target. Early boot debugging requires a KGDB
I/O driver that supports early debugging and the driver must be
built into the kernel directly. Kgdb I/O driver configuration
takes place via kernel or module parameters, see following
chapter.
Next you should choose one of more I/O drivers to interconnect
debugging host and debugged target. Early boot debugging requires
a KGDB I/O driver that supports early debugging and the driver
must be built into the kernel directly. Kgdb I/O driver
configuration takes place via kernel or module parameters which
you can learn more about in the in the section that describes the
parameter "kgdboc".
</para>
<para>
The kgdb test compile options are described in the kgdb test suite chapter.
<para>Here is an example set of .config symbols to enable or
disable for kgdb:
<itemizedlist>
<listitem><para># CONFIG_DEBUG_RODATA is not set</para></listitem>
<listitem><para>CONFIG_FRAME_POINTER=y</para></listitem>
<listitem><para>CONFIG_KGDB=y</para></listitem>
<listitem><para>CONFIG_KGDB_SERIAL_CONSOLE=y</para></listitem>
</itemizedlist>
</para>
</sect1>
<sect1 id="CompileKDB">
<title>Kernel config options for kdb</title>
<para>Kdb is quite a bit more complex than the simple gdbstub
sitting on top of the kernel's debug core. Kdb must implement a
shell, and also adds some helper functions in other parts of the
kernel, responsible for printing out interesting data such as what
you would see if you ran "lsmod", or "ps". In order to build kdb
into the kernel you follow the same steps as you would for kgdb.
</para>
<para>The main config option for kdb
is <symbol>CONFIG_KGDB_KDB</symbol> which is called "KGDB_KDB:
include kdb frontend for kgdb" in the config menu. In theory you
would have already also selected an I/O driver such as the
CONFIG_KGDB_SERIAL_CONSOLE interface if you plan on using kdb on a
serial port, when you were configuring kgdb.
</para>
<para>If you want to use a PS/2-style keyboard with kdb, you would
select CONFIG_KDB_KEYBOARD which is called "KGDB_KDB: keyboard as
input device" in the config menu. The CONFIG_KDB_KEYBOARD option
is not used for anything in the gdb interface to kgdb. The
CONFIG_KDB_KEYBOARD option only works with kdb.
</para>
<para>Here is an example set of .config symbols to enable/disable kdb:
<itemizedlist>
<listitem><para># CONFIG_DEBUG_RODATA is not set</para></listitem>
<listitem><para>CONFIG_FRAME_POINTER=y</para></listitem>
<listitem><para>CONFIG_KGDB=y</para></listitem>
<listitem><para>CONFIG_KGDB_SERIAL_CONSOLE=y</para></listitem>
<listitem><para>CONFIG_KGDB_KDB=y</para></listitem>
<listitem><para>CONFIG_KDB_KEYBOARD=y</para></listitem>
</itemizedlist>
</para>
</sect1>
</chapter>
<chapter id="EnableKGDB">
<title>Enable kgdb for debugging</title>
<para>
In order to use kgdb you must activate it by passing configuration
information to one of the kgdb I/O drivers. If you do not pass any
configuration information kgdb will not do anything at all. Kgdb
will only actively hook up to the kernel trap hooks if a kgdb I/O
driver is loaded and configured. If you unconfigure a kgdb I/O
driver, kgdb will unregister all the kernel hook points.
<chapter id="kgdbKernelArgs">
<title>Kernel Debugger Boot Arguments</title>
<para>This section describes the various runtime kernel
parameters that affect the configuration of the kernel debugger.
The following chapter covers using kdb and kgdb as well as
provides some examples of the configuration parameters.</para>
<sect1 id="kgdboc">
<title>Kernel parameter: kgdboc</title>
<para>The kgdboc driver was originally an abbreviation meant to
stand for "kgdb over console". Today it is the primary mechanism
to configure how to communicate from gdb to kgdb as well as the
devices you want to use to interact with the kdb shell.
</para>
<para>
All drivers can be reconfigured at run time, if
<symbol>CONFIG_SYSFS</symbol> and <symbol>CONFIG_MODULES</symbol>
are enabled, by echo'ing a new config string to
<constant>/sys/module/&lt;driver&gt;/parameter/&lt;option&gt;</constant>.
The driver can be unconfigured by passing an empty string. You cannot
change the configuration while the debugger is attached. Make sure
to detach the debugger with the <constant>detach</constant> command
prior to trying unconfigure a kgdb I/O driver.
<para>For kgdb/gdb, kgdboc is designed to work with a single serial
port. It is intended to cover the circumstance where you want to
use a serial console as your primary console as well as using it to
perform kernel debugging. It is also possible to use kgdb on a
serial port which is not designated as a system console. Kgdboc
may be configured as a kernel built-in or a kernel loadable module.
You can only make use of <constant>kgdbwait</constant> and early
debugging if you build kgdboc into the kernel as a built-in.
<para>Optionally you can elect to activate kms (Kernel Mode
Setting) integration. When you use kms with kgdboc and you have a
video driver that has atomic mode setting hooks, it is possible to
enter the debugger on the graphics console. When the kernel
execution is resumed, the previous graphics mode will be restored.
This integration can serve as a useful tool to aid in diagnosing
crashes or doing analysis of memory with kdb while allowing the
full graphics console applications to run.
</para>
</para>
<sect2 id="kgdbocArgs">
<title>kgdboc arguments</title>
<para>Usage: <constant>kgdboc=[kms][[,]kbd][[,]serial_device][,baud]</constant></para>
<para>The order listed above must be observed if you use any of the
optional configurations together.
</para>
<para>Abbreviations:
<itemizedlist>
<listitem><para>kms = Kernel Mode Setting</para></listitem>
<listitem><para>kbd = Keyboard</para></listitem>
</itemizedlist>
</para>
<para>You can configure kgdboc to use the keyboard, and or a serial
device depending on if you are using kdb and or kgdb, in one of the
following scenarios. The order listed above must be observed if
you use any of the optional configurations together. Using kms +
only gdb is generally not a useful combination.</para>
<sect3 id="kgdbocArgs1">
<title>Using loadable module or built-in</title>
<para>
<orderedlist>
<listitem><para>As a kernel built-in:</para>
<para>Use the kernel boot argument: <constant>kgdboc=&lt;tty-device&gt;,[baud]</constant></para></listitem>
<listitem>
<para>As a kernel loadable module:</para>
<para>Use the command: <constant>modprobe kgdboc kgdboc=&lt;tty-device&gt;,[baud]</constant></para>
<para>Here are two examples of how you might format the kgdboc
string. The first is for an x86 target using the first serial port.
The second example is for the ARM Versatile AB using the second
serial port.
<orderedlist>
<listitem><para><constant>kgdboc=ttyS0,115200</constant></para></listitem>
<listitem><para><constant>kgdboc=ttyAMA1,115200</constant></para></listitem>
</orderedlist>
</para>
</listitem>
</orderedlist></para>
</sect3>
<sect3 id="kgdbocArgs2">
<title>Configure kgdboc at runtime with sysfs</title>
<para>At run time you can enable or disable kgdboc by echoing a
parameters into the sysfs. Here are two examples:</para>
<orderedlist>
<listitem><para>Enable kgdboc on ttyS0</para>
<para><constant>echo ttyS0 &gt; /sys/module/kgdboc/parameters/kgdboc</constant></para></listitem>
<listitem><para>Disable kgdboc</para>
<para><constant>echo "" &gt; /sys/module/kgdboc/parameters/kgdboc</constant></para></listitem>
</orderedlist>
<para>NOTE: You do not need to specify the baud if you are
configuring the console on tty which is already configured or
open.</para>
</sect3>
<sect3 id="kgdbocArgs3">
<title>More examples</title>
<para>You can configure kgdboc to use the keyboard, and or a serial
device depending on if you are using kdb and or kgdb, in one of the
following scenarios.</para>
<para>You can configure kgdboc to use the keyboard, and or a serial device
depending on if you are using kdb and or kgdb, in one of the
following scenarios.
<orderedlist>
<listitem><para>kdb and kgdb over only a serial port</para>
<para><constant>kgdboc=&lt;serial_device&gt;[,baud]</constant></para>
<para>Example: <constant>kgdboc=ttyS0,115200</constant></para>
</listitem>
<listitem><para>kdb and kgdb with keyboard and a serial port</para>
<para><constant>kgdboc=kbd,&lt;serial_device&gt;[,baud]</constant></para>
<para>Example: <constant>kgdboc=kbd,ttyS0,115200</constant></para>
</listitem>
<listitem><para>kdb with a keyboard</para>
<para><constant>kgdboc=kbd</constant></para>
</listitem>
<listitem><para>kdb with kernel mode setting</para>
<para><constant>kgdboc=kms,kbd</constant></para>
</listitem>
<listitem><para>kdb with kernel mode setting and kgdb over a serial port</para>
<para><constant>kgdboc=kms,kbd,ttyS0,115200</constant></para>
</listitem>
</orderedlist>
</para>
</sect3>
<para>NOTE: Kgdboc does not support interrupting the target via the
gdb remote protocol. You must manually send a sysrq-g unless you
have a proxy that splits console output to a terminal program.
A console proxy has a separate TCP port for the debugger and a separate
TCP port for the "human" console. The proxy can take care of sending
the sysrq-g for you.
</para>
<para>When using kgdboc with no debugger proxy, you can end up
connecting the debugger at one of two entry points. If an
exception occurs after you have loaded kgdboc, a message should
print on the console stating it is waiting for the debugger. In
this case you disconnect your terminal program and then connect the
debugger in its place. If you want to interrupt the target system
and forcibly enter a debug session you have to issue a Sysrq
sequence and then type the letter <constant>g</constant>. Then
you disconnect the terminal session and connect gdb. Your options
if you don't like this are to hack gdb to send the sysrq-g for you
as well as on the initial connect, or to use a debugger proxy that
allows an unmodified gdb to do the debugging.
</para>
</sect2>
</sect1>
<sect1 id="kgdbwait">
<title>Kernel parameter: kgdbwait</title>
<para>
@ -162,103 +326,204 @@
</para>
<para>
The kernel will stop and wait as early as the I/O driver and
architecture will allow when you use this option. If you build the
kgdb I/O driver as a kernel module kgdbwait will not do anything.
architecture allows when you use this option. If you build the
kgdb I/O driver as a loadable kernel module kgdbwait will not do
anything.
</para>
</sect1>
<sect1 id="kgdboc">
<title>Kernel parameter: kgdboc</title>
<para>
The kgdboc driver was originally an abbreviation meant to stand for
"kgdb over console". Kgdboc is designed to work with a single
serial port. It was meant to cover the circumstance
where you wanted to use a serial console as your primary console as
well as using it to perform kernel debugging. Of course you can
also use kgdboc without assigning a console to the same port.
</para>
<sect2 id="UsingKgdboc">
<title>Using kgdboc</title>
<para>
You can configure kgdboc via sysfs or a module or kernel boot line
parameter depending on if you build with CONFIG_KGDBOC as a module
or built-in.
<orderedlist>
<listitem><para>From the module load or build-in</para>
<para><constant>kgdboc=&lt;tty-device&gt;,[baud]</constant></para>
<para>
The example here would be if your console port was typically ttyS0, you would use something like <constant>kgdboc=ttyS0,115200</constant> or on the ARM Versatile AB you would likely use <constant>kgdboc=ttyAMA0,115200</constant>
</para>
</listitem>
<listitem><para>From sysfs</para>
<para><constant>echo ttyS0 &gt; /sys/module/kgdboc/parameters/kgdboc</constant></para>
</listitem>
</orderedlist>
</para>
<para>
NOTE: Kgdboc does not support interrupting the target via the
gdb remote protocol. You must manually send a sysrq-g unless you
have a proxy that splits console output to a terminal problem and
has a separate port for the debugger to connect to that sends the
sysrq-g for you.
</para>
<para>When using kgdboc with no debugger proxy, you can end up
connecting the debugger for one of two entry points. If an
exception occurs after you have loaded kgdboc a message should print
on the console stating it is waiting for the debugger. In case you
disconnect your terminal program and then connect the debugger in
its place. If you want to interrupt the target system and forcibly
enter a debug session you have to issue a Sysrq sequence and then
type the letter <constant>g</constant>. Then you disconnect the
terminal session and connect gdb. Your options if you don't like
this are to hack gdb to send the sysrq-g for you as well as on the
initial connect, or to use a debugger proxy that allows an
unmodified gdb to do the debugging.
</para>
</sect2>
</sect1>
<sect1 id="kgdbcon">
<title>Kernel parameter: kgdbcon</title>
<para>
Kgdb supports using the gdb serial protocol to send console messages
to the debugger when the debugger is connected and running. There
are two ways to activate this feature.
<orderedlist>
<listitem><para>Activate with the kernel command line option:</para>
<para><constant>kgdbcon</constant></para>
</listitem>
<listitem><para>Use sysfs before configuring an io driver</para>
<para>
<constant>echo 1 &gt; /sys/module/kgdb/parameters/kgdb_use_con</constant>
</para>
<para>
NOTE: If you do this after you configure the kgdb I/O driver, the
setting will not take effect until the next point the I/O is
reconfigured.
</para>
</listitem>
</orderedlist>
</para>
<para>
IMPORTANT NOTE: Using this option with kgdb over the console
(kgdboc) is not supported.
<sect1 id="kgdbcon">
<title>Kernel parameter: kgdbcon</title>
<para> The kgdbcon feature allows you to see printk() messages
inside gdb while gdb is connected to the kernel. Kdb does not make
use of the kgdbcon feature.
</para>
<para>Kgdb supports using the gdb serial protocol to send console
messages to the debugger when the debugger is connected and running.
There are two ways to activate this feature.
<orderedlist>
<listitem><para>Activate with the kernel command line option:</para>
<para><constant>kgdbcon</constant></para>
</listitem>
<listitem><para>Use sysfs before configuring an I/O driver</para>
<para>
<constant>echo 1 &gt; /sys/module/kgdb/parameters/kgdb_use_con</constant>
</para>
<para>
NOTE: If you do this after you configure the kgdb I/O driver, the
setting will not take effect until the next point the I/O is
reconfigured.
</para>
</listitem>
</orderedlist>
<para>IMPORTANT NOTE: You cannot use kgdboc + kgdbcon on a tty that is an
active system console. An example incorrect usage is <constant>console=ttyS0,115200 kgdboc=ttyS0 kgdbcon</constant>
</para>
<para>It is possible to use this option with kgdboc on a tty that is not a system console.
</para>
</para>
</sect1>
</chapter>
<chapter id="ConnectingGDB">
<title>Connecting gdb</title>
<chapter id="usingKDB">
<title>Using kdb</title>
<para>
</para>
<sect1 id="quickKDBserial">
<title>Quick start for kdb on a serial port</title>
<para>This is a quick example of how to use kdb.</para>
<para><orderedlist>
<listitem><para>Boot kernel with arguments:
<itemizedlist>
<listitem><para><constant>console=ttyS0,115200 kgdboc=ttyS0,115200</constant></para></listitem>
</itemizedlist></para>
<para>OR</para>
<para>Configure kgdboc after the kernel booted; assuming you are using a serial port console:
<itemizedlist>
<listitem><para><constant>echo ttyS0 &gt; /sys/module/kgdboc/parameters/kgdboc</constant></para></listitem>
</itemizedlist>
</para>
</listitem>
<listitem><para>Enter the kernel debugger manually or by waiting for an oops or fault. There are several ways you can enter the kernel debugger manually; all involve using the sysrq-g, which means you must have enabled CONFIG_MAGIC_SYSRQ=y in your kernel config.</para>
<itemizedlist>
<listitem><para>When logged in as root or with a super user session you can run:</para>
<para><constant>echo g &gt; /proc/sysrq-trigger</constant></para></listitem>
<listitem><para>Example using minicom 2.2</para>
<para>Press: <constant>Control-a</constant></para>
<para>Press: <constant>f</constant></para>
<para>Press: <constant>g</constant></para>
</listitem>
<listitem><para>When you have telneted to a terminal server that supports sending a remote break</para>
<para>Press: <constant>Control-]</constant></para>
<para>Type in:<constant>send break</constant></para>
<para>Press: <constant>Enter</constant></para>
<para>Press: <constant>g</constant></para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>From the kdb prompt you can run the "help" command to see a complete list of the commands that are available.</para>
<para>Some useful commands in kdb include:
<itemizedlist>
<listitem><para>lsmod -- Shows where kernel modules are loaded</para></listitem>
<listitem><para>ps -- Displays only the active processes</para></listitem>
<listitem><para>ps A -- Shows all the processes</para></listitem>
<listitem><para>summary -- Shows kernel version info and memory usage</para></listitem>
<listitem><para>bt -- Get a backtrace of the current process using dump_stack()</para></listitem>
<listitem><para>dmesg -- View the kernel syslog buffer</para></listitem>
<listitem><para>go -- Continue the system</para></listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>When you are done using kdb you need to consider rebooting the
system or using the "go" command to resuming normal kernel
execution. If you have paused the kernel for a lengthy period of
time, applications that rely on timely networking or anything to do
with real wall clock time could be adversely affected, so you
should take this into consideration when using the kernel
debugger.</para>
</listitem>
</orderedlist></para>
</sect1>
<sect1 id="quickKDBkeyboard">
<title>Quick start for kdb using a keyboard connected console</title>
<para>This is a quick example of how to use kdb with a keyboard.</para>
<para><orderedlist>
<listitem><para>Boot kernel with arguments:
<itemizedlist>
<listitem><para><constant>kgdboc=kbd</constant></para></listitem>
</itemizedlist></para>
<para>OR</para>
<para>Configure kgdboc after the kernel booted:
<itemizedlist>
<listitem><para><constant>echo kbd &gt; /sys/module/kgdboc/parameters/kgdboc</constant></para></listitem>
</itemizedlist>
</para>
</listitem>
<listitem><para>Enter the kernel debugger manually or by waiting for an oops or fault. There are several ways you can enter the kernel debugger manually; all involve using the sysrq-g, which means you must have enabled CONFIG_MAGIC_SYSRQ=y in your kernel config.</para>
<itemizedlist>
<listitem><para>When logged in as root or with a super user session you can run:</para>
<para><constant>echo g &gt; /proc/sysrq-trigger</constant></para></listitem>
<listitem><para>Example using a laptop keyboard</para>
<para>Press and hold down: <constant>Alt</constant></para>
<para>Press and hold down: <constant>Fn</constant></para>
<para>Press and release the key with the label: <constant>SysRq</constant></para>
<para>Release: <constant>Fn</constant></para>
<para>Press and release: <constant>g</constant></para>
<para>Release: <constant>Alt</constant></para>
</listitem>
<listitem><para>Example using a PS/2 101-key keyboard</para>
<para>Press and hold down: <constant>Alt</constant></para>
<para>Press and release the key with the label: <constant>SysRq</constant></para>
<para>Press and release: <constant>g</constant></para>
<para>Release: <constant>Alt</constant></para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>Now type in a kdb command such as "help", "dmesg", "bt" or "go" to continue kernel execution.</para>
</listitem>
</orderedlist></para>
</sect1>
</chapter>
<chapter id="EnableKGDB">
<title>Using kgdb / gdb</title>
<para>In order to use kgdb you must activate it by passing
configuration information to one of the kgdb I/O drivers. If you
do not pass any configuration information kgdb will not do anything
at all. Kgdb will only actively hook up to the kernel trap hooks
if a kgdb I/O driver is loaded and configured. If you unconfigure
a kgdb I/O driver, kgdb will unregister all the kernel hook points.
</para>
<para> All kgdb I/O drivers can be reconfigured at run time, if
<symbol>CONFIG_SYSFS</symbol> and <symbol>CONFIG_MODULES</symbol>
are enabled, by echo'ing a new config string to
<constant>/sys/module/&lt;driver&gt;/parameter/&lt;option&gt;</constant>.
The driver can be unconfigured by passing an empty string. You cannot
change the configuration while the debugger is attached. Make sure
to detach the debugger with the <constant>detach</constant> command
prior to trying to unconfigure a kgdb I/O driver.
</para>
<sect1 id="ConnectingGDB">
<title>Connecting with gdb to a serial port</title>
<orderedlist>
<listitem><para>Configure kgdboc</para>
<para>Boot kernel with arguments:
<itemizedlist>
<listitem><para><constant>kgdboc=ttyS0,115200</constant></para></listitem>
</itemizedlist></para>
<para>OR</para>
<para>Configure kgdboc after the kernel booted:
<itemizedlist>
<listitem><para><constant>echo ttyS0 &gt; /sys/module/kgdboc/parameters/kgdboc</constant></para></listitem>
</itemizedlist></para>
</listitem>
<listitem>
<para>Stop kernel execution (break into the debugger)</para>
<para>In order to connect to gdb via kgdboc, the kernel must
first be stopped. There are several ways to stop the kernel which
include using kgdbwait as a boot argument, via a sysrq-g, or running
the kernel until it takes an exception where it waits for the
debugger to attach.
<itemizedlist>
<listitem><para>When logged in as root or with a super user session you can run:</para>
<para><constant>echo g &gt; /proc/sysrq-trigger</constant></para></listitem>
<listitem><para>Example using minicom 2.2</para>
<para>Press: <constant>Control-a</constant></para>
<para>Press: <constant>f</constant></para>
<para>Press: <constant>g</constant></para>
</listitem>
<listitem><para>When you have telneted to a terminal server that supports sending a remote break</para>
<para>Press: <constant>Control-]</constant></para>
<para>Type in:<constant>send break</constant></para>
<para>Press: <constant>Enter</constant></para>
<para>Press: <constant>g</constant></para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>Connect from from gdb</para>
<para>
If you are using kgdboc, you need to have used kgdbwait as a boot
argument, issued a sysrq-g, or the system you are going to debug
has already taken an exception and is waiting for the debugger to
attach before you can connect gdb.
</para>
<para>
If you are not using different kgdb I/O driver other than kgdboc,
you should be able to connect and the target will automatically
respond.
</para>
<para>
Example (using a serial port):
Example (using a directly connected port):
</para>
<programlisting>
% gdb ./vmlinux
@ -266,7 +531,7 @@
(gdb) target remote /dev/ttyS0
</programlisting>
<para>
Example (kgdb to a terminal server on tcp port 2012):
Example (kgdb to a terminal server on TCP port 2012):
</para>
<programlisting>
% gdb ./vmlinux
@ -283,6 +548,83 @@
communications. You do this prior to issuing the <constant>target
remote</constant> command by typing in: <constant>set debug remote 1</constant>
</para>
</listitem>
</orderedlist>
<para>Remember if you continue in gdb, and need to "break in" again,
you need to issue an other sysrq-g. It is easy to create a simple
entry point by putting a breakpoint at <constant>sys_sync</constant>
and then you can run "sync" from a shell or script to break into the
debugger.</para>
</sect1>
</chapter>
<chapter id="switchKdbKgdb">
<title>kgdb and kdb interoperability</title>
<para>It is possible to transition between kdb and kgdb dynamically.
The debug core will remember which you used the last time and
automatically start in the same mode.</para>
<sect1>
<title>Switching between kdb and kgdb</title>
<sect2>
<title>Switching from kgdb to kdb</title>
<para>
There are two ways to switch from kgdb to kdb: you can use gdb to
issue a maintenance packet, or you can blindly type the command $3#33.
Whenever kernel debugger stops in kgdb mode it will print the
message <constant>KGDB or $3#33 for KDB</constant>. It is important
to note that you have to type the sequence correctly in one pass.
You cannot type a backspace or delete because kgdb will interpret
that as part of the debug stream.
<orderedlist>
<listitem><para>Change from kgdb to kdb by blindly typing:</para>
<para><constant>$3#33</constant></para></listitem>
<listitem><para>Change from kgdb to kdb with gdb</para>
<para><constant>maintenance packet 3</constant></para>
<para>NOTE: Now you must kill gdb. Typically you press control-z and
issue the command: kill -9 %</para></listitem>
</orderedlist>
</para>
</sect2>
<sect2>
<title>Change from kdb to kgdb</title>
<para>There are two ways you can change from kdb to kgdb. You can
manually enter kgdb mode by issuing the kgdb command from the kdb
shell prompt, or you can connect gdb while the kdb shell prompt is
active. The kdb shell looks for the typical first commands that gdb
would issue with the gdb remote protocol and if it sees one of those
commands it automatically changes into kgdb mode.</para>
<orderedlist>
<listitem><para>From kdb issue the command:</para>
<para><constant>kgdb</constant></para>
<para>Now disconnect your terminal program and connect gdb in its place</para></listitem>
<listitem><para>At the kdb prompt, disconnect the terminal program and connect gdb in its place.</para></listitem>
</orderedlist>
</sect2>
</sect1>
<sect1>
<title>Running kdb commands from gdb</title>
<para>It is possible to run a limited set of kdb commands from gdb,
using the gdb monitor command. You don't want to execute any of the
run control or breakpoint operations, because it can disrupt the
state of the kernel debugger. You should be using gdb for
breakpoints and run control operations if you have gdb connected.
The more useful commands to run are things like lsmod, dmesg, ps or
possibly some of the memory information commands. To see all the kdb
commands you can run <constant>monitor help</constant>.</para>
<para>Example:
<informalexample><programlisting>
(gdb) monitor ps
1 idle process (state I) and
27 sleeping system daemon (state M) processes suppressed,
use 'ps A' to see all.
Task Addr Pid Parent [*] cpu State Thread Command
0xc78291d0 1 0 0 0 S 0xc7829404 init
0xc7954150 942 1 0 0 S 0xc7954384 dropbear
0xc78789c0 944 1 0 0 S 0xc7878bf4 sh
(gdb)
</programlisting></informalexample>
</para>
</sect1>
</chapter>
<chapter id="KGDBTestSuite">
<title>kgdb Test Suite</title>
@ -309,34 +651,38 @@
</para>
</chapter>
<chapter id="CommonBackEndReq">
<title>KGDB Internals</title>
<title>Kernel Debugger Internals</title>
<sect1 id="kgdbArchitecture">
<title>Architecture Specifics</title>
<para>
Kgdb is organized into three basic components:
The kernel debugger is organized into a number of components:
<orderedlist>
<listitem><para>kgdb core</para>
<listitem><para>The debug core</para>
<para>
The kgdb core is found in kernel/kgdb.c. It contains:
The debug core is found in kernel/debugger/debug_core.c. It contains:
<itemizedlist>
<listitem><para>All the logic to implement the gdb serial protocol</para></listitem>
<listitem><para>A generic OS exception handler which includes sync'ing the processors into a stopped state on an multi cpu system.</para></listitem>
<listitem><para>A generic OS exception handler which includes
sync'ing the processors into a stopped state on an multi-CPU
system.</para></listitem>
<listitem><para>The API to talk to the kgdb I/O drivers</para></listitem>
<listitem><para>The API to make calls to the arch specific kgdb implementation</para></listitem>
<listitem><para>The API to make calls to the arch-specific kgdb implementation</para></listitem>
<listitem><para>The logic to perform safe memory reads and writes to memory while using the debugger</para></listitem>
<listitem><para>A full implementation for software breakpoints unless overridden by the arch</para></listitem>
<listitem><para>The API to invoke either the kdb or kgdb frontend to the debug core.</para></listitem>
<listitem><para>The structures and callback API for atomic kernel mode setting.</para>
<para>NOTE: kgdboc is where the kms callbacks are invoked.</para></listitem>
</itemizedlist>
</para>
</listitem>
<listitem><para>kgdb arch specific implementation</para>
<listitem><para>kgdb arch-specific implementation</para>
<para>
This implementation is generally found in arch/*/kernel/kgdb.c.
As an example, arch/x86/kernel/kgdb.c contains the specifics to
implement HW breakpoint as well as the initialization to
dynamically register and unregister for the trap handlers on
this architecture. The arch specific portion implements:
this architecture. The arch-specific portion implements:
<itemizedlist>
<listitem><para>contains an arch specific trap catcher which
<listitem><para>contains an arch-specific trap catcher which
invokes kgdb_handle_exception() to start kgdb about doing its
work</para></listitem>
<listitem><para>translation to and from gdb specific packet format to pt_regs</para></listitem>
@ -347,11 +693,46 @@
</itemizedlist>
</para>
</listitem>
<listitem><para>gdbstub frontend (aka kgdb)</para>
<para>The gdbstub is located in kernel/debug/gdbstub.c. It contains:</para>
<itemizedlist>
<listitem><para>All the logic to implement the gdb serial protocol</para></listitem>
</itemizedlist>
</listitem>
<listitem><para>kdb frontend</para>
<para>The kdb debugger shell is broken down into a number of
components. The kdb core is located in kernel/debug/kdb. There
are a number of helper functions in some of the other kernel
components to make it possible for kdb to examine and report
information about the kernel without taking locks that could
cause a kernel deadlock. The kdb core contains implements the following functionality.</para>
<itemizedlist>
<listitem><para>A simple shell</para></listitem>
<listitem><para>The kdb core command set</para></listitem>
<listitem><para>A registration API to register additional kdb shell commands.</para>
<itemizedlist>
<listitem><para>A good example of a self-contained kdb module
is the "ftdump" command for dumping the ftrace buffer. See:
kernel/trace/trace_kdb.c</para></listitem>
<listitem><para>For an example of how to dynamically register
a new kdb command you can build the kdb_hello.ko kernel module
from samples/kdb/kdb_hello.c. To build this example you can
set CONFIG_SAMPLES=y and CONFIG_SAMPLE_KDB=m in your kernel
config. Later run "modprobe kdb_hello" and the next time you
enter the kdb shell, you can run the "hello"
command.</para></listitem>
</itemizedlist></listitem>
<listitem><para>The implementation for kdb_printf() which
emits messages directly to I/O drivers, bypassing the kernel
log.</para></listitem>
<listitem><para>SW / HW breakpoint management for the kdb shell</para></listitem>
</itemizedlist>
</listitem>
<listitem><para>kgdb I/O driver</para>
<para>
Each kgdb I/O driver has to provide an implemenation for the following:
Each kgdb I/O driver has to provide an implementation for the following:
<itemizedlist>
<listitem><para>configuration via builtin or module</para></listitem>
<listitem><para>configuration via built-in or module</para></listitem>
<listitem><para>dynamic configuration and kgdb hook registration calls</para></listitem>
<listitem><para>read and write character interface</para></listitem>
<listitem><para>A cleanup handler for unconfiguring from the kgdb core</para></listitem>
@ -411,20 +792,19 @@
</sect1>
<sect1 id="kgdbocDesign">
<title>kgdboc internals</title>
<sect2>
<title>kgdboc and uarts</title>
<para>
The kgdboc driver is actually a very thin driver that relies on the
underlying low level to the hardware driver having "polling hooks"
which the to which the tty driver is attached. In the initial
implementation of kgdboc it the serial_core was changed to expose a
low level uart hook for doing polled mode reading and writing of a
low level UART hook for doing polled mode reading and writing of a
single character while in an atomic context. When kgdb makes an I/O
request to the debugger, kgdboc invokes a call back in the serial
core which in turn uses the call back in the uart driver. It is
certainly possible to extend kgdboc to work with non-uart based
consoles in the future.
</para>
request to the debugger, kgdboc invokes a callback in the serial
core which in turn uses the callback in the UART driver.</para>
<para>
When using kgdboc with a uart, the uart driver must implement two callbacks in the <constant>struct uart_ops</constant>. Example from drivers/8250.c:<programlisting>
When using kgdboc with a UART, the UART driver must implement two callbacks in the <constant>struct uart_ops</constant>. Example from drivers/8250.c:<programlisting>
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = serial8250_get_poll_char,
.poll_put_char = serial8250_put_poll_char,
@ -434,11 +814,70 @@
<constant>#ifdef CONFIG_CONSOLE_POLL</constant>, as shown above.
Keep in mind that polling hooks have to be implemented in such a way
that they can be called from an atomic context and have to restore
the state of the uart chip on return such that the system can return
the state of the UART chip on return such that the system can return
to normal when the debugger detaches. You need to be very careful
with any kind of lock you consider, because failing here is most
with any kind of lock you consider, because failing here is most likely
going to mean pressing the reset button.
</para>
</sect2>
<sect2 id="kgdbocKbd">
<title>kgdboc and keyboards</title>
<para>The kgdboc driver contains logic to configure communications
with an attached keyboard. The keyboard infrastructure is only
compiled into the kernel when CONFIG_KDB_KEYBOARD=y is set in the
kernel configuration.</para>
<para>The core polled keyboard driver driver for PS/2 type keyboards
is in drivers/char/kdb_keyboard.c. This driver is hooked into the
debug core when kgdboc populates the callback in the array
called <constant>kdb_poll_funcs[]</constant>. The
kdb_get_kbd_char() is the top-level function which polls hardware
for single character input.
</para>
</sect2>
<sect2 id="kgdbocKms">
<title>kgdboc and kms</title>
<para>The kgdboc driver contains logic to request the graphics
display to switch to a text context when you are using
"kgdboc=kms,kbd", provided that you have a video driver which has a
frame buffer console and atomic kernel mode setting support.</para>
<para>
Every time the kernel
debugger is entered it calls kgdboc_pre_exp_handler() which in turn
calls con_debug_enter() in the virtual console layer. On resuming kernel
execution, the kernel debugger calls kgdboc_post_exp_handler() which
in turn calls con_debug_leave().</para>
<para>Any video driver that wants to be compatible with the kernel
debugger and the atomic kms callbacks must implement the
mode_set_base_atomic, fb_debug_enter and fb_debug_leave operations.
For the fb_debug_enter and fb_debug_leave the option exists to use
the generic drm fb helper functions or implement something custom for
the hardware. The following example shows the initialization of the
.mode_set_base_atomic operation in
drivers/gpu/drm/i915/intel_display.c:
<informalexample>
<programlisting>
static const struct drm_crtc_helper_funcs intel_helper_funcs = {
[...]
.mode_set_base_atomic = intel_pipe_set_base_atomic,
[...]
};
</programlisting>
</informalexample>
</para>
<para>Here is an example of how the i915 driver initializes the fb_debug_enter and fb_debug_leave functions to use the generic drm helpers in
drivers/gpu/drm/i915/intel_fb.c:
<informalexample>
<programlisting>
static struct fb_ops intelfb_ops = {
[...]
.fb_debug_enter = drm_fb_helper_debug_enter,
.fb_debug_leave = drm_fb_helper_debug_leave,
[...]
};
</programlisting>
</informalexample>
</para>
</sect2>
</sect1>
</chapter>
<chapter id="credits">
@ -453,6 +892,10 @@
<itemizedlist>
<listitem><para>Jason Wessel<email>jason.wessel@windriver.com</email></para></listitem>
</itemizedlist>
In Jan 2010 this document was updated to include kdb.
<itemizedlist>
<listitem><para>Jason Wessel<email>jason.wessel@windriver.com</email></para></listitem>
</itemizedlist>
</para>
</chapter>
</book>

View File

@ -81,16 +81,14 @@ void (*port_disable) (struct ata_port *);
</programlisting>
<para>
Called from ata_bus_probe() and ata_bus_reset() error paths,
as well as when unregistering from the SCSI module (rmmod, hot
unplug).
Called from ata_bus_probe() error path, as well as when
unregistering from the SCSI module (rmmod, hot unplug).
This function should do whatever needs to be done to take the
port out of use. In most cases, ata_port_disable() can be used
as this hook.
</para>
<para>
Called from ata_bus_probe() on a failed probe.
Called from ata_bus_reset() on a failed bus reset.
Called from ata_scsi_release().
</para>
@ -107,10 +105,6 @@ void (*dev_config) (struct ata_port *, struct ata_device *);
issue of SET FEATURES - XFER MODE, and prior to operation.
</para>
<para>
Called by ata_device_add() after ata_dev_identify() determines
a device is present.
</para>
<para>
This entry may be specified as NULL in ata_port_operations.
</para>
@ -154,8 +148,8 @@ unsigned int (*mode_filter) (struct ata_port *, struct ata_device *, unsigned in
<sect2><title>Taskfile read/write</title>
<programlisting>
void (*tf_load) (struct ata_port *ap, struct ata_taskfile *tf);
void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf);
void (*sff_tf_load) (struct ata_port *ap, struct ata_taskfile *tf);
void (*sff_tf_read) (struct ata_port *ap, struct ata_taskfile *tf);
</programlisting>
<para>
@ -164,36 +158,35 @@ void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf);
hardware registers / DMA buffers, to obtain the current set of
taskfile register values.
Most drivers for taskfile-based hardware (PIO or MMIO) use
ata_tf_load() and ata_tf_read() for these hooks.
ata_sff_tf_load() and ata_sff_tf_read() for these hooks.
</para>
</sect2>
<sect2><title>PIO data read/write</title>
<programlisting>
void (*data_xfer) (struct ata_device *, unsigned char *, unsigned int, int);
void (*sff_data_xfer) (struct ata_device *, unsigned char *, unsigned int, int);
</programlisting>
<para>
All bmdma-style drivers must implement this hook. This is the low-level
operation that actually copies the data bytes during a PIO data
transfer.
Typically the driver
will choose one of ata_pio_data_xfer_noirq(), ata_pio_data_xfer(), or
ata_mmio_data_xfer().
Typically the driver will choose one of ata_sff_data_xfer_noirq(),
ata_sff_data_xfer(), or ata_sff_data_xfer32().
</para>
</sect2>
<sect2><title>ATA command execute</title>
<programlisting>
void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf);
void (*sff_exec_command)(struct ata_port *ap, struct ata_taskfile *tf);
</programlisting>
<para>
causes an ATA command, previously loaded with
->tf_load(), to be initiated in hardware.
Most drivers for taskfile-based hardware use ata_exec_command()
Most drivers for taskfile-based hardware use ata_sff_exec_command()
for this hook.
</para>
@ -218,8 +211,8 @@ command.
<sect2><title>Read specific ATA shadow registers</title>
<programlisting>
u8 (*check_status)(struct ata_port *ap);
u8 (*check_altstatus)(struct ata_port *ap);
u8 (*sff_check_status)(struct ata_port *ap);
u8 (*sff_check_altstatus)(struct ata_port *ap);
</programlisting>
<para>
@ -227,20 +220,26 @@ u8 (*check_altstatus)(struct ata_port *ap);
hardware. On some hardware, reading the Status register has
the side effect of clearing the interrupt condition.
Most drivers for taskfile-based hardware use
ata_check_status() for this hook.
ata_sff_check_status() for this hook.
</para>
</sect2>
<sect2><title>Write specific ATA shadow register</title>
<programlisting>
void (*sff_set_devctl)(struct ata_port *ap, u8 ctl);
</programlisting>
<para>
Note that because this is called from ata_device_add(), at
least a dummy function that clears device interrupts must be
provided for all drivers, even if the controller doesn't
actually have a taskfile status register.
Write the device control ATA shadow register to the hardware.
Most drivers don't need to define this.
</para>
</sect2>
<sect2><title>Select ATA device on bus</title>
<programlisting>
void (*dev_select)(struct ata_port *ap, unsigned int device);
void (*sff_dev_select)(struct ata_port *ap, unsigned int device);
</programlisting>
<para>
@ -251,9 +250,7 @@ void (*dev_select)(struct ata_port *ap, unsigned int device);
</para>
<para>
Most drivers for taskfile-based hardware use
ata_std_dev_select() for this hook. Controllers which do not
support second drives on a port (such as SATA contollers) will
use ata_noop_dev_select().
ata_sff_dev_select() for this hook.
</para>
</sect2>
@ -441,13 +438,13 @@ void (*irq_clear) (struct ata_port *);
to struct ata_host_set.
</para>
<para>
Most legacy IDE drivers use ata_interrupt() for the
Most legacy IDE drivers use ata_sff_interrupt() for the
irq_handler hook, which scans all ports in the host_set,
determines which queued command was active (if any), and calls
ata_host_intr(ap,qc).
ata_sff_host_intr(ap,qc).
</para>
<para>
Most legacy IDE drivers use ata_bmdma_irq_clear() for the
Most legacy IDE drivers use ata_sff_irq_clear() for the
irq_clear() hook, which simply clears the interrupt and error
flags in the DMA status register.
</para>
@ -490,16 +487,12 @@ void (*host_stop) (struct ata_host_set *host_set);
allocates space for a legacy IDE PRD table and returns.
</para>
<para>
->port_stop() is called after ->host_stop(). It's sole function
->port_stop() is called after ->host_stop(). Its sole function
is to release DMA/memory resources, now that they are no longer
actively being used. Many drivers also free driver-private
data from port at this time.
</para>
<para>
Many drivers use ata_port_stop() as this hook, which frees the
PRD table.
</para>
<para>
->host_stop() is called after all ->port_stop() calls
have completed. The hook must finalize hardware shutdown, release DMA
and other resources, etc.

View File

@ -1,338 +0,0 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
<book id="mac80211-developers-guide">
<bookinfo>
<title>The mac80211 subsystem for kernel developers</title>
<authorgroup>
<author>
<firstname>Johannes</firstname>
<surname>Berg</surname>
<affiliation>
<address><email>johannes@sipsolutions.net</email></address>
</affiliation>
</author>
</authorgroup>
<copyright>
<year>2007-2009</year>
<holder>Johannes Berg</holder>
</copyright>
<legalnotice>
<para>
This documentation is free software; you can redistribute
it and/or modify it under the terms of the GNU General Public
License version 2 as published by the Free Software Foundation.
</para>
<para>
This documentation is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
</para>
<para>
You should have received a copy of the GNU General Public
License along with this documentation; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
</para>
<para>
For more details see the file COPYING in the source
distribution of Linux.
</para>
</legalnotice>
<abstract>
!Pinclude/net/mac80211.h Introduction
!Pinclude/net/mac80211.h Warning
</abstract>
</bookinfo>
<toc></toc>
<!--
Generally, this document shall be ordered by increasing complexity.
It is important to note that readers should be able to read only
the first few sections to get a working driver and only advanced
usage should require reading the full document.
-->
<part>
<title>The basic mac80211 driver interface</title>
<partintro>
<para>
You should read and understand the information contained
within this part of the book while implementing a driver.
In some chapters, advanced usage is noted, that may be
skipped at first.
</para>
<para>
This part of the book only covers station and monitor mode
functionality, additional information required to implement
the other modes is covered in the second part of the book.
</para>
</partintro>
<chapter id="basics">
<title>Basic hardware handling</title>
<para>TBD</para>
<para>
This chapter shall contain information on getting a hw
struct allocated and registered with mac80211.
</para>
<para>
Since it is required to allocate rates/modes before registering
a hw struct, this chapter shall also contain information on setting
up the rate/mode structs.
</para>
<para>
Additionally, some discussion about the callbacks and
the general programming model should be in here, including
the definition of ieee80211_ops which will be referred to
a lot.
</para>
<para>
Finally, a discussion of hardware capabilities should be done
with references to other parts of the book.
</para>
<!-- intentionally multiple !F lines to get proper order -->
!Finclude/net/mac80211.h ieee80211_hw
!Finclude/net/mac80211.h ieee80211_hw_flags
!Finclude/net/mac80211.h SET_IEEE80211_DEV
!Finclude/net/mac80211.h SET_IEEE80211_PERM_ADDR
!Finclude/net/mac80211.h ieee80211_ops
!Finclude/net/mac80211.h ieee80211_alloc_hw
!Finclude/net/mac80211.h ieee80211_register_hw
!Finclude/net/mac80211.h ieee80211_get_tx_led_name
!Finclude/net/mac80211.h ieee80211_get_rx_led_name
!Finclude/net/mac80211.h ieee80211_get_assoc_led_name
!Finclude/net/mac80211.h ieee80211_get_radio_led_name
!Finclude/net/mac80211.h ieee80211_unregister_hw
!Finclude/net/mac80211.h ieee80211_free_hw
</chapter>
<chapter id="phy-handling">
<title>PHY configuration</title>
<para>TBD</para>
<para>
This chapter should describe PHY handling including
start/stop callbacks and the various structures used.
</para>
!Finclude/net/mac80211.h ieee80211_conf
!Finclude/net/mac80211.h ieee80211_conf_flags
</chapter>
<chapter id="iface-handling">
<title>Virtual interfaces</title>
<para>TBD</para>
<para>
This chapter should describe virtual interface basics
that are relevant to the driver (VLANs, MGMT etc are not.)
It should explain the use of the add_iface/remove_iface
callbacks as well as the interface configuration callbacks.
</para>
<para>Things related to AP mode should be discussed there.</para>
<para>
Things related to supporting multiple interfaces should be
in the appropriate chapter, a BIG FAT note should be here about
this though and the recommendation to allow only a single
interface in STA mode at first!
</para>
!Finclude/net/mac80211.h ieee80211_if_init_conf
</chapter>
<chapter id="rx-tx">
<title>Receive and transmit processing</title>
<sect1>
<title>what should be here</title>
<para>TBD</para>
<para>
This should describe the receive and transmit
paths in mac80211/the drivers as well as
transmit status handling.
</para>
</sect1>
<sect1>
<title>Frame format</title>
!Pinclude/net/mac80211.h Frame format
</sect1>
<sect1>
<title>Packet alignment</title>
!Pnet/mac80211/rx.c Packet alignment
</sect1>
<sect1>
<title>Calling into mac80211 from interrupts</title>
!Pinclude/net/mac80211.h Calling mac80211 from interrupts
</sect1>
<sect1>
<title>functions/definitions</title>
!Finclude/net/mac80211.h ieee80211_rx_status
!Finclude/net/mac80211.h mac80211_rx_flags
!Finclude/net/mac80211.h ieee80211_tx_info
!Finclude/net/mac80211.h ieee80211_rx
!Finclude/net/mac80211.h ieee80211_rx_irqsafe
!Finclude/net/mac80211.h ieee80211_tx_status
!Finclude/net/mac80211.h ieee80211_tx_status_irqsafe
!Finclude/net/mac80211.h ieee80211_rts_get
!Finclude/net/mac80211.h ieee80211_rts_duration
!Finclude/net/mac80211.h ieee80211_ctstoself_get
!Finclude/net/mac80211.h ieee80211_ctstoself_duration
!Finclude/net/mac80211.h ieee80211_generic_frame_duration
!Finclude/net/mac80211.h ieee80211_wake_queue
!Finclude/net/mac80211.h ieee80211_stop_queue
!Finclude/net/mac80211.h ieee80211_wake_queues
!Finclude/net/mac80211.h ieee80211_stop_queues
</sect1>
</chapter>
<chapter id="filters">
<title>Frame filtering</title>
!Pinclude/net/mac80211.h Frame filtering
!Finclude/net/mac80211.h ieee80211_filter_flags
</chapter>
</part>
<part id="advanced">
<title>Advanced driver interface</title>
<partintro>
<para>
Information contained within this part of the book is
of interest only for advanced interaction of mac80211
with drivers to exploit more hardware capabilities and
improve performance.
</para>
</partintro>
<chapter id="hardware-crypto-offload">
<title>Hardware crypto acceleration</title>
!Pinclude/net/mac80211.h Hardware crypto acceleration
<!-- intentionally multiple !F lines to get proper order -->
!Finclude/net/mac80211.h set_key_cmd
!Finclude/net/mac80211.h ieee80211_key_conf
!Finclude/net/mac80211.h ieee80211_key_alg
!Finclude/net/mac80211.h ieee80211_key_flags
</chapter>
<chapter id="powersave">
<title>Powersave support</title>
!Pinclude/net/mac80211.h Powersave support
</chapter>
<chapter id="beacon-filter">
<title>Beacon filter support</title>
!Pinclude/net/mac80211.h Beacon filter support
!Finclude/net/mac80211.h ieee80211_beacon_loss
</chapter>
<chapter id="qos">
<title>Multiple queues and QoS support</title>
<para>TBD</para>
!Finclude/net/mac80211.h ieee80211_tx_queue_params
!Finclude/net/mac80211.h ieee80211_tx_queue_stats
</chapter>
<chapter id="AP">
<title>Access point mode support</title>
<para>TBD</para>
<para>Some parts of the if_conf should be discussed here instead</para>
<para>
Insert notes about VLAN interfaces with hw crypto here or
in the hw crypto chapter.
</para>
!Finclude/net/mac80211.h ieee80211_get_buffered_bc
!Finclude/net/mac80211.h ieee80211_beacon_get
</chapter>
<chapter id="multi-iface">
<title>Supporting multiple virtual interfaces</title>
<para>TBD</para>
<para>
Note: WDS with identical MAC address should almost always be OK
</para>
<para>
Insert notes about having multiple virtual interfaces with
different MAC addresses here, note which configurations are
supported by mac80211, add notes about supporting hw crypto
with it.
</para>
</chapter>
<chapter id="hardware-scan-offload">
<title>Hardware scan offload</title>
<para>TBD</para>
!Finclude/net/mac80211.h ieee80211_scan_completed
</chapter>
</part>
<part id="rate-control">
<title>Rate control interface</title>
<partintro>
<para>TBD</para>
<para>
This part of the book describes the rate control algorithm
interface and how it relates to mac80211 and drivers.
</para>
</partintro>
<chapter id="dummy">
<title>dummy chapter</title>
<para>TBD</para>
</chapter>
</part>
<part id="internal">
<title>Internals</title>
<partintro>
<para>TBD</para>
<para>
This part of the book describes mac80211 internals.
</para>
</partintro>
<chapter id="key-handling">
<title>Key handling</title>
<sect1>
<title>Key handling basics</title>
!Pnet/mac80211/key.c Key handling basics
</sect1>
<sect1>
<title>MORE TBD</title>
<para>TBD</para>
</sect1>
</chapter>
<chapter id="rx-processing">
<title>Receive processing</title>
<para>TBD</para>
</chapter>
<chapter id="tx-processing">
<title>Transmit processing</title>
<para>TBD</para>
</chapter>
<chapter id="sta-info">
<title>Station info handling</title>
<sect1>
<title>Programming information</title>
!Fnet/mac80211/sta_info.h sta_info
!Fnet/mac80211/sta_info.h ieee80211_sta_info_flags
</sect1>
<sect1>
<title>STA information lifetime rules</title>
!Pnet/mac80211/sta_info.c STA information lifetime rules
</sect1>
</chapter>
<chapter id="synchronisation">
<title>Synchronisation</title>
<para>TBD</para>
<para>Locking, lots of RCU</para>
</chapter>
</part>
</book>

View File

@ -17,6 +17,7 @@
<!ENTITY VIDIOC-DBG-G-REGISTER "<link linkend='vidioc-dbg-g-register'><constant>VIDIOC_DBG_G_REGISTER</constant></link>">
<!ENTITY VIDIOC-DBG-S-REGISTER "<link linkend='vidioc-dbg-g-register'><constant>VIDIOC_DBG_S_REGISTER</constant></link>">
<!ENTITY VIDIOC-DQBUF "<link linkend='vidioc-qbuf'><constant>VIDIOC_DQBUF</constant></link>">
<!ENTITY VIDIOC-DQEVENT "<link linkend='vidioc-dqevent'><constant>VIDIOC_DQEVENT</constant></link>">
<!ENTITY VIDIOC-ENCODER-CMD "<link linkend='vidioc-encoder-cmd'><constant>VIDIOC_ENCODER_CMD</constant></link>">
<!ENTITY VIDIOC-ENUMAUDIO "<link linkend='vidioc-enumaudio'><constant>VIDIOC_ENUMAUDIO</constant></link>">
<!ENTITY VIDIOC-ENUMAUDOUT "<link linkend='vidioc-enumaudioout'><constant>VIDIOC_ENUMAUDOUT</constant></link>">
@ -60,6 +61,7 @@
<!ENTITY VIDIOC-REQBUFS "<link linkend='vidioc-reqbufs'><constant>VIDIOC_REQBUFS</constant></link>">
<!ENTITY VIDIOC-STREAMOFF "<link linkend='vidioc-streamon'><constant>VIDIOC_STREAMOFF</constant></link>">
<!ENTITY VIDIOC-STREAMON "<link linkend='vidioc-streamon'><constant>VIDIOC_STREAMON</constant></link>">
<!ENTITY VIDIOC-SUBSCRIBE-EVENT "<link linkend='vidioc-subscribe-event'><constant>VIDIOC_SUBSCRIBE_EVENT</constant></link>">
<!ENTITY VIDIOC-S-AUDIO "<link linkend='vidioc-g-audio'><constant>VIDIOC_S_AUDIO</constant></link>">
<!ENTITY VIDIOC-S-AUDOUT "<link linkend='vidioc-g-audioout'><constant>VIDIOC_S_AUDOUT</constant></link>">
<!ENTITY VIDIOC-S-CROP "<link linkend='vidioc-g-crop'><constant>VIDIOC_S_CROP</constant></link>">
@ -83,6 +85,7 @@
<!ENTITY VIDIOC-TRY-ENCODER-CMD "<link linkend='vidioc-encoder-cmd'><constant>VIDIOC_TRY_ENCODER_CMD</constant></link>">
<!ENTITY VIDIOC-TRY-EXT-CTRLS "<link linkend='vidioc-g-ext-ctrls'><constant>VIDIOC_TRY_EXT_CTRLS</constant></link>">
<!ENTITY VIDIOC-TRY-FMT "<link linkend='vidioc-g-fmt'><constant>VIDIOC_TRY_FMT</constant></link>">
<!ENTITY VIDIOC-UNSUBSCRIBE-EVENT "<link linkend='vidioc-subscribe-event'><constant>VIDIOC_UNSUBSCRIBE_EVENT</constant></link>">
<!-- Types -->
<!ENTITY v4l2-std-id "<link linkend='v4l2-std-id'>v4l2_std_id</link>">
@ -141,6 +144,9 @@
<!ENTITY v4l2-enc-idx "struct&nbsp;<link linkend='v4l2-enc-idx'>v4l2_enc_idx</link>">
<!ENTITY v4l2-enc-idx-entry "struct&nbsp;<link linkend='v4l2-enc-idx-entry'>v4l2_enc_idx_entry</link>">
<!ENTITY v4l2-encoder-cmd "struct&nbsp;<link linkend='v4l2-encoder-cmd'>v4l2_encoder_cmd</link>">
<!ENTITY v4l2-event "struct&nbsp;<link linkend='v4l2-event'>v4l2_event</link>">
<!ENTITY v4l2-event-subscription "struct&nbsp;<link linkend='v4l2-event-subscription'>v4l2_event_subscription</link>">
<!ENTITY v4l2-event-vsync "struct&nbsp;<link linkend='v4l2-event-vsync'>v4l2_event_vsync</link>">
<!ENTITY v4l2-ext-control "struct&nbsp;<link linkend='v4l2-ext-control'>v4l2_ext_control</link>">
<!ENTITY v4l2-ext-controls "struct&nbsp;<link linkend='v4l2-ext-controls'>v4l2_ext_controls</link>">
<!ENTITY v4l2-fmtdesc "struct&nbsp;<link linkend='v4l2-fmtdesc'>v4l2_fmtdesc</link>">
@ -200,6 +206,7 @@
<!ENTITY sub-controls SYSTEM "v4l/controls.xml">
<!ENTITY sub-dev-capture SYSTEM "v4l/dev-capture.xml">
<!ENTITY sub-dev-codec SYSTEM "v4l/dev-codec.xml">
<!ENTITY sub-dev-event SYSTEM "v4l/dev-event.xml">
<!ENTITY sub-dev-effect SYSTEM "v4l/dev-effect.xml">
<!ENTITY sub-dev-osd SYSTEM "v4l/dev-osd.xml">
<!ENTITY sub-dev-output SYSTEM "v4l/dev-output.xml">
@ -211,6 +218,7 @@
<!ENTITY sub-dev-teletext SYSTEM "v4l/dev-teletext.xml">
<!ENTITY sub-driver SYSTEM "v4l/driver.xml">
<!ENTITY sub-libv4l SYSTEM "v4l/libv4l.xml">
<!ENTITY sub-lirc_device_interface SYSTEM "v4l/lirc_device_interface.xml">
<!ENTITY sub-remote_controllers SYSTEM "v4l/remote_controllers.xml">
<!ENTITY sub-fdl-appendix SYSTEM "v4l/fdl-appendix.xml">
<!ENTITY sub-close SYSTEM "v4l/func-close.xml">
@ -242,6 +250,9 @@
<!ENTITY sub-yuv422p SYSTEM "v4l/pixfmt-yuv422p.xml">
<!ENTITY sub-yuyv SYSTEM "v4l/pixfmt-yuyv.xml">
<!ENTITY sub-yvyu SYSTEM "v4l/pixfmt-yvyu.xml">
<!ENTITY sub-srggb10 SYSTEM "v4l/pixfmt-srggb10.xml">
<!ENTITY sub-srggb8 SYSTEM "v4l/pixfmt-srggb8.xml">
<!ENTITY sub-y10 SYSTEM "v4l/pixfmt-y10.xml">
<!ENTITY sub-pixfmt SYSTEM "v4l/pixfmt.xml">
<!ENTITY sub-cropcap SYSTEM "v4l/vidioc-cropcap.xml">
<!ENTITY sub-dbg-g-register SYSTEM "v4l/vidioc-dbg-g-register.xml">
@ -292,6 +303,8 @@
<!ENTITY sub-v4l2grab-c SYSTEM "v4l/v4l2grab.c.xml">
<!ENTITY sub-videodev2-h SYSTEM "v4l/videodev2.h.xml">
<!ENTITY sub-v4l2 SYSTEM "v4l/v4l2.xml">
<!ENTITY sub-dqevent SYSTEM "v4l/vidioc-dqevent.xml">
<!ENTITY sub-subscribe-event SYSTEM "v4l/vidioc-subscribe-event.xml">
<!ENTITY sub-intro SYSTEM "dvb/intro.xml">
<!ENTITY sub-frontend SYSTEM "dvb/frontend.xml">
<!ENTITY sub-dvbproperty SYSTEM "dvb/dvbproperty.xml">
@ -337,6 +350,9 @@
<!ENTITY yuv422p SYSTEM "v4l/pixfmt-yuv422p.xml">
<!ENTITY yuyv SYSTEM "v4l/pixfmt-yuyv.xml">
<!ENTITY yvyu SYSTEM "v4l/pixfmt-yvyu.xml">
<!ENTITY srggb10 SYSTEM "v4l/pixfmt-srggb10.xml">
<!ENTITY srggb8 SYSTEM "v4l/pixfmt-srggb8.xml">
<!ENTITY y10 SYSTEM "v4l/pixfmt-y10.xml">
<!ENTITY cropcap SYSTEM "v4l/vidioc-cropcap.xml">
<!ENTITY dbg-g-register SYSTEM "v4l/vidioc-dbg-g-register.xml">
<!ENTITY encoder-cmd SYSTEM "v4l/vidioc-encoder-cmd.xml">
@ -381,3 +397,5 @@
<!ENTITY reqbufs SYSTEM "v4l/vidioc-reqbufs.xml">
<!ENTITY s-hw-freq-seek SYSTEM "v4l/vidioc-s-hw-freq-seek.xml">
<!ENTITY streamon SYSTEM "v4l/vidioc-streamon.xml">
<!ENTITY dqevent SYSTEM "v4l/vidioc-dqevent.xml">
<!ENTITY subscribe_event SYSTEM "v4l/vidioc-subscribe-event.xml">

View File

@ -28,7 +28,7 @@
<title>LINUX MEDIA INFRASTRUCTURE API</title>
<copyright>
<year>2009</year>
<year>2009-2010</year>
<holder>LinuxTV Developers</holder>
</copyright>
@ -61,7 +61,7 @@ Foundation. A copy of the license is included in the chapter entitled
in fact it covers several different video standards including
DVB-T, DVB-S, DVB-C and ATSC. The API is currently being updated
to documment support also for DVB-S2, ISDB-T and ISDB-S.</para>
<para>The third part covers other API's used by all media infrastructure devices</para>
<para>The third part covers Remote Controller API</para>
<para>For additional information and for the latest development code,
see: <ulink url="http://linuxtv.org">http://linuxtv.org</ulink>.</para>
<para>For discussing improvements, reporting troubles, sending new drivers, etc, please mail to: <ulink url="http://vger.kernel.org/vger-lists.html#linux-media">Linux Media Mailing List (LMML).</ulink>.</para>
@ -86,7 +86,7 @@ Foundation. A copy of the license is included in the chapter entitled
</author>
</authorgroup>
<copyright>
<year>2009</year>
<year>2009-2010</year>
<holder>Mauro Carvalho Chehab</holder>
</copyright>
@ -101,7 +101,7 @@ Foundation. A copy of the license is included in the chapter entitled
</revhistory>
</partinfo>
<title>Other API's used by media infrastructure drivers</title>
<title>Remote Controller API</title>
<chapter id="remote_controllers">
&sub-remote_controllers;
</chapter>

View File

@ -250,7 +250,7 @@ static void board_hwcontrol(struct mtd_info *mtd, int cmd)
<title>Device ready function</title>
<para>
If the hardware interface has the ready busy pin of the NAND chip connected to a
GPIO or other accesible I/O pin, this function is used to read back the state of the
GPIO or other accessible I/O pin, this function is used to read back the state of the
pin. The function has no arguments and should return 0, if the device is busy (R/B pin
is low) and 1, if the device is ready (R/B pin is high).
If the hardware interface does not give access to the ready busy pin, then
@ -269,7 +269,7 @@ static void board_hwcontrol(struct mtd_info *mtd, int cmd)
information about the device.
</para>
<programlisting>
int __init board_init (void)
static int __init board_init (void)
{
struct nand_chip *this;
int err = 0;
@ -488,7 +488,7 @@ static void board_select_chip (struct mtd_info *mtd, int chip)
The ECC bytes must be placed immidiately after the data
bytes in order to make the syndrome generator work. This
is contrary to the usual layout used by software ECC. The
seperation of data and out of band area is not longer
separation of data and out of band area is not longer
possible. The nand driver code handles this layout and
the remaining free bytes in the oob area are managed by
the autoplacement code. Provide a matching oob-layout
@ -560,7 +560,7 @@ static void board_select_chip (struct mtd_info *mtd, int chip)
bad blocks. They have factory marked good blocks. The marker pattern
is erased when the block is erased to be reused. So in case of
powerloss before writing the pattern back to the chip this block
would be lost and added to the bad blocks. Therefor we scan the
would be lost and added to the bad blocks. Therefore we scan the
chip(s) when we detect them the first time for good blocks and
store this information in a bad block table before erasing any
of the blocks.
@ -1094,7 +1094,7 @@ in this page</entry>
manufacturers specifications. This applies similar to the spare area.
</para>
<para>
Therefor NAND aware filesystems must either write in page size chunks
Therefore NAND aware filesystems must either write in page size chunks
or hold a writebuffer to collect smaller writes until they sum up to
pagesize. Available NAND aware filesystems: JFFS2, YAFFS.
</para>

View File

@ -393,7 +393,7 @@
</para>
<para>
For documentation see
<ulink url='http://www.torque.net/sg/sdebug26.html'>http://www.torque.net/sg/sdebug26.html</ulink>
<ulink url='http://sg.danny.cz/sg/sdebug26.html'>http://sg.danny.cz/sg/sdebug26.html</ulink>
</para>
<!-- !Edrivers/scsi/scsi_debug.c -->
</sect2>

View File

@ -19,13 +19,17 @@
</authorgroup>
<copyright>
<year>2008</year>
<year>2008-2010</year>
<holder>Paul Mundt</holder>
</copyright>
<copyright>
<year>2008</year>
<year>2008-2010</year>
<holder>Renesas Technology Corp.</holder>
</copyright>
<copyright>
<year>2010</year>
<holder>Renesas Electronics Corp.</holder>
</copyright>
<legalnotice>
<para>
@ -75,10 +79,6 @@
</sect2>
</sect1>
</chapter>
<chapter id="clk">
<title>Clock Framework Extensions</title>
!Iarch/sh/include/asm/clock.h
</chapter>
<chapter id="mach">
<title>Machine Specific Interfaces</title>
<sect1 id="dreamcast">

View File

@ -6,4 +6,5 @@
<param name="callout.graphics">0</param>
<!-- <param name="paper.type">A4</param> -->
<param name="generate.section.toc.level">2</param>
<param name="use.id.as.filename">1</param>
</stylesheet>

View File

@ -16,6 +16,15 @@
</address>
</affiliation>
</author>
<author>
<firstname>William</firstname>
<surname>Cohen</surname>
<affiliation>
<address>
<email>wcohen@redhat.com</email>
</address>
</affiliation>
</author>
</authorgroup>
<legalnotice>
@ -91,4 +100,13 @@
!Iinclude/trace/events/signal.h
</chapter>
<chapter id="block">
<title>Block IO</title>
!Iinclude/trace/events/block.h
</chapter>
<chapter id="workqueue">
<title>Workqueue</title>
!Iinclude/trace/events/workqueue.h
</chapter>
</book>

View File

@ -16,7 +16,7 @@
</orgname>
<address>
<email>hjk@linutronix.de</email>
<email>hjk@hansjkoch.de</email>
</address>
</affiliation>
</author>
@ -114,7 +114,7 @@ GPL version 2.
<para>If you know of any translations for this document, or you are
interested in translating it, please email me
<email>hjk@linutronix.de</email>.
<email>hjk@hansjkoch.de</email>.
</para>
</sect1>
@ -171,7 +171,7 @@ interested in translating it, please email me
<title>Feedback</title>
<para>Find something wrong with this document? (Or perhaps something
right?) I would love to hear from you. Please email me at
<email>hjk@linutronix.de</email>.</para>
<email>hjk@hansjkoch.de</email>.</para>
</sect1>
</chapter>

View File

@ -1170,7 +1170,7 @@ frames per second. If less than this number of frames is to be
captured or output, applications can request frame skipping or
duplicating on the driver side. This is especially useful when using
the &func-read; or &func-write;, which are not augmented by timestamps
or sequence counters, and to avoid unneccessary data copying.</para>
or sequence counters, and to avoid unnecessary data copying.</para>
<para>Finally these ioctls can be used to determine the number of
buffers used internally by a driver in read/write mode. For

View File

@ -21,11 +21,15 @@ API.</para>
<title>Opening and Closing Devices</title>
<para>For compatibility reasons the character device file names
recommended for V4L2 video capture, overlay, radio, teletext and raw
recommended for V4L2 video capture, overlay, radio and raw
vbi capture devices did not change from those used by V4L. They are
listed in <xref linkend="devices" /> and below in <xref
linkend="v4l-dev" />.</para>
<para>The teletext devices (minor range 192-223) have been removed in
V4L2 and no longer exist. There is no hardware available anymore for handling
pure teletext. Instead raw or sliced VBI is used.</para>
<para>The V4L <filename>videodev</filename> module automatically
assigns minor numbers to drivers in load order, depending on the
registered device type. We recommend that V4L2 drivers by default
@ -65,13 +69,6 @@ not compatible with V4L or V4L2.</para> </footnote>,
<filename>/dev/radio63</filename></para></entry>
<entry>64-127</entry>
</row>
<row>
<entry>Teletext decoder</entry>
<entry><para><filename>/dev/vtx</filename>,
<filename>/dev/vtx0</filename> to
<filename>/dev/vtx31</filename></para></entry>
<entry>192-223</entry>
</row>
<row>
<entry>Raw VBI capture</entry>
<entry><para><filename>/dev/vbi</filename>,
@ -1091,8 +1088,9 @@ signed 64-bit integer. Output devices should not send a buffer out
until the time in the timestamp field has arrived. I would like to
follow SGI's lead, and adopt a multimedia timestamping system like
their UST (Unadjusted System Time). See
http://reality.sgi.com/cpirazzi_engr/lg/time/intro.html. [This link is
no longer valid.] UST uses timestamps that are 64-bit signed integers
http://web.archive.org/web/*/http://reality.sgi.com
/cpirazzi_engr/lg/time/intro.html.
UST uses timestamps that are 64-bit signed integers
(not struct timeval's) and given in nanosecond units. The UST clock
starts at zero when the system is booted and runs continuously and
uniformly. It takes a little over 292 years for UST to overflow. There
@ -2332,15 +2330,37 @@ more information.</para>
</listitem>
</orderedlist>
</section>
</section>
<section>
<title>V4L2 in Linux 2.6.34</title>
<orderedlist>
<listitem>
<para>Added
<constant>V4L2_CID_IRIS_ABSOLUTE</constant> and
<constant>V4L2_CID_IRIS_RELATIVE</constant> controls to the
<link linkend="camera-controls">Camera controls class</link>.
</para>
</listitem>
</orderedlist>
</section>
<section>
<title>V4L2 in Linux 2.6.37</title>
<orderedlist>
<listitem>
<para>Remove the vtx (videotext/teletext) API. This API was no longer
used and no hardware exists to verify the API. Nor were any userspace applications found
that used it. It was originally scheduled for removal in 2.6.35.
</para>
</listitem>
</orderedlist>
</section>
<section id="other">
<title>Relation of V4L2 to other Linux multimedia APIs</title>
<section id="other">
<title>Relation of V4L2 to other Linux multimedia APIs</title>
<section id="xvideo">
<title>X Video Extension</title>
<section id="xvideo">
<title>X Video Extension</title>
<para>The X Video Extension (abbreviated XVideo or just Xv) is
<para>The X Video Extension (abbreviated XVideo or just Xv) is
an extension of the X Window system, implemented for example by the
XFree86 project. Its scope is similar to V4L2, an API to video capture
and output devices for X clients. Xv allows applications to display
@ -2351,7 +2371,7 @@ capture or output still images in XPixmaps<footnote>
extension available across many operating systems and
architectures.</para>
<para>Because the driver is embedded into the X server Xv has a
<para>Because the driver is embedded into the X server Xv has a
number of advantages over the V4L2 <link linkend="overlay">video
overlay interface</link>. The driver can easily determine the overlay
target, &ie; visible graphics memory or off-screen buffers for a
@ -2360,16 +2380,16 @@ overlay, scaling or color-keying, or the clipping functions of the
video capture hardware, always in sync with drawing operations or
windows moving or changing their stacking order.</para>
<para>To combine the advantages of Xv and V4L a special Xv
<para>To combine the advantages of Xv and V4L a special Xv
driver exists in XFree86 and XOrg, just programming any overlay capable
Video4Linux device it finds. To enable it
<filename>/etc/X11/XF86Config</filename> must contain these lines:</para>
<para><screen>
<para><screen>
Section "Module"
Load "v4l"
EndSection</screen></para>
<para>As of XFree86 4.2 this driver still supports only V4L
<para>As of XFree86 4.2 this driver still supports only V4L
ioctls, however it should work just fine with all V4L2 devices through
the V4L2 backward-compatibility layer. Since V4L2 permits multiple
opens it is possible (if supported by the V4L2 driver) to capture
@ -2377,83 +2397,84 @@ video while an X client requested video overlay. Restrictions of
simultaneous capturing and overlay are discussed in <xref
linkend="overlay" /> apply.</para>
<para>Only marginally related to V4L2, XFree86 extended Xv to
<para>Only marginally related to V4L2, XFree86 extended Xv to
support hardware YUV to RGB conversion and scaling for faster video
playback, and added an interface to MPEG-2 decoding hardware. This API
is useful to display images captured with V4L2 devices.</para>
</section>
</section>
<section>
<title>Digital Video</title>
<section>
<title>Digital Video</title>
<para>V4L2 does not support digital terrestrial, cable or
<para>V4L2 does not support digital terrestrial, cable or
satellite broadcast. A separate project aiming at digital receivers
exists. You can find its homepage at <ulink
url="http://linuxtv.org">http://linuxtv.org</ulink>. The Linux DVB API
has no connection to the V4L2 API except that drivers for hybrid
hardware may support both.</para>
</section>
<section>
<title>Audio Interfaces</title>
<para>[to do - OSS/ALSA]</para>
</section>
</section>
<section>
<title>Audio Interfaces</title>
<section id="experimental">
<title>Experimental API Elements</title>
<para>[to do - OSS/ALSA]</para>
</section>
</section>
<section id="experimental">
<title>Experimental API Elements</title>
<para>The following V4L2 API elements are currently experimental
<para>The following V4L2 API elements are currently experimental
and may change in the future.</para>
<itemizedlist>
<listitem>
<para>Video Output Overlay (OSD) Interface, <xref
<itemizedlist>
<listitem>
<para>Video Output Overlay (OSD) Interface, <xref
linkend="osd" />.</para>
</listitem>
</listitem>
<listitem>
<para><constant>V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY</constant>,
<para><constant>V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY</constant>,
&v4l2-buf-type;, <xref linkend="v4l2-buf-type" />.</para>
</listitem>
<listitem>
<para><constant>V4L2_CAP_VIDEO_OUTPUT_OVERLAY</constant>,
</listitem>
<listitem>
<para><constant>V4L2_CAP_VIDEO_OUTPUT_OVERLAY</constant>,
&VIDIOC-QUERYCAP; ioctl, <xref linkend="device-capabilities" />.</para>
</listitem>
<listitem>
<para>&VIDIOC-ENUM-FRAMESIZES; and
</listitem>
<listitem>
<para>&VIDIOC-ENUM-FRAMESIZES; and
&VIDIOC-ENUM-FRAMEINTERVALS; ioctls.</para>
</listitem>
<listitem>
<para>&VIDIOC-G-ENC-INDEX; ioctl.</para>
</listitem>
<listitem>
<para>&VIDIOC-ENCODER-CMD; and &VIDIOC-TRY-ENCODER-CMD;
</listitem>
<listitem>
<para>&VIDIOC-G-ENC-INDEX; ioctl.</para>
</listitem>
<listitem>
<para>&VIDIOC-ENCODER-CMD; and &VIDIOC-TRY-ENCODER-CMD;
ioctls.</para>
</listitem>
<listitem>
<para>&VIDIOC-DBG-G-REGISTER; and &VIDIOC-DBG-S-REGISTER;
</listitem>
<listitem>
<para>&VIDIOC-DBG-G-REGISTER; and &VIDIOC-DBG-S-REGISTER;
ioctls.</para>
</listitem>
<listitem>
<para>&VIDIOC-DBG-G-CHIP-IDENT; ioctl.</para>
</listitem>
</itemizedlist>
</section>
</listitem>
<listitem>
<para>&VIDIOC-DBG-G-CHIP-IDENT; ioctl.</para>
</listitem>
</itemizedlist>
</section>
<section id="obsolete">
<title>Obsolete API Elements</title>
<section id="obsolete">
<title>Obsolete API Elements</title>
<para>The following V4L2 API elements were superseded by new
<para>The following V4L2 API elements were superseded by new
interfaces and should not be implemented in new drivers.</para>
<itemizedlist>
<listitem>
<para><constant>VIDIOC_G_MPEGCOMP</constant> and
<itemizedlist>
<listitem>
<para><constant>VIDIOC_G_MPEGCOMP</constant> and
<constant>VIDIOC_S_MPEGCOMP</constant> ioctls. Use Extended Controls,
<xref linkend="extended-controls" />.</para>
</listitem>
</itemizedlist>
</listitem>
</itemizedlist>
</section>
</section>
<!--

View File

@ -266,6 +266,12 @@ minimum value disables backlight compensation.</entry>
<entry>boolean</entry>
<entry>Chroma automatic gain control.</entry>
</row>
<row>
<entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
<entry>integer</entry>
<entry>Adjusts the Chroma gain control (for use when chroma AGC
is disabled).</entry>
</row>
<row>
<entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
<entry>boolean</entry>
@ -277,8 +283,15 @@ minimum value disables backlight compensation.</entry>
<entry>Selects a color effect. Possible values for
<constant>enum v4l2_colorfx</constant> are:
<constant>V4L2_COLORFX_NONE</constant> (0),
<constant>V4L2_COLORFX_BW</constant> (1) and
<constant>V4L2_COLORFX_SEPIA</constant> (2).</entry>
<constant>V4L2_COLORFX_BW</constant> (1),
<constant>V4L2_COLORFX_SEPIA</constant> (2),
<constant>V4L2_COLORFX_NEGATIVE</constant> (3),
<constant>V4L2_COLORFX_EMBOSS</constant> (4),
<constant>V4L2_COLORFX_SKETCH</constant> (5),
<constant>V4L2_COLORFX_SKY_BLUE</constant> (6),
<constant>V4L2_COLORFX_GRASS_GREEN</constant> (7),
<constant>V4L2_COLORFX_SKIN_WHITEN</constant> (8) and
<constant>V4L2_COLORFX_VIVID</constant> (9).</entry>
</row>
<row>
<entry><constant>V4L2_CID_ROTATE</constant></entry>
@ -298,11 +311,18 @@ minimum value disables backlight compensation.</entry>
bits 8-15 Green color information, bits 16-23 Blue color
information and bits 24-31 must be zero.</entry>
</row>
<row>
<entry><constant>V4L2_CID_ILLUMINATORS_1</constant>
<constant>V4L2_CID_ILLUMINATORS_2</constant></entry>
<entry>boolean</entry>
<entry>Switch on or off the illuminator 1 or 2 of the device
(usually a microscope).</entry>
</row>
<row>
<entry><constant>V4L2_CID_LASTP1</constant></entry>
<entry></entry>
<entry>End of the predefined control IDs (currently
<constant>V4L2_CID_BG_COLOR</constant> + 1).</entry>
<constant>V4L2_CID_ILLUMINATORS_2</constant> + 1).</entry>
</row>
<row>
<entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
@ -344,9 +364,6 @@ enumerate_menu (void)
querymenu.index++) {
if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &amp;querymenu)) {
printf (" %s\n", querymenu.name);
} else {
perror ("VIDIOC_QUERYMENU");
exit (EXIT_FAILURE);
}
}
}
@ -1824,6 +1841,25 @@ wide-angle direction. The zoom speed unit is driver-specific.</entry>
</row>
<row><entry></entry></row>
<row>
<entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant>&nbsp;</entry>
<entry>integer</entry>
</row><row><entry spanname="descr">This control sets the
camera's aperture to the specified value. The unit is undefined.
Larger values open the iris wider, smaller values close it.</entry>
</row>
<row><entry></entry></row>
<row>
<entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant>&nbsp;</entry>
<entry>integer</entry>
</row><row><entry spanname="descr">This control modifies the
camera's aperture by the specified amount. The unit is undefined.
Positive values open the iris one step further, negative values close
it one step further. This is a write-only control.</entry>
</row>
<row><entry></entry></row>
<row>
<entry spanname="id"><constant>V4L2_CID_PRIVACY</constant>&nbsp;</entry>
<entry>boolean</entry>

View File

@ -0,0 +1,31 @@
<title>Event Interface</title>
<para>The V4L2 event interface provides means for user to get
immediately notified on certain conditions taking place on a device.
This might include start of frame or loss of signal events, for
example.
</para>
<para>To receive events, the events the user is interested in first must
be subscribed using the &VIDIOC-SUBSCRIBE-EVENT; ioctl. Once an event is
subscribed, the events of subscribed types are dequeueable using the
&VIDIOC-DQEVENT; ioctl. Events may be unsubscribed using
VIDIOC_UNSUBSCRIBE_EVENT ioctl. The special event type V4L2_EVENT_ALL may
be used to unsubscribe all the events the driver supports.</para>
<para>The event subscriptions and event queues are specific to file
handles. Subscribing an event on one file handle does not affect
other file handles.
</para>
<para>The information on dequeueable events is obtained by using select or
poll system calls on video devices. The V4L2 events use POLLPRI events on
poll system call and exceptions on select system call. </para>
<!--
Local Variables:
mode: sgml
sgml-parent-document: "v4l2.sgml"
indent-tabs-mode: nil
End:
-->

View File

@ -3,15 +3,16 @@
<para>The Radio Data System transmits supplementary
information in binary format, for example the station name or travel
information, on an inaudible audio subcarrier of a radio program. This
interface is aimed at devices capable of receiving and decoding RDS
interface is aimed at devices capable of receiving and/or transmitting RDS
information.</para>
<para>For more information see the core RDS standard <xref linkend="en50067" />
and the RBDS standard <xref linkend="nrsc4" />.</para>
<para>Note that the RBDS standard as is used in the USA is almost identical
to the RDS standard. Any RDS decoder can also handle RBDS. Only some of the fields
have slightly different meanings. See the RBDS standard for more information.</para>
to the RDS standard. Any RDS decoder/encoder can also handle RBDS. Only some of the
fields have slightly different meanings. See the RBDS standard for more
information.</para>
<para>The RBDS standard also specifies support for MMBS (Modified Mobile Search).
This is a proprietary format which seems to be discontinued. The RDS interface does not
@ -21,16 +22,25 @@ be needed, then please contact the linux-media mailing list: &v4l-ml;.</para>
<section>
<title>Querying Capabilities</title>
<para>Devices supporting the RDS capturing API
set the <constant>V4L2_CAP_RDS_CAPTURE</constant> flag in
<para>Devices supporting the RDS capturing API set
the <constant>V4L2_CAP_RDS_CAPTURE</constant> flag in
the <structfield>capabilities</structfield> field of &v4l2-capability;
returned by the &VIDIOC-QUERYCAP; ioctl.
Any tuner that supports RDS will set the
<constant>V4L2_TUNER_CAP_RDS</constant> flag in the <structfield>capability</structfield>
field of &v4l2-tuner;.
Whether an RDS signal is present can be detected by looking at
the <structfield>rxsubchans</structfield> field of &v4l2-tuner;: the
<constant>V4L2_TUNER_SUB_RDS</constant> will be set if RDS data was detected.</para>
returned by the &VIDIOC-QUERYCAP; ioctl. Any tuner that supports RDS
will set the <constant>V4L2_TUNER_CAP_RDS</constant> flag in
the <structfield>capability</structfield> field of &v4l2-tuner;. If
the driver only passes RDS blocks without interpreting the data
the <constant>V4L2_TUNER_SUB_RDS_BLOCK_IO</constant> flag has to be
set, see <link linkend="reading-rds-data">Reading RDS data</link>.
For future use the
flag <constant>V4L2_TUNER_SUB_RDS_CONTROLS</constant> has also been
defined. However, a driver for a radio tuner with this capability does
not yet exist, so if you are planning to write such a driver you
should discuss this on the linux-media mailing list: &v4l-ml;.</para>
<para> Whether an RDS signal is present can be detected by looking
at the <structfield>rxsubchans</structfield> field of &v4l2-tuner;:
the <constant>V4L2_TUNER_SUB_RDS</constant> will be set if RDS data
was detected.</para>
<para>Devices supporting the RDS output API
set the <constant>V4L2_CAP_RDS_OUTPUT</constant> flag in
@ -40,16 +50,31 @@ Any modulator that supports RDS will set the
<constant>V4L2_TUNER_CAP_RDS</constant> flag in the <structfield>capability</structfield>
field of &v4l2-modulator;.
In order to enable the RDS transmission one must set the <constant>V4L2_TUNER_SUB_RDS</constant>
bit in the <structfield>txsubchans</structfield> field of &v4l2-modulator;.</para>
bit in the <structfield>txsubchans</structfield> field of &v4l2-modulator;.
If the driver only passes RDS blocks without interpreting the data
the <constant>V4L2_TUNER_SUB_RDS_BLOCK_IO</constant> flag has to be set. If the
tuner is capable of handling RDS entities like program identification codes and radio
text, the flag <constant>V4L2_TUNER_SUB_RDS_CONTROLS</constant> should be set,
see <link linkend="writing-rds-data">Writing RDS data</link> and
<link linkend="fm-tx-controls">FM Transmitter Control Reference</link>.</para>
</section>
<section>
<section id="reading-rds-data">
<title>Reading RDS data</title>
<para>RDS data can be read from the radio device
with the &func-read; function. The data is packed in groups of three bytes,
with the &func-read; function. The data is packed in groups of three bytes.</para>
</section>
<section id="writing-rds-data">
<title>Writing RDS data</title>
<para>RDS data can be written to the radio device
with the &func-write; function. The data is packed in groups of three bytes,
as follows:</para>
</section>
<section>
<table frame="none" pgwide="1" id="v4l2-rds-data">
<title>struct
<structname>v4l2_rds_data</structname></title>
@ -111,48 +136,57 @@ as follows:</para>
<tbody valign="top">
<row>
<entry>V4L2_RDS_BLOCK_MSK</entry>
<entry> </entry>
<entry>7</entry>
<entry>Mask for bits 0-2 to get the block ID.</entry>
</row>
<row>
<entry>V4L2_RDS_BLOCK_A</entry>
<entry> </entry>
<entry>0</entry>
<entry>Block A.</entry>
</row>
<row>
<entry>V4L2_RDS_BLOCK_B</entry>
<entry> </entry>
<entry>1</entry>
<entry>Block B.</entry>
</row>
<row>
<entry>V4L2_RDS_BLOCK_C</entry>
<entry> </entry>
<entry>2</entry>
<entry>Block C.</entry>
</row>
<row>
<entry>V4L2_RDS_BLOCK_D</entry>
<entry> </entry>
<entry>3</entry>
<entry>Block D.</entry>
</row>
<row>
<entry>V4L2_RDS_BLOCK_C_ALT</entry>
<entry> </entry>
<entry>4</entry>
<entry>Block C'.</entry>
</row>
<row>
<entry>V4L2_RDS_BLOCK_INVALID</entry>
<entry>read-only</entry>
<entry>7</entry>
<entry>An invalid block.</entry>
</row>
<row>
<entry>V4L2_RDS_BLOCK_CORRECTED</entry>
<entry>read-only</entry>
<entry>0x40</entry>
<entry>A bit error was detected but corrected.</entry>
</row>
<row>
<entry>V4L2_RDS_BLOCK_ERROR</entry>
<entry>read-only</entry>
<entry>0x80</entry>
<entry>An incorrectable error occurred.</entry>
<entry>An uncorrectable error occurred.</entry>
</row>
</tbody>
</tgroup>

View File

@ -1,35 +1,32 @@
<title>Teletext Interface</title>
<para>This interface aims at devices receiving and demodulating
<para>This interface was aimed at devices receiving and demodulating
Teletext data [<xref linkend="ets300706" />, <xref linkend="itu653" />], evaluating the
Teletext packages and storing formatted pages in cache memory. Such
devices are usually implemented as microcontrollers with serial
interface (I<superscript>2</superscript>C) and can be found on older
interface (I<superscript>2</superscript>C) and could be found on old
TV cards, dedicated Teletext decoding cards and home-brew devices
connected to the PC parallel port.</para>
<para>The Teletext API was designed by Martin Buck. It is defined in
<para>The Teletext API was designed by Martin Buck. It was defined in
the kernel header file <filename>linux/videotext.h</filename>, the
specification is available from <ulink url="ftp://ftp.gwdg.de/pub/linux/misc/videotext/">
ftp://ftp.gwdg.de/pub/linux/misc/videotext/</ulink>. (Videotext is the name of
the German public television Teletext service.) Conventional character
device file names are <filename>/dev/vtx</filename> and
<filename>/dev/vttuner</filename>, with device number 83, 0 and 83, 16
respectively. A similar interface exists for the Philips SAA5249
Teletext decoder [specification?] with character device file names
<filename>/dev/tlkN</filename>, device number 102, N.</para>
the German public television Teletext service.)</para>
<para>Eventually the Teletext API was integrated into the V4L API
with character device file names <filename>/dev/vtx0</filename> to
<filename>/dev/vtx31</filename>, device major number 81, minor numbers
192 to 223. For reference the V4L Teletext API specification is
reproduced here in full: "Teletext interfaces talk the existing VTX
API." Teletext devices with major number 83 and 102 will be removed in
Linux 2.6.</para>
192 to 223.</para>
<para>There are no plans to replace the Teletext API or to integrate
it into V4L2. Please write to the linux-media mailing list: &v4l-ml;
when the need arises.</para>
<para>However, teletext decoders were quickly replaced by more
generic VBI demodulators and those dedicated teletext decoders no longer exist.
For many years the vtx devices were still around, even though nobody used
them. So the decision was made to finally remove support for the Teletext API in
kernel 2.6.37.</para>
<para>Modern devices all use the <link linkend="raw-vbi">raw</link> or
<link linkend="sliced">sliced</link> VBI API.</para>
<!--
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@ -2,7 +2,7 @@
The GNU Free Documentation License 1.1 in DocBook
Markup by Eric Baudais <baudais@okstate.edu>
Maintained by the GNOME Documentation Project
http://developer.gnome.org/projects/gdp
http://live.gnome.org/DocumentationProject
Version: 1.0.1
Last Modified: Nov 16, 2000
-->

View File

@ -34,8 +34,7 @@
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>V4L2 ioctl request code as defined in the <link
linkend="videodev">videodev.h</link> header file, for example
<para>V4L2 ioctl request code as defined in the <filename>videodev2.h</filename> header file, for example
VIDIOC_QUERYCAP.</para>
</listitem>
</varlistentry>
@ -57,7 +56,7 @@ file descriptor. An ioctl <parameter>request</parameter> has encoded
in it whether the argument is an input, output or read/write
parameter, and the size of the argument <parameter>argp</parameter> in
bytes. Macros and defines specifying V4L2 ioctl requests are located
in the <link linkend="videodev">videodev.h</link> header file.
in the <filename>videodev2.h</filename> header file.
Applications should use their own copy, not include the version in the
kernel sources on the system they compile on. All V4L2 ioctl requests,
their respective function and parameters are specified in <xref

View File

@ -589,7 +589,8 @@ number of a video input as in &v4l2-input; field
<entry></entry>
<entry>A place holder for future extensions and custom
(driver defined) buffer types
<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher.</entry>
<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher. Applications
should set this to 0.</entry>
</row>
</tbody>
</tgroup>
@ -700,6 +701,16 @@ buffer cannot be on both queues at the same time, the
They can be both cleared however, then the buffer is in "dequeued"
state, in the application domain to say so.</entry>
</row>
<row>
<entry><constant>V4L2_BUF_FLAG_ERROR</constant></entry>
<entry>0x0040</entry>
<entry>When this flag is set, the buffer has been dequeued
successfully, although the data might have been corrupted.
This is recoverable, streaming may continue as normal and
the buffer may be reused normally.
Drivers set this flag when the <constant>VIDIOC_DQBUF</constant>
ioctl is called.</entry>
</row>
<row>
<entry><constant>V4L2_BUF_FLAG_KEYFRAME</constant></entry>
<entry>0x0008</entry>
@ -917,8 +928,8 @@ order</emphasis>.</para>
<para>When the driver provides or accepts images field by field
rather than interleaved, it is also important applications understand
how the fields combine to frames. We distinguish between top and
bottom fields, the <emphasis>spatial order</emphasis>: The first line
how the fields combine to frames. We distinguish between top (aka odd) and
bottom (aka even) fields, the <emphasis>spatial order</emphasis>: The first line
of the top field is the first line of an interlaced frame, the first
line of the bottom field is the second line of that frame.</para>
@ -971,12 +982,12 @@ between <constant>V4L2_FIELD_TOP</constant> and
<row>
<entry><constant>V4L2_FIELD_TOP</constant></entry>
<entry>2</entry>
<entry>Images consist of the top field only.</entry>
<entry>Images consist of the top (aka odd) field only.</entry>
</row>
<row>
<entry><constant>V4L2_FIELD_BOTTOM</constant></entry>
<entry>3</entry>
<entry>Images consist of the bottom field only.
<entry>Images consist of the bottom (aka even) field only.
Applications may wish to prevent a device from capturing interlaced
images because they will have "comb" or "feathering" artefacts around
moving objects.</entry>

View File

@ -0,0 +1,251 @@
<section id="lirc_dev">
<title>LIRC Device Interface</title>
<section id="lirc_dev_intro">
<title>Introduction</title>
<para>The LIRC device interface is a bi-directional interface for
transporting raw IR data between userspace and kernelspace. Fundamentally,
it is just a chardev (/dev/lircX, for X = 0, 1, 2, ...), with a number
of standard struct file_operations defined on it. With respect to
transporting raw IR data to and fro, the essential fops are read, write
and ioctl.</para>
<para>Example dmesg output upon a driver registering w/LIRC:</para>
<blockquote>
<para>$ dmesg |grep lirc_dev</para>
<para>lirc_dev: IR Remote Control driver registered, major 248</para>
<para>rc rc0: lirc_dev: driver ir-lirc-codec (mceusb) registered at minor = 0</para>
</blockquote>
<para>What you should see for a chardev:</para>
<blockquote>
<para>$ ls -l /dev/lirc*</para>
<para>crw-rw---- 1 root root 248, 0 Jul 2 22:20 /dev/lirc0</para>
</blockquote>
</section>
<section id="lirc_read">
<title>LIRC read fop</title>
<para>The lircd userspace daemon reads raw IR data from the LIRC chardev. The
exact format of the data depends on what modes a driver supports, and what
mode has been selected. lircd obtains supported modes and sets the active mode
via the ioctl interface, detailed at <xref linkend="lirc_ioctl"/>. The generally
preferred mode is LIRC_MODE_MODE2, in which packets containing an int value
describing an IR signal are read from the chardev.</para>
<para>See also <ulink url="http://www.lirc.org/html/technical.html">http://www.lirc.org/html/technical.html</ulink> for more info.</para>
</section>
<section id="lirc_write">
<title>LIRC write fop</title>
<para>The data written to the chardev is a pulse/space sequence of integer
values. Pulses and spaces are only marked implicitly by their position. The
data must start and end with a pulse, therefore, the data must always include
an unevent number of samples. The write function must block until the data has
been transmitted by the hardware.</para>
</section>
<section id="lirc_ioctl">
<title>LIRC ioctl fop</title>
<para>The LIRC device's ioctl definition is bound by the ioctl function
definition of struct file_operations, leaving us with an unsigned int
for the ioctl command and an unsigned long for the arg. For the purposes
of ioctl portability across 32-bit and 64-bit, these values are capped
to their 32-bit sizes.</para>
<para>The following ioctls can be used to change specific hardware settings.
In general each driver should have a default set of settings. The driver
implementation is expected to re-apply the default settings when the device
is closed by user-space, so that every application opening the device can rely
on working with the default settings initially.</para>
<variablelist>
<varlistentry>
<term>LIRC_GET_FEATURES</term>
<listitem>
<para>Obviously, get the underlying hardware device's features. If a driver
does not announce support of certain features, calling of the corresponding
ioctls is undefined.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_GET_SEND_MODE</term>
<listitem>
<para>Get supported transmit mode. Only LIRC_MODE_PULSE is supported by lircd.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_GET_REC_MODE</term>
<listitem>
<para>Get supported receive modes. Only LIRC_MODE_MODE2 and LIRC_MODE_LIRCCODE
are supported by lircd.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_GET_SEND_CARRIER</term>
<listitem>
<para>Get carrier frequency (in Hz) currently used for transmit.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_GET_REC_CARRIER</term>
<listitem>
<para>Get carrier frequency (in Hz) currently used for IR reception.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_{G,S}ET_{SEND,REC}_DUTY_CYCLE</term>
<listitem>
<para>Get/set the duty cycle (from 0 to 100) of the carrier signal. Currently,
no special meaning is defined for 0 or 100, but this could be used to switch
off carrier generation in the future, so these values should be reserved.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_GET_REC_RESOLUTION</term>
<listitem>
<para>Some receiver have maximum resolution which is defined by internal
sample rate or data format limitations. E.g. it's common that signals can
only be reported in 50 microsecond steps. This integer value is used by
lircd to automatically adjust the aeps tolerance value in the lircd
config file.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_GET_M{IN,AX}_TIMEOUT</term>
<listitem>
<para>Some devices have internal timers that can be used to detect when
there's no IR activity for a long time. This can help lircd in detecting
that a IR signal is finished and can speed up the decoding process.
Returns an integer value with the minimum/maximum timeout that can be
set. Some devices have a fixed timeout, in that case both ioctls will
return the same value even though the timeout cannot be changed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_GET_M{IN,AX}_FILTER_{PULSE,SPACE}</term>
<listitem>
<para>Some devices are able to filter out spikes in the incoming signal
using given filter rules. These ioctls return the hardware capabilities
that describe the bounds of the possible filters. Filter settings depend
on the IR protocols that are expected. lircd derives the settings from
all protocols definitions found in its config file.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_GET_LENGTH</term>
<listitem>
<para>Retrieves the code length in bits (only for LIRC_MODE_LIRCCODE).
Reads on the device must be done in blocks matching the bit count.
The bit could should be rounded up so that it matches full bytes.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_{SEND,REC}_MODE</term>
<listitem>
<para>Set send/receive mode. Largely obsolete for send, as only
LIRC_MODE_PULSE is supported.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_{SEND,REC}_CARRIER</term>
<listitem>
<para>Set send/receive carrier (in Hz).</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_TRANSMITTER_MASK</term>
<listitem>
<para>This enables the given set of transmitters. The first transmitter
is encoded by the least significant bit, etc. When an invalid bit mask
is given, i.e. a bit is set, even though the device does not have so many
transitters, then this ioctl returns the number of available transitters
and does nothing otherwise.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_REC_TIMEOUT</term>
<listitem>
<para>Sets the integer value for IR inactivity timeout (cf.
LIRC_GET_MIN_TIMEOUT and LIRC_GET_MAX_TIMEOUT). A value of 0 (if
supported by the hardware) disables all hardware timeouts and data should
be reported as soon as possible. If the exact value cannot be set, then
the next possible value _greater_ than the given value should be set.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_REC_TIMEOUT_REPORTS</term>
<listitem>
<para>Enable (1) or disable (0) timeout reports in LIRC_MODE_MODE2. By
default, timeout reports should be turned off.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_REC_FILTER_{,PULSE,SPACE}</term>
<listitem>
<para>Pulses/spaces shorter than this are filtered out by hardware. If
filters cannot be set independently for pulse/space, the corresponding
ioctls must return an error and LIRC_SET_REC_FILTER shall be used instead.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_MEASURE_CARRIER_MODE</term>
<listitem>
<para>Enable (1)/disable (0) measure mode. If enabled, from the next key
press on, the driver will send LIRC_MODE2_FREQUENCY packets. By default
this should be turned off.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_REC_{DUTY_CYCLE,CARRIER}_RANGE</term>
<listitem>
<para>To set a range use LIRC_SET_REC_DUTY_CYCLE_RANGE/LIRC_SET_REC_CARRIER_RANGE
with the lower bound first and later LIRC_SET_REC_DUTY_CYCLE/LIRC_SET_REC_CARRIER
with the upper bound.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_NOTIFY_DECODE</term>
<listitem>
<para>This ioctl is called by lircd whenever a successful decoding of an
incoming IR signal could be done. This can be used by supporting hardware
to give visual feedback to the user e.g. by flashing a LED.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SETUP_{START,END}</term>
<listitem>
<para>Setting of several driver parameters can be optimized by encapsulating
the according ioctl calls with LIRC_SETUP_START/LIRC_SETUP_END. When a
driver receives a LIRC_SETUP_START ioctl it can choose to not commit
further setting changes to the hardware until a LIRC_SETUP_END is received.
But this is open to the driver implementation and every driver must also
handle parameter changes which are not encapsulated by LIRC_SETUP_START
and LIRC_SETUP_END. Drivers can also choose to ignore these ioctls.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>LIRC_SET_WIDEBAND_RECEIVER</term>
<listitem>
<para>Some receivers are equipped with special wide band receiver which is intended
to be used to learn output of existing remote.
Calling that ioctl with (1) will enable it, and with (0) disable it.
This might be useful of receivers that have otherwise narrow band receiver
that prevents them to be used with some remotes.
Wide band receiver might also be more precise
On the other hand its disadvantage it usually reduced range of reception.
Note: wide band receiver might be implictly enabled if you enable
carrier reports. In that case it will be disabled as soon as you disable
carrier reports. Trying to disable wide band receiver while carrier
reports are active will do nothing.</para>
</listitem>
</varlistentry>
</variablelist>
</section>
</section>

View File

@ -240,6 +240,45 @@ colorspace <constant>V4L2_COLORSPACE_SRGB</constant>.</para>
<entry>r<subscript>1</subscript></entry>
<entry>r<subscript>0</subscript></entry>
</row>
<row id="V4L2-PIX-FMT-BGR666">
<entry><constant>V4L2_PIX_FMT_BGR666</constant></entry>
<entry>'BGRH'</entry>
<entry></entry>
<entry>b<subscript>5</subscript></entry>
<entry>b<subscript>4</subscript></entry>
<entry>b<subscript>3</subscript></entry>
<entry>b<subscript>2</subscript></entry>
<entry>b<subscript>1</subscript></entry>
<entry>b<subscript>0</subscript></entry>
<entry>g<subscript>5</subscript></entry>
<entry>g<subscript>4</subscript></entry>
<entry></entry>
<entry>g<subscript>3</subscript></entry>
<entry>g<subscript>2</subscript></entry>
<entry>g<subscript>1</subscript></entry>
<entry>g<subscript>0</subscript></entry>
<entry>r<subscript>5</subscript></entry>
<entry>r<subscript>4</subscript></entry>
<entry>r<subscript>3</subscript></entry>
<entry>r<subscript>2</subscript></entry>
<entry></entry>
<entry>r<subscript>1</subscript></entry>
<entry>r<subscript>0</subscript></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
</row>
<row id="V4L2-PIX-FMT-BGR24">
<entry><constant>V4L2_PIX_FMT_BGR24</constant></entry>
<entry>'BGR3'</entry>
@ -700,6 +739,45 @@ defined in error. Drivers may interpret them as in <xref
<entry>b<subscript>1</subscript></entry>
<entry>b<subscript>0</subscript></entry>
</row>
<row><!-- id="V4L2-PIX-FMT-BGR666" -->
<entry><constant>V4L2_PIX_FMT_BGR666</constant></entry>
<entry>'BGRH'</entry>
<entry></entry>
<entry>b<subscript>5</subscript></entry>
<entry>b<subscript>4</subscript></entry>
<entry>b<subscript>3</subscript></entry>
<entry>b<subscript>2</subscript></entry>
<entry>b<subscript>1</subscript></entry>
<entry>b<subscript>0</subscript></entry>
<entry>g<subscript>5</subscript></entry>
<entry>g<subscript>4</subscript></entry>
<entry></entry>
<entry>g<subscript>3</subscript></entry>
<entry>g<subscript>2</subscript></entry>
<entry>g<subscript>1</subscript></entry>
<entry>g<subscript>0</subscript></entry>
<entry>r<subscript>5</subscript></entry>
<entry>r<subscript>4</subscript></entry>
<entry>r<subscript>3</subscript></entry>
<entry>r<subscript>2</subscript></entry>
<entry></entry>
<entry>r<subscript>1</subscript></entry>
<entry>r<subscript>0</subscript></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
<entry></entry>
</row>
<row><!-- id="V4L2-PIX-FMT-BGR24" -->
<entry><constant>V4L2_PIX_FMT_BGR24</constant></entry>
<entry>'BGR3'</entry>

View File

@ -0,0 +1,90 @@
<refentry>
<refmeta>
<refentrytitle>V4L2_PIX_FMT_SRGGB10 ('RG10'),
V4L2_PIX_FMT_SGRBG10 ('BA10'),
V4L2_PIX_FMT_SGBRG10 ('GB10'),
V4L2_PIX_FMT_SBGGR10 ('BG10'),
</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname id="V4L2-PIX-FMT-SRGGB10"><constant>V4L2_PIX_FMT_SRGGB10</constant></refname>
<refname id="V4L2-PIX-FMT-SGRBG10"><constant>V4L2_PIX_FMT_SGRBG10</constant></refname>
<refname id="V4L2-PIX-FMT-SGBRG10"><constant>V4L2_PIX_FMT_SGBRG10</constant></refname>
<refname id="V4L2-PIX-FMT-SBGGR10"><constant>V4L2_PIX_FMT_SBGGR10</constant></refname>
<refpurpose>10-bit Bayer formats expanded to 16 bits</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<para>The following four pixel formats are raw sRGB / Bayer formats with
10 bits per colour. Each colour component is stored in a 16-bit word, with 6
unused high bits filled with zeros. Each n-pixel row contains n/2 green samples
and n/2 blue or red samples, with alternating red and blue rows. Bytes are
stored in memory in little endian order. They are conventionally described
as GRGR... BGBG..., RGRG... GBGB..., etc. Below is an example of one of these
formats</para>
<example>
<title><constant>V4L2_PIX_FMT_SBGGR10</constant> 4 &times; 4
pixel image</title>
<formalpara>
<title>Byte Order.</title>
<para>Each cell is one byte, high 6 bits in high bytes are 0.
<informaltable frame="none">
<tgroup cols="5" align="center">
<colspec align="left" colwidth="2*" />
<tbody valign="top">
<row>
<entry>start&nbsp;+&nbsp;0:</entry>
<entry>B<subscript>00low</subscript></entry>
<entry>B<subscript>00high</subscript></entry>
<entry>G<subscript>01low</subscript></entry>
<entry>G<subscript>01high</subscript></entry>
<entry>B<subscript>02low</subscript></entry>
<entry>B<subscript>02high</subscript></entry>
<entry>G<subscript>03low</subscript></entry>
<entry>G<subscript>03high</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;8:</entry>
<entry>G<subscript>10low</subscript></entry>
<entry>G<subscript>10high</subscript></entry>
<entry>R<subscript>11low</subscript></entry>
<entry>R<subscript>11high</subscript></entry>
<entry>G<subscript>12low</subscript></entry>
<entry>G<subscript>12high</subscript></entry>
<entry>R<subscript>13low</subscript></entry>
<entry>R<subscript>13high</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;16:</entry>
<entry>B<subscript>20low</subscript></entry>
<entry>B<subscript>20high</subscript></entry>
<entry>G<subscript>21low</subscript></entry>
<entry>G<subscript>21high</subscript></entry>
<entry>B<subscript>22low</subscript></entry>
<entry>B<subscript>22high</subscript></entry>
<entry>G<subscript>23low</subscript></entry>
<entry>G<subscript>23high</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;24:</entry>
<entry>G<subscript>30low</subscript></entry>
<entry>G<subscript>30high</subscript></entry>
<entry>R<subscript>31low</subscript></entry>
<entry>R<subscript>31high</subscript></entry>
<entry>G<subscript>32low</subscript></entry>
<entry>G<subscript>32high</subscript></entry>
<entry>R<subscript>33low</subscript></entry>
<entry>R<subscript>33high</subscript></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</formalpara>
</example>
</refsect1>
</refentry>

View File

@ -0,0 +1,67 @@
<refentry id="V4L2-PIX-FMT-SRGGB8">
<refmeta>
<refentrytitle>V4L2_PIX_FMT_SRGGB8 ('RGGB')</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname><constant>V4L2_PIX_FMT_SRGGB8</constant></refname>
<refpurpose>Bayer RGB format</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<para>This is commonly the native format of digital cameras,
reflecting the arrangement of sensors on the CCD device. Only one red,
green or blue value is given for each pixel. Missing components must
be interpolated from neighbouring pixels. From left to right the first
row consists of a red and green value, the second row of a green and
blue value. This scheme repeats to the right and down for every two
columns and rows.</para>
<example>
<title><constant>V4L2_PIX_FMT_SRGGB8</constant> 4 &times; 4
pixel image</title>
<formalpara>
<title>Byte Order.</title>
<para>Each cell is one byte.
<informaltable frame="none">
<tgroup cols="5" align="center">
<colspec align="left" colwidth="2*" />
<tbody valign="top">
<row>
<entry>start&nbsp;+&nbsp;0:</entry>
<entry>R<subscript>00</subscript></entry>
<entry>G<subscript>01</subscript></entry>
<entry>R<subscript>02</subscript></entry>
<entry>G<subscript>03</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;4:</entry>
<entry>G<subscript>10</subscript></entry>
<entry>B<subscript>11</subscript></entry>
<entry>G<subscript>12</subscript></entry>
<entry>B<subscript>13</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;8:</entry>
<entry>R<subscript>20</subscript></entry>
<entry>G<subscript>21</subscript></entry>
<entry>R<subscript>22</subscript></entry>
<entry>G<subscript>23</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;12:</entry>
<entry>G<subscript>30</subscript></entry>
<entry>B<subscript>31</subscript></entry>
<entry>G<subscript>32</subscript></entry>
<entry>B<subscript>33</subscript></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</formalpara>
</example>
</refsect1>
</refentry>

View File

@ -0,0 +1,79 @@
<refentry id="V4L2-PIX-FMT-Y10">
<refmeta>
<refentrytitle>V4L2_PIX_FMT_Y10 ('Y10 ')</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname><constant>V4L2_PIX_FMT_Y10</constant></refname>
<refpurpose>Grey-scale image</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<para>This is a grey-scale image with a depth of 10 bits per pixel. Pixels
are stored in 16-bit words with unused high bits padded with 0. The least
significant byte is stored at lower memory addresses (little-endian).</para>
<example>
<title><constant>V4L2_PIX_FMT_Y10</constant> 4 &times; 4
pixel image</title>
<formalpara>
<title>Byte Order.</title>
<para>Each cell is one byte.
<informaltable frame="none">
<tgroup cols="9" align="center">
<colspec align="left" colwidth="2*" />
<tbody valign="top">
<row>
<entry>start&nbsp;+&nbsp;0:</entry>
<entry>Y'<subscript>00low</subscript></entry>
<entry>Y'<subscript>00high</subscript></entry>
<entry>Y'<subscript>01low</subscript></entry>
<entry>Y'<subscript>01high</subscript></entry>
<entry>Y'<subscript>02low</subscript></entry>
<entry>Y'<subscript>02high</subscript></entry>
<entry>Y'<subscript>03low</subscript></entry>
<entry>Y'<subscript>03high</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;8:</entry>
<entry>Y'<subscript>10low</subscript></entry>
<entry>Y'<subscript>10high</subscript></entry>
<entry>Y'<subscript>11low</subscript></entry>
<entry>Y'<subscript>11high</subscript></entry>
<entry>Y'<subscript>12low</subscript></entry>
<entry>Y'<subscript>12high</subscript></entry>
<entry>Y'<subscript>13low</subscript></entry>
<entry>Y'<subscript>13high</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;16:</entry>
<entry>Y'<subscript>20low</subscript></entry>
<entry>Y'<subscript>20high</subscript></entry>
<entry>Y'<subscript>21low</subscript></entry>
<entry>Y'<subscript>21high</subscript></entry>
<entry>Y'<subscript>22low</subscript></entry>
<entry>Y'<subscript>22high</subscript></entry>
<entry>Y'<subscript>23low</subscript></entry>
<entry>Y'<subscript>23high</subscript></entry>
</row>
<row>
<entry>start&nbsp;+&nbsp;24:</entry>
<entry>Y'<subscript>30low</subscript></entry>
<entry>Y'<subscript>30high</subscript></entry>
<entry>Y'<subscript>31low</subscript></entry>
<entry>Y'<subscript>31high</subscript></entry>
<entry>Y'<subscript>32low</subscript></entry>
<entry>Y'<subscript>32high</subscript></entry>
<entry>Y'<subscript>33low</subscript></entry>
<entry>Y'<subscript>33high</subscript></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</formalpara>
</example>
</refsect1>
</refentry>

View File

@ -142,8 +142,8 @@ leftmost pixel of the second row from the top, and so on. The last row
has just as many pad bytes after it as the other rows.</para>
<para>In V4L2 each format has an identifier which looks like
<constant>PIX_FMT_XXX</constant>, defined in the <link
linkend="videodev">videodev.h</link> header file. These identifiers
<constant>PIX_FMT_XXX</constant>, defined in the <filename>videodev2.h</filename>
header file. These identifiers
represent <link linkend="v4l2-fourcc">four character codes</link>
which are also listed below, however they are not the same as those
used in the Windows world.</para>
@ -566,7 +566,9 @@ access the palette, this must be done with ioctls of the Linux framebuffer API.<
&sub-sbggr8;
&sub-sgbrg8;
&sub-sgrbg8;
&sub-srggb8;
&sub-sbggr16;
&sub-srggb10;
</section>
<section id="yuv-formats">
@ -589,6 +591,7 @@ information.</para>
&sub-packed-yuv;
&sub-grey;
&sub-y10;
&sub-y16;
&sub-yuyv;
&sub-uyvy;
@ -685,6 +688,11 @@ http://www.ivtvdriver.org/</ulink></para><para>The format is documented in the
kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.hm12</filename>
</para></entry>
</row>
<row id="V4L2-PIX-FMT-CPIA1">
<entry><constant>V4L2_PIX_FMT_CPIA1</constant></entry>
<entry>'CPIA'</entry>
<entry>YUV format used by the gspca cpia1 driver.</entry>
</row>
<row id="V4L2-PIX-FMT-SPCA501">
<entry><constant>V4L2_PIX_FMT_SPCA501</constant></entry>
<entry>'S501'</entry>
@ -705,11 +713,6 @@ kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.hm
<entry>'S561'</entry>
<entry>Compressed GBRG Bayer format used by the gspca driver.</entry>
</row>
<row id="V4L2-PIX-FMT-SGRBG10">
<entry><constant>V4L2_PIX_FMT_SGRBG10</constant></entry>
<entry>'DA10'</entry>
<entry>10 bit raw Bayer, expanded to 16 bits.</entry>
</row>
<row id="V4L2-PIX-FMT-SGRBG10DPCM8">
<entry><constant>V4L2_PIX_FMT_SGRBG10DPCM8</constant></entry>
<entry>'DB10'</entry>
@ -770,6 +773,11 @@ kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.hm
<entry>'S920'</entry>
<entry>YUV 4:2:0 format of the gspca sn9c20x driver.</entry>
</row>
<row id="V4L2-PIX-FMT-SN9C2028">
<entry><constant>V4L2_PIX_FMT_SN9C2028</constant></entry>
<entry>'SONX'</entry>
<entry>Compressed GBRG bayer format of the gspca sn9c2028 driver.</entry>
</row>
<row id="V4L2-PIX-FMT-STV0680">
<entry><constant>V4L2_PIX_FMT_STV0680</constant></entry>
<entry>'S680'</entry>
@ -787,11 +795,37 @@ http://www.thedirks.org/winnov/</ulink></para></entry>
<entry>'TM60'</entry>
<entry><para>Used by Trident tm6000</para></entry>
</row>
<row id="V4L2-PIX-FMT-CIT-YYVYUY">
<entry><constant>V4L2_PIX_FMT_CIT_YYVYUY</constant></entry>
<entry>'CITV'</entry>
<entry><para>Used by xirlink CIT, found at IBM webcams.</para>
<para>Uses one line of Y then 1 line of VYUY</para>
</entry>
</row>
<row id="V4L2-PIX-FMT-KONICA420">
<entry><constant>V4L2_PIX_FMT_KONICA420</constant></entry>
<entry>'KONI'</entry>
<entry><para>Used by Konica webcams.</para>
<para>YUV420 planar in blocks of 256 pixels.</para>
</entry>
</row>
<row id="V4L2-PIX-FMT-YYUV">
<entry><constant>V4L2_PIX_FMT_YYUV</constant></entry>
<entry>'YYUV'</entry>
<entry>unknown</entry>
</row>
<row id="V4L2-PIX-FMT-Y4">
<entry><constant>V4L2_PIX_FMT_Y4</constant></entry>
<entry>'Y04 '</entry>
<entry>Old 4-bit greyscale format. Only the least significant 4 bits of each byte are used,
the other bits are set to 0.</entry>
</row>
<row id="V4L2-PIX-FMT-Y6">
<entry><constant>V4L2_PIX_FMT_Y6</constant></entry>
<entry>'Y06 '</entry>
<entry>Old 6-bit greyscale format. Only the least significant 6 bits of each byte are used,
the other bits are set to 0.</entry>
</row>
</tbody>
</tgroup>
</table>

View File

@ -173,3 +173,5 @@ keymapping.</para>
<para>This program demonstrates how to replace the keymap tables.</para>
&sub-keytable-c;
</section>
&sub-lirc_device_interface;

View File

@ -58,7 +58,7 @@ MPEG stream embedded, sliced VBI data format in this specification.
</contrib>
<affiliation>
<address>
<email>awalls@radix.net</email>
<email>awalls@md.metrocast.net</email>
</address>
</affiliation>
</author>
@ -99,6 +99,7 @@ Remote Controller chapter.</contrib>
<year>2007</year>
<year>2008</year>
<year>2009</year>
<year>2010</year>
<holder>Bill Dirks, Michael H. Schimek, Hans Verkuil, Martin
Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab</holder>
</copyright>
@ -110,9 +111,16 @@ Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab</holder>
<!-- Put document revisions here, newest first. -->
<!-- API revisions (changes and additions of defines, enums,
structs, ioctls) must be noted in more detail in the history chapter
(compat.sgml), along with the possible impact on existing drivers and
(compat.xml), along with the possible impact on existing drivers and
applications. -->
<revision>
<revnumber>2.6.37</revnumber>
<date>2010-08-06</date>
<authorinitials>hv</authorinitials>
<revremark>Removed obsolete vtx (videotext) API.</revremark>
</revision>
<revision>
<revnumber>2.6.33</revnumber>
<date>2009-12-03</date>
@ -401,6 +409,7 @@ and discussions on the V4L mailing list.</revremark>
<section id="ttx"> &sub-dev-teletext; </section>
<section id="radio"> &sub-dev-radio; </section>
<section id="rds"> &sub-dev-rds; </section>
<section id="event"> &sub-dev-event; </section>
</chapter>
<chapter id="driver">
@ -426,6 +435,7 @@ and discussions on the V4L mailing list.</revremark>
&sub-cropcap;
&sub-dbg-g-chip-ident;
&sub-dbg-g-register;
&sub-dqevent;
&sub-encoder-cmd;
&sub-enumaudio;
&sub-enumaudioout;
@ -467,6 +477,7 @@ and discussions on the V4L mailing list.</revremark>
&sub-reqbufs;
&sub-s-hw-freq-seek;
&sub-streamon;
&sub-subscribe-event;
<!-- End of ioctls. -->
&sub-mmap;
&sub-munmap;

View File

@ -154,23 +154,13 @@ enum <link linkend="v4l2-buf-type">v4l2_buf_type</link> {
V4L2_BUF_TYPE_VBI_OUTPUT = 5,
V4L2_BUF_TYPE_SLICED_VBI_CAPTURE = 6,
V4L2_BUF_TYPE_SLICED_VBI_OUTPUT = 7,
#if 1 /*KEEP*/
#if 1
/* Experimental */
V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY = 8,
#endif
V4L2_BUF_TYPE_PRIVATE = 0x80,
};
enum <link linkend="v4l2-ctrl-type">v4l2_ctrl_type</link> {
V4L2_CTRL_TYPE_INTEGER = 1,
V4L2_CTRL_TYPE_BOOLEAN = 2,
V4L2_CTRL_TYPE_MENU = 3,
V4L2_CTRL_TYPE_BUTTON = 4,
V4L2_CTRL_TYPE_INTEGER64 = 5,
V4L2_CTRL_TYPE_CTRL_CLASS = 6,
V4L2_CTRL_TYPE_STRING = 7,
};
enum <link linkend="v4l2-tuner-type">v4l2_tuner_type</link> {
V4L2_TUNER_RADIO = 1,
V4L2_TUNER_ANALOG_TV = 2,
@ -288,6 +278,7 @@ struct <link linkend="v4l2-pix-format">v4l2_pix_format</link> {
#define <link linkend="V4L2-PIX-FMT-RGB565">V4L2_PIX_FMT_RGB565</link> v4l2_fourcc('R', 'G', 'B', 'P') /* 16 RGB-5-6-5 */
#define <link linkend="V4L2-PIX-FMT-RGB555X">V4L2_PIX_FMT_RGB555X</link> v4l2_fourcc('R', 'G', 'B', 'Q') /* 16 RGB-5-5-5 BE */
#define <link linkend="V4L2-PIX-FMT-RGB565X">V4L2_PIX_FMT_RGB565X</link> v4l2_fourcc('R', 'G', 'B', 'R') /* 16 RGB-5-6-5 BE */
#define <link linkend="V4L2-PIX-FMT-BGR666">V4L2_PIX_FMT_BGR666</link> v4l2_fourcc('B', 'G', 'R', 'H') /* 18 BGR-6-6-6 */
#define <link linkend="V4L2-PIX-FMT-BGR24">V4L2_PIX_FMT_BGR24</link> v4l2_fourcc('B', 'G', 'R', '3') /* 24 BGR-8-8-8 */
#define <link linkend="V4L2-PIX-FMT-RGB24">V4L2_PIX_FMT_RGB24</link> v4l2_fourcc('R', 'G', 'B', '3') /* 24 RGB-8-8-8 */
#define <link linkend="V4L2-PIX-FMT-BGR32">V4L2_PIX_FMT_BGR32</link> v4l2_fourcc('B', 'G', 'R', '4') /* 32 BGR-8-8-8-8 */
@ -295,6 +286,9 @@ struct <link linkend="v4l2-pix-format">v4l2_pix_format</link> {
/* Grey formats */
#define <link linkend="V4L2-PIX-FMT-GREY">V4L2_PIX_FMT_GREY</link> v4l2_fourcc('G', 'R', 'E', 'Y') /* 8 Greyscale */
#define <link linkend="V4L2-PIX-FMT-Y4">V4L2_PIX_FMT_Y4</link> v4l2_fourcc('Y', '0', '4', ' ') /* 4 Greyscale */
#define <link linkend="V4L2-PIX-FMT-Y6">V4L2_PIX_FMT_Y6</link> v4l2_fourcc('Y', '0', '6', ' ') /* 6 Greyscale */
#define <link linkend="V4L2-PIX-FMT-Y10">V4L2_PIX_FMT_Y10</link> v4l2_fourcc('Y', '1', '0', ' ') /* 10 Greyscale */
#define <link linkend="V4L2-PIX-FMT-Y16">V4L2_PIX_FMT_Y16</link> v4l2_fourcc('Y', '1', '6', ' ') /* 16 Greyscale */
/* Palette formats */
@ -330,7 +324,11 @@ struct <link linkend="v4l2-pix-format">v4l2_pix_format</link> {
#define <link linkend="V4L2-PIX-FMT-SBGGR8">V4L2_PIX_FMT_SBGGR8</link> v4l2_fourcc('B', 'A', '8', '1') /* 8 BGBG.. GRGR.. */
#define <link linkend="V4L2-PIX-FMT-SGBRG8">V4L2_PIX_FMT_SGBRG8</link> v4l2_fourcc('G', 'B', 'R', 'G') /* 8 GBGB.. RGRG.. */
#define <link linkend="V4L2-PIX-FMT-SGRBG8">V4L2_PIX_FMT_SGRBG8</link> v4l2_fourcc('G', 'R', 'B', 'G') /* 8 GRGR.. BGBG.. */
#define <link linkend="V4L2-PIX-FMT-SGRBG10">V4L2_PIX_FMT_SGRBG10</link> v4l2_fourcc('B', 'A', '1', '0') /* 10bit raw bayer */
#define <link linkend="V4L2-PIX-FMT-SRGGB8">V4L2_PIX_FMT_SRGGB8</link> v4l2_fourcc('R', 'G', 'G', 'B') /* 8 RGRG.. GBGB.. */
#define <link linkend="V4L2-PIX-FMT-SBGGR10">V4L2_PIX_FMT_SBGGR10</link> v4l2_fourcc('B', 'G', '1', '0') /* 10 BGBG.. GRGR.. */
#define <link linkend="V4L2-PIX-FMT-SGBRG10">V4L2_PIX_FMT_SGBRG10</link> v4l2_fourcc('G', 'B', '1', '0') /* 10 GBGB.. RGRG.. */
#define <link linkend="V4L2-PIX-FMT-SGRBG10">V4L2_PIX_FMT_SGRBG10</link> v4l2_fourcc('B', 'A', '1', '0') /* 10 GRGR.. BGBG.. */
#define <link linkend="V4L2-PIX-FMT-SRGGB10">V4L2_PIX_FMT_SRGGB10</link> v4l2_fourcc('R', 'G', '1', '0') /* 10 RGRG.. GBGB.. */
/* 10bit raw bayer DPCM compressed to 8 bits */
#define <link linkend="V4L2-PIX-FMT-SGRBG10DPCM8">V4L2_PIX_FMT_SGRBG10DPCM8</link> v4l2_fourcc('B', 'D', '1', '0')
/*
@ -346,6 +344,7 @@ struct <link linkend="v4l2-pix-format">v4l2_pix_format</link> {
#define <link linkend="V4L2-PIX-FMT-MPEG">V4L2_PIX_FMT_MPEG</link> v4l2_fourcc('M', 'P', 'E', 'G') /* MPEG-1/2/4 */
/* Vendor-specific formats */
#define <link linkend="V4L2-PIX-FMT-CPIA1">V4L2_PIX_FMT_CPIA1</link> v4l2_fourcc('C', 'P', 'I', 'A') /* cpia1 YUV */
#define <link linkend="V4L2-PIX-FMT-WNVA">V4L2_PIX_FMT_WNVA</link> v4l2_fourcc('W', 'N', 'V', 'A') /* Winnov hw compress */
#define <link linkend="V4L2-PIX-FMT-SN9C10X">V4L2_PIX_FMT_SN9C10X</link> v4l2_fourcc('S', '9', '1', '0') /* SN9C10x compression */
#define <link linkend="V4L2-PIX-FMT-SN9C20X-I420">V4L2_PIX_FMT_SN9C20X_I420</link> v4l2_fourcc('S', '9', '2', '0') /* SN9C20x YUV 4:2:0 */
@ -358,12 +357,15 @@ struct <link linkend="v4l2-pix-format">v4l2_pix_format</link> {
#define <link linkend="V4L2-PIX-FMT-SPCA561">V4L2_PIX_FMT_SPCA561</link> v4l2_fourcc('S', '5', '6', '1') /* compressed GBRG bayer */
#define <link linkend="V4L2-PIX-FMT-PAC207">V4L2_PIX_FMT_PAC207</link> v4l2_fourcc('P', '2', '0', '7') /* compressed BGGR bayer */
#define <link linkend="V4L2-PIX-FMT-MR97310A">V4L2_PIX_FMT_MR97310A</link> v4l2_fourcc('M', '3', '1', '0') /* compressed BGGR bayer */
#define <link linkend="V4L2-PIX-FMT-SN9C2028">V4L2_PIX_FMT_SN9C2028</link> v4l2_fourcc('S', 'O', 'N', 'X') /* compressed GBRG bayer */
#define <link linkend="V4L2-PIX-FMT-SQ905C">V4L2_PIX_FMT_SQ905C</link> v4l2_fourcc('9', '0', '5', 'C') /* compressed RGGB bayer */
#define <link linkend="V4L2-PIX-FMT-PJPG">V4L2_PIX_FMT_PJPG</link> v4l2_fourcc('P', 'J', 'P', 'G') /* Pixart 73xx JPEG */
#define <link linkend="V4L2-PIX-FMT-OV511">V4L2_PIX_FMT_OV511</link> v4l2_fourcc('O', '5', '1', '1') /* ov511 JPEG */
#define <link linkend="V4L2-PIX-FMT-OV518">V4L2_PIX_FMT_OV518</link> v4l2_fourcc('O', '5', '1', '8') /* ov518 JPEG */
#define <link linkend="V4L2-PIX-FMT-TM6000">V4L2_PIX_FMT_TM6000</link> v4l2_fourcc('T', 'M', '6', '0') /* tm5600/tm60x0 */
#define <link linkend="V4L2-PIX-FMT-STV0680">V4L2_PIX_FMT_STV0680</link> v4l2_fourcc('S', '6', '8', '0') /* stv0680 bayer */
#define <link linkend="V4L2-PIX-FMT-TM6000">V4L2_PIX_FMT_TM6000</link> v4l2_fourcc('T', 'M', '6', '0') /* tm5600/tm60x0 */
#define <link linkend="V4L2-PIX-FMT-CIT-YYVYUY">V4L2_PIX_FMT_CIT_YYVYUY</link> v4l2_fourcc('C', 'I', 'T', 'V') /* one line of Y then 1 line of VYUY */
#define <link linkend="V4L2-PIX-FMT-KONICA420">V4L2_PIX_FMT_KONICA420</link> v4l2_fourcc('K', 'O', 'N', 'I') /* YUV420 planar in blocks of 256 pixels */
/*
* F O R M A T E N U M E R A T I O N
@ -380,7 +382,7 @@ struct <link linkend="v4l2-fmtdesc">v4l2_fmtdesc</link> {
#define V4L2_FMT_FLAG_COMPRESSED 0x0001
#define V4L2_FMT_FLAG_EMULATED 0x0002
#if 1 /*KEEP*/
#if 1
/* Experimental Frame Size and frame rate enumeration */
/*
* F R A M E S I Z E E N U M E R A T I O N
@ -544,6 +546,8 @@ struct <link linkend="v4l2-buffer">v4l2_buffer</link> {
#define V4L2_BUF_FLAG_KEYFRAME 0x0008 /* Image is a keyframe (I-frame) */
#define V4L2_BUF_FLAG_PFRAME 0x0010 /* Image is a P-frame */
#define V4L2_BUF_FLAG_BFRAME 0x0020 /* Image is a B-frame */
/* Buffer is ready, but the data contained within is corrupted. */
#define V4L2_BUF_FLAG_ERROR 0x0040
#define V4L2_BUF_FLAG_TIMECODE 0x0100 /* timecode field is valid */
#define V4L2_BUF_FLAG_INPUT 0x0200 /* input field is valid */
@ -934,6 +938,16 @@ struct <link linkend="v4l2-ext-controls">v4l2_ext_controls</link> {
#define V4L2_CTRL_ID2CLASS(id) ((id) &amp; 0x0fff0000UL)
#define V4L2_CTRL_DRIVER_PRIV(id) (((id) &amp; 0xffff) &gt;= 0x1000)
enum <link linkend="v4l2-ctrl-type">v4l2_ctrl_type</link> {
V4L2_CTRL_TYPE_INTEGER = 1,
V4L2_CTRL_TYPE_BOOLEAN = 2,
V4L2_CTRL_TYPE_MENU = 3,
V4L2_CTRL_TYPE_BUTTON = 4,
V4L2_CTRL_TYPE_INTEGER64 = 5,
V4L2_CTRL_TYPE_CTRL_CLASS = 6,
V4L2_CTRL_TYPE_STRING = 7,
};
/* Used in the VIDIOC_QUERYCTRL ioctl for querying controls */
struct <link linkend="v4l2-queryctrl">v4l2_queryctrl</link> {
__u32 id;
@ -1018,14 +1032,27 @@ enum <link linkend="v4l2-colorfx">v4l2_colorfx</link> {
V4L2_COLORFX_NONE = 0,
V4L2_COLORFX_BW = 1,
V4L2_COLORFX_SEPIA = 2,
V4L2_COLORFX_NEGATIVE = 3,
V4L2_COLORFX_EMBOSS = 4,
V4L2_COLORFX_SKETCH = 5,
V4L2_COLORFX_SKY_BLUE = 6,
V4L2_COLORFX_GRASS_GREEN = 7,
V4L2_COLORFX_SKIN_WHITEN = 8,
V4L2_COLORFX_VIVID = 9,
};
#define V4L2_CID_AUTOBRIGHTNESS (V4L2_CID_BASE+32)
#define V4L2_CID_BAND_STOP_FILTER (V4L2_CID_BASE+33)
#define V4L2_CID_ROTATE (V4L2_CID_BASE+34)
#define V4L2_CID_BG_COLOR (V4L2_CID_BASE+35)
#define V4L2_CID_CHROMA_GAIN (V4L2_CID_BASE+36)
#define V4L2_CID_ILLUMINATORS_1 (V4L2_CID_BASE+37)
#define V4L2_CID_ILLUMINATORS_2 (V4L2_CID_BASE+38)
/* last CID + 1 */
#define V4L2_CID_LASTP1 (V4L2_CID_BASE+36)
#define V4L2_CID_LASTP1 (V4L2_CID_BASE+39)
/* MPEG-class control IDs defined by V4L2 */
#define V4L2_CID_MPEG_BASE (V4L2_CTRL_CLASS_MPEG | 0x900)
@ -1271,6 +1298,9 @@ enum <link linkend="v4l2-exposure-auto-type">v4l2_exposure_auto_type</link> {
#define V4L2_CID_PRIVACY (V4L2_CID_CAMERA_CLASS_BASE+16)
#define V4L2_CID_IRIS_ABSOLUTE (V4L2_CID_CAMERA_CLASS_BASE+17)
#define V4L2_CID_IRIS_RELATIVE (V4L2_CID_CAMERA_CLASS_BASE+18)
/* FM Modulator class control IDs */
#define V4L2_CID_FM_TX_CLASS_BASE (V4L2_CTRL_CLASS_FM_TX | 0x900)
#define V4L2_CID_FM_TX_CLASS (V4L2_CTRL_CLASS_FM_TX | 1)
@ -1339,6 +1369,8 @@ struct <link linkend="v4l2-modulator">v4l2_modulator</link> {
#define V4L2_TUNER_CAP_SAP 0x0020
#define V4L2_TUNER_CAP_LANG1 0x0040
#define V4L2_TUNER_CAP_RDS 0x0080
#define V4L2_TUNER_CAP_RDS_BLOCK_IO 0x0100
#define V4L2_TUNER_CAP_RDS_CONTROLS 0x0200
/* Flags for the 'rxsubchans' field */
#define V4L2_TUNER_SUB_MONO 0x0001
@ -1368,7 +1400,8 @@ struct <link linkend="v4l2-hw-freq-seek">v4l2_hw_freq_seek</link> {
enum <link linkend="v4l2-tuner-type">v4l2_tuner_type</link> type;
__u32 seek_upward;
__u32 wrap_around;
__u32 reserved[8];
__u32 spacing;
__u32 reserved[7];
};
/*
@ -1423,7 +1456,7 @@ struct <link linkend="v4l2-audioout">v4l2_audioout</link> {
*
* NOTE: EXPERIMENTAL API
*/
#if 1 /*KEEP*/
#if 1
#define V4L2_ENC_IDX_FRAME_I (0)
#define V4L2_ENC_IDX_FRAME_P (1)
#define V4L2_ENC_IDX_FRAME_B (2)
@ -1615,6 +1648,38 @@ struct <link linkend="v4l2-streamparm">v4l2_streamparm</link> {
} parm;
};
/*
* E V E N T S
*/
#define V4L2_EVENT_ALL 0
#define V4L2_EVENT_VSYNC 1
#define V4L2_EVENT_EOS 2
#define V4L2_EVENT_PRIVATE_START 0x08000000
/* Payload for V4L2_EVENT_VSYNC */
struct <link linkend="v4l2-event-vsync">v4l2_event_vsync</link> {
/* Can be V4L2_FIELD_ANY, _NONE, _TOP or _BOTTOM */
__u8 field;
} __attribute__ ((packed));
struct <link linkend="v4l2-event">v4l2_event</link> {
__u32 type;
union {
struct <link linkend="v4l2-event-vsync">v4l2_event_vsync</link> vsync;
__u8 data[64];
} u;
__u32 pending;
__u32 sequence;
struct timespec timestamp;
__u32 reserved[9];
};
struct <link linkend="v4l2-event-subscription">v4l2_event_subscription</link> {
__u32 type;
__u32 reserved[7];
};
/*
* A D V A N C E D D E B U G G I N G
*
@ -1710,7 +1775,7 @@ struct <link linkend="v4l2-dbg-chip-ident">v4l2_dbg_chip_ident</link> {
#define VIDIOC_G_EXT_CTRLS _IOWR('V', 71, struct <link linkend="v4l2-ext-controls">v4l2_ext_controls</link>)
#define VIDIOC_S_EXT_CTRLS _IOWR('V', 72, struct <link linkend="v4l2-ext-controls">v4l2_ext_controls</link>)
#define VIDIOC_TRY_EXT_CTRLS _IOWR('V', 73, struct <link linkend="v4l2-ext-controls">v4l2_ext_controls</link>)
#if 1 /*KEEP*/
#if 1
#define VIDIOC_ENUM_FRAMESIZES _IOWR('V', 74, struct <link linkend="v4l2-frmsizeenum">v4l2_frmsizeenum</link>)
#define VIDIOC_ENUM_FRAMEINTERVALS _IOWR('V', 75, struct <link linkend="v4l2-frmivalenum">v4l2_frmivalenum</link>)
#define VIDIOC_G_ENC_INDEX _IOR('V', 76, struct <link linkend="v4l2-enc-idx">v4l2_enc_idx</link>)
@ -1718,7 +1783,7 @@ struct <link linkend="v4l2-dbg-chip-ident">v4l2_dbg_chip_ident</link> {
#define VIDIOC_TRY_ENCODER_CMD _IOWR('V', 78, struct <link linkend="v4l2-encoder-cmd">v4l2_encoder_cmd</link>)
#endif
#if 1 /*KEEP*/
#if 1
/* Experimental, meant for debugging, testing and internal use.
Only implemented if CONFIG_VIDEO_ADV_DEBUG is defined.
You must be root to use these ioctls. Never use these in applications! */
@ -1737,6 +1802,9 @@ struct <link linkend="v4l2-dbg-chip-ident">v4l2_dbg_chip_ident</link> {
#define VIDIOC_QUERY_DV_PRESET _IOR('V', 86, struct <link linkend="v4l2-dv-preset">v4l2_dv_preset</link>)
#define VIDIOC_S_DV_TIMINGS _IOWR('V', 87, struct <link linkend="v4l2-dv-timings">v4l2_dv_timings</link>)
#define VIDIOC_G_DV_TIMINGS _IOWR('V', 88, struct <link linkend="v4l2-dv-timings">v4l2_dv_timings</link>)
#define VIDIOC_DQEVENT _IOR('V', 89, struct <link linkend="v4l2-event">v4l2_event</link>)
#define VIDIOC_SUBSCRIBE_EVENT _IOW('V', 90, struct <link linkend="v4l2-event-subscription">v4l2_event_subscription</link>)
#define VIDIOC_UNSUBSCRIBE_EVENT _IOW('V', 91, struct <link linkend="v4l2-event-subscription">v4l2_event_subscription</link>)
/* Reminder: when adding new ioctls please add support for them to
drivers/media/video/v4l2-compat-ioctl32.c as well! */

View File

@ -0,0 +1,131 @@
<refentry id="vidioc-dqevent">
<refmeta>
<refentrytitle>ioctl VIDIOC_DQEVENT</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>VIDIOC_DQEVENT</refname>
<refpurpose>Dequeue event</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>struct v4l2_event
*<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fd;</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>VIDIOC_DQEVENT</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>Dequeue an event from a video device. No input is required
for this ioctl. All the fields of the &v4l2-event; structure are
filled by the driver. The file handle will also receive exceptions
which the application may get by e.g. using the select system
call.</para>
<table frame="none" pgwide="1" id="v4l2-event">
<title>struct <structname>v4l2_event</structname></title>
<tgroup cols="4">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>type</structfield></entry>
<entry></entry>
<entry>Type of the event.</entry>
</row>
<row>
<entry>union</entry>
<entry><structfield>u</structfield></entry>
<entry></entry>
<entry></entry>
</row>
<row>
<entry></entry>
<entry>&v4l2-event-vsync;</entry>
<entry><structfield>vsync</structfield></entry>
<entry>Event data for event V4L2_EVENT_VSYNC.
</entry>
</row>
<row>
<entry></entry>
<entry>__u8</entry>
<entry><structfield>data</structfield>[64]</entry>
<entry>Event data. Defined by the event type. The union
should be used to define easily accessible type for
events.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>pending</structfield></entry>
<entry></entry>
<entry>Number of pending events excluding this one.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>sequence</structfield></entry>
<entry></entry>
<entry>Event sequence number. The sequence number is
incremented for every subscribed event that takes place.
If sequence numbers are not contiguous it means that
events have been lost.
</entry>
</row>
<row>
<entry>struct timespec</entry>
<entry><structfield>timestamp</structfield></entry>
<entry></entry>
<entry>Event timestamp.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>reserved</structfield>[9]</entry>
<entry></entry>
<entry>Reserved for future extensions. Drivers must set
the array to zero.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
</refentry>
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@ -283,7 +283,7 @@ input/output interface to linux-media@vger.kernel.org on 19 Oct 2009.
<entry>This input supports setting DV presets by using VIDIOC_S_DV_PRESET.</entry>
</row>
<row>
<entry><constant>V4L2_OUT_CAP_CUSTOM_TIMINGS</constant></entry>
<entry><constant>V4L2_IN_CAP_CUSTOM_TIMINGS</constant></entry>
<entry>0x00000002</entry>
<entry>This input supports setting custom video timings by using VIDIOC_S_DV_TIMINGS.</entry>
</row>

View File

@ -16,8 +16,7 @@
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>&v4l2-dv-preset;
*<parameter>argp</parameter></paramdef>
<paramdef>struct v4l2_dv_preset *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>

View File

@ -16,8 +16,7 @@
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>&v4l2-dv-timings;
*<parameter>argp</parameter></paramdef>
<paramdef>struct v4l2_dv_timings *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>

View File

@ -55,7 +55,7 @@ captured or output, applications can request frame skipping or
duplicating on the driver side. This is especially useful when using
the <function>read()</function> or <function>write()</function>, which
are not augmented by timestamps or sequence counters, and to avoid
unneccessary data copying.</para>
unnecessary data copying.</para>
<para>Further these ioctls can be used to determine the number of
buffers used internally by a driver in read/write mode. For

View File

@ -54,12 +54,10 @@ to enqueue an empty (capturing) or filled (output) buffer in the
driver's incoming queue. The semantics depend on the selected I/O
method.</para>
<para>To enqueue a <link linkend="mmap">memory mapped</link>
buffer applications set the <structfield>type</structfield> field of a
&v4l2-buffer; to the same buffer type as previously &v4l2-format;
<structfield>type</structfield> and &v4l2-requestbuffers;
<structfield>type</structfield>, the <structfield>memory</structfield>
field to <constant>V4L2_MEMORY_MMAP</constant> and the
<para>To enqueue a buffer applications set the <structfield>type</structfield>
field of a &v4l2-buffer; to the same buffer type as was previously used
with &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers;
<structfield>type</structfield>. Applications must also set the
<structfield>index</structfield> field. Valid index numbers range from
zero to the number of buffers allocated with &VIDIOC-REQBUFS;
(&v4l2-requestbuffers; <structfield>count</structfield>) minus one. The
@ -70,8 +68,19 @@ intended for output (<structfield>type</structfield> is
<constant>V4L2_BUF_TYPE_VBI_OUTPUT</constant>) applications must also
initialize the <structfield>bytesused</structfield>,
<structfield>field</structfield> and
<structfield>timestamp</structfield> fields. See <xref
linkend="buffer" /> for details. When
<structfield>timestamp</structfield> fields, see <xref
linkend="buffer" /> for details.
Applications must also set <structfield>flags</structfield> to 0. If a driver
supports capturing from specific video inputs and you want to specify a video
input, then <structfield>flags</structfield> should be set to
<constant>V4L2_BUF_FLAG_INPUT</constant> and the field
<structfield>input</structfield> must be initialized to the desired input.
The <structfield>reserved</structfield> field must be set to 0.
</para>
<para>To enqueue a <link linkend="mmap">memory mapped</link>
buffer applications set the <structfield>memory</structfield>
field to <constant>V4L2_MEMORY_MMAP</constant>. When
<constant>VIDIOC_QBUF</constant> is called with a pointer to this
structure the driver sets the
<constant>V4L2_BUF_FLAG_MAPPED</constant> and
@ -81,14 +90,10 @@ structure the driver sets the
&EINVAL;.</para>
<para>To enqueue a <link linkend="userp">user pointer</link>
buffer applications set the <structfield>type</structfield> field of a
&v4l2-buffer; to the same buffer type as previously &v4l2-format;
<structfield>type</structfield> and &v4l2-requestbuffers;
<structfield>type</structfield>, the <structfield>memory</structfield>
field to <constant>V4L2_MEMORY_USERPTR</constant> and the
buffer applications set the <structfield>memory</structfield>
field to <constant>V4L2_MEMORY_USERPTR</constant>, the
<structfield>m.userptr</structfield> field to the address of the
buffer and <structfield>length</structfield> to its size. When the
buffer is intended for output additional fields must be set as above.
buffer and <structfield>length</structfield> to its size.
When <constant>VIDIOC_QBUF</constant> is called with a pointer to this
structure the driver sets the <constant>V4L2_BUF_FLAG_QUEUED</constant>
flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and
@ -96,16 +101,21 @@ flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and
<structfield>flags</structfield> field, or it returns an error code.
This ioctl locks the memory pages of the buffer in physical memory,
they cannot be swapped out to disk. Buffers remain locked until
dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl are
dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is
called, or until the device is closed.</para>
<para>Applications call the <constant>VIDIOC_DQBUF</constant>
ioctl to dequeue a filled (capturing) or displayed (output) buffer
from the driver's outgoing queue. They just set the
<structfield>type</structfield> and <structfield>memory</structfield>
<structfield>type</structfield>, <structfield>memory</structfield>
and <structfield>reserved</structfield>
fields of a &v4l2-buffer; as above, when <constant>VIDIOC_DQBUF</constant>
is called with a pointer to this structure the driver fills the
remaining fields or returns an error code.</para>
remaining fields or returns an error code. The driver may also set
<constant>V4L2_BUF_FLAG_ERROR</constant> in the <structfield>flags</structfield>
field. It indicates a non-critical (recoverable) streaming error. In such case
the application may continue as normal, but should be aware that data in the
dequeued buffer might be corrupted.</para>
<para>By default <constant>VIDIOC_DQBUF</constant> blocks when no
buffer is in the outgoing queue. When the
@ -152,7 +162,13 @@ enqueue a user pointer buffer.</para>
<para><constant>VIDIOC_DQBUF</constant> failed due to an
internal error. Can also indicate temporary problems like signal
loss. Note the driver might dequeue an (empty) buffer despite
returning an error, or even stop capturing.</para>
returning an error, or even stop capturing. Reusing such buffer may be unsafe
though and its details (e.g. <structfield>index</structfield>) may not be
returned either. It is recommended that drivers indicate recoverable errors
by setting the <constant>V4L2_BUF_FLAG_ERROR</constant> and returning 0 instead.
In that case the application should be able to safely reuse the buffer and
continue streaming.
</para>
</listitem>
</varlistentry>
</variablelist>

View File

@ -16,7 +16,7 @@ input</refpurpose>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>&v4l2-dv-preset; *<parameter>argp</parameter></paramdef>
<paramdef>struct v4l2_dv_preset *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
@ -53,8 +53,10 @@ input</refpurpose>
automatically, similar to sensing the video standard. To do so, applications
call <constant> VIDIOC_QUERY_DV_PRESET</constant> with a pointer to a
&v4l2-dv-preset; type. Once the hardware detects a preset, that preset is
returned in the preset field of &v4l2-dv-preset;. When detection is not
possible or fails, the value V4L2_DV_INVALID is returned.</para>
returned in the preset field of &v4l2-dv-preset;. If the preset could not be
detected because there was no signal, or the signal was unreliable, or the
signal did not map to a supported preset, then the value V4L2_DV_INVALID is
returned.</para>
</refsect1>
<refsect1>

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