Some devices are designed and manufactured with some components having
multiple drop-in replacement options. These components are often
connected to the mainboard via ribbon cables, having the same signals
and pin assignments across all options. These may include the display
panel and touchscreen on laptops and tablets, and the trackpad on
laptops. Sometimes which component option is used in a particular device
can be detected by some firmware provided identifier, other times that
information is not available, and the kernel has to try to probe each
device.
This change attempts to make the "probe each device" case cleaner. The
current approach is to have all options added and enabled in the device
tree. The kernel would then bind each device and run each driver's probe
function. This works, but has been broken before due to the introduction
of asynchronous probing, causing multiple instances requesting "shared"
resources, such as pinmuxes, GPIO pins, interrupt lines, at the same
time, with only one instance succeeding. Work arounds for these include
moving the pinmux to the parent I2C controller, using GPIO hogs or
pinmux settings to keep the GPIO pins in some fixed configuration, and
requesting the interrupt line very late. Such configurations can be seen
on the MT8183 Krane Chromebook tablets, and the Qualcomm sc8280xp-based
Lenovo Thinkpad 13S.
Instead of this delicate dance between drivers and device tree quirks,
this change introduces a simple I2C component probe function. For a
given class of devices on the same I2C bus, it will go through all of
them, doing a simple I2C read transfer and see which one of them responds.
It will then enable the device that responds.
This requires some minor modifications in the existing device tree. The
status for all the device nodes for the component options must be set
to "fail-needs-probe". This makes it clear that some mechanism is
needed to enable one of them, and also prevents the prober and device
drivers running at the same time.
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
*-objs suffix is reserved rather for (user-space) host programs while
usually *-y suffix is used for kernel drivers (although *-objs works
for that purpose for now).
Let's correct the old usages of *-objs in Makefiles.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Some lines in the Makefile have a space before tabs. Remove those.
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Closes: https://lore.kernel.org/all/ZsdE0PxKnGRjzChl@smile.fi.intel.com/
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
An ATR is a device that looks similar to an i2c-mux: it has an I2C
slave "upstream" port and N master "downstream" ports, and forwards
transactions from upstream to the appropriate downstream port. But it
is different in that the forwarded transaction has a different slave
address. The address used on the upstream bus is called the "alias"
and is (potentially) different from the physical slave address of the
downstream chip.
Add a helper file (just like i2c-mux.c for a mux or switch) to allow
implementing ATR features in a device driver. The helper takes care of
adapter creation/destruction and translates addresses at each transaction.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Here is an I2C slave backend driver which allows to test some uncommon
functionalities of the I2C and SMBus world. Usually, you need specific
devices to test e.g. SMBus Host Notify and such. With this driver you
just need the slave interface of another I2C controller.
This initial version has testcases for multi-master and SMBus Host
Notify. Already planned but not yet implemented are SMBus Alert and
messages with I2C_M_RECV_LEN.
Please read the documentation for further details.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This can be dropped with commit 771c035372
("deprecate the '__deprecated' attribute warnings entirely and for good")
now in upstream.
And we got rid of the last __deprecated use, too.
Signed-off-by: Sedat Dilek <sedat.dilek@credativ.de>
[wsa: shortened commit message to reflect the current situation]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Removes some ifdeffery. Also add the new file to the relevant
MAINTAINERS section.
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Break out the exported SMBus functions and the emulation layer into a
separate file. This also involved splitting up the tracing header into
an I2C and an SMBus part.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The I2C core became quite huge and its monolithic structure makes
maintenance hard. So, prepare to break out some functionality into
separate files by renaming the source file. Note that we keep the
resulting object name constant to avoid regressions.
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The first user of the i2c-slave interface is an eeprom simulator. It is
a shared memory which can be accessed by the remote master via I2C and
locally via sysfs.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Commit 5d98e61d33 ("I2C/ACPI: Add i2c ACPI operation region support")
renamed the i2c-core module. This may cause regressions for
distributions, so put the ACPI code back into the core.
Reported-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Lan Tianyu <tianyu.lan@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Commit da3c6647(I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI
config) adds a new kernel config I2C_ACPI and make I2C core built in
when the config is selected. This is wrong because distributions
etc generally compile I2C as a module and the commit broken that.
This patch is to rename I2C_ACPI to ACPI_I2C_OPREGION. New config
only controls ACPI I2C operation region code and depends on I2C=y.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[wsa: removed unrelated change for Kconfig]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Clean up ACPI related code in the i2c core and add CONFIG_I2C_ACPI
to enable I2C ACPI code.
Current there is a race between removing I2C ACPI operation region
and ACPI AML code accessing. So make i2c core built-in if CONFIG_I2C_ACPI
is set.
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
ACPI 5.0 spec(5.5.2.4.5) defines GenericSerialBus(i2c, spi, uart) operation region.
It allows ACPI aml code able to access such kind of devices to implement
some ACPI standard method.
ACPI Spec defines some access attribute to associate with i2c protocol.
AttribQuick Read/Write Quick Protocol
AttribSendReceive Send/Receive Byte Protocol
AttribByte Read/Write Byte Protocol
AttribWord Read/Write Word Protocol
AttribBlock Read/Write Block Protocol
AttribBytes Read/Write N-Bytes Protocol
AttribProcessCall Process Call Protocol
AttribBlockProcessCall Write Block-Read Block Process Call Protocol
AttribRawBytes Raw Read/Write N-BytesProtocol
AttribRawProcessBytes Raw Process Call Protocol
On the Asus T100TA, Bios use GenericSerialBus operation region to access
i2c device to get battery info.
Sample code From Asus T100TA
Scope (_SB.I2C1)
{
Name (UMPC, ResourceTemplate ()
{
I2cSerialBus (0x0066, ControllerInitiated, 0x00061A80,
AddressingMode7Bit, "\\_SB.I2C1",
0x00, ResourceConsumer, ,
)
})
...
OperationRegion (DVUM, GenericSerialBus, Zero, 0x0100)
Field (DVUM, BufferAcc, NoLock, Preserve)
{
Connection (UMPC),
Offset (0x81),
AccessAs (BufferAcc, AttribBytes (0x3E)),
FGC0, 8
}
...
}
Device (BATC)
{
Name (_HID, EisaId ("PNP0C0A")) // _HID: Hardware ID
Name (_UID, One) // _UID: Unique ID
...
Method (_BST, 0, NotSerialized) // _BST: Battery Status
{
If (LEqual (AVBL, One))
{
Store (FGC0, BFFG)
If (LNotEqual (STAT, One))
{
ShiftRight (CHST, 0x04, Local0)
And (Local0, 0x03, Local0)
If (LOr (LEqual (Local0, One), LEqual (Local0, 0x02)))
{
Store (0x02, Local1)
}
...
}
The i2c operation region is defined under I2C1 scope. _BST method under
battery device BATC read battery status from the field "FCG0". The request
would be sent to i2c operation region handler.
This patch is to add i2c ACPI operation region support. Due to there are
only "Byte" and "Bytes" protocol access on the Asus T100TA, other protocols
have not been tested.
About RawBytes and RawProcessBytes protocol, they needs specific drivers to interpret
reference data from AML code according ACPI 5.0 SPEC(5.5.2.4.5.3.9 and 5.5.2.4.5.3.10).
So far, not found such case and will add when find real case.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Move the i2c-stub driver to drivers/i2c, to match the Kconfig entry.
This is less confusing that way.
I also fixed all checkpatch warnings and errors.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Peter Huewe <peterhuewe@gmx.de>
The last legitimate user of i2c_driver.attach_adapter and
.detach_adapter is gone, so we can finally deprecate these callbacks.
The last few drivers which still use these will have to be updated to
make use of standard I2C device instantiation ways instead.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Add multiplexed bus core support. I2C multiplexer and switches
like pca954x get instantiated as new adapters per port.
Signed-off-by: Michael Lawnick <ml.lawnick@gmx.de>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Move the last remaining driver from i2c/chips to misc. Good ridance!
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Having a separate Kconfig option for i2c-smbus makes it possible to
build that support as a module even when i2c-core itself is built-in.
Bus drivers which implement SMBus alert should select this option, so
in most cases this option is hidden and the user doesn't have to care
about it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
SMBus alert support. The SMBus alert protocol allows several SMBus
slave devices to share a single interrupt pin on the SMBus master,
while still allowing the master to know which slave triggered the
interrupt.
This is based on preliminary work by David Brownell. The key
difference between David's implementation and mine is that his was
part of i2c-core, while mine is split into a separate, standalone
module named i2c-smbus. The i2c-smbus module is meant to include
support for all SMBus extensions to the I2C protocol in the future.
The benefit of this approach is a zero cost for I2C bus segments which
do not need SMBus alert support. Where David's implementation
increased the size of struct i2c_adapter by 7% (40 bytes on i386),
mine doesn't touch it. Where David's implementation added over 150
lines of code to i2c-core (+10%), mine doesn't touch it. The only
change that touches all the users of the i2c subsystem is a new
callback in struct i2c_driver (common to both implementations.) I seem
to remember Trent was worried about the footprint of David'd
implementation, hopefully mine addresses the issue.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
This provides partial support for new-style I2C driver binding. It builds
on "struct i2c_board_info" declarations that identify I2C devices on a given
board. This is needed on systems with I2C devices that can't be fully probed
and/or autoconfigured, such as many embedded Linux configurations where the
way a given I2C device is wired may affect how it must be used.
There are two models for declaring such devices:
* LATE -- using a public function i2c_new_device(). This lets modules
declare I2C devices found *AFTER* a given I2C adapter becomes available.
For example, a PCI card could create adapters giving access to utility
chips on that card, and this would be used to associate those chips with
those adapters.
* EARLY -- from arch_initcall() level code, using a non-exported function
i2c_register_board_info(). This copies the declarations *BEFORE* such
an i2c_adapter becomes available, arranging that i2c_new_device() will
be called later when i2c-core registers the relevant i2c_adapter.
For example, arch/.../.../board-*.c files would declare the I2C devices
along with their platform data, and I2C devices would behave much like
PNPACPI devices. (That is, both enumerate from board-specific tables.)
To match the exported i2c_new_device(), the previously-private function
i2c_unregister_device() is now exported.
Pending later patches using these new APIs, this is effectively a NOP.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The only part left in i2c-sensor is the VRM/VRD/VID handling code.
This is in no way related to i2c, so it doesn't belong there. Move
the code to hwmon, where it belongs.
Note that not all hardware monitoring drivers do VRM/VRD/VID
operations, so less drivers depend on hwmon-vid than there were
depending on i2c-sensor.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The i2c_detect function has no more user, delete it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
