97 Commits

Author SHA1 Message Date
Bartosz Golaszewski
5a7119e0d9 gpio: sysfs: emit chardev line-state events on active-low changes
The sysfs active_low attribute doesn't go through the usual paths so it
doesn't emit the line-state event. Add the missing call to
gpiod_line_state_notify() to gpio_sysfs_set_active_low().

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241031-gpio-notify-sysfs-v4-4-142021c2195c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-11-04 08:56:19 +01:00
Bartosz Golaszewski
285678c947 gpio: sysfs: emit chardev line-state events on GPIO export
We already emit a CONFIG_RELEASED event when a line is unexported over
sysfs (this is handled by gpiod_free()) but we don't do the opposite
when it's exported. This adds the missing call to
gpiod_line_state_notify().

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241031-gpio-notify-sysfs-v4-3-142021c2195c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-11-04 08:56:19 +01:00
Bartosz Golaszewski
f4af1671c2 gpio: sysfs: use cleanup guards for the sysfs_lock mutex
Shrink the code and remove some goto labels by using guards around the
sysfs_lock mutex.

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241031-gpio-notify-sysfs-v4-2-142021c2195c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-11-04 08:56:19 +01:00
Bartosz Golaszewski
d99c980cfe gpio: sysfs: use cleanup guards for gpiod_data::mutex
Shrink the code and drop some goto labels by using lock guards around
gpiod_data::mutex.

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241031-gpio-notify-sysfs-v4-1-142021c2195c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-11-04 08:56:19 +01:00
Bartosz Golaszewski
37d5a6d6f4 gpio: sysfs: demote warning messages on invalid user input to debug
We should not emit a non-ratelimited warning everytime a user passes an
invalid value to /sys/class/gpio/export as it's an easy way to spam the
kernel log. Change the relevant messages to pr_debug_ratelimited().

Link: https://lore.kernel.org/r/20241021185717.96449-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-10-31 13:34:13 +01:00
Bartosz Golaszewski
b6f7aeaf1b gpio: sysfs: constify gpio class
All class functions used here take a const pointer to the class
structure. We can constify gpio_class.

While at it: remove a stray newline and use a tab in the struct
definition for consistency with the line above.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241014121831.106532-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-10-17 08:53:02 +02:00
Bartosz Golaszewski
700cdf7ed0 gpio: sysfs: make the sysfs export behavior consistent
For drivers or board files that set gpio_chip->names, the links to the
GPIO attribute group created on sysfs export will be named after the
line's name set in that array. For lines that are named using device
properties, the names pointer of the gpio_chip struct is never assigned
so they are exported as if they're not named.

The ABI documentation does not mention the former behavior and given
that the majority of modern systems use device-tree, ACPI or other way
of passing GPIO names using device properties - bypassing gc->names -
it's better to make the behavior consistent by always exporting lines as
"gpioXYZ".

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240930083029.17694-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-10-02 16:30:12 +02:00
Andy Shevchenko
94bd9ce160 gpiolib: Update the kernel documentation - add Return sections
$ scripts/kernel-doc -v -none -Wall drivers/gpio/gpiolib* 2>&1 | grep -w warning | wc -l
67

Fix these by adding Return sections. While at it, make sure all of
Return sections use the same style.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240828164449.2777666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-09-02 12:27:36 +02:00
Andy Shevchenko
8a7a610325 gpiolib: Get rid of never false gpio_is_valid() calls
In the cases when gpio_is_valid() is called with unsigned parameter
the result is always true in the GPIO library code, hence the check
for false won't ever be true. Get rid of such calls.

While at it, move GPIO device base to be unsigned to clearly show
it won't ever be negative. This requires a new definition for the
maximum GPIO number in the system.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-04-17 22:46:44 +02:00
Alexander Sverdlin
8636f19c2d gpio: sysfs: repair export returning -EPERM on 1st attempt
It would make sense to return -EPERM if the bit was already set (already
used), not if it was cleared. Before this fix pins can only be exported on
the 2nd attempt:

$ echo 522 > /sys/class/gpio/export
sh: write error: Operation not permitted
$ echo 522 > /sys/class/gpio/export

Fixes: 35b545332b80 ("gpio: remove gpio_lock")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-03-08 10:32:00 +01:00
Bartosz Golaszewski
be91c19e47 gpio: sysfs: fix inverted pointer logic
The logic is inverted, we want to return if the chip *IS* NULL.

Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-gpio/15671341-0b29-40e0-b487-0a4cdc414d8e@moroto.mountain/
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-02-15 08:40:40 +01:00
Bartosz Golaszewski
d82b9e0887 gpio: use srcu_dereference() with SRCU-protected pointers
Lockdep with CONFIG_PROVE_RCU enabled reports false positives about
suspicious rcu_dereference() usage. Let's silence it by using
srcu_dereference() which is the correct helper with SRCU.

Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
2024-02-15 08:39:25 +01:00
Bartosz Golaszewski
d83cee3d2b gpio: protect the pointer to gpio_chip in gpio_device with SRCU
Ensure we cannot crash if the GPIO device gets unregistered (and the
chip pointer set to NULL) during any of the API calls.

To that end: wait for all users of gdev->chip to exit their read-only
SRCU critical sections in gpiochip_remove().

For brevity: add a guard class which can be instantiated at the top of
every function requiring read-only access to the chip pointer and use it
in all API calls taking a GPIO descriptor as argument. In places where
we only deal with the GPIO device - use regular guard() helpers and
rcu_dereference() for chip access. Do the same in API calls taking a
const pointer to gpio_desc.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2024-02-12 11:00:31 +01:00
Bartosz Golaszewski
5694f274a0 gpio: sysfs: don't access gdev->chip if it's not needed
Don't dereference gdev->chip if the same information can be obtained
from struct gpio_device.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2024-02-12 10:51:13 +01:00
Bartosz Golaszewski
b93bca4bd6 gpio: sysfs: pass the GPIO device - not chip - to sysfs callbacks
We're working towards protecting the chip pointer in struct gpio_device
with SRCU. In order to use it in sysfs callbacks we must pass the pointer
to the GPIO device that wraps the chip instead of the address of the
chip itself as the user data.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2024-02-12 10:50:58 +01:00
Bartosz Golaszewski
59cba4a0e6 gpio: sysfs: extend the critical section for unregistering sysfs devices
Checking the gdev->mockdev pointer for NULL must be part of the critical
section.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2024-02-12 10:50:55 +01:00
Bartosz Golaszewski
35b545332b gpio: remove gpio_lock
The "multi-function" gpio_lock is pretty much useless with how it's used
in GPIOLIB currently. Because many GPIO API calls can be called from all
contexts but may also call into sleeping driver callbacks, there are
many places with utterly broken workarounds like yielding the lock to
call a possibly sleeping function and then re-acquiring it again without
taking into account that the protected state may have changed.

It was also used to protect several unrelated things: like individual
descriptors AND the GPIO device list. We now serialize access to these
two with SRCU and so can finally remove the spinlock.

There is of course the question of consistency of lockless access to
GPIO descriptors. Because we only support exclusive access to GPIOs
(officially anyway, I'm looking at you broken
GPIOD_FLAGS_BIT_NONEXCLUSIVE bit...) and the API contract with providers
does not guarantee serialization, it's enough to ensure we cannot
accidentally dereference an invalid pointer and that the state we present
to both users and providers remains consistent. To achieve that: read the
flags field atomically except for a few special cases. Read their current
value before executing callback code and use this value for any subsequent
logic. Modifying the flags depends on the particular use-case and can
differ. For instance: when requesting a GPIO, we need to set the
REQUESTED bit immediately so that the next user trying to request the
same line sees -EBUSY.

While at it: the allocations that used GFP_ATOMIC until this point can
now switch to GFP_KERNEL.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2024-02-12 10:50:45 +01:00
Bartosz Golaszewski
2a9101e875 gpio: sysfs: use gpio_device_find() to iterate over existing devices
With the list of GPIO devices now protected with SRCU we can use
gpio_device_find() to traverse it from sysfs.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2024-02-12 10:50:42 +01:00
Bartosz Golaszewski
efb8235bfd gpiolib: revert the attempt to protect the GPIO device list with an rwsem
This reverts commits 1979a2807547 ("gpiolib: replace the GPIO device
mutex with a read-write semaphore") and 65a828bab158 ("gpiolib: use
a mutex to protect the list of GPIO devices").

Unfortunately the legacy GPIO API that's still used in older code has to
translate numbers from the global GPIO numberspace to descriptors. This
results in a GPIO device lookup in every call to legacy functions. Some
of those functions - like gpio_set/get_value() - can be called from
atomic context so taking a sleeping lock that is an RW semaphore results
in an error.

We'll probably have to protect this list with SRCU.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-wireless/f7b5ff1e-8f34-4d98-a7be-b826cb897dc8@moroto.mountain/
Fixes: 1979a2807547 ("gpiolib: replace the GPIO device mutex with a read-write semaphore")
Fixes: 65a828bab158 ("gpiolib: use a mutex to protect the list of GPIO devices")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-17 09:52:37 +01:00
Bartosz Golaszewski
1979a28075 gpiolib: replace the GPIO device mutex with a read-write semaphore
There are only two spots where we modify (add to or remove objects from)
the GPIO device list. Readers should be able to access it concurrently.
Replace the mutex with a read-write semaphore and adjust the locking
operations accordingly.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2024-01-04 10:29:16 +01:00
Bartosz Golaszewski
513246a34b gpio: sysfs: drop tabs from local variable declarations
Older code has an annoying habit of putting tabs between the type and the
name of the variable. This doesn't really add to readability and newer
code doesn't do it so make the entire file consistent.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-12-27 16:01:37 +01:00
Bartosz Golaszewski
4ccdaba5ab Linux 6.7-rc7
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Merge tag 'v6.7-rc7' into gpio/for-next

Linux 6.7-rc7
2023-12-27 15:41:04 +01:00
Bartosz Golaszewski
65a828bab1 gpiolib: use a mutex to protect the list of GPIO devices
The global list of GPIO devices is never modified or accessed from
atomic context so it's fine to protect it using a mutex. Add a new
global lock dedicated to the gpio_devices list and use it whenever
accessing or modifying it.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-12-18 10:00:43 +01:00
Boerge Struempfel
95dd1e34ff gpiolib: sysfs: Fix error handling on failed export
If gpio_set_transitory() fails, we should free the GPIO again. Most
notably, the flag FLAG_REQUESTED has previously been set in
gpiod_request_commit(), and should be reset on failure.

To my knowledge, this does not affect any current users, since the
gpio_set_transitory() mainly returns 0 and -ENOTSUPP, which is converted
to 0. However the gpio_set_transitory() function calles the .set_config()
function of the corresponding GPIO chip and there are some GPIO drivers in
which some (unlikely) branches return other values like -EPROBE_DEFER,
and -EINVAL. In these cases, the above mentioned FLAG_REQUESTED would not
be reset, which results in the pin being blocked until the next reboot.

Fixes: e10f72bf4b3e ("gpio: gpiolib: Generalise state persistence beyond sleep")
Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-12-01 10:44:48 +01:00
Bartosz Golaszewski
e404b0cc9f gpio: sysfs: drop the mention of gpiochip_find() from sysfs code
We have removed all callers of gpiochip_find() so don't mention it in
gpiolib-sysfs.c.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2023-10-04 13:36:23 +02:00
Andy Shevchenko
20d9b3b5f2 gpiolib: sysfs: Do unexport GPIO when user asks for it
It seems that sysfs interface implicitly relied on the gpiod_free() to
unexport the line. This is logically incorrect as core gpiolib should
not deal with sysfs so instead of restoring it, let's call
gpiod_unexport() from sysfs code.

Fixes: b0ce9ce408b6 ("gpiolib: Do not unexport GPIO on freeing")
Reported-by: Marek Behún <kabel@kernel.org>
Closes: https://lore.kernel.org/r/20230808102828.4a9eac09@dellmb
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Marek Behún <kabel@kernel.org>
[Bartosz: tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-08-16 13:34:31 +02:00
Linus Torvalds
556eb8b791 Driver core changes for 6.4-rc1
Here is the large set of driver core changes for 6.4-rc1.
 
 Once again, a busy development cycle, with lots of changes happening in
 the driver core in the quest to be able to move "struct bus" and "struct
 class" into read-only memory, a task now complete with these changes.
 
 This will make the future rust interactions with the driver core more
 "provably correct" as well as providing more obvious lifetime rules for
 all busses and classes in the kernel.
 
 The changes required for this did touch many individual classes and
 busses as many callbacks were changed to take const * parameters
 instead.  All of these changes have been submitted to the various
 subsystem maintainers, giving them plenty of time to review, and most of
 them actually did so.
 
 Other than those changes, included in here are a small set of other
 things:
   - kobject logging improvements
   - cacheinfo improvements and updates
   - obligatory fw_devlink updates and fixes
   - documentation updates
   - device property cleanups and const * changes
   - firwmare loader dependency fixes.
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...
2023-04-27 11:53:57 -07:00
Greg Kroah-Hartman
6f14c02220 driver core: create class_is_registered()
Some classes (i.e. gpio), want to know if they have been registered or
not, and poke around in the class's internal structures to try to figure
this out.  Because this is not really a good idea, provide a function
for classes to call to try to figure this out.

Note, this is racy as the state of the class could change at any moment
in time after the call is made, but as usually a class only wants to
know if it has been registered yet or not, it should be fairly safe to
use, and is just as safe as the previous "poke at the class internals"
check was.

Move the gpiolib code to use this function as proof that it works
properly.

Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-gpio@vger.kernel.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-31 17:44:54 +02:00
Greg Kroah-Hartman
75a2d4226b driver core: class: mark the struct class for sysfs callbacks as constant
struct class should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, the structure is almost
never used in a sysfs callback, so mark it as constant to allow struct
class to be moved to read-only memory.

While we are touching all class sysfs callbacks also mark the attribute
as constant as it can not be modified.  The bonding code still uses this
structure so it can not be removed from the function callbacks.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Russ Weight <russell.h.weight@intel.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steve French <sfrench@samba.org>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: linux-cifs@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: netdev@vger.kernel.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20230325084537.3622280-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29 07:54:58 +02:00
Greg Kroah-Hartman
10a03c36b7 drivers: remove struct module * setting from struct class
There is no need to manually set the owner of a struct class, as the
registering function does it automatically, so remove all of the
explicit settings from various drivers that did so as it is unneeded.

This allows us to remove this pointer entirely from this structure going
forward.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:27 +01:00
Andy Shevchenko
380c7ba392 gpiolib: Clean up headers
There is a few things done:
- include only the headers we are direct user of
- when pointer is in use, provide a forward declaration
- add missing headers
- group generic headers and subsystem headers
- sort each group alphabetically

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-03-06 12:33:02 +02:00
Arnd Bergmann
d74e316633 gpiolib: remove legacy gpio_export()
There are only a handful of users of gpio_export() and
related functions.

As these are just wrappers around the modern gpiod_export()
helper, remove the wrappers and open-code the gpio_to_desc
in all callers to shrink the legacy API.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-03-06 12:33:01 +02:00
Andy Shevchenko
57017edd46 gpiolib: Embed iterator variable into for_each_gpio_desc_with_flag()
The iterator loop is used exclusively to get a descriptor, which in its
turn is what is being used by the caller. Embed the iterator variable
into the loop in the for_each_gpio_desc_with_flag() macro helper.

Suggested-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-04-09 22:37:48 +02:00
Linus Torvalds
ebcb577aee gpio updates for v5.18-rc1
- new driver: gpio-en7523
 - dt-bindings: convertion of faraday,ftgpio010 to YAML, new compatible string
   in gpio-vf610 and a bugfix in an example
 - gpiolib core: several improvements and some code shrink
 - documentation: convert all public docs into kerneldoc format
 - set IRQ bus token in gpio-crystalcove (addresses a debugfs issue)
 - add a missing return value check for kstrdup() in gpio-merrifield
 - allow gpio-tps68470 to be built as module
 - more work on limiting usage of of_node in GPIO drivers
 - several sysfs interface improvements
 - use SDPX in gpio-ts4900
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Merge tag 'gpio-updates-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio updates from Bartosz Golaszewski:
 "Relatively few updates for this release cycle. We have a single new
  driver and some minor changes in drivers, more work on limiting the
  usage of of_node in drivers and DT updates:

   - new driver: gpio-en7523

   - dt-bindings: convertion of faraday,ftgpio010 to YAML, new
     compatible string in gpio-vf610 and a bugfix in an example

   - gpiolib core: several improvements and some code shrink

   - documentation: convert all public docs into kerneldoc format

   - set IRQ bus token in gpio-crystalcove (addresses a debugfs issue)

   - add a missing return value check for kstrdup() in gpio-merrifield

   - allow gpio-tps68470 to be built as module

   - more work on limiting usage of of_node in GPIO drivers

   - several sysfs interface improvements

   - use SDPX in gpio-ts4900"

* tag 'gpio-updates-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: ts4900: Use SPDX header
  gpiolib: Use list_first_entry()/list_last_entry()
  gpiolib: sysfs: Simplify edge handling in the code
  gpiolib: sysfs: Move kstrtox() calls outside of the mutex lock
  gpiolib: sysfs: Move sysfs_emit() calls outside of the mutex lock
  gpiolib: make struct comments into real kernel docs
  dt-bindings: gpio: convert faraday,ftgpio01 to yaml
  dt-bindings: gpio: gpio-vf610: Add imx93 compatible string
  gpiolib: Simplify error path in gpiod_get_index() when requesting GPIO
  gpiolib: Use short form of ternary operator in gpiod_get_index()
  gpiolib: Introduce for_each_gpio_desc_with_flag() macro
  gpio: Add support for Airoha EN7523 GPIO controller
  dt-bindings: arm: airoha: Add binding for Airoha GPIO controller
  dt-bindings: gpio: fix gpio-hog example
  gpio: tps68470: Allow building as module
  gpio: tegra: Get rid of duplicate of_node assignment
  gpio: altera-a10sr: Switch to use fwnode instead of of_node
  gpio: merrifield: check the return value of devm_kstrdup()
  gpio: crystalcove: Set IRQ domain bus token to DOMAIN_BUS_WIRED
2022-03-25 12:28:23 -07:00
Andy Shevchenko
667630edb5 gpiolib: sysfs: Simplify edge handling in the code
Instead of keeping specific data structure for IRQ trigger types, switch
to array of trigger names and use index as a type.

The code is in maintenance mode and that array is not going to grow.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-02-16 16:03:08 +01:00
Andy Shevchenko
6b3c1791ae gpiolib: sysfs: Move kstrtox() calls outside of the mutex lock
In a few places we perform kstrtox() operations under mutex that
do not require any locking. Move them outside of the mutex locks.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-02-16 16:02:34 +01:00
Andy Shevchenko
e28747da77 gpiolib: sysfs: Move sysfs_emit() calls outside of the mutex lock
In a few places we perform sysfs_emit() operations under mutex that
do not require any locking. Move them outside of the mutex locks.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-02-16 16:02:11 +01:00
Andy Shevchenko
80c78fbeef gpiolib: Introduce for_each_gpio_desc_with_flag() macro
In a few places we are using a loop against all GPIO descriptors
with a given flag for a given device. Replace it with a consolidated
for_each type of macro.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-02-08 10:35:49 +01:00
Andy Shevchenko
95a4eed7dd gpiolib: Never return internal error codes to user space
Currently it's possible that character device interface may return
the error codes which are not supposed to be seen by user space.
In this case it's EPROBE_DEFER.

Wrap it to return -ENODEV instead as sysfs does.

Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 61f922db7221 ("gpio: userspace ABI for reading GPIO line events")
Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Reported-by: Suresh Balakrishnan <suresh.balakrishnan@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-02-08 10:34:15 +01:00
Andy Shevchenko
9e23bf6b00 gpiolib: Use sysfs_emit() in "show" functions
The sysfs_emit() function was introduced to make it less ambiguous
which function is preferred when writing to the output buffer in
a "show" callback [1].

Convert the GPIO library sysfs interface from sprintf() to sysfs_emit()
accordingly, as the latter is aware of the PAGE_SIZE buffer and correctly
returns the number of bytes written into the buffer.

No functional change intended.

[1] Documentation/filesystems/sysfs.rst

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-05-21 14:56:10 +02:00
Andy Shevchenko
fd80b8ba3a gpiolib: Make use of assign_bit() API (part 2)
We have for some time the assign_bit() API to replace open coded

	if (foo)
		set_bit(n, bar);
	else
		clear_bit(n, bar);

Use this API in GPIO library code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-05-21 14:53:35 +02:00
Matti Vaittinen
23cf00ddd2 gpio: sysfs: Obey valid_mask
Do not allow exporting GPIOs which are set invalid
by the driver's valid mask.

Fixes: 726cb3ba4969 ("gpiolib: Support 'gpio-reserved-ranges' property")
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-03-31 20:32:38 +02:00
Andy Shevchenko
8bbff39c6c gpiolib: Unify expectations about ->request() returned value
Half of the code in the GPIO library is written in an expectation that
any non-zero value returned from the ->request() callback is an error code,
while some code checks only for negative values.

Unify expectations about ->request() returned value to be non-zero
for an error and 0 for the success.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-10-26 15:43:15 +01:00
Kent Gibson
ef087d8e95 gpiolib: move gpiolib-sysfs function declarations into their own header
Move gpiolib-sysfs function declarations into their own header.

These functions are in gpiolib-sysfs.c, and are only required by gpiolib.c,
and so should be in a module header, not gpiolib.h.

This brings gpiolib-sysfs into line with gpiolib-cdev, and is another step
towards removing the sysfs inferface.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-12 10:22:00 +02:00
Wang Qing
97cd738c44 gpiolib: sysfs: use kobj_to_dev
Use kobj_to_dev() API instead of container_of().

Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-06-15 10:07:49 +02:00
Geert Uytterhoeven
ddd8891e01 gpiolib: Add GPIOCHIP_NAME definition
The string literal "gpiochip" is used in several places.
Add a definition for it, and use it everywhere, to make sure everything
stays in sync.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20191127084253.16356-2-geert+renesas@glider.be
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-12-12 11:36:13 +01:00
Linus Walleij
dae5f0afcf gpio: Use SPDX header for core library
Use the SPDX headers and cut down on boilerplate to indicate the
license in the core gpiolib implementation.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-09-25 09:08:48 +02:00
Linus Walleij
f13a0b0bb4 gpio: Get rid of legacy header
A bunch of core gpiolib files still include the <linux/gpio.h>
legacy API header for no good reason. After this only the
gpiolib-legacy.c file includes it, which is fine.

The sysfs ABI code has a pointless wrapper function around
gpio_to_desc() we can just loose.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-09-17 10:55:24 -07:00
Christophe Leroy
1efba35afa gpio: sysfs: avoid using kstrtol() in 'value' attribute write
A 'perf record' on an app continuously writing in the 'value'
attribute show that most of the time is spent in kstrtol()

--17.99%--value_store
          |
          |--10.17%--kstrtoint
          |          |
          |          |--8.82%--kstrtoll
          |
          |--2.50%--gpiod_set_value_cansleep
          |
          |--1.82%--u16_gpio_set
          |
          |--1.46%--value_store

The normal case is to write 0 or 1 in the attribute, therefore
this patch avoids the call to kstrtol() in the most common cases

Then 'perf record' shows

--7.21%--value_store
          |
          |--2.69%--u16_gpio_set
          |
          |--1.47%--value_store
          |
          |--1.08%--gpiod_set_value_cansleep
          |
          |--0.60%--mutex_lock
          |
           --0.58%--mutex_unlock

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-12-20 10:34:58 +01:00
Christophe Leroy
7a94b88cb7 gpio: sysfs: don't use sprintf() for 'value' attribute
A bench with 'perf record' shows that most of time spent in value_show()
is spent in sprintf()

--42.41%--sysfs_kf_read
          |
          |--39.73%--dev_attr_show
          |          |
          |          |--38.23%--value_show
          |          |          |
          |          |          |--29.22%--sprintf
          |          |          |
          |          |          |--2.94%--gpiod_get_value_cansleep
          |          |          |

value_show() only returns "0\n" or "1\n", therefore the use of
sprintf() can be avoided

With this patch we get the following result with 'perf record'

--13.89%--sysfs_kf_read
          |
          |--10.72%--dev_attr_show
          |          |
          |          |--9.44%--value_show
          |          |          |
          |          |          |--4.61%--gpiod_get_value_cansleep

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-12-20 10:34:01 +01:00