linux-toradex.git/drivers/gpio/gpiolib.h, branch v6.5-rc4

gpiolib: Introduce gpio_device_get() and gpio_device_put()

2023-01-30T14:55:29+00:00

Introduce gpio_device_get() and gpio_device_put() helpers
and convert existing users.

Signed-off-by: Andy Shevchenko 
Reviewed-by: Linus Walleij 
Signed-off-by: Bartosz Golaszewski

gpiolib: protect the GPIO device against being dropped while in use by user-space

2022-12-07T08:35:59+00:00

While any of the GPIO cdev syscalls is in progress, the kernel can call
gpiochip_remove() (for instance, when a USB GPIO expander is disconnected)
which will set gdev->chip to NULL after which any subsequent access will
cause a crash.

To avoid that: use an RW-semaphore in which the syscalls take it for
reading (so that we don't needlessly prohibit the user-space from calling
syscalls simultaneously) while gpiochip_remove() takes it for writing so
that it can only happen once all syscalls return.

Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24ea ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d98168 ("gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL")
Signed-off-by: Bartosz Golaszewski 
[Nick: fixed a build failure with CDEV_V1 disabled]
Co-authored-by: Nick Hainke 
Reviewed-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Linus Walleij

gpiolib: Provide to_gpio_device() helper

2022-11-29T13:52:20+00:00

Provide to_gpio_device() helper which can be utilized in the existing
and future code.

While at it, make sure it becomes no-op at compilation time.

Signed-off-by: Andy Shevchenko 
Reviewed-by: Linus Walleij 
Signed-off-by: Bartosz Golaszewski

Merge tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux

2022-06-05T16:12:28+00:00

Pull hardware timestamping subsystem from Thierry Reding:
 "This contains the new HTE (hardware timestamping engine) subsystem
  that has been in the works for a couple of months now.

  The infrastructure provided allows for drivers to register as hardware
  timestamp providers, while consumers will be able to request events
  that they are interested in (such as GPIOs and IRQs) to be timestamped
  by the hardware providers.

  Note that this currently supports only one provider, but there seems
  to be enough interest in this functionality and we expect to see more
  drivers added once this is merged"

[ Linus Walleij mentions the Intel PMC in the Elkhart and Tiger Lake
  platforms as another future timestamp provider ]

* tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  dt-bindings: timestamp: Correct id path
  dt-bindings: Renamed hte directory to timestamp
  hte: Uninitialized variable in hte_ts_get()
  hte: Fix off by one in hte_push_ts_ns()
  hte: Fix possible use-after-free in tegra_hte_test_remove()
  hte: Remove unused including 
  MAINTAINERS: Add HTE Subsystem
  hte: Add Tegra HTE test driver
  tools: gpio: Add new hardware clock type
  gpiolib: cdev: Add hardware timestamp clock type
  gpio: tegra186: Add HTE support
  gpiolib: Add HTE support
  dt-bindings: Add HTE bindings
  hte: Add Tegra194 HTE kernel provider
  drivers: Add hardware timestamp engine (HTE) subsystem
  Documentation: Add HTE subsystem guide

gpiolib: Add HTE support

2022-05-04T09:06:13+00:00

Some GPIO chip can provide hardware timestamp support on its GPIO lines
, in order to support that, additional API needs to be added which
can talk to both GPIO chip and HTE (hardware timestamping engine)
providers if there is any dependencies. This patch introduces optional
hooks to enable and disable hardware timestamping related features
in the GPIO controller chip.

Signed-off-by: Dipen Patel 
Reviewed-by: Linus Walleij 
Reported-by: kernel test robot 
Signed-off-by: Thierry Reding

gpiolib: Split out for_each_gpio_desc() macro

2022-04-09T20:38:17+00:00

In some cases we want to traverse all GPIO descriptors for given
chip, let's split out for_each_gpio_desc() macro for such cases.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

gpiolib: Embed iterator variable into for_each_gpio_desc_with_flag()

2022-04-09T20:37:48+00:00

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 
Signed-off-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

Merge tag 'gpio-updates-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

2022-03-25T19:28:23+00:00

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

gpiolib: make struct comments into real kernel docs

2022-02-09T09:07:10+00:00

We have several comments that start with '/**' but don't conform to the
kernel doc standard. Add proper detailed descriptions for the affected
definitions and move the docs from the forward declarations to the
struct definitions where applicable.

Reported-by: Randy Dunlap 
Signed-off-by: Bartosz Golaszewski 
Reviewed-by: Andy Shevchenko 
Tested-by: Randy Dunlap

gpiolib: Introduce for_each_gpio_desc_with_flag() macro

2022-02-08T09:35:49+00:00

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 
Reviewed-by: Linus Walleij 
Signed-off-by: Bartosz Golaszewski