linux.git/drivers/gpio/gpiolib-cdev.c, branch v6.0

gpiolib: cdev: Set lineevent_state::irq after IRQ register successfully

2022-09-21T07:32:11+00:00

When running gpio test on nxp-ls1028 platform with below command
gpiomon --num-events=3 --rising-edge gpiochip1 25
There will be a warning trace as below:
Call trace:
free_irq+0x204/0x360
lineevent_free+0x64/0x70
gpio_ioctl+0x598/0x6a0
__arm64_sys_ioctl+0xb4/0x100
invoke_syscall+0x5c/0x130
......
el0t_64_sync+0x1a0/0x1a4
The reason of this issue is that calling request_threaded_irq()
function failed, and then lineevent_free() is invoked to release
the resource. Since the lineevent_state::irq was already set, so
the subsequent invocation of free_irq() would trigger the above
warning call trace. To fix this issue, set the lineevent_state::irq
after the IRQ register successfully.

Fixes: 468242724143 ("gpiolib: cdev: refactor lineevent cleanup into lineevent_free")
Cc: stable@vger.kernel.org
Signed-off-by: Meng Li 
Reviewed-by: Kent Gibson 
Signed-off-by: Bartosz Golaszewski

Merge tag 'gpio-updates-for-v6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

2022-08-05T01:34:05+00:00

Pull gpio updates from Bartosz Golaszewski:
 "Here are the updates for this merge window from the GPIO subsystem.

  We have more lines removed than added thanks to dropping of a driver
  for a platform that's no longer supported. Otherwise the changes are
  pretty straightforward: support for some new models, various
  improvements to existing drivers, some tweaks to the core library code
  and DT bindings updates.

  Summary:

   - remove gpio-vr41xx driver as the only platform using it got dropped
     too

   - add support for suspend/resume to gpio-davinci

   - improvements to the GPIO character device code

   - add support for disabling bias for in-kernel users (up until now
     only user-space could set it)

   - drop unused devm_gpio_free()

   - fix a refcount issue in gpiolib OF

   - use device match helpers where applicable

   - add support for a new model to gpio-rockchip

   - non-functional improvements in gpio-adp5588

   - improve and simplify teardown in gpio-twl4030 and gpio-ucb1400

   - modernize the gpio-74xx-mmio and gpio-adnp drivers

   - coding style improvements in gpio-xilinx, gpio-104-idi-48

   - support new model (pca9571) in gpio-pca9570

   - convert the DT bindings to YAML for gpio-mvebu and update the
     document

   - don't return error codes from remove() in gpio-brcmstb

   - add a library for the intel 8255 PPI interface and use it in
     drivers

   - reduce using magic numbers and improve code readability in several
     drivers

   - convert DT bindings to YAML for gpio-tpic2810

   - add new models to DT bindings for gpio-frl-imx

   - Kconfig improvements

   - other minor tweaks and improvements"

* tag 'gpio-updates-for-v6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (52 commits)
  dt-bindings: gpio: fsl-imx-gpio: Add i.MXRT compatibles
  gpio: 74xx-mmio: Use bits instead of plain numbers for flags
  gpio: xilinx: add missing blank line after declarations
  MAINTAINERS: Update Intel 8255 GPIO driver file list
  gpio: gpio-mm: Implement and utilize register structures
  gpio: 104-idi-48: Implement and utilize register structures
  gpio: 104-dio-48e: Implement and utilize register structures
  gpio: i8255: Introduce the Intel 8255 interface library module
  gpio: 104-idio-16: Implement and utilize register structures
  gpio: ws16c48: Implement and utilize register structures
  gpio: remove VR41XX related gpio driver
  dt-bindings: gpio: add pull-disable flag
  gpiolib: acpi: support bias pull disable
  gpiolib: of: support bias pull disable
  gpiolib: add support for bias pull disable
  gpio: 74xx-mmio: use bits.h macros for all masks
  gpio: 74xx-mmio: Check MMIO_74XX_DIR_IN flag in mmio_74xx_dir_in()
  gpio: 74xx-mmio: Make use of device properties
  gpiolib: cdev: compile out HTE unless CONFIG_HTE selected
  gpiolib: cdev: consolidate edge detector configuration flags
  ...

gpiolib: cdev: compile out HTE unless CONFIG_HTE selected

2022-07-19T08:02:46+00:00

The majority of builds do not include HTE, so compile out hte
functionality unless CONFIG_HTE is selected.

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

gpiolib: cdev: consolidate edge detector configuration flags

2022-07-19T08:02:12+00:00

Combine the polarity_change flag, struct line eflags, and hte enable
flag into a single flag variable.

The combination of these flags describes the configuration state
of the edge detector, so formalize and clarify that by combining
them into a single variable, edflags, in struct line.

The edflags is a subset of the GPIO_V2_LINE_FLAGsb relevant to
the edge detector, and is also a superset of the eflags it replaces.
The eflags name is still used to describe the subset of edflags
corresponding to the rising/falling edge flags where edflags is
masked down to that subset.

This consolidation reduces the number of variables being passed,
simplifies state comparisons, and provides a more extensible
foundation should additional edge sources be integrated in the
future.

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

gpiolib: cdev: simplify line event identification

2022-07-19T08:01:25+00:00

Reorganise line event identification code to reduce code duplication,
and replace if-else initializers with a helper function to improve
readability.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Linus Walleij

gpiolib: cdev: replace if-else chains with switches

2022-07-19T08:01:25+00:00

Improve readability by replacing if-else chains with switch
statements.

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

gpiolib: cdev: simplify parameter in call to hte_edge_setup

2022-07-19T08:01:25+00:00

Improve readability by using the GPIO_V2_LINE_FLAG_EDGE_BOTH instead
of combining the rising and falling edge flags.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Acked-by: Dipen Patel 
Tested-by: Dipen Patel 
Reviewed-by: Linus Walleij 
Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: simplify linereq_free

2022-07-19T08:01:22+00:00

The edge detector is only ever started after the line desc has been
determined, so move edge_detector_stop() inside the line desc check,
and merge the two checked regions into one.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Acked-by: Dipen Patel 
Reviewed-by: Linus Walleij 
Signed-off-by: Bartosz Golaszewski

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

2022-07-18T18:47:04+00:00

Pull hardware timestamp fix from Thierry Reding:
 "A single fix for an out-of-sync kerneldoc comment"

* tag 'hte/for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  gpiolib: cdev: Fix kernel doc for struct line

gpiolib: cdev: fix null pointer dereference in linereq_free()

2022-07-07T10:18:18+00:00

Fix a kernel NULL pointer dereference reported by gpio kselftests.

linereq_free() can be called as part of the cleanup of a failed request,
at which time the desc for a line may not have been determined, so it
is unsafe to dereference without a check.

Add a check prior to dereferencing the line desc.

Fixes: 2068339a6c35 ("gpiolib: cdev: Add hardware timestamp clock type")
Signed-off-by: Kent Gibson 
Signed-off-by: Bartosz Golaszewski