Commit Graph

64 Commits

Author SHA1 Message Date
Bartosz Golaszewski
9ce4ed5b4d gpiolib: provide and use gpiod_line_state_notify()
Wrap the calls to blocking_notifier_call_chain() for the line state
notifier with a helper that allows us to use fewer lines of code and
simpler syntax.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2023-08-22 09:37:46 +02:00
Bartosz Golaszewski
91043f5593 gpio: cdev: wake up lineevent poll() on device unbind
Add a notifier block to the lineevent_state structure and register it
with the gpio_device's device notifier. Upon reception of an event, wake
up the wait queue so that the user-space be forced out of poll() and
need to go into a new system call which will then fail due to the chip
being gone.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21 15:57:05 +02:00
Bartosz Golaszewski
a0dda508bd gpio: cdev: wake up linereq poll() on device unbind
Add a notifier block to the linereq structure and register it with the
gpio_device's device notifier. Upon reception of an event, wake up the
wait queue so that the user-space be forced out of poll() and need to go
into a new system call which will then fail due to the chip being gone.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21 15:57:05 +02:00
Bartosz Golaszewski
d2e2586a32 gpio: cdev: wake up chardev poll() on device unbind
Add a notifier block to the gpio_chardev_data structure and register it
with the gpio_device's device notifier. Upon reception of an event, wake
up the wait queue so that the user-space be forced out of poll() and need
to go into a new system call which will then fail due to the chip being
gone.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21 15:57:05 +02:00
Bartosz Golaszewski
a067419ba7 gpiolib: add a second blocking notifier to struct gpio_device
Add a new blocking notifier to struct gpio_device and use it to notify
subscribers about the GPIO device being unregistered from the device
model.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21 15:57:05 +02:00
Bartosz Golaszewski
e82bbd6761 gpio: cdev: open-code to_gpio_chardev_data()
This function is a wrapper around container_of(). It's used only once and
we will have a second notifier soon, so instead of having two flavors of
this helper, let's just open-code where needed.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21 15:57:05 +02:00
Bartosz Golaszewski
17a7ca3589 gpiolib: rename the gpio_device notifier
Change the generic "notifier" name to "line_state_notifier" in order to
reflect its purpose in preparation for adding a second notifier which
will be used to notify wait queues about device unregistering.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
2023-08-21 15:57:05 +02:00
Andy Shevchenko
dc0989e3aa gpiolib: Introduce gpio_device_get() and gpio_device_put()
Introduce gpio_device_get() and gpio_device_put() helpers
and convert existing users.

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>
2023-01-30 15:55:29 +01:00
Linus Torvalds
c0f234ff90 gpio: updates for v6.2
GPIO core:
 - teach gpiolib to work with software nodes for HW description
 - remove ARCH_NR_GPIOS treewide as we no longer impose any limit on the number
   of GPIOS since the allocation became entirely dynamic
 - add support for HW quirks for Cirrus CS42L56 codec, Marvell NFC controller,
   Freescale PCIe and Ethernet controller, Himax LCDs and Mediatek mt2701
 - refactor OF quirk code
 - some general refactoring of the OF and ACPI code, adding new helpers, minor
   tweaks and fixes, making fwnode usage consistent etc.
 
 GPIO uAPI:
 - fix an issue where the user-space can trigger a NULL-pointer dereference in
   the kernel by opening a device file, forcing a driver unbind and then calling
   one of the syscalls on the associated file descriptor
 
 New drivers:
 - add gpio-latch: a new GPIO multiplexer based on latches connected to other
   GPIOs
 
 Driver updates:
 - convert i2c GPIO expanders to using .probe_new()
 - drop the gpio-sta2x11 driver
 - factor out common code for the ACCES IDIO-16 family of controllers and use
   this new library wherever applicable in drivers
 - add DT support to gpio-hisi
 - allow building gpio-davinci as a module and increase its maxItems property
 - add support for a new model to gpio-pca9570
 - other minor changes to various drivers
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Merge tag 'gpio-updates-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio updates from Bartosz Golaszewski:
 "We have a new GPIO multiplexer driver, bunch of driver updates and
  refactoring in the core GPIO library.

  GPIO core:
   - teach gpiolib to work with software nodes for HW description
   - remove ARCH_NR_GPIOS treewide as we no longer impose any limit on
     the number of GPIOS since the allocation became entirely dynamic
   - add support for HW quirks for Cirrus CS42L56 codec, Marvell NFC
     controller, Freescale PCIe and Ethernet controller, Himax LCDs and
     Mediatek mt2701
   - refactor OF quirk code
   - some general refactoring of the OF and ACPI code, adding new
     helpers, minor tweaks and fixes, making fwnode usage consistent
     etc.

  GPIO uAPI:
   - fix an issue where the user-space can trigger a NULL-pointer
     dereference in the kernel by opening a device file, forcing a
     driver unbind and then calling one of the syscalls on the
     associated file descriptor

  New drivers:
   - add gpio-latch: a new GPIO multiplexer based on latches connected
     to other GPIOs

  Driver updates:
   - convert i2c GPIO expanders to using .probe_new()
   - drop the gpio-sta2x11 driver
   - factor out common code for the ACCES IDIO-16 family of controllers
     and use this new library wherever applicable in drivers
   - add DT support to gpio-hisi
   - allow building gpio-davinci as a module and increase its maxItems
     property
   - add support for a new model to gpio-pca9570
   - other minor changes to various drivers"

* tag 'gpio-updates-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (66 commits)
  gpio: sim: set a limit on the number of GPIOs
  gpiolib: protect the GPIO device against being dropped while in use by user-space
  gpiolib: cdev: fix NULL-pointer dereferences
  gpiolib: Provide to_gpio_device() helper
  gpiolib: Unify access to the device properties
  gpio: Do not include <linux/kernel.h> when not really needed.
  gpio: pcf857x: Convert to i2c's .probe_new()
  gpio: pca953x: Convert to i2c's .probe_new()
  gpio: max732x: Convert to i2c's .probe_new()
  dt-bindings: gpio: gpio-davinci: Increase maxItems in gpio-line-names
  gpiolib: ensure that fwnode is properly set
  gpio: sl28cpld: Replace irqchip mask_invert with unmask_base
  gpiolib: of: Use correct fwnode for DT-probed chips
  gpiolib: of: Drop redundant check in of_mm_gpiochip_remove()
  gpiolib: of: Prepare of_mm_gpiochip_add_data() for fwnode
  gpiolib: add support for software nodes
  gpiolib: consolidate GPIO lookups
  gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers
  gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes
  gpiolib: acpi: change acpi_find_gpio() to accept firmware node
  ...
2022-12-15 09:45:51 -08:00
Bartosz Golaszewski
bdbbae241a gpiolib: protect the GPIO device against being dropped while in use by user-space
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: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635a ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24 ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d981 ("gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
[Nick: fixed a build failure with CDEV_V1 disabled]
Co-authored-by: Nick Hainke <vincent@systemli.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2022-12-07 09:35:59 +01:00
Bartosz Golaszewski
533aae7c94 gpiolib: cdev: fix NULL-pointer dereferences
There are several places where we can crash the kernel by requesting
lines, unbinding the GPIO device, then calling any of the system calls
relevant to the GPIO character device's annonymous file descriptors:
ioctl(), read(), poll().

While I observed it with the GPIO simulator, it will also happen for any
of the GPIO devices that can be hot-unplugged - for instance any HID GPIO
expander (e.g. CP2112).

This affects both v1 and v2 uAPI.

This fixes it partially by checking if gdev->chip is not NULL but it
doesn't entirely remedy the situation as we still have a race condition
in which another thread can remove the device after the check.

Fixes: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635a ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24 ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d981 ("gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2022-12-07 09:35:48 +01:00
Andy Shevchenko
8d25984724 gpiolib: cdev: Fix typo in kernel doc for struct line
When eflags has been renamed to the edflags, the kernel doc change were
missed. Update kernel doc accordingly.

Fixes: b1a92e9456 ("gpiolib: cdev: consolidate edge detector configuration flags")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
2022-10-25 19:48:55 +03:00
Andy Shevchenko
52ee7c02f6 gpiolib: cdev: Add missing header(s)
Do not imply that some of the generic headers may be always included.
Instead, include explicitly what we are direct user of.

While at it, sort headers alphabetically.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Rewiewed-by: Kent Gibson <warthog618@gmail.com>
2022-10-24 12:30:00 +03:00
Linus Torvalds
f01603979a gpio updates for v6.1-rc1
New drivers:
 - add a new driver for the IMX System Controller Unit GPIOs
 
 GPIO core:
 - add fdinfo output for the GPIO character device file descriptors (allows
   user-space to determine which processes own which GPIO lines)
 - improvements to OF GPIO code
 - new quirk for Asus UM325UAZ in gpiolib-acpi
 - new quirk for Freescale SPI in gpiolib-of
 
 Driver improvements:
 - add a new macro that reduces the amount of boilerplate code in ISA drivers
   and use it in relevant drivers
 - support two new models in gpio-pca953x
 - support new model in gpio-f7188x
 - convert more drivers to use immutable irq chips
 - other minor tweaks
 
 Device-tree bindings:
 - add DT bindings for gpio-imx-scu
 - convert Xilinx GPIO bindings to YAML
 - reference the properties from the SPI peripheral device-tree bindings
   instead of providing custom ones in the GPIO controller document
 - add parsing of GPIO hog nodes to the DT bindings for gpio-mpfs-gpio
 - relax the node name requirements in gpio-stmpe
 - add new models for gpio-rcar and gpio-pxa95xx
 - add a new vendor prefix: Diodes (for Diodes, Inc.)
 
 Misc:
 - pulled in the immutable branch from the x86 platform drivers tree including
   support for a new simatic board that depends on GPIO changes
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Merge tag 'gpio-updates-for-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio updates from Bartosz Golaszewski:
 "We have a single new driver, support for a bunch of new models,
  improvements in drivers and core gpiolib code as well device-tree
  bindings changes.

  Summary:

  New driver:
   - IMX System Controller Unit GPIOs

  GPIO core:
   - add fdinfo output for the GPIO character device file descriptors
     (allows user-space to determine which processes own which GPIO
     lines)
   - improvements to OF GPIO code
   - new quirk for Asus UM325UAZ in gpiolib-acpi
   - new quirk for Freescale SPI in gpiolib-of

  Driver improvements:
   - add a new macro that reduces the amount of boilerplate code in ISA
     drivers and use it in relevant drivers
   - support two new models in gpio-pca953x
   - support new model in gpio-f7188x
   - convert more drivers to use immutable irq chips
   - other minor tweaks

  Device-tree bindings:
   - add DT bindings for gpio-imx-scu
   - convert Xilinx GPIO bindings to YAML
   - reference the properties from the SPI peripheral device-tree
     bindings instead of providing custom ones in the GPIO controller
     document
   - add parsing of GPIO hog nodes to the DT bindings for gpio-mpfs-gpio
   - relax the node name requirements in gpio-stmpe
   - add new models for gpio-rcar and gpio-pxa95xx
   - add a new vendor prefix: Diodes (for Diodes, Inc.)

  Misc:
   - pulled in the immutable branch from the x86 platform drivers tree
     including support for a new simatic board that depends on GPIO
     changes"

* tag 'gpio-updates-for-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (36 commits)
  gpio: tc3589x: Make irqchip immutable
  gpiolib: cdev: add fdinfo output for line request file descriptors
  gpio: twl4030: Reorder functions which allows to drop a forward declaraion
  gpiolib: fix OOB access in quirk callbacks
  gpiolib: of: factor out conversion from OF flags
  gpiolib: rework quirk handling in of_find_gpio()
  gpiolib: of: make Freescale SPI quirk similar to all others
  gpiolib: of: do not ignore requested index when applying quirks
  gpio: ws16c48: Ensure number of irq matches number of base
  gpio: 104-idio-16: Ensure number of irq matches number of base
  gpio: 104-idi-48: Ensure number of irq matches number of base
  gpio: 104-dio-48e: Ensure number of irq matches number of base
  counter: 104-quad-8: Ensure number of irq matches number of base
  isa: Introduce the module_isa_driver_with_irq helper macro
  gpio: pca953x: Add support for PCAL6534
  gpio: pca953x: Swap if statements to save later complexity
  gpio: pca953x: Fix pca953x_gpio_set_pull_up_down()
  dt-bindings: gpio: pca95xx: add entry for pcal6534 and PI4IOE5V6534Q
  dt-bindings: vendor-prefixes: add Diodes
  gpio: mt7621: Switch to use platform_get_irq() function
  ...
2022-10-08 09:46:29 -07:00
Bartosz Golaszewski
0ae3109a83 gpiolib: cdev: add fdinfo output for line request file descriptors
Add fdinfo output for file descriptors created for user-space line
requests in GPIO uAPI v2. The fdinfo file now contains the name of the
GPIO chip that is the "parent" of the request as well as offsets of
the lines requested. This allows user-space to parse the /proc/$PID/fdinfo
entries and deduce the PID of the process that requested a specific line.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
2022-09-26 14:15:38 +02:00
Meng Li
69bef19d6b gpiolib: cdev: Set lineevent_state::irq after IRQ register successfully
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: 4682427241 ("gpiolib: cdev: refactor lineevent cleanup into lineevent_free")
Cc: stable@vger.kernel.org
Signed-off-by: Meng Li <Meng.Li@windriver.com>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-09-21 09:32:11 +02:00
Linus Torvalds
37644cac6e gpio: updates for v6.0-rc1
- 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
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Merge tag 'gpio-updates-for-v6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

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
  ...
2022-08-04 18:34:05 -07:00
Kent Gibson
272ddba004 gpiolib: cdev: compile out HTE unless CONFIG_HTE selected
The majority of builds do not include HTE, so compile out hte
functionality unless CONFIG_HTE is selected.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:02:46 +02:00
Kent Gibson
b1a92e9456 gpiolib: cdev: consolidate edge detector configuration flags
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 <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:02:12 +02:00
Kent Gibson
242202329f gpiolib: cdev: simplify line event identification
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 <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2022-07-19 10:01:25 +02:00
Kent Gibson
cfa53463ac gpiolib: cdev: replace if-else chains with switches
Improve readability by replacing if-else chains with switch
statements.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:01:25 +02:00
Kent Gibson
2487a81223 gpiolib: cdev: simplify parameter in call to hte_edge_setup
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 <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Tested-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:01:25 +02:00
Kent Gibson
160d6e4029 gpiolib: cdev: simplify linereq_free
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 <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-19 10:01:22 +02:00
Linus Torvalds
80e19f34c2 hte: Fixes for v5.19
This contains a single fix for an out-of-sync kerneldoc comment.
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Merge tag 'hte/for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux

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
2022-07-18 11:47:04 -07:00
Kent Gibson
c8e27a4a51 gpiolib: cdev: fix null pointer dereference in linereq_free()
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: 2068339a6c ("gpiolib: cdev: Add hardware timestamp clock type")
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-07-07 12:18:18 +02:00
Andy Shevchenko
85ff37e302 gpiolib: cdev: Fix kernel doc for struct line
Kernel doc validator is not happy:
  gpiolib-cdev.c:487: warning: Function parameter or member 'hdesc' not described in 'line'
  gpiolib-cdev.c:487: warning: Function parameter or member 'raw_level' not described in 'line'
  gpiolib-cdev.c:487: warning: Function parameter or member 'total_discard_seq' not described in 'line'
  gpiolib-cdev.c:487: warning: Function parameter or member 'last_seqno' not described in 'line'

Describe above mentioned parameters.

Fixes: 2068339a6c ("gpiolib: cdev: Add hardware timestamp clock type")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Acked-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2022-06-17 12:58:57 +02:00
Linus Torvalds
2981436374 hte: New subsystem for v5.19-rc1
This contains the new HTE 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.
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Merge tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux

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 <linux/version.h>
  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
2022-06-05 09:12:28 -07:00
Dipen Patel
2068339a6c gpiolib: cdev: Add hardware timestamp clock type
This patch adds new clock type for the GPIO controller which can
timestamp gpio lines in using hardware means. To expose such
functionalities to the userspace, code has been added where
during line create or set config API calls, it checks for new
clock type and if requested, calls HTE API. During line change
event, the HTE subsystem pushes timestamp data to userspace
through gpiolib-cdev.

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2022-05-04 11:06:13 +02:00
Andy Shevchenko
1cef8b5019 gpiolib: Get rid of redundant 'else'
In the snippets like the following

	if (...)
		return / goto / break / continue ...;
	else
		...

the 'else' is redundant. Get rid of it. In case of IOCTLs use
switch-case pattern that seems the usual in such cases.

While at it, clarify necessity of else in gpiod_direction_output()
by attaching else if to the closing curly brace on a previous line.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2022-04-05 14:20:07 +02:00
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: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Fixes: 3c0d9c635a ("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
Gabriel Knezek
cb8f63b8cb gpiolib: cdev: zero padding during conversion to gpioline_info_changed
When userspace requests a GPIO v1 line info changed event,
lineinfo_watch_read() populates and returns the gpioline_info_changed
structure. It contains 5 words of padding at the end which are not
initialized before being returned to userspace.

Zero the structure in gpio_v2_line_info_change_to_v1() before populating
its contents.

Fixes: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Signed-off-by: Gabriel Knezek <gabeknez@linux.microsoft.com>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-06-22 09:54:13 +02:00
Kent Gibson
03a58ea590 gpiolib: cdev: clear debounce period if line set to output
When set_config changes a line from input to output debounce is
implicitly disabled, as debounce makes no sense for outputs, but the
debounce period is not being cleared and is still reported in the
line info.

So clear the debounce period when the debouncer is stopped in
edge_detector_stop().

Fixes: 65cff70464 ("gpiolib: cdev: support setting debounce")
Cc: stable@vger.kernel.org
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-01-27 15:52:13 +01:00
Kent Gibson
2e202ad873 gpiolib: cdev: fix frame size warning in gpio_ioctl()
The kernel test robot reports the following warning in [1]:

 drivers/gpio/gpiolib-cdev.c: In function 'gpio_ioctl':
 >>drivers/gpio/gpiolib-cdev.c:1437:1: warning: the frame size of 1040 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Refactor gpio_ioctl() to handle each ioctl in its own helper function
and so reduce the variables stored on the stack to those explicitly
required to service the ioctl at hand.

The lineinfo_get_v1() helper handles both the GPIO_GET_LINEINFO_IOCTL
and GPIO_GET_LINEINFO_WATCH_IOCTL, as per the corresponding v2
implementation - lineinfo_get().

[1] https://lore.kernel.org/lkml/202012270910.VW3qc1ER-lkp@intel.com/

Fixes: aad955842d ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-01-03 16:32:21 +01:00
Linus Walleij
40b37008eb gpio updates for v5.11-rc1
- several refactoring patches of the core gpiolib code
 - add support for NXP PCAL9554B/C to gpio-pca953x
 - allow probing mockup devices from device tree
 - refactoring and improvements to gpio-rcar
 - improvements to locking in gpio-tegra
 - code shrink in gpiolib devres
 - get the irq offset from device tree in gpio-sifive
 - major refactoring of gpio-exar
 - convert gpio-mvebu pwm access to regmap
 - create a new submenu for virtual GPIO drivers
 - fix clang fall-through warnings treewide
 - minor driver refactoring and tweaks sprinkled all over
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Merge tag 'gpio-updates-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into devel

gpio updates for v5.11-rc1

- several refactoring patches of the core gpiolib code
- add support for NXP PCAL9554B/C to gpio-pca953x
- allow probing mockup devices from device tree
- refactoring and improvements to gpio-rcar
- improvements to locking in gpio-tegra
- code shrink in gpiolib devres
- get the irq offset from device tree in gpio-sifive
- major refactoring of gpio-exar
- convert gpio-mvebu pwm access to regmap
- create a new submenu for virtual GPIO drivers
- fix clang fall-through warnings treewide
- minor driver refactoring and tweaks sprinkled all over
2020-12-09 15:17:24 +01:00
Marc Zyngier
a0db197f53 gpiolib: cdev: Flag invalid GPIOs as used
When reporting the state of a GPIO to userspace, we never check
for the actual validity of the line, meaning we report invalid
lines as being usable. A subsequent request will fail though,
which is an inconsistent behaviour from a userspace perspective.

Instead, let's check for the validity of the line and report it
as used if it is invalid. This allows a tool such as gpioinfo
to report something sensible:

gpiochip3 - 4 lines:
	line   0:      unnamed       unused   input  active-high
	line   1:      unnamed       kernel   input  active-high [used]
	line   2:      unnamed       kernel   input  active-high [used]
	line   3:      unnamed       unused   input  active-high

In this example, lines 1 and 2 are invalid, and cannot be used by
userspace.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20201204164739.781812-2-maz@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-12-09 10:23:04 +01:00
Kent Gibson
26d060e47e gpiolib: cdev: allow edge event timestamps to be configured as REALTIME
Using CLOCK_REALTIME as the source for event timestamps is crucial for
some specific applications, particularly those requiring timetamps
relative to a PTP clock, so provide an option to switch the event
timestamp source from the default CLOCK_MONOTONIC to CLOCK_REALTIME.

Note that CLOCK_REALTIME was the default source clock for GPIO until
Linux 5.7 when it was changed to CLOCK_MONOTONIC due to issues with the
shifting of the realtime clock.
Providing this option maintains the CLOCK_MONOTONIC as the default,
while also providing a path forward for those dependent on the pre-5.7
behaviour.

Suggested-by: Jack Winch <sunt.un.morcov@gmail.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20201014231158.34117-2-warthog618@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-12-05 23:22:47 +01:00
Kent Gibson
5e2ca893d7 gpiolib: cdev: add GPIO_V2_LINE_FLAG_EDGE_BOTH and use it in edge_irq_thread()
Add GPIO_V2_LINE_FLAG_EDGE_BOTH macro and use it in edge_irq_thread() to
improve readability of edge handling cases.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-10-30 15:53:19 +01:00
Andy Shevchenko
163d1719d3 gpiolib: Switch to use compat_need_64bit_alignment_fixup() helper
Use the new compat_need_64bit_alignment_fixup() helper to avoid
ugly ifdeffery in IOCTL compatibility code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Kent Gibson <warthog618@gmail.com>
Depends-on: 527c412519 ("compat: add a compat_need_64bit_alignment_fixup() helper")
Link: https://lore.kernel.org/r/20201014103315.82662-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-10-28 15:47:00 +01:00
Kent Gibson
3ffb7c45d1 gpiolib: cdev: document that line eflags are shared
The line.eflags field is shared so document this fact and highlight it
throughout using READ_ONCE() and WRITE_ONCE() accessors.

Also use a local copy of the eflags in edge_irq_thread() to ensure
consistent control flow even if eflags changes.  This is only a defensive
measure as edge_irq_thread() is currently disabled when the eflags are
changed.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-10-26 15:26:31 +01:00
Linus Torvalds
0486beaf88 GPIO bulk changes for the v5.10 kernel cycle:
Core changes:
 
 - The big core change is the updated (v2) userspace character
   device API. This corrects badly designed 64-bit alignment around
   the line events. We also add the debounce request feature.
   This echoes the often quotes passage from Frederick Brooks
   "The mythical man-month" to always throw one away, which we
   have seen before in things such as V4L2. So we put in a new
   one and deprecate and obsolete the old one.
 
 - All example tools in tools/gpio/* are migrated to the new API
   to set a good example. The libgpiod userspace library has been
   augmented to use this new API pretty much from day 1.
 
 - Some misc API hardening by using strn* function calls has been
   added as well.
 
 - Use the simpler IDA interface for GPIO chip instance enumeration.
 
 - Add device core function for counting string arrays in
   device properties.
 
 - Provide a generic library function kfree_strarray() that can
   be used throughout the kernel.
 
 Driver enhancements:
 
 - The DesignWare dwapb-gpio driver has been enhanced and now
   uses the IRQ handling in the gpiolib core.
 
 - The mockup and aggregator drivers have seen some substantial
   code clean-up and now use more of the core kernel
   inftrastructure.
 
 - Misc cleanups using dev_err_probe().
 
 - The MXC drivers (Freescale/NXP) can now be built modularized,
   which makes modularized GKI Android kernels happy.
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Merge tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This time very little driver changes but lots of core changes.

  We have some interesting cooperative work for ARM and Intel alike,
  making the GPIO subsystem more and more suitable for industrial
  systems and the like, in addition to the in-kernel users.

  We touch driver core (device properties) and lib/* by adding one
  simple string array free function, these are authored by Andy
  Shevchenko who is a well known and recognized core helpers maintainers
  so this should be fine.

  We also see some Android GKI-related modularization in the MXC
  drivers.

  Core changes:

   - The big core change is the updated (v2) userspace character device
     API.

     This corrects badly designed 64-bit alignment around the line
     events. We also add the debounce request feature. This echoes the
     often quotes passage from Frederick Brooks "The mythical man-month"
     to always throw one away, which we have seen before in things such
     as V4L2. So we put in a new one and deprecate and obsolete the old
     one.

   - All example tools in tools/gpio/* are migrated to the new API to
     set a good example. The libgpiod userspace library has been
     augmented to use this new API pretty much from day 1.

   - Some misc API hardening by using strn* function calls has been
     added as well.

   - Use the simpler IDA interface for GPIO chip instance enumeration.

   - Add device core function for counting string arrays in device
     properties.

   - Provide a generic library function kfree_strarray() that can be
     used throughout the kernel.

  Driver enhancements:

   - The DesignWare dwapb-gpio driver has been enhanced and now uses the
     IRQ handling in the gpiolib core.

   - The mockup and aggregator drivers have seen some substantial code
     clean-up and now use more of the core kernel inftrastructure.

   - Misc cleanups using dev_err_probe().

   - The MXC drivers (Freescale/NXP) can now be built modularized, which
     makes modularized GKI Android kernels happy"

* tag 'gpio-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (73 commits)
  gpiolib: Update header block in gpiolib-cdev.h
  gpiolib: cdev: switch from kstrdup() to kstrndup()
  docs: gpio: add a new document to its index.rst
  gpio: pca953x: Add support for the NXP PCAL9554B/C
  tools: gpio: add debounce support to gpio-event-mon
  tools: gpio: add multi-line monitoring to gpio-event-mon
  tools: gpio: port gpio-event-mon to v2 uAPI
  tools: gpio: port gpio-hammer to v2 uAPI
  tools: gpio: rename nlines to num_lines
  tools: gpio: port gpio-watch to v2 uAPI
  tools: gpio: port lsgpio to v2 uAPI
  gpio: uapi: document uAPI v1 as deprecated
  gpiolib: cdev: support setting debounce
  gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL
  gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL
  gpiolib: cdev: support edge detection for uAPI v2
  gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL
  gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL
  gpiolib: add build option for CDEV v1 ABI
  gpiolib: make cdev a build option
  ...
2020-10-13 10:09:33 -07:00
Kent Gibson
f188ac1251 gpiolib: cdev: switch from kstrdup() to kstrndup()
Use kstrndup() to copy line labels from the userspace provided char
array, rather than ensuring the char array contains a null terminator
and using kstrdup().

Note that the length provided to kstrndup() still assumes that the char
array does contain a null terminator, so the maximum string length is one
less than the array.  This is consistent with the previous behaviour.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20201005070246.20927-1-warthog618@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-10-08 22:57:16 +02:00
Andy Shevchenko
47e538d86d gpiolib: Disable compat ->read() code in UML case
It appears that UML (arch/um) has no compat.h header defined and hence
can't compile a recently provided piece of code in GPIO library.

Disable compat ->read() code in UML case to avoid compilation errors.

While at it, use pattern which is already being used in the kernel elsewhere.

Fixes: 5ad284ab3a ("gpiolib: Fix line event handling in syscall compatible mode")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20201005131044.87276-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-10-07 11:42:03 +02:00
Kent Gibson
65cff70464 gpiolib: cdev: support setting debounce
Add support for setting debounce on a line via the GPIO uAPI.
Where debounce is not supported by hardware, a software debounce is
provided.

The implementation of the software debouncer waits for the line to be
stable for the debounce period before determining if a level change,
and a corresponding edge event, has occurred.  This provides maximum
protection against glitches, but also introduces a debounce_period
latency to edge events.

The software debouncer is integrated with the edge detection as it
utilises the line interrupt, and integration is simpler than getting
the two to interwork.  Where software debounce AND edge detection is
required, the debouncer provides both.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:57:04 +02:00
Kent Gibson
7b8e00d981 gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL
Add support for the GPIO_V2_LINE_SET_VALUES_IOCTL.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:57:02 +02:00
Kent Gibson
a54756cb24 gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL
Add support for GPIO_V2_LINE_SET_CONFIG_IOCTL, the uAPI v2
line set config ioctl.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:59 +02:00
Kent Gibson
73e0341992 gpiolib: cdev: support edge detection for uAPI v2
Add support for edge detection to lines requested using
GPIO_V2_GET_LINE_IOCTL.

The edge_detector implementation is based on the v1 lineevent
implementation.  Unlike the v1 implementation, an overflow of the event
buffer results in discarding older events, rather than the most
recent, so the final event in a burst will correspond to the current
state of the line.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:56 +02:00
Kent Gibson
aad955842d gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL
Add support for GPIO_V2_GET_LINEINFO_IOCTL and
GPIO_V2_GET_LINEINFO_WATCH_IOCTL.

The core of this change is the event kfifo switching to contain
struct gpioline_info_changed_v2, instead of v1 as v2 is richer.

The two uAPI versions are mostly independent - other than where they both
provide line info changes via reads on the chip fd.  As the info change
structs differ between v1 and v2, the infowatch implementation tracks which
version of the infowatch ioctl, either GPIO_GET_LINEINFO_WATCH_IOCTL or
GPIO_V2_GET_LINEINFO_WATCH_IOCTL, initiates the initial watch and returns
the corresponding info change struct to the read.  The version supported
on that fd locks to that version on the first watch request, so subsequent
watches from that process must use the same uAPI version.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:52 +02:00
Kent Gibson
3c0d9c635a gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL
Add support for requesting lines using the GPIO_V2_GET_LINE_IOCTL, and
returning their current values using GPIO_V2_LINE_GET_VALUES_IOCTL.

The struct linereq implementation is based on the v1 struct linehandle
implementation.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:49 +02:00
Kent Gibson
69e4e13688 gpiolib: cdev: replace strncpy() with strscpy()
Replace usage of strncpy() with strscpy() to remove -Wstringop-truncation
warnings.

The structures being populated are zeroed, to prevent stack leakage as
they are returned to userspace, so strscpy() performs the equivalent
function without the warnings.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:27 +02:00
Kent Gibson
0dc11e3ad3 gpiolib: cdev: gpio_desc_to_lineinfo() should set info offset
Set the value of the line info offset in gpio_desc_to_lineinfo(), rather
than relying on it being passed in the info.  This makes the function
behave as you would expect from the name - it generates the line info
corresponding to a given GPIO desc.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-09-30 10:56:23 +02:00