kernel/linux.git/drivers/gpio/gpiolib-cdev.c, branch v6.12.80

gpio: cdev: Correct return code on memory allocation failure

2026-01-30T09:28:47+00:00

commit faff6846474e99295a139997f93ef6db222b5cee upstream. -ENOMEM is a more appropriate return code for memory allocation failures. Correct it. Cc: stable@vger.kernel.org Fixes: 20bddcb40b2b ("gpiolib: cdev: replace locking wrappers for gpio_device with guards") Signed-off-by: Tzung-Bi Shih Link: https://lore.kernel.org/r/20260116081036.352286-6-tzungbi@kernel.org Signed-off-by: Bartosz Golaszewski Signed-off-by: Greg Kroah-Hartman

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

gpiolib: Update the kernel documentation - add Return sections

2024-09-02T10:27:36+00:00

$ 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 Reviewed-by: Randy Dunlap Tested-by: Randy Dunlap Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240828164449.2777666-1-andriy.shevchenko@linux.intel.com Signed-off-by: Bartosz Golaszewski

Merge tag 'gpio-updates-for-v6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

2024-07-16T00:53:24+00:00

Pull gpio updates from Bartosz Golaszewski: "The majority of added lines are two new modules: the GPIO virtual consumer module that improves our ability to add automated tests for the kernel API and the "sloppy" logic analyzer module that uses the GPIO API to implement a coarse-grained debugging tool for useful for remote development. Other than that we have the usual assortment of various driver extensions, improvements to the core GPIO code, DT-bindings and other documentation updates as well as an extension to the interrupt simulator: GPIOLIB core: - rework kfifo handling rework in the character device code - improve the labeling of GPIOs requested as interrupts and show more info on interrupt-only GPIOs in debugfs - remove unused APIs - unexport interfaces that are only used from the core GPIO code - drop the return value from gpiochip_set_desc_names() as it cannot fail - move a string array definition out of a header and into a specific compilation unit - convert the last user of gpiochip_get_desc() other than GPIO core to using a safer alternative - use array_index_nospec() where applicable New drivers: - add a "virtual GPIO consumer" module that allows requesting GPIOs from actual hardware and driving tests of the in-kernel GPIO API from user-space over debugfs - add a GPIO-based "sloppy" logic analyzer module useful for "first glance" debugging on remote boards Driver improvements: - add support for a new model to gpio-pca953x - lock GPIOs as interrupts in gpio-sim when the lines are requested as irqs via the simulator domain + some other minor improvements - improve error reporting in gpio-syscon - convert gpio-ath79 to using dynamic GPIO base and range - use pcibios_err_to_errno() for converting PCIBIOS error codes to errno vaues in gpio-amd8111 and gpio-rdc321x - allow building gpio-brcmstb for the BCM2835 architecture DT bindings: - convert DT bindings for lsi,zevio, mpc8xxx, and atmel to DT schema - document new properties for aspeed,gpio, fsl,qoriq-gpio and gpio-vf610 - document new compatibles for pca953x and fsl,qoriq-gpio Documentation: - document stricter behavior of the GPIO character device uAPI with regards to reconfiguring requested line without direction set - clarify the effect of the active-low flag on line values and edges - remove documentation for the legacy GPIO API in order to stop tempting people to use it - document the preference for using pread() for reading edge events in the sysfs API Other: - add an extended initializer to the interrupt simulator allowing to specify a number of callbacks callers can use to be notified about irqs being requested and released" * tag 'gpio-updates-for-v6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (41 commits) gpio: mc33880: Convert comma to semicolon gpio: virtuser: actually use the "trimmed" local variable dt-bindings: gpio: convert Atmel GPIO to json-schema gpio: virtuser: new virtual testing driver for the GPIO API dt-bindings: gpio: vf610: Allow gpio-line-names to be set gpio: sim: lock GPIOs as interrupts when they are requested genirq/irq_sim: add an extended irq_sim initializer dt-bindings: gpio: fsl,qoriq-gpio: Add compatible string fsl,ls1046a-gpio gpiolib: unexport gpiochip_get_desc() gpio: add sloppy logic analyzer using polling Documentation: gpio: Reconfiguration with unset direction (uAPI v2) Documentation: gpio: Reconfiguration with unset direction (uAPI v1) dt-bindings: gpio: fsl,qoriq-gpio: add common property gpio-line-names gpio: ath79: convert to dynamic GPIO base allocation pinctrl: da9062: replace gpiochip_get_desc() with gpio_device_get_desc() gpiolib: put gpio_suffixes in a single compilation unit Documentation: gpio: Clarify effect of active low flag on line edges Documentation: gpio: Clarify effect of active low flag on line values gpiolib: Remove data-less gpiochip_add() function gpio: sim: use devm_mutex_init() ...

gpiolib: cdev: Ignore reconfiguration without direction

2024-06-27T15:21:28+00:00

linereq_set_config() behaves badly when direction is not set. The configuration validation is borrowed from linereq_create(), where, to verify the intent of the user, the direction must be set to in order to effect a change to the electrical configuration of a line. But, when applied to reconfiguration, that validation does not allow for the unset direction case, making it possible to clear flags set previously without specifying the line direction. Adding to the inconsistency, those changes are not immediately applied by linereq_set_config(), but will take effect when the line value is next get or set. For example, by requesting a configuration with no flags set, an output line with GPIO_V2_LINE_FLAG_ACTIVE_LOW and GPIO_V2_LINE_FLAG_OPEN_DRAIN set could have those flags cleared, inverting the sense of the line and changing the line drive to push-pull on the next line value set. Skip the reconfiguration of lines for which the direction is not set, and only reconfigure the lines for which direction is set. Fixes: a54756cb24ea ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL") Signed-off-by: Kent Gibson Link: https://lore.kernel.org/r/20240626052925.174272-3-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: Disallow reconfiguration without direction (uAPI v1)

2024-06-27T15:21:28+00:00

linehandle_set_config() behaves badly when direction is not set. The configuration validation is borrowed from linehandle_create(), where, to verify the intent of the user, the direction must be set to in order to effect a change to the electrical configuration of a line. But, when applied to reconfiguration, that validation does not allow for the unset direction case, making it possible to clear flags set previously without specifying the line direction. Adding to the inconsistency, those changes are not immediately applied by linehandle_set_config(), but will take effect when the line value is next get or set. For example, by requesting a configuration with no flags set, an output line with GPIOHANDLE_REQUEST_ACTIVE_LOW and GPIOHANDLE_REQUEST_OPEN_DRAIN requested could have those flags cleared, inverting the sense of the line and changing the line drive to push-pull on the next line value set. Ensure the intent of the user by disallowing configurations which do not have direction set, returning an error to userspace to indicate that the configuration is invalid. And, for clarity, use lflags, a local copy of gcnf.flags, throughout when dealing with the requested flags, rather than a mixture of both. Fixes: e588bb1eae31 ("gpio: add new SET_CONFIG ioctl() to gpio chardev") Signed-off-by: Kent Gibson Link: https://lore.kernel.org/r/20240626052925.174272-2-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: Cleanup kfifo_out() error handling

2024-05-30T09:29:10+00:00

The handling of kfifo_out() errors in read functions obscures any error. The error condition should never occur but, while a ret is set to -EIO, it is subsequently ignored and the read functions instead return the number of bytes copied to that point, potentially masking the fact that any error occurred. Log a warning and return -EIO in the case of a kfifo_out() error to make it clear something very odd is going on here. Signed-off-by: Kent Gibson Link: https://lore.kernel.org/r/20240529131953.195777-4-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: Refactor allocation of linereq events kfifo

2024-05-30T09:29:10+00:00

The allocation of the linereq events kfifo is performed in two separate places. Add a helper function to remove the duplication. Signed-off-by: Kent Gibson Link: https://lore.kernel.org/r/20240529131953.195777-3-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: Add INIT_KFIFO() for linereq events

2024-05-30T09:29:10+00:00

The initialisation of the linereq events kfifo relies on the struct being zeroed and a subsequent call to kfifo_alloc(). The call to kfifo_alloc() is deferred until edge detection is first enabled for the linereq. If the kfifo is inadvertently accessed before the call to kfifo_alloc(), as was the case in a recently discovered bug, it behaves as a FIFO of size 1 with an element size of 0, so writes and reads to the kfifo appear successful but copy no actual data. As a defensive measure, initialise the kfifo with INIT_KFIFO() when the events kfifo is constructed. This initialises the kfifo element size and zeroes its data pointer, so any inadvertant access prior to the kfifo_alloc() call will trigger an oops. Signed-off-by: Kent Gibson Link: https://lore.kernel.org/r/20240529131953.195777-2-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: fix uninitialised kfifo

2024-05-10T14:38:27+00:00

If a line is requested with debounce, and that results in debouncing in software, and the line is subsequently reconfigured to enable edge detection then the allocation of the kfifo to contain edge events is overlooked. This results in events being written to and read from an uninitialised kfifo. Read events are returned to userspace. Initialise the kfifo in the case where the software debounce is already active. Fixes: 65cff7046406 ("gpiolib: cdev: support setting debounce") Signed-off-by: Kent Gibson Link: https://lore.kernel.org/r/20240510065342.36191-1-warthog618@gmail.com Signed-off-by: Bartosz Golaszewski