- 03 May, 2021 2 commits
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Philippe Gerum authored
Out-of-band IRQs and EVL thread contexts would usually compete for such lock, which would require hard irqs to be disabled while holding it. Therefore we would not generally benefit from the preemption disabling feature we are going to add to the EVL-specific spinlock. Make it a hard lock to clarify the intent. Signed-off-by:Philippe Gerum <rpm@xenomai.org>
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Philippe Gerum authored
Signed-off-by:
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- 27 Jan, 2021 1 commit
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Kent Gibson authored
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: 65cff704 ("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>
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- 03 Jan, 2021 1 commit
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Kent Gibson authored
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: aad95584 ("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:
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- 09 Dec, 2020 1 commit
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Marc Zyngier authored
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:
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- 05 Dec, 2020 1 commit
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Kent Gibson authored
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:
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- 30 Oct, 2020 1 commit
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Kent Gibson authored
Add GPIO_V2_LINE_FLAG_EDGE_BOTH macro and use it in edge_irq_thread() to improve readability of edge handling cases. Suggested-by:
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- 28 Oct, 2020 1 commit
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Andy Shevchenko authored
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:
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- 26 Oct, 2020 1 commit
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Kent Gibson authored
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:
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- 08 Oct, 2020 1 commit
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Kent Gibson authored
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:
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- 07 Oct, 2020 1 commit
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Andy Shevchenko authored
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: 5ad284ab ("gpiolib: Fix line event handling in syscall compatible mode") Reported-by:
Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by:
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- 30 Sep, 2020 8 commits
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Kent Gibson authored
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:
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Kent Gibson authored
Add support for the GPIO_V2_LINE_SET_VALUES_IOCTL. Signed-off-by:
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Kent Gibson authored
Add support for GPIO_V2_LINE_SET_CONFIG_IOCTL, the uAPI v2 line set config ioctl. Signed-off-by:
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Kent Gibson authored
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:
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Kent Gibson authored
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:
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Kent Gibson authored
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:
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Kent Gibson authored
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:
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Kent Gibson authored
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:
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- 17 Sep, 2020 1 commit
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Andy Shevchenko authored
The introduced line event handling ABI in the commit 61f922db ("gpio: userspace ABI for reading GPIO line events") missed the fact that 64-bit kernel may serve for 32-bit applications. In such case the very first check in the lineevent_read() will fail due to alignment differences. To workaround this introduce lineevent_get_size() helper which returns actual size of the structure in user space. Fixes: 61f922db ("gpio: userspace ABI for reading GPIO line events") Suggested-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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- 12 Jul, 2020 12 commits
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Kent Gibson authored
Consolidate the cleanup of lineevents, currently duplicated in lineevent_create and lineevent_release, into a helper function lineevent_free. Signed-off-by:
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Kent Gibson authored
Consolidate the cleanup of linehandles, currently duplicated in linehandle_create and linehandle_release, into a helper function linehandle_free. Signed-off-by:
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Kent Gibson authored
Remove recalculation of offset from desc, where desc itself was calculated from offset. There is no benefit from the desc -> hwgpio conversion in this context. The only implicit benefit of the offset -> desc -> hwgpio is the range check in the offset -> desc, but where desc is required you still get that, and where desc isn't required it is simpler to perform the range check directly. Signed-off-by:
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Kent Gibson authored
Merge separate usage of test_bit/set_bit into test_and_set_bit to remove the possibility of a race between the test and set. Similarly test_bit and clear_bit. In the existing code it is possible for two threads to race past the test_bit and then set or clear the watch bit, and neither return EBUSY. Signed-off-by:
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Kent Gibson authored
Rename priv to cdev to improve readability. The name "priv" indicates that the object is pointed to by file->private_data, not what the object is actually is. As it is always used to point to a struct gpio_chardev_data, renaming it to cdev is more appropriate. Signed-off-by:
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Kent Gibson authored
Replace usage of atomic_notifier_call_chain with blocking_notifier_call_chain as the notifier function, lineinfo_changed_notify, calls gpio_desc_to_lineinfo, which calls pinctrl_gpio_can_use_line, which can sleep. The chain isn't being called from an atomic context so the the blocking notifier is a suitable substitute. Signed-off-by:
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Kent Gibson authored
Remove pointless decrement of variable, and associated comment. While i is used subsequently, it is re-initialized so this decrement serves no purpose. Signed-off-by:
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Kent Gibson authored
Rename numdescs to num_descs to be more consistent with the naming of other counters and improve readability. Signed-off-by:
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Kent Gibson authored
Rename 'filep' and 'filp' to 'file' to be consistent with other use and improve readability. Signed-off-by:
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Kent Gibson authored
Refactor the mapping from handle flags to desc flags into a helper function. The assign_bit is overkill where it is replacing the set_bit cases, as is rechecking bits known to be clear in some circumstances, but the DRY simplification more than makes up for any performance degradation, especially as this is not a hot path. Signed-off-by:
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Kent Gibson authored
Make indentation consistent with other use to improve readability. Signed-off-by:
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Kent Gibson authored
Sort the includes of gpiolib-cdev.c to make it easier to identify if a module is included and to avoid duplication. Signed-off-by:
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- 20 Jun, 2020 1 commit
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Kent Gibson authored
Split the cdev specific functionality out of gpiolib.c and into gpiolib-cdev.c. This improves the readability and maintainability of both the cdev and core gpiolib code. Suggested-by:
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