#
8a7a6103 |
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21-Feb-2024 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: Get rid of never false gpio_is_valid() calls In the cases when gpio_is_valid() is called with unsigned parameter the result is always true in the GPIO library code, hence the check for false won't ever be true. Get rid of such calls. While at it, move GPIO device base to be unsigned to clearly show it won't ever be negative. This requires a new definition for the maximum GPIO number in the system. 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>
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#
8636f19c |
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07-Mar-2024 |
Alexander Sverdlin <alexander.sverdlin@gmail.com> |
gpio: sysfs: repair export returning -EPERM on 1st attempt It would make sense to return -EPERM if the bit was already set (already used), not if it was cleared. Before this fix pins can only be exported on the 2nd attempt: $ echo 522 > /sys/class/gpio/export sh: write error: Operation not permitted $ echo 522 > /sys/class/gpio/export Fixes: 35b545332b80 ("gpio: remove gpio_lock") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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#
be91c19e |
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14-Feb-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: sysfs: fix inverted pointer logic The logic is inverted, we want to return if the chip *IS* NULL. Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/linux-gpio/15671341-0b29-40e0-b487-0a4cdc414d8e@moroto.mountain/ Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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#
d82b9e08 |
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14-Feb-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: use srcu_dereference() with SRCU-protected pointers Lockdep with CONFIG_PROVE_RCU enabled reports false positives about suspicious rcu_dereference() usage. Let's silence it by using srcu_dereference() which is the correct helper with SRCU. Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU") Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Acked-by: Paul E. McKenney <paulmck@kernel.org>
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#
d83cee3d |
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22-Jan-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: protect the pointer to gpio_chip in gpio_device with SRCU Ensure we cannot crash if the GPIO device gets unregistered (and the chip pointer set to NULL) during any of the API calls. To that end: wait for all users of gdev->chip to exit their read-only SRCU critical sections in gpiochip_remove(). For brevity: add a guard class which can be instantiated at the top of every function requiring read-only access to the chip pointer and use it in all API calls taking a GPIO descriptor as argument. In places where we only deal with the GPIO device - use regular guard() helpers and rcu_dereference() for chip access. Do the same in API calls taking a const pointer to gpio_desc. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
5694f274 |
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05-Feb-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: sysfs: don't access gdev->chip if it's not needed Don't dereference gdev->chip if the same information can be obtained from struct gpio_device. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
b93bca4b |
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24-Jan-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: sysfs: pass the GPIO device - not chip - to sysfs callbacks We're working towards protecting the chip pointer in struct gpio_device with SRCU. In order to use it in sysfs callbacks we must pass the pointer to the GPIO device that wraps the chip instead of the address of the chip itself as the user data. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
59cba4a0 |
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24-Jan-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: sysfs: extend the critical section for unregistering sysfs devices Checking the gdev->mockdev pointer for NULL must be part of the critical section. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
35b54533 |
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12-Jan-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: remove gpio_lock The "multi-function" gpio_lock is pretty much useless with how it's used in GPIOLIB currently. Because many GPIO API calls can be called from all contexts but may also call into sleeping driver callbacks, there are many places with utterly broken workarounds like yielding the lock to call a possibly sleeping function and then re-acquiring it again without taking into account that the protected state may have changed. It was also used to protect several unrelated things: like individual descriptors AND the GPIO device list. We now serialize access to these two with SRCU and so can finally remove the spinlock. There is of course the question of consistency of lockless access to GPIO descriptors. Because we only support exclusive access to GPIOs (officially anyway, I'm looking at you broken GPIOD_FLAGS_BIT_NONEXCLUSIVE bit...) and the API contract with providers does not guarantee serialization, it's enough to ensure we cannot accidentally dereference an invalid pointer and that the state we present to both users and providers remains consistent. To achieve that: read the flags field atomically except for a few special cases. Read their current value before executing callback code and use this value for any subsequent logic. Modifying the flags depends on the particular use-case and can differ. For instance: when requesting a GPIO, we need to set the REQUESTED bit immediately so that the next user trying to request the same line sees -EBUSY. While at it: the allocations that used GFP_ATOMIC until this point can now switch to GFP_KERNEL. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
2a9101e8 |
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24-Jan-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: sysfs: use gpio_device_find() to iterate over existing devices With the list of GPIO devices now protected with SRCU we can use gpio_device_find() to traverse it from sysfs. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
efb8235b |
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14-Jan-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpiolib: revert the attempt to protect the GPIO device list with an rwsem This reverts commits 1979a2807547 ("gpiolib: replace the GPIO device mutex with a read-write semaphore") and 65a828bab158 ("gpiolib: use a mutex to protect the list of GPIO devices"). Unfortunately the legacy GPIO API that's still used in older code has to translate numbers from the global GPIO numberspace to descriptors. This results in a GPIO device lookup in every call to legacy functions. Some of those functions - like gpio_set/get_value() - can be called from atomic context so taking a sleeping lock that is an RW semaphore results in an error. We'll probably have to protect this list with SRCU. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/linux-wireless/f7b5ff1e-8f34-4d98-a7be-b826cb897dc8@moroto.mountain/ Fixes: 1979a2807547 ("gpiolib: replace the GPIO device mutex with a read-write semaphore") Fixes: 65a828bab158 ("gpiolib: use a mutex to protect the list of GPIO devices") Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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#
1979a280 |
|
02-Jan-2024 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpiolib: replace the GPIO device mutex with a read-write semaphore There are only two spots where we modify (add to or remove objects from) the GPIO device list. Readers should be able to access it concurrently. Replace the mutex with a read-write semaphore and adjust the locking operations accordingly. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
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#
513246a3 |
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21-Dec-2023 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: sysfs: drop tabs from local variable declarations Older code has an annoying habit of putting tabs between the type and the name of the variable. This doesn't really add to readability and newer code doesn't do it so make the entire file consistent. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
65a828ba |
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15-Dec-2023 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpiolib: use a mutex to protect the list of GPIO devices The global list of GPIO devices is never modified or accessed from atomic context so it's fine to protect it using a mutex. Add a new global lock dedicated to the gpio_devices list and use it whenever accessing or modifying it. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
95dd1e34 |
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29-Nov-2023 |
Boerge Struempfel <boerge.struempfel@gmail.com> |
gpiolib: sysfs: Fix error handling on failed export If gpio_set_transitory() fails, we should free the GPIO again. Most notably, the flag FLAG_REQUESTED has previously been set in gpiod_request_commit(), and should be reset on failure. To my knowledge, this does not affect any current users, since the gpio_set_transitory() mainly returns 0 and -ENOTSUPP, which is converted to 0. However the gpio_set_transitory() function calles the .set_config() function of the corresponding GPIO chip and there are some GPIO drivers in which some (unlikely) branches return other values like -EPROBE_DEFER, and -EINVAL. In these cases, the above mentioned FLAG_REQUESTED would not be reset, which results in the pin being blocked until the next reboot. Fixes: e10f72bf4b3e ("gpio: gpiolib: Generalise state persistence beyond sleep") Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com> Reviewed-by: Andy Shevchenko <andy@kernel.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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#
e404b0cc |
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27-Sep-2023 |
Bartosz Golaszewski <bartosz.golaszewski@linaro.org> |
gpio: sysfs: drop the mention of gpiochip_find() from sysfs code We have removed all callers of gpiochip_find() so don't mention it in gpiolib-sysfs.c. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
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#
20d9b3b5 |
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14-Aug-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: sysfs: Do unexport GPIO when user asks for it It seems that sysfs interface implicitly relied on the gpiod_free() to unexport the line. This is logically incorrect as core gpiolib should not deal with sysfs so instead of restoring it, let's call gpiod_unexport() from sysfs code. Fixes: b0ce9ce408b6 ("gpiolib: Do not unexport GPIO on freeing") Reported-by: Marek Behún <kabel@kernel.org> Closes: https://lore.kernel.org/r/20230808102828.4a9eac09@dellmb Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Marek Behún <kabel@kernel.org> [Bartosz: tweaked the commit message] Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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#
6f14c022 |
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31-Mar-2023 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: create class_is_registered() Some classes (i.e. gpio), want to know if they have been registered or not, and poke around in the class's internal structures to try to figure this out. Because this is not really a good idea, provide a function for classes to call to try to figure this out. Note, this is racy as the state of the class could change at any moment in time after the call is made, but as usually a class only wants to know if it has been registered yet or not, it should be fairly safe to use, and is just as safe as the previous "poke at the class internals" check was. Move the gpiolib code to use this function as proof that it works properly. Cc: Bartosz Golaszewski <brgl@bgdev.pl> Cc: Sebastian Reichel <sre@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: linux-gpio@vger.kernel.org Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230331093318.82288-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
75a2d422 |
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25-Mar-2023 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: class: mark the struct class for sysfs callbacks as constant struct class should never be modified in a sysfs callback as there is nothing in the structure to modify, and frankly, the structure is almost never used in a sysfs callback, so mark it as constant to allow struct class to be moved to read-only memory. While we are touching all class sysfs callbacks also mark the attribute as constant as it can not be modified. The bonding code still uses this structure so it can not be removed from the function callbacks. Cc: "David S. Miller" <davem@davemloft.net> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Bartosz Golaszewski <brgl@bgdev.pl> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Miquel Raynal <miquel.raynal@bootlin.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Russ Weight <russell.h.weight@intel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steve French <sfrench@samba.org> Cc: Vignesh Raghavendra <vigneshr@ti.com> Cc: linux-cifs@vger.kernel.org Cc: linux-gpio@vger.kernel.org Cc: linux-mtd@lists.infradead.org Cc: linux-rdma@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: netdev@vger.kernel.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20230325084537.3622280-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
10a03c36 |
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13-Mar-2023 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
drivers: remove struct module * setting from struct class There is no need to manually set the owner of a struct class, as the registering function does it automatically, so remove all of the explicit settings from various drivers that did so as it is unneeded. This allows us to remove this pointer entirely from this structure going forward. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
380c7ba3 |
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08-Feb-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: Clean up headers There is a few things done: - include only the headers we are direct user of - when pointer is in use, provide a forward declaration - add missing headers - group generic headers and subsystem headers - sort each group alphabetically Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
d74e3166 |
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07-Feb-2023 |
Arnd Bergmann <arnd@arndb.de> |
gpiolib: remove legacy gpio_export() There are only a handful of users of gpio_export() and related functions. As these are just wrappers around the modern gpiod_export() helper, remove the wrappers and open-code the gpio_to_desc in all callers to shrink the legacy API. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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#
57017edd |
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08-Apr-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: Embed iterator variable into for_each_gpio_desc_with_flag() 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 <brgl@bgdev.pl> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
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#
667630ed |
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09-Feb-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: sysfs: Simplify edge handling in the code Instead of keeping specific data structure for IRQ trigger types, switch to array of trigger names and use index as a type. The code is in maintenance mode and that array is not going to grow. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
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#
6b3c1791 |
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09-Feb-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: sysfs: Move kstrtox() calls outside of the mutex lock In a few places we perform kstrtox() operations under mutex that do not require any locking. Move them outside of the mutex locks. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
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#
e28747da |
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09-Feb-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: sysfs: Move sysfs_emit() calls outside of the mutex lock In a few places we perform sysfs_emit() operations under mutex that do not require any locking. Move them outside of the mutex locks. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
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#
80c78fbe |
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01-Feb-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: Introduce for_each_gpio_desc_with_flag() macro 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 <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
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#
95a4eed7 |
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01-Feb-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
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: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines") Fixes: 61f922db7221 ("gpio: userspace ABI for reading GPIO line events") Fixes: 3c0d9c635ae2 ("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>
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#
9e23bf6b |
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18-May-2021 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: Use sysfs_emit() in "show" functions The sysfs_emit() function was introduced to make it less ambiguous which function is preferred when writing to the output buffer in a "show" callback [1]. Convert the GPIO library sysfs interface from sprintf() to sysfs_emit() accordingly, as the latter is aware of the PAGE_SIZE buffer and correctly returns the number of bytes written into the buffer. No functional change intended. [1] Documentation/filesystems/sysfs.rst Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
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#
fd80b8ba |
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18-May-2021 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: Make use of assign_bit() API (part 2) We have for some time the assign_bit() API to replace open coded if (foo) set_bit(n, bar); else clear_bit(n, bar); Use this API in GPIO library code. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
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#
23cf00dd |
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29-Mar-2021 |
Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> |
gpio: sysfs: Obey valid_mask Do not allow exporting GPIOs which are set invalid by the driver's valid mask. Fixes: 726cb3ba4969 ("gpiolib: Support 'gpio-reserved-ranges' property") Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
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#
8bbff39c |
|
21-Oct-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
gpiolib: Unify expectations about ->request() returned value Half of the code in the GPIO library is written in an expectation that any non-zero value returned from the ->request() callback is an error code, while some code checks only for negative values. Unify expectations about ->request() returned value to be non-zero for an error and 0 for the success. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
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#
ef087d8e |
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07-Jul-2020 |
Kent Gibson <warthog618@gmail.com> |
gpiolib: move gpiolib-sysfs function declarations into their own header Move gpiolib-sysfs function declarations into their own header. These functions are in gpiolib-sysfs.c, and are only required by gpiolib.c, and so should be in a module header, not gpiolib.h. This brings gpiolib-sysfs into line with gpiolib-cdev, and is another step towards removing the sysfs inferface. Signed-off-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
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#
97cd738c |
|
12-Jun-2020 |
Wang Qing <wangqing@vivo.com> |
gpiolib: sysfs: use kobj_to_dev Use kobj_to_dev() API instead of container_of(). Signed-off-by: Wang Qing <wangqing@vivo.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
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#
ddd8891e |
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27-Nov-2019 |
Geert Uytterhoeven <geert+renesas@glider.be> |
gpiolib: Add GPIOCHIP_NAME definition The string literal "gpiochip" is used in several places. Add a definition for it, and use it everywhere, to make sure everything stays in sync. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20191127084253.16356-2-geert+renesas@glider.be Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
dae5f0af |
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25-Sep-2018 |
Linus Walleij <linus.walleij@linaro.org> |
gpio: Use SPDX header for core library Use the SPDX headers and cut down on boilerplate to indicate the license in the core gpiolib implementation. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
f13a0b0b |
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13-Sep-2018 |
Linus Walleij <linus.walleij@linaro.org> |
gpio: Get rid of legacy header A bunch of core gpiolib files still include the <linux/gpio.h> legacy API header for no good reason. After this only the gpiolib-legacy.c file includes it, which is fine. The sysfs ABI code has a pointless wrapper function around gpio_to_desc() we can just loose. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
1efba35a |
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18-Dec-2017 |
Christophe Leroy <christophe.leroy@c-s.fr> |
gpio: sysfs: avoid using kstrtol() in 'value' attribute write A 'perf record' on an app continuously writing in the 'value' attribute show that most of the time is spent in kstrtol() --17.99%--value_store | |--10.17%--kstrtoint | | | |--8.82%--kstrtoll | |--2.50%--gpiod_set_value_cansleep | |--1.82%--u16_gpio_set | |--1.46%--value_store The normal case is to write 0 or 1 in the attribute, therefore this patch avoids the call to kstrtol() in the most common cases Then 'perf record' shows --7.21%--value_store | |--2.69%--u16_gpio_set | |--1.47%--value_store | |--1.08%--gpiod_set_value_cansleep | |--0.60%--mutex_lock | --0.58%--mutex_unlock Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
7a94b88c |
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18-Dec-2017 |
Christophe Leroy <christophe.leroy@c-s.fr> |
gpio: sysfs: don't use sprintf() for 'value' attribute A bench with 'perf record' shows that most of time spent in value_show() is spent in sprintf() --42.41%--sysfs_kf_read | |--39.73%--dev_attr_show | | | |--38.23%--value_show | | | | | |--29.22%--sprintf | | | | | |--2.94%--gpiod_get_value_cansleep | | | value_show() only returns "0\n" or "1\n", therefore the use of sprintf() can be avoided With this patch we get the following result with 'perf record' --13.89%--sysfs_kf_read | |--10.72%--dev_attr_show | | | |--9.44%--value_show | | | | | |--4.61%--gpiod_get_value_cansleep Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
9295c012 |
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18-Dec-2017 |
Christophe Leroy <christophe.leroy@c-s.fr> |
gpio: sysfs: correct error handling on 'value' attribute read. 'value' attribute is supposed to only return 0 or 1 according to the documentation. With today's implementation, if gpiod_get_value_cansleep() fails the printed 'value' is a negative value. This patch ensures that an error is returned on read instead. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
7fda9100 |
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18-Dec-2017 |
Christophe Leroy <christophe.leroy@c-s.fr> |
gpio: sysfs: change 'value' attribute to prealloc The GPIO 'value' attribute is time critical. A small bench with 'perf record' on the app below shows that 80% of the time spent in sysfs_kf_seq_show() is spent in memset() for zeroising the buffer. |--67.48%--sysfs_kf_seq_show | | | |--54.40%--memset | | | |--11.49%--dev_attr_show | | | | | |--10.06%--value_show | | | | | | | |--4.75%--sprintf | | | | | This patch changes the attribute type to prealloc, eliminating the need to zeroise the buffer at each read. 'perf record' gives the following result. |--42.41%--sysfs_kf_read | | | |--39.73%--dev_attr_show | | | | | |--38.23%--value_show | | | | | | | |--29.22%--sprintf | | | | | Test done with the following small app: int main(int argc, char **argv) { int fd = open(argv[1], O_RDONLY); for (;;) { int buf[512]; read(fd, buf, 512); lseek(fd, 0, SEEK_SET); } exit(0); } Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
e10f72bf |
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29-Nov-2017 |
Andrew Jeffery <andrew@aj.id.au> |
gpio: gpiolib: Generalise state persistence beyond sleep General support for state persistence is added to gpiolib with the introduction of a new pinconf parameter to propagate the request to hardware. The existing persistence support for sleep is adapted to include hardware support if the GPIO driver provides it. Persistence continues to be enabled by default; in-kernel consumers can opt out, but userspace (currently) does not have a choice. The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are renamed, dropping the SLEEP prefix to reflect that the concept is no longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE could initially be misinterpreted, so I've further changed the symbols to *_TRANSITORY and *_PERSISTENT to address this. The sysfs interface is modified only to keep consistency with the chardev interface in enforcing persistence for userspace exports. Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
2d9d0519 |
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24-Jul-2017 |
Thierry Reding <treding@nvidia.com> |
gpio: sysfs: Fixup kerneldoc Fix up some references to parameters to match the code. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
90b05b05 |
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01-Aug-2017 |
Masami Hiramatsu <mhiramat@kernel.org> |
gpio: reject invalid gpio before getting gpio_desc Check user-given gpio number and reject it before calling gpio_to_desc() because gpio_to_desc() is for kernel driver and it expects given gpio number is valid (means 0 to 511). If given number is invalid, gpio_to_desc() calls WARN() and dump registers and stack for debug. This means user can easily kick WARN() just by writing invalid gpio number (e.g. 512) to /sys/class/gpio/export. Fixes: 0e9a5edf5d01 ("gpio: fix deferred probe detection for legacy API") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
d83bb159 |
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08-Jun-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
gpio: use class_groups instead of class_attrs The class_attrs pointer is long depreciated, and is about to be finally removed, so move to use the class_groups pointer instead. Acked-by: Linus Walleij <linus.walleij@linaro.org> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: <linux-gpio@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
31963eb0 |
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08-Sep-2016 |
Amitesh Singh <singh.amitesh@gmail.com> |
gpio: fix documentation for gpiod_unexport Both gpio_export and gpio_free APIs are obsolete now. Signed-off-by: Amitesh Singh <singh.amitesh@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
d27c1728 |
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24-Feb-2016 |
Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> |
gpio: fix abi regression in sysfs We started to assign the gpio_device as parent for the sysfs but this changes the expected layout of sysfs. Restore the previous behaviour. Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
fdeb8e15 |
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10-Feb-2016 |
Linus Walleij <linus.walleij@linaro.org> |
gpio: reflect base and ngpio into gpio_device Some information about the GPIO chip need to stay around also after the gpio_chip has been removed and only the gpio_device persist. The base and ngpio are such things, for example we don't want a new chip arriving to overlap the number space of a dangling gpio_device, and the chardev may still query the device for the number of lines etc. Note that the code that assigns base and insert gpio_device into the global list no longer check for a missing gpio_chip: we respect the number space allocated by any other gpio_device. As a consequence of the gdev being referenced directly from the gpio_desc, we need to verify it differently from all in-kernel API calls that fall through to direct queries to the gpio_chip vtable: we first check that desc is !NULL, then that desc->gdev is !NULL, then, if desc->gdev->chip is NULL, we *BAIL OUT* without any error, so as to manage the case where operations are requested on a device that is gone. These checks were non-uniform and partly missing in the past: so to simplify: create the macros VALIDATE_DESC() that will return -EINVAL if the desc or desc->gdev is missing and just 0 if the chip is gone, and conversely VALIDATE_DESC_VOID() for the case where the function does not return an error. By using these macros, we get warning messages about missing gdev with reference to the right function in the kernel log. Despite the macro business this simplifies the code and make it more readable than if we copy/paste the same descriptor checking code into all code ABI call sites (IMHO). Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
1c3cdb18 |
|
09-Feb-2016 |
Linus Walleij <linus.walleij@linaro.org> |
gpio: move descriptors into gpio_device We need gpio_device to hold the descriptors so that they can be lifecycled with the struct gpio_device held from userspace. Move the descriptor array into gpio_device. Also rename it from "desc" (singularis) to "descs" (pluralis) to reflect the fact that it is an array. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
afbc4f31 |
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09-Feb-2016 |
Linus Walleij <linus.walleij@linaro.org> |
gpio: move sysfs mock device to the gpio_device Since gpio_device is the struct that survives if the backing gpio_chip is removed, move the sysfs mock device to this state container so it becomes part of the dangling state of the GPIO device on removal. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
ff2b1359 |
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20-Oct-2015 |
Linus Walleij <linus.walleij@linaro.org> |
gpio: make the gpiochip a real device GPIO chips have been around for years, but were never real devices, instead they were piggy-backing on a parent device (such as a platform_device or amba_device) but this was always optional. GPIO chips could also exist without any device at all, with its struct device *parent (ex *dev) pointer being set to null. When sysfs was in use, a mock device would be created, with the optional parent assigned, or just floating orphaned with NULL as parent. If sysfs is active, it will use this device as parent. We now create a gpio_device struct containing a real struct device and move the subsystem over to using that. The list of struct gpio_chip:s is augmented to hold struct gpio_device:s and we find gpio_chips:s by first looking up the struct gpio_device. The struct gpio_device is designed to stay around even if the gpio_chip is removed, so as to satisfy users in userspace that need a backing data structure to hold the state of the session initiated with e.g. a character device even if there is no physical chip anymore. From this point on, gpiochips are devices. Cc: Johan Hovold <johan@kernel.org> Cc: Michael Welling <mwelling@ieee.org> Cc: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
58383c78 |
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04-Nov-2015 |
Linus Walleij <linus.walleij@linaro.org> |
gpio: change member .dev to .parent The name .dev in a struct is normally reserved for a struct device that is let us say a superclass to the thing described by the struct. struct gpio_chip stands out by confusingly using a struct device *dev to point to the parent device (such as a platform_device) that represents the hardware. As we want to give gpio_chip:s real devices, this is not working. We need to rename this member to parent. This was done by two coccinelle scripts, I guess it is possible to combine them into one, but I don't know such stuff. They look like this: @@ struct gpio_chip *var; @@ -var->dev +var->parent and: @@ struct gpio_chip var; @@ -var.dev +var.parent and: @@ struct bgpio_chip *var; @@ -var->gc.dev +var->gc.parent Plus a few instances of bgpio that I couldn't figure out how to teach Coccinelle to rewrite. This patch hits all over the place, but I *strongly* prefer this solution to any piecemal approaches that just exercise patch mechanics all over the place. It mainly hits drivers/gpio and drivers/pinctrl which is my own backyard anyway. Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Rafał Miłecki <zajec5@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Cc: Alek Du <alek.du@intel.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Lee Jones <lee.jones@linaro.org> Acked-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
78856ac0 |
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05-Oct-2015 |
Linus Walleij <linus.walleij@linaro.org> |
Revert "gpio-sysfs: Use gpio descriptor name instead of gpiochip names array" This reverts commit ddd5404007b8496f20ad2efe1147e102e6226634. We need to preserve only using this naming strategy for names coming from chip->names[], the descripor->name field is for the new interface.
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#
ddd54040 |
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14-Aug-2015 |
Markus Pargmann <mpa@pengutronix.de> |
gpio-sysfs: Use gpio descriptor name instead of gpiochip names array The name is now stored in the gpio descriptor as well, for example to allow to store names from DT. This patch changes the sysfs gpio files to use the gpio descriptor name. Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
cef1717b |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: move irq trigger flags to class-device data Move irq trigger flags, which as sysfs-interface specific, to the class device data. This avoids accessing the gpio-descriptor flags field using non-atomic operations without any locking, and allows for a more clear separation of the sysfs interface from gpiolib core. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
427fdeef |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: remove FLAG_SYSFS_DIR Remove FLAG_SYSFS_DIR, which is sysfs-interface specific, and store it in the class-device data instead. Note that the flag is only used during export. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
2f323b85 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: rename active-low helper Rename active-low helper using common prefix. Also remove unnecessary manipulation of value argument. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
72eba6f6 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: fix race between gpiod export and unexport Make sure to deregister the class device (and release the irq) while holding the sysfs lock in gpio_unexport to prevent racing with gpio_export. Note that this requires the recently introduced per-gpio locking to avoid a deadlock with the kernfs active protection when waiting for the attribute operations to drain during deregistration. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
6ffcb797 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: use per-gpio locking Add a per-gpio mutex to serialise attribute operations rather than use one global mutex for all gpios and chips. Having a single global lock for all gpios in a system adds unnecessary latency to the sysfs interface, and especially when having gpio controllers connected over slow buses. Now that the global gpio-sysfs interrupt table is gone and with per-gpio data in place, we can easily switch to using a more fine-grained locking scheme. Keep the global mutex to serialise the global (class) operations of gpio export and unexport and chip removal. Also document the locking assumptions made. Note that this is also needed to fix a race between gpiod_export and gpiod_unexport. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
56d30ec1 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: clean up gpiod_export_link locking Drop unnecessary locking from gpiod_export_link. If the class device has not already been unregistered, class_find_device returns the ref-counted class device so there's no need for locking. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
e4339ce3 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: clean up edge_store Remove goto from success path. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
2ec74a95 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: split irq allocation and deallocation Add separate helper functions for irq request and free. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
b91e1807 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: only call irq helper if needed Only call irq helper if actually reconfiguring interrupt state. This is a preparatory step in introducing separate gpio-irq request and free functions. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
a08f5c21 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: clean up interrupt-interface implementation Store the value sysfs entry in the gpiod data rather than in a global table accessed through an index stored in the overloaded gpio-descriptor flag field. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
0f628508 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: remove redundant gpio-descriptor parameters Remove redundant gpio-descriptor parameters from sysfs_set_active_low and gpio_setup_irq. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
c43960fb |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: add gpiod class-device data Add gpiod class-device data. This is a first step in getting rid of the insane gpio-descriptor flag overloading, backward irq-interface implementation, and course grained sysfs-interface locking (a single static mutex for every operation on all exported gpios in a system). Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
f0b7866a |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: remove redundant export tests The attribute operations will never be called for an unregistered device so remove redundant checks for FLAG_EXPORT. Note that kernfs will also guarantee that any active sysfs operation has finished before the attribute is removed during deregistration. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
54d9acd7 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: release irq after class-device deregistration Make sure to release any irq only after the class device has been deregistered. This avoids a race between gpiod_unexport and edge_store, where an irq could be allocated just before the gpio class device is deregistered without relying on FLAG_EXPORT and the global sysfs lock. Note that there is no need to hold the sysfs lock when releasing the irq after the class device is gone as kernfs will prevent further attribute operations. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
6beac9d1 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: use DEVICE_ATTR macros Use DEVICE_ATTR_RO and DEVICE_ATTR_RW rather than specifying masks and callbacks directly. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
166a85e4 |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: remove gpiod_sysfs_set_active_low Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which allowed code to change the polarity of a gpio line even after it had been exported through sysfs. Drivers should not care, and generally does not know, about gpio-line polarity which is a hardware feature that needs to be described by firmware. It is currently possible to define gpio-line polarity in device-tree and acpi firmware or using platform data. Userspace can also change the polarity through sysfs. Note that drivers using the legacy gpio interface could still use GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio. There are no in-kernel users of this interface. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Harry Wei <harryxiyou@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@zh-kernel.org Cc: linux-arch@vger.kernel.org Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
426577bd |
|
04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: rename gpiochip registration functions Rename the gpio-chip export/unexport functions to the more descriptive names gpiochip_sysfs_register and gpiochip_sysfs_unregister. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
6a4b6b0a |
|
04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: clean up chip class-device handling Clean gpio-chip class device registration and deregistration. The class device is registered when a gpio-chip is added (or from gpiolib_sysfs_init post-core init call), and deregistered when the chip is removed. Store the class device in struct gpio_chip directly rather than do a class-device lookup on deregistration. This also removes the need for the exported flag. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
3ff74be5 |
|
04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: reduce gpiochip-export locking scope Reduce scope of sysfs_lock protection during chip export and unexport, which is only needed to prevent gpiod (re-)exports during chip removal. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
cecf58ab |
|
04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: preparatory clean ups Put the recently introduced gpio-chip pointer to some more use in gpiod_export. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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#
52176d0d |
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04-May-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: fix redundant lock-as-irq handling Drivers should call gpiochip_lock_as_irq (which prevents the pin direction from being changed) in their irq_request_resources callbacks but some drivers currently fail to do so. Instead a second, explicit and often redundant call to lock-as-irq is made by the sysfs-interface implementation after an irq has been requested. Move the explicit call before the irq-request to match the unlock done after the irq is later released. Note that this also fixes an irq leak, should the explicit call ever have failed. Also add a comment about removing the redundant call once the broken drivers have been fixed. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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483d8211 |
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21-Apr-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: fix memory leaks and device hotplug Unregister GPIOs requested through sysfs at chip remove to avoid leaking the associated memory and sysfs entries. The stale sysfs entries prevented the gpio numbers from being exported when the gpio range was later reused (e.g. at device reconnect). This also fixes the related module-reference leak. Note that kernfs makes sure that any on-going sysfs operations finish before the class devices are unregistered and that further accesses fail. The chip exported flag is used to prevent gpiod exports during removal. This also makes it harder to trigger, but does not fix, the related race between gpiochip_remove and export_store, which is really a race with gpiod_request that needs to be addressed separately. Also note that this would prevent the crashes (e.g. NULL-dereferences) at reconnect that affects pre-3.18 kernels, as well as use-after-free on operations on open attribute files on pre-3.14 kernels (prior to kernfs). Fixes: d8f388d8dc8d ("gpio: sysfs interface") Cc: stable <stable@vger.kernel.org> # v2.6.27: 01cca93a9491 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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49d2ca84 |
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25-Jan-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: fix memory leak in gpiod_sysfs_set_active_low Fix memory leak in the gpio sysfs interface due to failure to drop reference to device returned by class_find_device when setting the gpio-line polarity. Fixes: 0769746183ca ("gpiolib: add support for changing value polarity in sysfs") Cc: stable <stable@vger.kernel.org> # v2.6.33 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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0f303db0 |
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25-Jan-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: fix memory leak in gpiod_export_link Fix memory leak in the gpio sysfs interface due to failure to drop reference to device returned by class_find_device when creating a link. Fixes: a4177ee7f1a8 ("gpiolib: allow exported GPIO nodes to be named using sysfs links") Cc: stable <stable@vger.kernel.org> # v2.6.32 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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ebbeba12 |
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13-Jan-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: fix gpio attribute-creation race Fix attribute-creation race with userspace by using the default group to create also the contingent gpio device attributes. Fixes: d8f388d8dc8d ("gpio: sysfs interface") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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0915e6fe |
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13-Jan-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: fix gpio device-attribute leak The gpio device attributes were never destroyed when the gpio was unexported (or on export failures). Use device_create_with_groups() to create the default device attributes of the gpio class device. Note that this also fixes the attribute-creation race with userspace for these attributes. Remove contingent attributes in export error path and on unexport. Fixes: d8f388d8dc8d ("gpio: sysfs interface") Cc: stable <stable@vger.kernel.org> # v2.6.27+ Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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121b6a79 |
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13-Jan-2015 |
Johan Hovold <johan@kernel.org> |
gpio: sysfs: fix gpio-chip device-attribute leak The gpio-chip device attributes were never destroyed when the device was removed. Fix by using device_create_with_groups() to create the device attributes of the chip class device. Note that this also fixes the attribute-creation race with userspace. Fixes: d8f388d8dc8d ("gpio: sysfs interface") Cc: stable <stable@vger.kernel.org> # v2.6.27+ Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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8e53b0f1 |
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25-Nov-2014 |
Alexandre Courbot <acourbot@nvidia.com> |
gpio: remove const modifier from gpiod_get_direction() Although gpiod_get_direction() can be considered side-effect free for consumers, its internals involve setting or clearing bits in the affected GPIO descriptor, for which we need to force-cast the const descriptor variable to non-const. This could lead to incorrect behavior if the compiler decides to optimize here, so remove this const attribute. The intent is to make gpiod_get_direction() private anyway, so it does not really matter. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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e3a2e878 |
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23-Oct-2014 |
Alexandre Courbot <acourbot@nvidia.com> |
gpio: rename gpio_lock_as_irq to gpiochip_lock_as_irq This function actually operates on a gpio_chip, so its prefix should reflect that fact for consistency with other functions defined in gpio/driver.h. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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7fd834ad |
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23-Jul-2014 |
Alexandre Courbot <acourbot@nvidia.com> |
gpio: remove useless check in gpiolib_sysfs_init() An iterator variable cannot be NULL in its loop. Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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d74be6df |
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22-Jul-2014 |
Alexandre Courbot <acourbot@nvidia.com> |
gpio: remove gpiod_lock/unlock_as_irq() gpio_lock/unlock_as_irq() are working with (chip, offset) arguments and are thus not using the old integer namespace. Therefore, there is no reason to have gpiod variants of these functions working with descriptors, especially since the (chip, offset) tuple is more suitable to the users of these functions (GPIO drivers, whereas GPIO descriptors are targeted at GPIO consumers). Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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14141a93 |
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22-Jul-2014 |
Alexandre Courbot <acourbot@nvidia.com> |
gpio: simplify gpiochip_export() For some reason gpiochip_export() would invalidate all the descriptors of a chip if exporting it to sysfs failed. This does not appear as necessary. Remove that part of the code. While we are at it, add a note about the non-safety of temporarily releasing a spinlock in the middle of the loop that protects its iterator, and explain why this is done. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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0eb4c6c2 |
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30-Jun-2014 |
Alexandre Courbot <acourbot@nvidia.com> |
gpio: move sysfs support to its own file sysfs support is currently entangled within the core GPIO support, while it should relly just be a (privileged) user of the integer GPIO API. This patch is a first step towards making the gpiolib code more readable by splitting it into logical parts. Move all sysfs support to their own source file, and share static members of gpiolib that need to be in the private gpiolib.h file. In the future we will want to put some of them back into gpiolib.c, but this first patch let us at least identify them. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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