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path: root/drivers/gpio/gpiolib-sysfs.c
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2023-04-27Merge tag 'driver-core-6.4-rc1' of ↵Linus Torvalds1-8/+6
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the large set of driver core changes for 6.4-rc1. Once again, a busy development cycle, with lots of changes happening in the driver core in the quest to be able to move "struct bus" and "struct class" into read-only memory, a task now complete with these changes. This will make the future rust interactions with the driver core more "provably correct" as well as providing more obvious lifetime rules for all busses and classes in the kernel. The changes required for this did touch many individual classes and busses as many callbacks were changed to take const * parameters instead. All of these changes have been submitted to the various subsystem maintainers, giving them plenty of time to review, and most of them actually did so. Other than those changes, included in here are a small set of other things: - kobject logging improvements - cacheinfo improvements and updates - obligatory fw_devlink updates and fixes - documentation updates - device property cleanups and const * changes - firwmare loader dependency fixes. All of these have been in linux-next for a while with no reported problems" * tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits) device property: make device_property functions take const device * driver core: update comments in device_rename() driver core: Don't require dynamic_debug for initcall_debug probe timing firmware_loader: rework crypto dependencies firmware_loader: Strip off \n from customized path zram: fix up permission for the hot_add sysfs file cacheinfo: Add use_arch[|_cache]_info field/function arch_topology: Remove early cacheinfo error message if -ENOENT cacheinfo: Check cache properties are present in DT cacheinfo: Check sib_leaf in cache_leaves_are_shared() cacheinfo: Allow early level detection when DT/ACPI info is missing/broken cacheinfo: Add arm64 early level initializer implementation cacheinfo: Add arch specific early level initializer tty: make tty_class a static const structure driver core: class: remove struct class_interface * from callbacks driver core: class: mark the struct class in struct class_interface constant driver core: class: make class_register() take a const * driver core: class: mark class_release() as taking a const * driver core: remove incorrect comment for device_create* MIPS: vpe-cmp: remove module owner pointer from struct class usage. ...
2023-03-31driver core: create class_is_registered()Greg Kroah-Hartman1-2/+2
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>
2023-03-29driver core: class: mark the struct class for sysfs callbacks as constantGreg Kroah-Hartman1-4/+4
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>
2023-03-17drivers: remove struct module * setting from struct classGreg Kroah-Hartman1-2/+0
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>
2023-03-06gpiolib: Clean up headersAndy Shevchenko1-5/+16
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>
2023-03-06gpiolib: remove legacy gpio_export()Arnd Bergmann1-2/+2
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>
2022-04-09gpiolib: Embed iterator variable into for_each_gpio_desc_with_flag()Andy Shevchenko1-2/+1
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>
2022-03-25Merge tag 'gpio-updates-for-v5.18' of ↵Linus Torvalds1-60/+40
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux Pull gpio updates from Bartosz Golaszewski: "Relatively few updates for this release cycle. We have a single new driver and some minor changes in drivers, more work on limiting the usage of of_node in drivers and DT updates: - new driver: gpio-en7523 - dt-bindings: convertion of faraday,ftgpio010 to YAML, new compatible string in gpio-vf610 and a bugfix in an example - gpiolib core: several improvements and some code shrink - documentation: convert all public docs into kerneldoc format - set IRQ bus token in gpio-crystalcove (addresses a debugfs issue) - add a missing return value check for kstrdup() in gpio-merrifield - allow gpio-tps68470 to be built as module - more work on limiting usage of of_node in GPIO drivers - several sysfs interface improvements - use SDPX in gpio-ts4900" * tag 'gpio-updates-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: gpio: ts4900: Use SPDX header gpiolib: Use list_first_entry()/list_last_entry() gpiolib: sysfs: Simplify edge handling in the code gpiolib: sysfs: Move kstrtox() calls outside of the mutex lock gpiolib: sysfs: Move sysfs_emit() calls outside of the mutex lock gpiolib: make struct comments into real kernel docs dt-bindings: gpio: convert faraday,ftgpio01 to yaml dt-bindings: gpio: gpio-vf610: Add imx93 compatible string gpiolib: Simplify error path in gpiod_get_index() when requesting GPIO gpiolib: Use short form of ternary operator in gpiod_get_index() gpiolib: Introduce for_each_gpio_desc_with_flag() macro gpio: Add support for Airoha EN7523 GPIO controller dt-bindings: arm: airoha: Add binding for Airoha GPIO controller dt-bindings: gpio: fix gpio-hog example gpio: tps68470: Allow building as module gpio: tegra: Get rid of duplicate of_node assignment gpio: altera-a10sr: Switch to use fwnode instead of of_node gpio: merrifield: check the return value of devm_kstrdup() gpio: crystalcove: Set IRQ domain bus token to DOMAIN_BUS_WIRED
2022-02-16gpiolib: sysfs: Simplify edge handling in the codeAndy Shevchenko1-26/+14
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>
2022-02-16gpiolib: sysfs: Move kstrtox() calls outside of the mutex lockAndy Shevchenko1-16/+12
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>
2022-02-16gpiolib: sysfs: Move sysfs_emit() calls outside of the mutex lockAndy Shevchenko1-15/+14
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>
2022-02-08gpiolib: Introduce for_each_gpio_desc_with_flag() macroAndy Shevchenko1-5/+2
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>
2022-02-08gpiolib: Never return internal error codes to user spaceAndy Shevchenko1-5/+2
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>
2021-05-21gpiolib: Use sysfs_emit() in "show" functionsAndy Shevchenko1-17/+12
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>
2021-05-21gpiolib: Make use of assign_bit() API (part 2)Andy Shevchenko1-4/+1
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>
2021-03-31gpio: sysfs: Obey valid_maskMatti Vaittinen1-0/+8
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>
2020-10-26gpiolib: Unify expectations about ->request() returned valueAndy Shevchenko1-1/+1
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>
2020-07-12gpiolib: move gpiolib-sysfs function declarations into their own headerKent Gibson1-0/+1
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>
2020-06-15gpiolib: sysfs: use kobj_to_devWang Qing1-1/+1
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>
2019-12-12gpiolib: Add GPIOCHIP_NAME definitionGeert Uytterhoeven1-4/+3
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>
2018-09-25gpio: Use SPDX header for core libraryLinus Walleij1-0/+1
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>
2018-09-17gpio: Get rid of legacy headerLinus Walleij1-8/+2
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>
2017-12-20gpio: sysfs: avoid using kstrtol() in 'value' attribute writeChristophe Leroy1-2/+7
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>
2017-12-20gpio: sysfs: don't use sprintf() for 'value' attributeChristophe Leroy1-1/+3
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>
2017-12-20gpio: sysfs: correct error handling on 'value' attribute read.Christophe Leroy1-1/+5
'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>
2017-12-20gpio: sysfs: change 'value' attribute to preallocChristophe Leroy1-1/+1
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>
2017-12-03gpio: gpiolib: Generalise state persistence beyond sleepAndrew Jeffery1-5/+9
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>
2017-09-05Merge tag 'gpio-v4.14-1' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio Pull GPIO updates from Linus Walleij: "This is the bulk of the GPIO changes for the v4.14 cycle. Not so much changes this time, phew. David Daney and Bartosz Golaszewski did all the really interesting work in infrastructure improvement across GPIO and IRQ core, hats off for them and to tglx and Marc Z for general help with these patch sets. Core changes: - Allow the GPIO irqchip to allocate IRQs dynamically. This is an important change on systems where only a restricted number of IRQs, lesser than the number of GPIO lines, can be utilized. Now we can allocate these on a first-come-first-served basis instead of hogging up valuable IRQ lines. - Serious fix-up of the kerneldoc documentation and inclusion into the kerneldoc builds. - Pulled in the IRQ simulator from the IRQ core tree and use this in the GPIO mockup driver for exhaustive testing of interrupt abilities. New drivers: - New driver for ThunderX and OCTEON-TX. This is especially interesting as it picks up improvements from the IRQ core that allow us to handle fasteoi ACKs upwards in a hierarchy when there are IRQ flag latches on several levels in a hierarchy. Very interesting work here. - New subdriver for Renesas R-Car r8a7745 (RZ/G1E). Misc: - Several fixes and improvements for Xilinx Zynq GPIO. - Support an enablement GPIO for the 74x164 GPIO. - Switch a bunch of chips to use devres to allocate irq descriptors. - A bunch of constification fixes" * tag 'gpio-v4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (63 commits) gpio: mockup: remove unused variable gc gpio: pl061: constify amba_id Revert "gpiolib: request the gpio before querying its direction" gpio: twl6040: remove unneeded forward declaration gpio: zevio: make gpio_chip const gpio: add gpio_add_lookup_tables() to add several tables at once gpio: rcar: Add r8a7745 (RZ/G1E) support gpio: brcmstb: check return value of gpiochip_irqchip_add() MAINTAINERS: Add entry for THUNDERX GPIO Driver. gpio: Add gpio driver support for ThunderX and OCTEON-TX gpio: mockup: use irq_sim gpio: mxs: use devres for irq generic chip gpio: mxc: use devres for irq generic chip gpio: pch: use devres for irq generic chip gpio: ml-ioh: use devres for irq generic chip gpio: sta2x11: use devres for irq generic chip gpio: sta2x11: disallow unbinding the driver gpio: mxs: disallow unbinding the driver gpio: mxc: disallow unbinding the driver gpio: aspeed: Remove reference to clock name in debounce warning message ...
2017-08-14gpio: sysfs: Fixup kerneldocThierry Reding1-4/+4
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>
2017-08-14gpio: reject invalid gpio before getting gpio_descMasami Hiramatsu1-2/+8
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>
2017-06-09gpio: use class_groups instead of class_attrsGreg Kroah-Hartman1-5/+8
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>
2016-09-12gpio: fix documentation for gpiod_unexportAmitesh Singh1-2/+2
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>
2016-02-25gpio: fix abi regression in sysfsBamvor Jian Zhang1-1/+11
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>
2016-02-11gpio: reflect base and ngpio into gpio_deviceLinus Walleij1-6/+6
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>
2016-02-11gpio: move descriptors into gpio_deviceLinus Walleij1-1/+1
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>
2016-02-11gpio: move sysfs mock device to the gpio_deviceLinus Walleij1-11/+12
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>
2016-02-09gpio: make the gpiochip a real deviceLinus Walleij1-5/+7
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>
2015-11-19gpio: change member .dev to .parentLinus Walleij1-2/+3
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>
2015-05-12gpio: sysfs: move irq trigger flags to class-device dataJohan Hovold1-23/+24
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>
2015-05-12gpio: sysfs: remove FLAG_SYSFS_DIRJohan Hovold1-8/+7
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>
2015-05-12gpio: sysfs: rename active-low helperJohan Hovold1-2/+2
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>
2015-05-12gpio: sysfs: fix race between gpiod export and unexportJohan Hovold1-25/+26
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>
2015-05-12gpio: sysfs: use per-gpio lockingJohan Hovold1-18/+34
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>
2015-05-12gpio: sysfs: clean up gpiod_export_link lockingJohan Hovold1-20/+8
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>
2015-05-12gpio: sysfs: clean up edge_storeJohan Hovold1-5/+7
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>
2015-05-12gpio: sysfs: split irq allocation and deallocationJohan Hovold1-37/+37
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>
2015-05-12gpio: sysfs: only call irq helper if neededJohan Hovold1-5/+14
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>
2015-05-12gpio: sysfs: clean up interrupt-interface implementationJohan Hovold1-36/+18
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>
2015-05-12gpio: sysfs: remove redundant gpio-descriptor parametersJohan Hovold1-13/+11
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>
2015-05-12gpio: sysfs: add gpiod class-device dataJohan Hovold1-16/+46
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>