kernel/linux.git/include/linux/gpio/consumer.h, branch v4.19.77

gpio: don't WARN() on NULL descs if gpiolib is disabled

2019-09-16T06:22:22+00:00

[ Upstream commit ffe0bbabb0cffceceae07484fde1ec2a63b1537c ] If gpiolib is disabled, we use the inline stubs from gpio/consumer.h instead of regular definitions of GPIO API. The stubs for 'optional' variants of gpiod_get routines return NULL in this case as if the relevant GPIO wasn't found. This is correct so far. Calling other (non-gpio_get) stubs from this header triggers a warning because the GPIO descriptor couldn't have been requested. The warning however is unconditional (WARN_ON(1)) and is emitted even if the passed descriptor pointer is NULL. We don't want to force the users of 'optional' gpio_get to check the returned pointer before calling e.g. gpiod_set_value() so let's only WARN on non-NULL descriptors. Cc: stable@vger.kernel.org Reported-by: Claus H. Stovgaard Signed-off-by: Bartosz Golaszewski Signed-off-by: Sasha Levin

gpiolib: Fix possible use after free on label

2019-02-12T18:46:57+00:00

[ Upstream commit 18534df419041e6c1f4b41af56ee7d41f757815c ] gpiod_request_commit() copies the pointer to the label passed as an argument only to be used later. But there's a chance the caller could immediately free the passed string(e.g., local variable). This could trigger a use after free when we use gpio label(e.g., gpiochip_unlock_as_irq(), gpiochip_is_requested()). To be on the safe side: duplicate the string with kstrdup_const() so that if an unaware user passes an address to a stack-allocated buffer, we won't get the arbitrary label. Also fix gpiod_set_consumer_name(). Signed-off-by: Muchun Song Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin

gpiolib: Use GPIOD_OUT_{LOW,HIGH} macros in open drain ones

2018-07-29T22:06:33+00:00

There should not be anything more than stated by the name of newly introduced constants, i.e. GPIOD_OUT_LOW_OPEN_DRAIN == GPIOD_OUT_LOW + open drain and nothing more. Make it better to read and slightly more robust by using GPIOD_OUT_LOW and GPIOD_OUT_HIGH constants with open drain flag. No functional change intended. Signed-off-by: Andy Shevchenko Signed-off-by: Linus Walleij

gpio: Add API to explicitly name a consumer

2018-06-18T05:55:30+00:00

The GPIO (descriptor) API registers a "label" naming what is currently using the GPIO line. Typically this is taken from things like the device tree node, so "reset-gpios" will result in he line being labeled "reset". The technical effect is pretty much zero: the use is for debug and introspection, such as "lsgpio" and debugfs files. However sometimes the user want this cuddly feeling of listing all GPIO lines and seeing exactly what they are for and it gives a very fulfilling sense of control. Especially in the cases when the device tree node doesn't provide a good name, or anonymous GPIO lines assigned just to "gpios" in the device tree because the usage is implicit. For these cases it may be nice to be able to label the line directly and explicitly. Signed-off-by: Linus Walleij

gpio: Remove VLA from gpiolib

2018-05-23T12:01:03+00:00

The new challenge is to remove VLAs from the kernel (see https://lkml.org/lkml/2018/3/7/621) to eventually turn on -Wvla. Using a kmalloc array is the easy way to fix this but kmalloc is still more expensive than stack allocation. Introduce a fast path with a fixed size stack array to cover most chip with gpios below some fixed amount. The slow path dynamically allocates an array to cover those chips with a large number of gpios. Reviewed-by: Geert Uytterhoeven Reviewed-by: Phil Reid Reviewed-and-tested-by: Lukas Wunner Signed-off-by: Lukas Wunner Signed-off-by: Laura Abbott Reviewed-by: Andy Shevchenko Signed-off-by: Linus Walleij

gpio: Export devm_gpiod_get_from_of_node() for consumers

2018-01-12T10:05:24+00:00

We have been holding back on adding an API for fetching GPIO handles directly from device nodes, strongly preferring to get it from the spawn devices instead. The fwnode interface however already contains an API for doing this, as it is used for opaque device tree nodes or ACPI nodes for getting handles to LEDs and keys that use GPIO: those are specified as one child per LED/key in the device tree and are not individual devices. However regulators present a special problem as they already have helper functions to traverse the device tree from a regulator node and two levels down to fill in data, and as it already traverses GPIO nodes in its own way, and already holds a pointer to each regulators device tree node, it makes most sense to export an API to fetch the GPIO descriptor directly from the node. We only support the devm_* version for now, hopefully no non-devres version will be needed. Signed-off-by: Linus Walleij

gpio: gpiolib: Generalise state persistence beyond sleep

2017-12-02T21:42:34+00:00

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 Reviewed-by: Charles Keepax Acked-by: Rob Herring Signed-off-by: Linus Walleij

Merge branch 'i2c/for-4.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux

2017-11-15T01:52:21+00:00

Pull i2c updates from Wolfram Sang: "This contains two bigger than usual tree-wide changes this time. They all have proper acks, caused no merge conflicts in linux-next where they have been for a while. They are namely: - to-gpiod conversion of the i2c-gpio driver and its users (touching arch/* and drivers/mfd/*) - adding a sbs-manager based on I2C core updates to SMBus alerts (touching drivers/power/*) Other notable changes: - i2c_boardinfo can now carry a dev_name to be used when the device is created. This is because some devices in ACPI world need fixed names to find the regulators. - the designware driver got a long discussed overhaul of its PM handling. img-scb and davinci got PM support, too. - at24 driver has way better OF support. And it has a new maintainer. Thanks Bartosz for stepping up! The rest is regular driver updates and fixes" * 'i2c/for-4.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (55 commits) ARM: sa1100: simpad: Correct I2C GPIO offsets i2c: aspeed: Deassert reset in probe eeprom: at24: Add OF device ID table MAINTAINERS: new maintainer for AT24 driver i2c: nuc900: remove platform_data, too i2c: thunderx: Remove duplicate NULL check i2c: taos-evm: Remove duplicate NULL check i2c: Make i2c_unregister_device() NULL-aware i2c: xgene-slimpro: Support v2 i2c: mpc: remove useless variable initialization i2c: omap: Trigger bus recovery in lockup case i2c: gpio: Add support for named gpios in DT dt-bindings: i2c: i2c-gpio: Add support for named gpios i2c: gpio: Local vars in probe i2c: gpio: Augment all boardfiles to use open drain i2c: gpio: Enforce open drain through gpiolib gpio: Make it possible for consumers to enforce open drain i2c: gpio: Convert to use descriptors power: supply: sbs-message: fix some code style issues power: supply: sbs-battery: remove unchecked return var ...

Merge tag 'gpio-v4.15-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

2017-11-15T01:23:44+00:00

Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for the v4.15 kernel cycle: Core: - Fix the semantics of raw GPIO to actually be raw. No inversion semantics as before, but also no open draining, and allow the raw operations to affect lines used for interrupts as the caller supposedly knows what they are doing if they are getting the big hammer. - Rewrote the __inner_function() notation calls to names that make more sense. I just find this kind of code disturbing. - Drop the .irq_base() field from the gpiochip since now all IRQs are mapped dynamically. This is nice. - Support for .get_multiple() in the core driver API. This allows us to read several GPIO lines with a single register read. This has high value for some usecases: it can be used to create oscilloscopes and signal analyzers and other things that rely on reading several lines at exactly the same instant. Also a generally nice optimization. This uses the new assign_bit() macro from the bitops lib that was ACKed by Andrew Morton and is implemented for two drivers, one of them being the generic MMIO driver so everyone using that will be able to benefit from this. - Do not allow requests of Open Drain and Open Source setting of a GPIO line simultaneously. If the hardware actually supports enabling both at the same time the electrical result would be disastrous. - A new interrupt chip core helper. This will be helpful to deal with "banked" GPIOs, which means GPIO controllers with several logical blocks of GPIO inside them. This is several gpiochips per device in the device model, in contrast to the case when there is a 1-to-1 relationship between a device and a gpiochip. New drivers: - Maxim MAX3191x industrial serializer, a very interesting piece of professional I/O hardware. - Uniphier GPIO driver. This is the GPIO block from the recent Socionext (ex Fujitsu and Panasonic) platform. - Tegra 186 driver. This is based on the new banked GPIO infrastructure. Other improvements: - Some documentation improvements. - Wakeup support for the DesignWare DWAPB GPIO controller. - Reset line support on the DesignWare DWAPB GPIO controller. - Several non-critical bug fixes and improvements for the Broadcom BRCMSTB driver. - Misc non-critical bug fixes like exotic errorpaths, removal of dead code etc. - Explicit comments on fall-through switch() statements" * tag 'gpio-v4.15-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (65 commits) gpio: tegra186: Remove tegra186_gpio_lock_class gpio: rcar: Add r8a77995 (R-Car D3) support pinctrl: bcm2835: Fix some merge fallout gpio: Fix undefined lock_dep_class gpio: Automatically add lockdep keys gpio: Introduce struct gpio_irq_chip.first gpio: Disambiguate struct gpio_irq_chip.nested gpio: Add Tegra186 support gpio: Export gpiochip_irq_{map,unmap}() gpio: Implement tighter IRQ chip integration gpio: Move lock_key into struct gpio_irq_chip gpio: Move irq_valid_mask into struct gpio_irq_chip gpio: Move irq_nested into struct gpio_irq_chip gpio: Move irq_chained_parent to struct gpio_irq_chip gpio: Move irq_default_type to struct gpio_irq_chip gpio: Move irq_handler to struct gpio_irq_chip gpio: Move irqdomain into struct gpio_irq_chip gpio: Move irqchip into struct gpio_irq_chip gpio: Introduce struct gpio_irq_chip pinctrl: armada-37xx: remove unused variable ...

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman