kernel/linux.git/include/linux/gpio/consumer.h, branch linux-4.20.y

gpiolib: Fix possible use after free on label

2019-02-12T19:02:04+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

Merge tag 'gpio-v4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

2018-10-23T07:45:05+00:00

Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for the v4.20 series: Core changes: - A patch series from Hans Verkuil to make it possible to enable/disable IRQs on a GPIO line at runtime and drive GPIO lines as output without having to put/get them from scratch. The irqchip callbacks have been improved so that they can use only the fastpatch callbacks to enable/disable irqs like any normal irqchip, especially the gpiod_lock_as_irq() has been improved to be callable in fastpath context. A bunch of rework had to be done to achieve this but it is a big win since I never liked to restrict this to slowpath. The only call requireing slowpath was try_module_get() and this is kept at the .request_resources() slowpath callback. In the GPIO CEC driver this is a big win sine a single line is used for both outgoing and incoming traffic, and this needs to use IRQs for incoming traffic while actively driving the line for outgoing traffic. - Janusz Krzysztofik improved the GPIO array API to pass a "cookie" (struct gpio_array) and a bitmap for setting or getting multiple GPIO lines at once. This improvement orginated in a specific need to speed up an OMAP1 driver and has led to a much better API and real performance gains when the state of the array can be used to bypass a lot of checks and code when we want things to go really fast. The previous code would minimize the number of calls down to the driver callbacks assuming the CPU speed was orders of magnitude faster than the I/O latency, but this assumption was wrong on several platforms: what we needed to do was to profile and improve the speed on the hot path of the array functions and this change is now completed. - Clean out the painful and hard to grasp BNF experiments from the device tree bindings. Future approaches are looking into using JSON schema for this purpose. (Rob Herring is floating a patch series.) New drivers: - The RCAR driver now supports r8a774a1 (RZ/G2M). - Synopsys GPIO via CREGs driver. Major improvements: - Modernization of the EP93xx driver to use irqdomain and other contemporary concepts. - The ingenic driver has been merged into the Ingenic pin control driver and removed from the GPIO subsystem. - Debounce support in the ftgpio010 driver" * tag 'gpio-v4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (116 commits) gpio: Clarify kerneldoc on gpiochip_set_chained_irqchip() gpio: Remove unused 'irqchip' argument to gpiochip_set_cascaded_irqchip() gpio: Drop parent irq assignment during cascade setup mmc: pwrseq_simple: Fix incorrect handling of GPIO bitmap gpio: fix SNPS_CREG kconfig dependency warning gpiolib: Initialize gdev field before is used gpio: fix kernel-doc after devres.c file rename gpio: fix doc string for devm_gpiochip_add_data() to not talk about irq_chip gpio: syscon: Fix possible NULL ptr usage gpiolib: Show correct direction from the beginning pinctrl: msm: Use init_valid_mask exported function gpiolib: Add init_valid_mask exported function GPIO: add single-register GPIO via CREG driver dt-bindings: Document the Synopsys GPIO via CREG bindings gpio: mockup: use device properties instead of platform_data gpio: Slightly more helpful debugfs gpio: omap: Remove set but not used variable 'dev' gpio: omap: drop omap_gpio_list Accept partial 'gpio-line-names' property. gpio: omap: get rid of the conditional PM runtime calls ...

regulator/gpio: Allow nonexclusive GPIO access

2018-10-12T16:55:02+00:00

This allows nonexclusive (simultaneous) access to a single GPIO line for the fixed regulator enable line. This happens when several regulators use the same GPIO for enabling and disabling a regulator, and all need a handle on their GPIO descriptor. This solution with a special flag is not entirely elegant and should ideally be replaced by something more careful as this makes it possible for several consumers to enable/disable the same GPIO line to the left and right without any consistency. The current use inside the regulator core should however be fine as it takes special care to handle this. For the state of the GPIO backend, this is still the lesser evil compared to going back to global GPIO numbers. Cc: Marek Szyprowski Cc: Jon Hunter Fixes: efdfeb079cc3 ("regulator: fixed: Convert to use GPIO descriptor only") Reported-by: Marek Szyprowski Tested-by: Jon Hunter Tested-by: Marek Szyprowski Signed-off-by: Linus Walleij Signed-off-by: Mark Brown

gpio: Restore indentation of continued lines

2018-10-01T10:22:41+00:00

Fixes: 3027743f83f867d8 ("gpio: Remove VLA from gpiolib") Signed-off-by: Geert Uytterhoeven Signed-off-by: Linus Walleij

gpio: Propagate errors from gpiod_set_array_value_complex()

2018-10-01T10:22:15+00:00

Internal helper function gpiod_set_array_value_complex() was changed to return an error value, but not all gpiolib callers were updated to propagate the new error up. Fixes: 3027743f83f867d8 ("gpio: Remove VLA from gpiolib") Signed-off-by: Geert Uytterhoeven Signed-off-by: Linus Walleij

gpiolib: Pass array info to get/set array functions

2018-09-13T09:16:54+00:00

In order to make use of array info obtained from gpiod_get_array() and speed up processing of arrays matching single GPIO chip layout, that information must be passed to get/set array functions. Extend the functions' API with that additional parameter and update all users. Pass NULL if a user builds an array itself from single GPIOs. Cc: Jonathan Corbet Cc: Miguel Ojeda Sandonis Cc: Geert Uytterhoeven Cc: Sebastien Bourdelin Cc: Lukas Wunner Cc: Peter Korsgaard Cc: Peter Rosin Cc: Andrew Lunn Cc: Florian Fainelli Cc: "David S. Miller" Cc: Rojhalat Ibrahim Cc: Dominik Brodowski Cc: Russell King Cc: Kishon Vijay Abraham I Cc: Tony Lindgren Cc: Lars-Peter Clausen Cc: Michael Hennerich Cc: Jonathan Cameron Cc: Hartmut Knaack Cc: Peter Meerwald-Stadler Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Yegor Yefremov Cc: Uwe Kleine-König Signed-off-by: Janusz Krzysztofik Acked-by: Ulf Hansson Signed-off-by: Linus Walleij

gpiolib: Identify arrays matching GPIO hardware

2018-09-13T09:16:12+00:00

Certain GPIO array lookup results may map directly to GPIO pins of a single GPIO chip in hardware order. If that condition is recognized and handled efficiently, significant performance gain of get/set array functions may be possible. While processing a request for an array of GPIO descriptors, identify those which represent corresponding pins of a single GPIO chip. Skip over pins which require open source or open drain special processing. Moreover, identify pins which require inversion. Pass a pointer to that information with the array to the caller so it can benefit from enhanced performance as soon as get/set array functions can accept and make efficient use of it. Cc: Jonathan Corbet Signed-off-by: Janusz Krzysztofik Signed-off-by: Linus Walleij

gpiolib: Pass bitmaps, not integer arrays, to get/set array

2018-09-13T09:15:30+00:00

Most users of get/set array functions iterate consecutive bits of data, usually a single integer, while processing array of results obtained from, or building an array of values to be passed to those functions. Save time wasted on those iterations by changing the functions' API to accept bitmaps. All current users are updated as well. More benefits from the change are expected as soon as planned support for accepting/passing those bitmaps directly from/to respective GPIO chip callbacks if applicable is implemented. Cc: Jonathan Corbet Cc: Miguel Ojeda Sandonis Cc: Sebastien Bourdelin Cc: Lukas Wunner Cc: Peter Korsgaard Cc: Peter Rosin Cc: Andrew Lunn Cc: Florian Fainelli Cc: "David S. Miller" Cc: Rojhalat Ibrahim Cc: Dominik Brodowski Cc: Russell King Cc: Kishon Vijay Abraham I Cc: Tony Lindgren Cc: Lars-Peter Clausen Cc: Michael Hennerich Cc: Jonathan Cameron Cc: Hartmut Knaack Cc: Peter Meerwald-Stadler Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Yegor Yefremov Cc: Uwe Kleine-König Signed-off-by: Janusz Krzysztofik Acked-by: Ulf Hansson Reviewed-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Signed-off-by: Linus Walleij

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