kernel.git/drivers/gpio/gpiolib.c, branch linux-4.6.y

Revert "gpiolib: Split GPIO flags parsing and GPIO configuration"

2016-07-27T15:42:10Z

commit 85b03b3033fd4eba82665b3b9902c095a08cc52f upstream. This reverts commit 923b93e451db876d1479d3e4458fce14fec31d1c. Make sure consumers do not overwrite gpio flags for pins that have already been claimed. While adding support for gpio drivers to refuse a request using unsupported flags, the order of when the requested flag was checked and the new flags were applied was reversed to that consumers could overwrite flags for already requested gpios. This not only affects device-tree setups where two drivers could request the same gpio using conflicting configurations, but also allowed user space to clear gpio flags for already claimed pins simply by attempting to export them through the sysfs interface. By for example clearing the FLAG_ACTIVE_LOW flag this way, user space could effectively change the polarity of a signal. Reverting this change obviously prevents gpio drivers from doing sanity checks on the flags in their request callbacks. Fortunately only one recently added driver (gpio-tps65218 in v4.6) appears to do this, and a follow up patch could restore this functionality through a different interface. Signed-off-by: Johan Hovold Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman

gpio: make library immune to error pointers

2016-07-27T15:42:10Z

commit c0a1ecb9f4e208f4b75d88fa9669748e3fd705ab upstream. Most functions that take a GPIO descriptor in need to check the descriptor for IS_ERR(). We do this mostly in the VALIDATE_DESC() macro except for the gpiod_to_irq() function which needs special handling. Reported-by: Grygorii Strashko Reviewed-by: Grygorii Strashko Acked-by: Alexandre Courbot Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman

gpio: make sure gpiod_to_irq() returns negative on NULL desc

2016-06-24T17:22:06Z

commit 79bb71bd1d93197ce227fa167b450b633f30a52b upstream. commit 54d77198fdfbc4f0fe11b4252c1d9c97d51a3264 ("gpio: bail out silently on NULL descriptors") doesn't work for gpiod_to_irq(): drivers assume that NULL descriptors will give negative IRQ numbers in return. It has been pointed out that returning 0 is NO_IRQ and that drivers should be amended to treat this as an error, but that is for the longer term: now let us repair the semantics. Cc: Maxime Ripard Reported-by: Hans de Goede Tested-by: Hans de Goede Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman

gpiolib: Fix unaligned used of reference counters

2016-06-24T17:22:02Z

commit f4833b8cc7edab57d3f3033e549111a546c2e02b upstream. gpiolib relies on the reference counters to clean up the gpio_device structure. Although the number of get/put is properly aligned on gpiolib.c itself, it does not take into consideration how the referece counters are affected by other external functions such as cdev_add and device_add. Because of this, after the last call to put_device, the reference counter has a value of +3, therefore never calling gpiodevice_release. Due to the fact that some of the device has already been cleaned on gpiochip_remove, the library will end up OOPsing the kernel (e.g. a call to of_gpiochip_find_and_xlate). Signed-off-by: Ricardo Ribalda Delgado Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman

gpiolib: Fix NULL pointer deference

2016-06-24T17:22:02Z

commit 11f33a6d15bfa397867ac0d7f3481b6dd683286f upstream. Under some circumstances, a gpiochip might be half cleaned from the gpio_device list. This patch makes sure that the chip pointer is still valid, before calling the match function. [ 104.088296] BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 [ 104.089772] IP: [] of_gpiochip_find_and_xlate+0x15/0x80 [ 104.128273] Call Trace: [ 104.129802] [] ? of_parse_own_gpio+0x1f0/0x1f0 [ 104.131353] [] gpiochip_find+0x60/0x90 [ 104.132868] [] of_get_named_gpiod_flags+0x9a/0x120 ... [ 104.141586] [] gpio_led_probe+0x11b/0x360 Signed-off-by: Ricardo Ribalda Delgado Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman

gpio: bail out silently on NULL descriptors

2016-06-24T17:22:02Z

commit 54d77198fdfbc4f0fe11b4252c1d9c97d51a3264 upstream. In fdeb8e1547cb9dd39d5d7223b33f3565cf86c28e ("gpio: reflect base and ngpio into gpio_device") assumed that GPIO descriptors are either valid or error pointers, but gpiod_get_[index_]optional() actually return NULL descriptors and then all subsequent calls should just bail out. Cc: Sergei Shtylyov Cc: Florian Fainelli Cc: Andrew Lunn Fixes: fdeb8e1547cb ("gpio: reflect base and ngpio into gpio_device") Reported-by: Uwe Kleine-König Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman

gpiolib: Defer gpio device setup until after gpiolib initialization

2016-04-08T08:10:09Z

Since commit ff2b13592299 ("gpio: make the gpiochip a real device"), attempts to add a gpio chip prior to gpiolib initialization cause the system to crash. This happens because gpio_bus_type has not been registered yet. Defer creating gpio devices until after gpiolib has been initialized to fix the problem. Cc: Greg Ungerer Cc: Alexandre Courbot Fixes: ff2b13592299 ("gpio: make the gpiochip a real device") Signed-off-by: Guenter Roeck Signed-off-by: Linus Walleij

gpiolib: Do not use devm functions when registering gpio chip

2016-04-08T08:10:09Z

It is possible that a gpio chip is registered before the gpiolib initialization code has run. This means we can not use devm_ functions to allocate memory at that time. Do it the old fashioned way. Cc: Alexandre Courbot Cc: Greg Ungerer Signed-off-by: Guenter Roeck Signed-off-by: Linus Walleij

gpio / ACPI: ignore GpioInt() GPIOs when requesting GPIO_OUT_*

2016-04-08T08:10:08Z

When firmware does not use _DSD properties that allow properly name GPIO resources, the kernel falls back on parsing _CRS resources, and will return entries described as GpioInt() as general purpose GPIOs even though they are meant to be used simply as interrupt sources for the device: Device (ETSA) { Name (_HID, "ELAN0001") ... Method(_CRS, 0x0, NotSerialized) { Name(BUF0,ResourceTemplate () { I2CSerialBus( 0x10, /* SlaveAddress */ ControllerInitiated, /* SlaveMode */ 400000, /* ConnectionSpeed */ AddressingMode7Bit, /* AddressingMode */ "\\_SB.I2C1", /* ResourceSource */ ) GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone,, "\\_SB.GPSW") { BOARD_TOUCH_GPIO_INDEX } } ) Return (BUF0) } ... } This gives troubles with drivers such as Elan Touchscreen driver (elants_i2c) that uses devm_gpiod_get to look up "reset" GPIO line and decide whether the driver is responsible for powering up and resetting the device, or firmware is. In the above case the lookup succeeds, we map GPIO as output and later fail to request client->irq interrupt that is mapped to the same GPIO. Let's ignore resources described as GpioInt() while parsing _CRS when requesting output GPIOs (but allow them when requesting GPIOD_ASIS or GPIOD_IN as some drivers, such as i2c-hid, do request GPIO as input and then map it to interrupt with gpiod_to_irq). Acked-by: Mika Westerberg Signed-off-by: Dmitry Torokhov Signed-off-by: Linus Walleij

gpiolib: Fix comment referring to gpio_() in gpiod_()

2016-03-16T12:11:11Z

Fixes: 79a9becda8940deb ("gpiolib: export descriptor-based GPIO interface") Signed-off-by: Geert Uytterhoeven Signed-off-by: Linus Walleij

kernel.git/drivers/gpio/gpiolib.c, branch linux-4.6.y

Revert "gpiolib: Split GPIO flags parsing and GPIO configuration"

gpio: make library immune to error pointers

gpio: make sure gpiod_to_irq() returns negative on NULL desc

gpiolib: Fix unaligned used of reference counters

gpiolib: Fix NULL pointer deference

gpio: bail out silently on NULL descriptors

gpiolib: Defer gpio device setup until after gpiolib initialization

gpiolib: Do not use devm functions when registering gpio chip

gpio / ACPI: ignore GpioInt() GPIOs when requesting GPIO_OUT_*

gpiolib: Fix comment referring to gpio_*() in gpiod_*()

gpiolib: Fix comment referring to gpio_() in gpiod_()