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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-14 14:05:05 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-14 14:05:05 -0800 |
commit | 980f3c344ff1cb4a8be9a169c6bde2dc74ca6288 (patch) | |
tree | f7b22006dec2cebed697b0a2c6701ca16c58c7a2 /Documentation/gpio | |
parent | 7d22286ff757586f3cdbd70ded88b98250285ec5 (diff) | |
parent | 170680abd1eb98a9773ed068435fef9a6402a10f (diff) | |
download | linux-980f3c344ff1cb4a8be9a169c6bde2dc74ca6288.tar.gz |
Merge tag 'gpio-v3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull take two of the GPIO updates: "Same stuff as last time, now with a fixup patch for the previous compile error plus I ran a few extra rounds of compile-testing. This is the bulk of GPIO changes for the v3.19 series: - A new API that allows setting more than one GPIO at the time. This is implemented for the new descriptor-based API only and makes it possible to e.g. toggle a clock and data line at the same time, if the hardware can do this with a single register write. Both consumers and drivers need new calls, and the core will fall back to driving individual lines where needed. Implemented for the MPC8xxx driver initially - Patched the mdio-mux-gpio and the serial mctrl driver that drives modems to use the new multiple-setting API to set several signals simultaneously - Get rid of the global GPIO descriptor array, and instead allocate descriptors dynamically for each GPIO on a certain GPIO chip. This moves us closer to getting rid of the limitation of using the global, static GPIO numberspace - New driver and device tree bindings for 74xx ICs - New driver and device tree bindings for the VF610 Vybrid - Support the RCAR r8a7793 and r8a7794 - Guidelines for GPIO device tree bindings trying to get things a bit more strict with the advent of combined device properties - Suspend/resume support for the MVEBU driver - A slew of minor fixes and improvements" * tag 'gpio-v3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (33 commits) gpio: mcp23s08: fix up compilation error gpio: pl061: document gpio-ranges property for bindings file gpio: pl061: hook request if gpio-ranges avaiable gpio: mcp23s08: Add option to configure IRQ output polarity as active high gpio: fix deferred probe detection for legacy API serial: mctrl_gpio: use gpiod_set_array function mdio-mux-gpio: Use GPIO descriptor interface and new gpiod_set_array function gpio: remove const modifier from gpiod_get_direction() gpio: remove gpio_descs global array gpio: mxs: implement get_direction callback gpio: em: Use dynamic allocation of GPIOs gpio: Check if base is positive before calling gpio_is_valid() gpio: mcp23s08: Add simple IRQ support for SPI devices gpio: mcp23s08: request a shared interrupt gpio: mcp23s08: Do not free unrequested interrupt gpio: rcar: Add r8a7793 and r8a7794 support gpio-mpc8xxx: add mpc8xxx_gpio_set_multiple function gpiolib: allow simultaneous setting of multiple GPIO outputs gpio: mvebu: add suspend/resume support gpio: gpio-davinci: remove duplicate check on resource ..
Diffstat (limited to 'Documentation/gpio')
-rw-r--r-- | Documentation/gpio/consumer.txt | 27 | ||||
-rw-r--r-- | Documentation/gpio/driver.txt | 4 |
2 files changed, 29 insertions, 2 deletions
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index 859918db36b8..d85fbae451ea 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -199,6 +199,33 @@ The active-low state of a GPIO can also be queried using the following call: Note that these functions should only be used with great moderation ; a driver should not have to care about the physical line level. + +Set multiple GPIO outputs with a single function call +----------------------------------------------------- +The following functions set the output values of an array of GPIOs: + + void gpiod_set_array(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) + void gpiod_set_raw_array(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) + void gpiod_set_array_cansleep(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) + void gpiod_set_raw_array_cansleep(unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) + +The array can be an arbitrary set of GPIOs. The functions will try to set +GPIOs belonging to the same bank or chip simultaneously if supported by the +corresponding chip driver. In that case a significantly improved performance +can be expected. If simultaneous setting is not possible the GPIOs will be set +sequentially. +Note that for optimal performance GPIOs belonging to the same chip should be +contiguous within the array of descriptors. + + GPIOs mapped to IRQs -------------------- GPIO lines can quite often be used as IRQs. You can get the IRQ number diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt index 31e0b5db55d8..90d0f6aba7a6 100644 --- a/Documentation/gpio/driver.txt +++ b/Documentation/gpio/driver.txt @@ -158,12 +158,12 @@ Locking IRQ usage Input GPIOs can be used as IRQ signals. When this happens, a driver is requested to mark the GPIO as being used as an IRQ: - int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) + int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset) This will prevent the use of non-irq related GPIO APIs until the GPIO IRQ lock is released: - void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) + void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) When implementing an irqchip inside a GPIO driver, these two functions should typically be called in the .startup() and .shutdown() callbacks from the |