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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-14 14:05:05 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-14 14:05:05 -0800
commit980f3c344ff1cb4a8be9a169c6bde2dc74ca6288 (patch)
treef7b22006dec2cebed697b0a2c6701ca16c58c7a2 /Documentation/gpio
parent7d22286ff757586f3cdbd70ded88b98250285ec5 (diff)
parent170680abd1eb98a9773ed068435fef9a6402a10f (diff)
downloadlinux-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.txt27
-rw-r--r--Documentation/gpio/driver.txt4
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