diff options
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 |