Extend the documentation for the gpiod_set_array() functions and elaborate a bit on possible use cases.
Signed-off-by: Rojhalat Ibrahim <[email protected]> --- Documentation/gpio/consumer.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index d29a972..c21c131 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -259,6 +259,26 @@ 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. + +The gpiod_set_array() functions take three arguments: + * array_size - the number of array elements + * desc_array - an array of GPIO descriptors + * value_array - an array of values to assign to the GPIOs + +The descriptor array can be obtained using the gpiod_get_array() function +or one of its variants. If the group of descriptors returned by that function +matches the desired group of GPIOs, those GPIOs can be set by simply using +the struct gpio_descs returned by gpiod_get_array(): + + struct gpio_descs *my_gpio_descs = gpiod_get_array(...); + gpiod_set_array(my_gpio_descs->ndescs, my_gpio_descs->desc, + my_gpio_values); + +It is also possible to set a completely arbitrary array of descriptors. The +descriptors may be obtained using any combination of gpiod_get() and +gpiod_get_array(). Afterwards the array of descriptors has to be setup +manually before it can be used with gpiod_set_array(). + Note that for optimal performance GPIOs belonging to the same chip should be contiguous within the array of descriptors. -- 2.0.5 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
