diff options
Diffstat (limited to 'Documentation/gpio/consumer.txt')
| -rw-r--r-- | Documentation/gpio/consumer.txt | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index d85fbae451ea..2924f2ffcd91 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -58,7 +58,6 @@ pattern where a GPIO is optional, the gpiod_get_optional() and gpiod_get_index_optional() functions can be used. These functions return NULL instead of -ENOENT if no GPIO has been assigned to the requested function: - struct gpio_desc *gpiod_get_optional(struct device *dev, const char *con_id, enum gpiod_flags flags) @@ -68,6 +67,27 @@ instead of -ENOENT if no GPIO has been assigned to the requested function: unsigned int index, enum gpiod_flags flags) +For a function using multiple GPIOs all of those can be obtained with one call: + + struct gpio_descs *gpiod_get_array(struct device *dev, + const char *con_id, + enum gpiod_flags flags) + +This function returns a struct gpio_descs which contains an array of +descriptors: + + struct gpio_descs { + unsigned int ndescs; + struct gpio_desc *desc[]; + } + +The following function returns NULL instead of -ENOENT if no GPIOs have been +assigned to the requested function: + + struct gpio_descs *gpiod_get_array_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags) + Device-managed variants of these functions are also defined: struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id, @@ -91,8 +111,15 @@ A GPIO descriptor can be disposed of using the gpiod_put() function: void gpiod_put(struct gpio_desc *desc) -It is strictly forbidden to use a descriptor after calling this function. The -device-managed variant is, unsurprisingly: +For an array of GPIOs this function can be used: + + void gpiod_put_array(struct gpio_descs *descs) + +It is strictly forbidden to use a descriptor after calling these functions. +It is also not allowed to individually release descriptors (using gpiod_put()) +from an array acquired with gpiod_get_array(). + +The device-managed variant is, unsurprisingly: void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) |