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-rw-r--r--Documentation/gpio/consumer.txt33
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)