diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r-- | drivers/gpio/gpiolib.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 104ed299d5ea..fb33ff6fc1a9 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -4356,6 +4356,54 @@ static int platform_gpio_count(struct device *dev, const char *con_id) } /** + * fwnode_gpiod_get_index - obtain a GPIO from firmware node + * @fwnode: handle of the firmware node + * @con_id: function within the GPIO consumer + * @index: index of the GPIO to obtain for the consumer + * @flags: GPIO initialization flags + * @label: label to attach to the requested GPIO + * + * This function can be used for drivers that get their configuration + * from opaque firmware. + * + * The function properly finds the corresponding GPIO using whatever is the + * underlying firmware interface and then makes sure that the GPIO + * descriptor is requested before it is returned to the caller. + * + * Returns: + * On successful request the GPIO pin is configured in accordance with + * provided @flags. + * + * In case of error an ERR_PTR() is returned. + */ +struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode, + const char *con_id, int index, + enum gpiod_flags flags, + const char *label) +{ + struct gpio_desc *desc; + char prop_name[32]; /* 32 is max size of property name */ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { + if (con_id) + snprintf(prop_name, sizeof(prop_name), "%s-%s", + con_id, gpio_suffixes[i]); + else + snprintf(prop_name, sizeof(prop_name), "%s", + gpio_suffixes[i]); + + desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags, + label); + if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT)) + break; + } + + return desc; +} +EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index); + +/** * gpiod_count - return the number of GPIOs associated with a device / function * or -ENOENT if no GPIO has been assigned to the requested function * @dev: GPIO consumer, can be NULL for system-global GPIOs |