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path: root/drivers/gpio/gpiolib.c
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-rw-r--r--drivers/gpio/gpiolib.c48
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