[PATCH 03/11] gpiolib: introduce fwnode_gpiod_get_index()

Dmitry Torokhov
2019-09-11T07:52:26Z

This introduces fwnode_gpiod_get_index() that iterates through common gpio
suffixes when trying to locate a GPIO within a given firmware node.

We also switch devm_fwnode_gpiod_get_index() to call
fwnode_gpiod_get_index() instead of iterating through GPIO suffixes on
its own.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

drivers/gpio/gpiolib-devres.c | 16 +-----------
drivers/gpio/gpiolib.c | 48 +++++++++++++++++++++++++++++++++++
include/linux/gpio/consumer.h | 13 ++++++++++
3 files changed, 62 insertions(+), 15 deletions(-)

diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index 190ce7c43b4e..693dcaf811bb 100644
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -205,29 +205,15 @@ struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
enum gpiod_flags flags,
const char *label)
{
- char prop_name[32]; /* 32 is max size of property name */
struct gpio_desc **dr;
struct gpio_desc *desc;
- unsigned int i;

dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
GFP_KERNEL);
if (!dr)
return ERR_PTR(-ENOMEM);

- 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;
- }
+ desc = fwnode_gpiod_get_index(fwnode, con_id, index, flags, label);
if (IS_ERR(desc)) {
devres_free(dr);
return desc;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index edc1ea68db20..f15e3880aae5 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4314,6 +4314,54 @@ static int platform_gpio_count(struct device *dev, const char *con_id)
return count;
}

+/**
+ * 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
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index dc0ddcd30515..5215fdba6b9a 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -176,6 +176,10 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
const char *propname, int index,
enum gpiod_flags dflags,
const char *label);
+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 *devm_fwnode_gpiod_get_index(struct device *dev,
struct fwnode_handle *child,
const char *con_id, int index,
@@ -531,6 +535,15 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
return ERR_PTR(-ENOSYS);
}

+static inline
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+ const char *con_id, int index,
+ enum gpiod_flags flags,
+ const char *label)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
static inline
struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
struct fwnode_handle *fwnode,
--
2.23.0.162.g0b9fbb3734-goog