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authorThierry Reding <treding@nvidia.com>2014-04-25 17:10:06 +0200
committerMax Krummenacher <max.krummenacher@toradex.com>2015-12-26 14:42:48 +0100
commite5acf08e6f4d12255072aca969e890d32a08d93f (patch)
tree061163aaa8b8e14942752c78c477a2225a2eb2e1 /include
parent474c9180af673c6cd8ae8d3057ee9b67b7c4a9d3 (diff)
gpio: Add helpers for optional GPIOs
Introduce gpiod_get_optional() and gpiod_get_index_optional() helpers that make it easier for drivers to handle optional GPIOs. Currently in order to handle optional GPIOs, a driver needs to special case error handling for -ENOENT, such as this: gpio = gpiod_get(dev, "foo"); if (IS_ERR(gpio)) { if (PTR_ERR(gpio) != -ENOENT) return PTR_ERR(gpio); gpio = NULL; } if (gpio) { /* set up GPIO */ } With these new helpers the above is reduced to: gpio = gpiod_get_optional(dev, "foo"); if (IS_ERR(gpio)) return PTR_ERR(gpio); if (gpio) { /* set up GPIO */ } While at it, device-managed variants of these functions are also provided. Signed-off-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> (cherry picked from commit 29a1f2333e07bbbecb920cc78fd035fe8f53207a)
Diffstat (limited to 'include')
-rw-r--r--include/linux/gpio/consumer.h40
1 files changed, 40 insertions, 0 deletions
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index 7a8144fef406..c349021e8e4f 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -24,6 +24,12 @@ struct gpio_desc *__must_check gpiod_get(struct device *dev,
struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx);
+struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
+ const char *con_id);
+struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
+ const char *con_id,
+ unsigned int index);
+
void gpiod_put(struct gpio_desc *desc);
struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
@@ -31,6 +37,12 @@ struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx);
+struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
+ const char *con_id);
+struct gpio_desc *__must_check
+devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
+ unsigned int index);
+
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);
int gpiod_get_direction(const struct gpio_desc *desc);
@@ -74,6 +86,20 @@ static inline struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
{
return ERR_PTR(-ENOSYS);
}
+
+static inline struct gpio_desc *__must_check
+gpiod_get_optional(struct device *dev, const char *con_id)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline struct gpio_desc *__must_check
+gpiod_get_index_optional(struct device *dev, const char *con_id,
+ unsigned int index)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
static inline void gpiod_put(struct gpio_desc *desc)
{
might_sleep();
@@ -94,6 +120,20 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
{
return ERR_PTR(-ENOSYS);
}
+
+static inline struct gpio_desc *__must_check
+devm_gpiod_get_optional(struct device *dev, const char *con_id)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline struct gpio_desc *__must_check
+devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
+ unsigned int index)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
{
might_sleep();