gpiolib: add devm_gpiod_get_array and devm_gpiod_put_array functions
Add device managed variants of gpiod_get_array() / gpiod_put_array()
functions for conveniently obtaining and disposing of an entire array
of GPIOs with one function call.
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
index 2924f2f..d29a972 100644
--- a/Documentation/gpio/consumer.txt
+++ b/Documentation/gpio/consumer.txt
@@ -102,11 +102,19 @@
const char *con_id,
enum gpiod_flags flags)
- struct gpio_desc * devm_gpiod_get_index_optional(struct device *dev,
+ struct gpio_desc *devm_gpiod_get_index_optional(struct device *dev,
const char *con_id,
unsigned int index,
enum gpiod_flags flags)
+ struct gpio_descs *devm_gpiod_get_array(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+
+ struct gpio_descs *devm_gpiod_get_array_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+
A GPIO descriptor can be disposed of using the gpiod_put() function:
void gpiod_put(struct gpio_desc *desc)
@@ -119,10 +127,12 @@
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:
+The device-managed variants are, unsurprisingly:
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
+ void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
+
Using GPIOs
===========
diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
index 12c2082..ec24da2 100644
--- a/drivers/gpio/devres.c
+++ b/drivers/gpio/devres.c
@@ -35,6 +35,20 @@
return *this == *gpio;
}
+static void devm_gpiod_release_array(struct device *dev, void *res)
+{
+ struct gpio_descs **descs = res;
+
+ gpiod_put_array(*descs);
+}
+
+static int devm_gpiod_match_array(struct device *dev, void *res, void *data)
+{
+ struct gpio_descs **this = res, **gpios = data;
+
+ return *this == *gpios;
+}
+
/**
* devm_gpiod_get - Resource-managed gpiod_get()
* @dev: GPIO consumer
@@ -186,6 +200,66 @@
EXPORT_SYMBOL(__devm_gpiod_get_index_optional);
/**
+ * devm_gpiod_get_array - Resource-managed gpiod_get_array()
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * Managed gpiod_get_array(). GPIO descriptors returned from this function are
+ * automatically disposed on driver detach. See gpiod_get_array() for detailed
+ * information about behavior and return values.
+ */
+struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+{
+ struct gpio_descs **dr;
+ struct gpio_descs *descs;
+
+ dr = devres_alloc(devm_gpiod_release_array,
+ sizeof(struct gpio_descs *), GFP_KERNEL);
+ if (!dr)
+ return ERR_PTR(-ENOMEM);
+
+ descs = gpiod_get_array(dev, con_id, flags);
+ if (IS_ERR(descs)) {
+ devres_free(dr);
+ return descs;
+ }
+
+ *dr = descs;
+ devres_add(dev, dr);
+
+ return descs;
+}
+EXPORT_SYMBOL(devm_gpiod_get_array);
+
+/**
+ * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @flags: optional GPIO initialization flags
+ *
+ * Managed gpiod_get_array_optional(). GPIO descriptors returned from this
+ * function are automatically disposed on driver detach.
+ * See gpiod_get_array_optional() for detailed information about behavior and
+ * return values.
+ */
+struct gpio_descs *__must_check
+devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
+ enum gpiod_flags flags)
+{
+ struct gpio_descs *descs;
+
+ descs = devm_gpiod_get_array(dev, con_id, flags);
+ if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
+ return NULL;
+
+ return descs;
+}
+EXPORT_SYMBOL(devm_gpiod_get_array_optional);
+
+/**
* devm_gpiod_put - Resource-managed gpiod_put()
* @desc: GPIO descriptor to dispose of
*
@@ -200,6 +274,21 @@
}
EXPORT_SYMBOL(devm_gpiod_put);
+/**
+ * devm_gpiod_put_array - Resource-managed gpiod_put_array()
+ * @descs: GPIO descriptor array to dispose of
+ *
+ * Dispose of an array of GPIO descriptors obtained with devm_gpiod_get_array().
+ * Normally this function will not be called as the GPIOs will be disposed of
+ * by the resource management code.
+ */
+void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
+{
+ WARN_ON(devres_release(dev, devm_gpiod_release_array,
+ devm_gpiod_match_array, &descs));
+}
+EXPORT_SYMBOL(devm_gpiod_put_array);
+
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index 33eb52f..3a7c9ff 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -83,7 +83,14 @@
struct gpio_desc *__must_check
__devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
unsigned int index, enum gpiod_flags flags);
+struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags);
+struct gpio_descs *__must_check
+devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
+ enum gpiod_flags flags);
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);
+void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs);
int gpiod_get_direction(struct gpio_desc *desc);
int gpiod_direction_input(struct gpio_desc *desc);
@@ -228,6 +235,20 @@
return ERR_PTR(-ENOSYS);
}
+static inline struct gpio_descs *__must_check
+devm_gpiod_get_array(struct device *dev, const char *con_id,
+ enum gpiod_flags flags)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline struct gpio_descs *__must_check
+devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
+ enum gpiod_flags flags)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
{
might_sleep();
@@ -236,6 +257,15 @@
WARN_ON(1);
}
+static inline void devm_gpiod_put_array(struct device *dev,
+ struct gpio_descs *descs)
+{
+ might_sleep();
+
+ /* GPIO can never have been requested */
+ WARN_ON(1);
+}
+
static inline int gpiod_get_direction(const struct gpio_desc *desc)
{