[PATCH 2/2] gpiolib: Implement devm_gpio_request_one()

From: Mark Brown
Date: Wed May 02 2012 - 07:47:23 EST


Allow drivers to use the modern request and configure idiom together
with devres.

As with plain gpio_request() and gpio_request_one() we can't implement
the old school version in terms of _one() as this would force the
explicit selection of a direction in gpio_request() which could break
systems if we pick the wrong one. Implementing devm_gpio_request_one()
in terms of devm_gpio_request() would needlessly complicate things or
lead to duplication from the unmanaged version depending on how it's
done.

Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
---
drivers/gpio/devres.c | 29 +++++++++++++++++++++++++++++
include/asm-generic/gpio.h | 2 ++
include/linux/gpio.h | 6 ++++++
3 files changed, 37 insertions(+)

diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
index 3dd2939..d21a9ff 100644
--- a/drivers/gpio/devres.c
+++ b/drivers/gpio/devres.c
@@ -71,6 +71,35 @@ int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
EXPORT_SYMBOL(devm_gpio_request);

/**
+ * devm_gpio_request_one - request a single GPIO with initial setup
+ * @dev: device to request for
+ * @gpio: the GPIO number
+ * @flags: GPIO configuration as specified by GPIOF_*
+ * @label: a literal description string of this GPIO
+ */
+int devm_gpio_request_one(struct device *dev, unsigned gpio,
+ unsigned long flags, const char *label)
+{
+ unsigned *dr;
+ int rc;
+
+ dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
+ if (!dr)
+ return -ENOMEM;
+
+ rc = gpio_request_one(gpio, flags, label);
+ if (rc) {
+ devres_free(dr);
+ return rc;
+ }
+
+ *dr = gpio;
+ devres_add(dev, dr);
+
+ return 0;
+}
+
+/**
* devm_gpio_free - free an interrupt
* @dev: device to free gpio for
* @gpio: gpio to free
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 5f52690..4ead123 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -179,6 +179,8 @@ extern void gpio_free_array(const struct gpio *array, size_t num);

/* bindings for managed devices that want to request gpios */
int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
+int devm_gpio_request_one(struct device *dev, unsigned gpio,
+ unsigned long flags, const char *label);
void devm_gpio_free(struct device *dev, unsigned int gpio);

#ifdef CONFIG_GPIO_SYSFS
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 8e0fe1b..a68024e 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -78,6 +78,12 @@ static inline int gpio_request_one(unsigned gpio,
return -ENOSYS;
}

+static inline int devm_gpio_request_one(struct device *dev, unsigned gpio,
+ unsigned long flags, const char *label)
+{
+ return -ENOSYS;
+}
+
static inline int gpio_request_array(const struct gpio *array, size_t num)
{
return -ENOSYS;
--
1.7.10

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