gpiolib: Implement devm_gpio_request_one()

broonie · glikely · commit 09d71ff19404 · 2012-05-18T16:48:35.000-06:00
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 &lt;broonie@opensource.wolfsonmicro.com&gt;
Acked-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Grant Likely &lt;grant.likely@secretlab.ca&gt;
diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
@@ -70,6 +70,35 @@ 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
diff --git 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
@@ -106,6 +106,12 @@ 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;

Original file line number	Diff line number	Diff line change
`@@ -106,6 +106,12 @@ static inline int gpio_request_one(unsigned gpio,`
`106`	`106`	`return -ENOSYS;`
`107`	`107`	`}`
`108`	`108`
	`109`	`+static inline int devm_gpio_request_one(struct device *dev, unsigned gpio,`
	`110`	`+ unsigned long flags, const char *label)`
	`111`	`+{`
	`112`	`+ return -ENOSYS;`
	`113`	`+}`
	`114`	`+`
`109`	`115`	`static inline int gpio_request_array(const struct gpio *array, size_t num)`
`110`	`116`	`{`
`111`	`117`	`return -ENOSYS;`