gpiolib: Implement devm_gpio_request_one()

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@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 7a8816a1a0d8..f07fc2d08159 100644
--- 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;