gpio: devm_gpio_* support should not depend on GPIOLIB

Some architectures (e.g. blackfin) provide gpio API without requiring
GPIOLIB support (ARCH_WANT_OPTIONAL_GPIOLIB).  devm_gpio_* functions
should also work for these architectures, since they do not really
depend on GPIOLIB.

Add a new option GPIO_DEVRES (enabled by default) to control the build
of devres.c.  It also removes the empty version of devm_gpio_*
functions for !GENERIC_GPIO build from linux/gpio.h, and moves the
function declarations from asm-generic/gpio.h into linux/gpio.h.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 8 insertions, 20 deletions

diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index bfe665621536..f6c7ae3e223b 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -94,24 +94,12 @@ static inline int gpio_request(unsigned gpio, const char *label)
         return -ENOSYS;
 }
 
-static inline int devm_gpio_request(struct device *dev, unsigned gpio,
-                                    const char *label)
-{
-        return -ENOSYS;
-}
-
 static inline int gpio_request_one(unsigned gpio,
                                         unsigned long flags, const char *label)
 {
         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;
@@ -125,14 +113,6 @@ static inline void gpio_free(unsigned gpio)
         WARN_ON(1);
 }
 
-static inline void devm_gpio_free(struct device *dev, unsigned gpio)
-{
-        might_sleep();
-
-        /* GPIO can never have been requested */
-        WARN_ON(1);
-}
-
 static inline void gpio_free_array(const struct gpio *array, size_t num)
 {
         might_sleep();
@@ -248,4 +228,12 @@ gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 
 #endif /* ! CONFIG_GENERIC_GPIO */
 
+struct device;
+
+/* 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);
+
 #endif /* __LINUX_GPIO_H */