gpiolib: annotate gpio-intialization with __must_check

Because GPIOs can have crucial functions especially in embedded systems,
we are better safe than sorry regarding their configuration.  For
gpio_request, the documentation is simply enforced: <quote>"The return
value of gpio_request() must be checked."</quote> For gpio_direction_* and
gpio_request_*, we now act accordingly.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index e41f7dd1ae67..1d5214a89110 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -29,7 +29,7 @@ static inline int gpio_is_valid(int number)
         return 0;
 }
 
-static inline int gpio_request(unsigned gpio, const char *label)
+static inline int __must_check gpio_request(unsigned gpio, const char *label)
 {
         return -ENOSYS;
 }
@@ -42,12 +42,12 @@ static inline void gpio_free(unsigned gpio)
         WARN_ON(1);
 }
 
-static inline int gpio_direction_input(unsigned gpio)
+static inline int __must_check gpio_direction_input(unsigned gpio)
 {
         return -ENOSYS;
 }
 
-static inline int gpio_direction_output(unsigned gpio, int value)
+static inline int __must_check gpio_direction_output(unsigned gpio, int value)
 {
         return -ENOSYS;
 }