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>
int gpio_direction_input(unsigned gpio);
int gpio_direction_output(unsigned gpio, int value);
int gpio_direction_input(unsigned gpio);
int gpio_direction_output(unsigned gpio, int value);
-The return value is zero for success, else a negative errno. It should
+The return value is zero for success, else a negative errno. It must
be checked, since the get/set calls don't have error returns and since
misconfiguration is possible. You should normally issue these calls from
a task context. However, for spinlock-safe GPIOs it's OK to use them
be checked, since the get/set calls don't have error returns and since
misconfiguration is possible. You should normally issue these calls from
a task context. However, for spinlock-safe GPIOs it's OK to use them
/* Always use the library code for GPIO management calls,
* or when sleeping may be involved.
*/
/* Always use the library code for GPIO management calls,
* or when sleeping may be involved.
*/
-extern int gpio_request(unsigned gpio, const char *label);
+extern int __must_check gpio_request(unsigned gpio, const char *label);
extern void gpio_free(unsigned gpio);
extern void gpio_free(unsigned gpio);
-extern int gpio_direction_input(unsigned gpio);
-extern int gpio_direction_output(unsigned gpio, int value);
+extern int __must_check gpio_direction_input(unsigned gpio);
+extern int __must_check gpio_direction_output(unsigned gpio, int value);
extern int gpio_set_debounce(unsigned gpio, unsigned debounce);
extern int gpio_set_debounce(unsigned gpio, unsigned debounce);
-extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
-extern int gpio_request_array(struct gpio *array, size_t num);
+extern int __must_check gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
+extern int __must_check gpio_request_array(struct gpio *array, size_t num);
extern void gpio_free_array(struct gpio *array, size_t num);
#ifdef CONFIG_GPIO_SYSFS
extern void gpio_free_array(struct gpio *array, size_t num);
#ifdef CONFIG_GPIO_SYSFS
-static inline int gpio_request(unsigned gpio, const char *label)
+static inline int __must_check gpio_request(unsigned gpio, const char *label)
-static inline int gpio_direction_input(unsigned gpio)
+static inline int __must_check gpio_direction_input(unsigned gpio)
-static inline int gpio_direction_output(unsigned gpio, int value)
+static inline int __must_check gpio_direction_output(unsigned gpio, int value)