diff options
| author | Wolfram Sang <w.sang@pengutronix.de> | 2011-01-12 17:00:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 08:03:14 -0800 |
| commit | 0fdae42d361bbb431ca0ab0efed5126a94821177 (patch) | |
| tree | 958a045aca3e40ca487dac67597496a7ed885115 | |
| parent | 49a367937fe4250144e24440e5a11ae4344202b1 (diff) | |
| download | op-kernel-dev-0fdae42d361bbb431ca0ab0efed5126a94821177.zip op-kernel-dev-0fdae42d361bbb431ca0ab0efed5126a94821177.tar.gz | |
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>
| -rw-r--r-- | Documentation/gpio.txt | 2 | ||||
| -rw-r--r-- | include/asm-generic/gpio.h | 10 | ||||
| -rw-r--r-- | include/linux/gpio.h | 6 |
3 files changed, 9 insertions, 9 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 792faa3..a492d92 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -135,7 +135,7 @@ setting up a platform_device using the GPIO, is mark its direction: 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 diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index ff5c660..6098cae 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -147,11 +147,11 @@ extern struct gpio_chip *gpiochip_find(void *data, /* 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 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); @@ -192,8 +192,8 @@ struct gpio { const char *label; }; -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 diff --git a/include/linux/gpio.h b/include/linux/gpio.h index e41f7dd..1d5214a 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; } |
