From 0fdae42d361bbb431ca0ab0efed5126a94821177 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 12 Jan 2011 17:00:23 -0800 Subject: 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: "The return value of gpio_request() must be checked." For gpio_direction_* and gpio_request_*, we now act accordingly. Signed-off-by: Wolfram Sang Cc: David Brownell Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/gpio.txt | 2 +- include/asm-generic/gpio.h | 10 +++++----- include/linux/gpio.h | 6 +++--- 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 792faa3c06c..a492d92bb09 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 ff5c66080c8..6098cae2af8 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 e41f7dd1ae6..1d5214a8911 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; } -- cgit v1.2.3