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authorWolfram Sang <w.sang@pengutronix.de>2011-01-12 17:00:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 08:03:14 -0800
commit0fdae42d361bbb431ca0ab0efed5126a94821177 (patch)
tree958a045aca3e40ca487dac67597496a7ed885115
parent49a367937fe4250144e24440e5a11ae4344202b1 (diff)
downloadop-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.txt2
-rw-r--r--include/asm-generic/gpio.h10
-rw-r--r--include/linux/gpio.h6
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;
}
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