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authorBen Dooks <ben-linux@fluff.org>2010-05-24 12:21:40 +0900
committerBen Dooks <ben-linux@fluff.org>2010-05-28 19:31:32 +0900
commit189e0445d8b5246aa570fc3881b4739c443bec8a (patch)
treef05589cc120b4a14016dd22d8e2acc94cbb4a71d /arch/arm/plat-samsung/include/plat/gpio-cfg.h
parentd192baeaa7a068b4e5151a34b4121d99938e396d (diff)
ARM: SAMSUNG: gpio-cfg.h: update documentation
Update the documentation on the gpio configuration calls to add more references to useful information and also to document the values that are passed. Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'arch/arm/plat-samsung/include/plat/gpio-cfg.h')
-rw-r--r--arch/arm/plat-samsung/include/plat/gpio-cfg.h21
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/include/plat/gpio-cfg.h b/arch/arm/plat-samsung/include/plat/gpio-cfg.h
index 46838232b46..db4112c6f2b 100644
--- a/arch/arm/plat-samsung/include/plat/gpio-cfg.h
+++ b/arch/arm/plat-samsung/include/plat/gpio-cfg.h
@@ -43,6 +43,11 @@ struct s3c_gpio_chip;
* layouts. Provide an point to vector control routine and provide any
* per-bank configuration information that other systems such as the
* external interrupt code will need.
+ *
+ * @sa s3c_gpio_cfgpin
+ * @sa s3c_gpio_getcfg
+ * @sa s3c_gpio_setpull
+ * @sa s3c_gpio_getpull
*/
struct s3c_gpio_cfg {
unsigned int cfg_eint;
@@ -75,6 +80,20 @@ struct s3c_gpio_cfg {
* Configure which function is actually connected to the external
* pin, such as an gpio input, output or some form of special function
* connected to an internal peripheral block.
+ *
+ * The @to parameter can be one of the generic S3C_GPIO_INPUT, S3C_GPIO_OUTPUT
+ * or S3C_GPIO_SFN() to indicate one of the possible values that the helper
+ * will then generate the correct bit mask and shift for the configuration.
+ *
+ * If a bank of GPIOs all needs to be set to special-function 2, then
+ * the following code will work:
+ *
+ * for (gpio = start; gpio < end; gpio++)
+ * s3c_gpio_cfgpin(gpio, S3C_GPIO_SFN(2));
+ *
+ * The @to parameter can also be a specific value already shifted to the
+ * correct position in the control register, although these are discouraged
+ * in newer kernels and are only being kept for compatibility.
*/
extern int s3c_gpio_cfgpin(unsigned int pin, unsigned int to);
@@ -108,6 +127,8 @@ extern unsigned s3c_gpio_getcfg(unsigned int pin);
* This function sets the state of the pull-{up,down} resistor for the
* specified pin. It will return 0 if successfull, or a negative error
* code if the pin cannot support the requested pull setting.
+ *
+ * @pull is one of S3C_GPIO_PULL_NONE, S3C_GPIO_PULL_DOWN or S3C_GPIO_PULL_UP.
*/
extern int s3c_gpio_setpull(unsigned int pin, s3c_gpio_pull_t pull);