diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/plat-samsung/include/plat/gpio-cfg.h | 21 |
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); |