diff options
| -rw-r--r-- | drivers/of/gpio.c | 36 | ||||
| -rw-r--r-- | include/linux/of_gpio.h | 38 |
2 files changed, 63 insertions, 11 deletions
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c index 7cd7301b583..a4ba217116e 100644 --- a/drivers/of/gpio.c +++ b/drivers/of/gpio.c @@ -19,14 +19,17 @@ #include <asm/prom.h> /** - * of_get_gpio - Get a GPIO number from the device tree to use with GPIO API + * of_get_gpio_flags - Get a GPIO number and flags to use with GPIO API * @np: device node to get GPIO from * @index: index of the GPIO + * @flags: a flags pointer to fill in * * Returns GPIO number to use with Linux generic GPIO API, or one of the errno - * value on the error condition. + * value on the error condition. If @flags is not NULL the function also fills + * in flags for the GPIO. */ -int of_get_gpio(struct device_node *np, int index) +int of_get_gpio_flags(struct device_node *np, int index, + enum of_gpio_flags *flags) { int ret; struct device_node *gc; @@ -59,7 +62,11 @@ int of_get_gpio(struct device_node *np, int index) goto err1; } - ret = of_gc->xlate(of_gc, np, gpio_spec); + /* .xlate might decide to not fill in the flags, so clear it. */ + if (flags) + *flags = 0; + + ret = of_gc->xlate(of_gc, np, gpio_spec, flags); if (ret < 0) goto err1; @@ -70,26 +77,41 @@ err0: pr_debug("%s exited with status %d\n", __func__, ret); return ret; } -EXPORT_SYMBOL(of_get_gpio); +EXPORT_SYMBOL(of_get_gpio_flags); /** - * of_gpio_simple_xlate - translate gpio_spec to the GPIO number + * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags * @of_gc: pointer to the of_gpio_chip structure * @np: device node of the GPIO chip * @gpio_spec: gpio specifier as found in the device tree + * @flags: a flags pointer to fill in * * This is simple translation function, suitable for the most 1:1 mapped * gpio chips. This function performs only one sanity check: whether gpio * is less than ngpios (that is specified in the gpio_chip). */ int of_gpio_simple_xlate(struct of_gpio_chip *of_gc, struct device_node *np, - const void *gpio_spec) + const void *gpio_spec, enum of_gpio_flags *flags) { const u32 *gpio = gpio_spec; + /* + * We're discouraging gpio_cells < 2, since that way you'll have to + * write your own xlate function (that will have to retrive the GPIO + * number and the flags from a single gpio cell -- this is possible, + * but not recommended). + */ + if (of_gc->gpio_cells < 2) { + WARN_ON(1); + return -EINVAL; + } + if (*gpio > of_gc->gc.ngpio) return -EINVAL; + if (flags) + *flags = gpio[1]; + return *gpio; } EXPORT_SYMBOL(of_gpio_simple_xlate); diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h index 67db101d0eb..e25abf610cb 100644 --- a/include/linux/of_gpio.h +++ b/include/linux/of_gpio.h @@ -14,9 +14,22 @@ #ifndef __LINUX_OF_GPIO_H #define __LINUX_OF_GPIO_H +#include <linux/compiler.h> +#include <linux/kernel.h> #include <linux/errno.h> #include <linux/gpio.h> +struct device_node; + +/* + * This is Linux-specific flags. By default controllers' and Linux' mapping + * match, but GPIO controllers are free to translate their own flags to + * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. + */ +enum of_gpio_flags { + OF_GPIO_ACTIVE_LOW = 0x1, +}; + #ifdef CONFIG_OF_GPIO /* @@ -26,7 +39,7 @@ struct of_gpio_chip { struct gpio_chip gc; int gpio_cells; int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np, - const void *gpio_spec); + const void *gpio_spec, enum of_gpio_flags *flags); }; static inline struct of_gpio_chip *to_of_gpio_chip(struct gpio_chip *gc) @@ -50,20 +63,37 @@ static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) return container_of(of_gc, struct of_mm_gpio_chip, of_gc); } -extern int of_get_gpio(struct device_node *np, int index); +extern int of_get_gpio_flags(struct device_node *np, int index, + enum of_gpio_flags *flags); + extern int of_mm_gpiochip_add(struct device_node *np, struct of_mm_gpio_chip *mm_gc); extern int of_gpio_simple_xlate(struct of_gpio_chip *of_gc, struct device_node *np, - const void *gpio_spec); + const void *gpio_spec, + enum of_gpio_flags *flags); #else /* Drivers may not strictly depend on the GPIO support, so let them link. */ -static inline int of_get_gpio(struct device_node *np, int index) +static inline int of_get_gpio_flags(struct device_node *np, int index, + enum of_gpio_flags *flags) { return -ENOSYS; } #endif /* CONFIG_OF_GPIO */ +/** + * of_get_gpio - Get a GPIO number to use with GPIO API + * @np: device node to get GPIO from + * @index: index of the GPIO + * + * Returns GPIO number to use with Linux generic GPIO API, or one of the errno + * value on the error condition. + */ +static inline int of_get_gpio(struct device_node *np, int index) +{ + return of_get_gpio_flags(np, index, NULL); +} + #endif /* __LINUX_OF_GPIO_H */ |