From b908b53d580c3e9aba81ebe3339c5b7b4fa8031d Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Mon, 1 Dec 2008 06:30:04 +0000 Subject: of/gpio: Implement of_get_gpio_flags() This adds a new function, of_get_gpio_flags, which is like of_get_gpio(), but accepts a new "flags" argument. This new function will be used by the drivers that need to retrieve additional GPIO information, such as active-low flag. Also, this changes the default ("simple") .xlate routine to warn about bogus (< 2) #gpio-cells usage: the second cell should always be present for GPIO flags. Signed-off-by: Anton Vorontsov Signed-off-by: Paul Mackerras --- include/linux/of_gpio.h | 38 ++++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-) (limited to 'include/linux/of_gpio.h') 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 +#include #include #include +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 */ -- cgit v1.2.3-70-g09d2 From 749820928a2fd47ff536773d869d2c3f8038b7d1 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Fri, 5 Dec 2008 08:15:54 +0000 Subject: of/gpio: Implement of_gpio_count() This function is used to count how many GPIOs are specified for a device node. Signed-off-by: Anton Vorontsov Signed-off-by: Paul Mackerras --- drivers/of/gpio.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/of_gpio.h | 6 ++++++ 2 files changed, 40 insertions(+) (limited to 'include/linux/of_gpio.h') diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c index a4ba217116e..6eea601a920 100644 --- a/drivers/of/gpio.c +++ b/drivers/of/gpio.c @@ -79,6 +79,40 @@ err0: } EXPORT_SYMBOL(of_get_gpio_flags); +/** + * of_gpio_count - Count GPIOs for a device + * @np: device node to count GPIOs for + * + * The function returns the count of GPIOs specified for a node. + * + * Note that the empty GPIO specifiers counts too. For example, + * + * gpios = <0 + * &pio1 1 2 + * 0 + * &pio2 3 4>; + * + * defines four GPIOs (so this function will return 4), two of which + * are not specified. + */ +unsigned int of_gpio_count(struct device_node *np) +{ + unsigned int cnt = 0; + + do { + int ret; + + ret = of_parse_phandles_with_args(np, "gpios", "#gpio-cells", + cnt, NULL, NULL); + /* A hole in the gpios = <> counts anyway. */ + if (ret < 0 && ret != -EEXIST) + break; + } while (++cnt); + + return cnt; +} +EXPORT_SYMBOL(of_gpio_count); + /** * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags * @of_gc: pointer to the of_gpio_chip structure diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h index e25abf610cb..fc2472c3c25 100644 --- a/include/linux/of_gpio.h +++ b/include/linux/of_gpio.h @@ -65,6 +65,7 @@ static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) extern int of_get_gpio_flags(struct device_node *np, int index, enum of_gpio_flags *flags); +extern unsigned int of_gpio_count(struct device_node *np); extern int of_mm_gpiochip_add(struct device_node *np, struct of_mm_gpio_chip *mm_gc); @@ -81,6 +82,11 @@ static inline int of_get_gpio_flags(struct device_node *np, int index, return -ENOSYS; } +static inline unsigned int of_gpio_count(struct device_node *np) +{ + return 0; +} + #endif /* CONFIG_OF_GPIO */ /** -- cgit v1.2.3-70-g09d2