diff options
Diffstat (limited to 'kernel/include/linux/of_gpio.h')
| -rw-r--r-- | kernel/include/linux/of_gpio.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/kernel/include/linux/of_gpio.h b/kernel/include/linux/of_gpio.h new file mode 100644 index 000000000..69dbe312b --- /dev/null +++ b/kernel/include/linux/of_gpio.h @@ -0,0 +1,154 @@ +/* + * OF helpers for the GPIO API + * + * Copyright (c) 2007-2008 MontaVista Software, Inc. + * + * Author: Anton Vorontsov <avorontsov@ru.mvista.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#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> +#include <linux/of.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 + +/* + * OF GPIO chip for memory mapped banks + */ +struct of_mm_gpio_chip { + struct gpio_chip gc; + void (*save_regs)(struct of_mm_gpio_chip *mm_gc); + void __iomem *regs; +}; + +static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) +{ + return container_of(gc, struct of_mm_gpio_chip, gc); +} + +extern int of_get_named_gpio_flags(struct device_node *np, + const char *list_name, 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 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc); + +extern void of_gpiochip_add(struct gpio_chip *gc); +extern void of_gpiochip_remove(struct gpio_chip *gc); +extern int of_gpio_simple_xlate(struct gpio_chip *gc, + const struct of_phandle_args *gpiospec, + u32 *flags); + +#else /* CONFIG_OF_GPIO */ + +/* Drivers may not strictly depend on the GPIO support, so let them link. */ +static inline int of_get_named_gpio_flags(struct device_node *np, + const char *list_name, int index, enum of_gpio_flags *flags) +{ + return -ENOSYS; +} + +static inline int of_gpio_simple_xlate(struct gpio_chip *gc, + const struct of_phandle_args *gpiospec, + u32 *flags) +{ + return -ENOSYS; +} + +static inline void of_gpiochip_add(struct gpio_chip *gc) { } +static inline void of_gpiochip_remove(struct gpio_chip *gc) { } + +#endif /* CONFIG_OF_GPIO */ + +/** + * of_gpio_named_count() - Count GPIOs for a device + * @np: device node to count GPIOs for + * @propname: property name containing gpio specifier(s) + * + * The function returns the count of GPIOs specified for a node. + * Note that the empty GPIO specifiers count too. Returns either + * Number of gpios defined in property, + * -EINVAL for an incorrectly formed gpios property, or + * -ENOENT for a missing gpios property + * + * Example: + * gpios = <0 + * &gpio1 1 2 + * 0 + * &gpio2 3 4>; + * + * The above example defines four GPIOs, two of which are not specified. + * This function will return '4' + */ +static inline int of_gpio_named_count(struct device_node *np, const char* propname) +{ + return of_count_phandle_with_args(np, propname, "#gpio-cells"); +} + +/** + * of_gpio_count() - Count GPIOs for a device + * @np: device node to count GPIOs for + * + * Same as of_gpio_named_count, but hard coded to use the 'gpios' property + */ +static inline int of_gpio_count(struct device_node *np) +{ + return of_gpio_named_count(np, "gpios"); +} + +static inline int of_get_gpio_flags(struct device_node *np, int index, + enum of_gpio_flags *flags) +{ + return of_get_named_gpio_flags(np, "gpios", index, flags); +} + +/** + * of_get_named_gpio() - Get a GPIO number to use with GPIO API + * @np: device node to get GPIO from + * @propname: Name of property containing gpio specifier(s) + * @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_named_gpio(struct device_node *np, + const char *propname, int index) +{ + return of_get_named_gpio_flags(np, propname, index, NULL); +} + +/** + * 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 */ |