/* * 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> #include <linux/gpio/consumer.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 struct gpio_desc *of_get_named_gpiod_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_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 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, const char *list_name, int index, enum of_gpio_flags *flags) { return ERR_PTR(-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 */ static inline int of_get_named_gpio_flags(struct device_node *np, const char *list_name, int index, enum of_gpio_flags *flags) { struct gpio_desc *desc; desc = of_get_named_gpiod_flags(np, list_name, index, flags); if (IS_ERR(desc)) return PTR_ERR(desc); else return desc_to_gpio(desc); } /** * 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"); } /** * of_get_gpiod_flags() - Get a GPIO descriptor 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 descriptor to use with Linux generic GPIO API, or a errno * value on the error condition. If @flags is not NULL the function also fills * in flags for the GPIO. */ static inline struct gpio_desc *of_get_gpiod_flags(struct device_node *np, int index, enum of_gpio_flags *flags) { return of_get_named_gpiod_flags(np, "gpios", index, flags); } 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 */