of_gpio.h revision 15c9a0acc3f7873db4b7d35d016729b2dc229b49
1/* 2 * OF helpers for the GPIO API 3 * 4 * Copyright (c) 2007-2008 MontaVista Software, Inc. 5 * 6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 */ 13 14#ifndef __LINUX_OF_GPIO_H 15#define __LINUX_OF_GPIO_H 16 17#include <linux/compiler.h> 18#include <linux/kernel.h> 19#include <linux/errno.h> 20#include <linux/gpio.h> 21#include <linux/of.h> 22 23struct device_node; 24 25/* 26 * This is Linux-specific flags. By default controllers' and Linux' mapping 27 * match, but GPIO controllers are free to translate their own flags to 28 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. 29 */ 30enum of_gpio_flags { 31 OF_GPIO_ACTIVE_LOW = 0x1, 32}; 33 34#ifdef CONFIG_OF_GPIO 35 36/* 37 * OF GPIO chip for memory mapped banks 38 */ 39struct of_mm_gpio_chip { 40 struct gpio_chip gc; 41 void (*save_regs)(struct of_mm_gpio_chip *mm_gc); 42 void __iomem *regs; 43}; 44 45static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) 46{ 47 return container_of(gc, struct of_mm_gpio_chip, gc); 48} 49 50extern int of_get_named_gpio_flags(struct device_node *np, 51 const char *list_name, int index, enum of_gpio_flags *flags); 52 53extern unsigned int of_gpio_count(struct device_node *np); 54 55extern int of_mm_gpiochip_add(struct device_node *np, 56 struct of_mm_gpio_chip *mm_gc); 57 58extern void of_gpiochip_add(struct gpio_chip *gc); 59extern void of_gpiochip_remove(struct gpio_chip *gc); 60extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np); 61extern int of_gpio_simple_xlate(struct gpio_chip *gc, 62 const struct of_phandle_args *gpiospec, 63 u32 *flags); 64 65#else /* CONFIG_OF_GPIO */ 66 67/* Drivers may not strictly depend on the GPIO support, so let them link. */ 68static inline int of_get_named_gpio_flags(struct device_node *np, 69 const char *list_name, int index, enum of_gpio_flags *flags) 70{ 71 return -ENOSYS; 72} 73 74static inline unsigned int of_gpio_count(struct device_node *np) 75{ 76 return 0; 77} 78 79static inline int of_gpio_simple_xlate(struct gpio_chip *gc, 80 const struct of_phandle_args *gpiospec, 81 u32 *flags) 82{ 83 return -ENOSYS; 84} 85 86static inline void of_gpiochip_add(struct gpio_chip *gc) { } 87static inline void of_gpiochip_remove(struct gpio_chip *gc) { } 88 89#endif /* CONFIG_OF_GPIO */ 90 91/** 92 * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API 93 * @np: device node to get GPIO from 94 * @index: index of the GPIO 95 * @flags: a flags pointer to fill in 96 * 97 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 98 * value on the error condition. If @flags is not NULL the function also fills 99 * in flags for the GPIO. 100 */ 101static inline int of_get_gpio_flags(struct device_node *np, int index, 102 enum of_gpio_flags *flags) 103{ 104 return of_get_named_gpio_flags(np, "gpios", index, flags); 105} 106 107/** 108 * of_get_named_gpio() - Get a GPIO number to use with GPIO API 109 * @np: device node to get GPIO from 110 * @propname: Name of property containing gpio specifier(s) 111 * @index: index of the GPIO 112 * 113 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 114 * value on the error condition. 115 */ 116static inline int of_get_named_gpio(struct device_node *np, 117 const char *propname, int index) 118{ 119 return of_get_named_gpio_flags(np, propname, index, NULL); 120} 121 122/** 123 * of_get_gpio() - Get a GPIO number to use with GPIO API 124 * @np: device node to get GPIO from 125 * @index: index of the GPIO 126 * 127 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 128 * value on the error condition. 129 */ 130static inline int of_get_gpio(struct device_node *np, int index) 131{ 132 return of_get_gpio_flags(np, index, NULL); 133} 134 135#endif /* __LINUX_OF_GPIO_H */ 136