of_gpio.h revision 594fa265e084073443390c5b93d5410fd28e9bcd
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 22struct device_node; 23 24/* 25 * This is Linux-specific flags. By default controllers' and Linux' mapping 26 * match, but GPIO controllers are free to translate their own flags to 27 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. 28 */ 29enum of_gpio_flags { 30 OF_GPIO_ACTIVE_LOW = 0x1, 31}; 32 33#ifdef CONFIG_OF_GPIO 34 35/* 36 * OF GPIO chip for memory mapped banks 37 */ 38struct of_mm_gpio_chip { 39 struct gpio_chip gc; 40 void (*save_regs)(struct of_mm_gpio_chip *mm_gc); 41 void __iomem *regs; 42}; 43 44static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) 45{ 46 return container_of(gc, struct of_mm_gpio_chip, gc); 47} 48 49extern int of_get_gpio_flags(struct device_node *np, int index, 50 enum of_gpio_flags *flags); 51extern unsigned int of_gpio_count(struct device_node *np); 52 53extern int of_mm_gpiochip_add(struct device_node *np, 54 struct of_mm_gpio_chip *mm_gc); 55extern int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np, 56 const void *gpio_spec, u32 *flags); 57 58extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np); 59 60#else /* CONFIG_OF_GPIO */ 61 62/* Drivers may not strictly depend on the GPIO support, so let them link. */ 63static inline int of_get_gpio_flags(struct device_node *np, int index, 64 enum of_gpio_flags *flags) 65{ 66 return -ENOSYS; 67} 68 69static inline unsigned int of_gpio_count(struct device_node *np) 70{ 71 return 0; 72} 73 74#endif /* CONFIG_OF_GPIO */ 75 76/** 77 * of_get_gpio - Get a GPIO number to use with GPIO API 78 * @np: device node to get GPIO from 79 * @index: index of the GPIO 80 * 81 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 82 * value on the error condition. 83 */ 84static inline int of_get_gpio(struct device_node *np, int index) 85{ 86 return of_get_gpio_flags(np, index, NULL); 87} 88 89#endif /* __LINUX_OF_GPIO_H */ 90