LXR linux/include/linux/of

   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 * Generic OF GPIO chip
  37 */
  38struct of_gpio_chip {
  39        struct gpio_chip gc;
  40        int gpio_cells;
  41        int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np,
  42                     const void *gpio_spec, enum of_gpio_flags *flags);
  43};
  44
  45static inline struct of_gpio_chip *to_of_gpio_chip(struct gpio_chip *gc)
  46{
  47        return container_of(gc, struct of_gpio_chip, gc);
  48}
  49
  50/*
  51 * OF GPIO chip for memory mapped banks
  52 */
  53struct of_mm_gpio_chip {
  54        struct of_gpio_chip of_gc;
  55        void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
  56        void __iomem *regs;
  57};
  58
  59static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
  60{
  61        struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
  62
  63        return container_of(of_gc, struct of_mm_gpio_chip, of_gc);
  64}
  65
  66extern int of_get_gpio_flags(struct device_node *np, int index,
  67                             enum of_gpio_flags *flags);
  68extern unsigned int of_gpio_count(struct device_node *np);
  69
  70extern int of_mm_gpiochip_add(struct device_node *np,
  71                              struct of_mm_gpio_chip *mm_gc);
  72extern int of_gpio_simple_xlate(struct of_gpio_chip *of_gc,
  73                                struct device_node *np,
  74                                const void *gpio_spec,
  75                                enum of_gpio_flags *flags);
  76#else
  77
  78/* Drivers may not strictly depend on the GPIO support, so let them link. */
  79static inline int of_get_gpio_flags(struct device_node *np, int index,
  80                                    enum of_gpio_flags *flags)
  81{
  82        return -ENOSYS;
  83}
  84
  85static inline unsigned int of_gpio_count(struct device_node *np)
  86{
  87        return 0;
  88}
  89
  90#endif /* CONFIG_OF_GPIO */
  91
  92/**
  93 * of_get_gpio - Get a GPIO number to use with GPIO API
  94 * @np:         device node to get GPIO from
  95 * @index:      index of the GPIO
  96 *
  97 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
  98 * value on the error condition.
  99 */
 100static inline int of_get_gpio(struct device_node *np, int index)
 101{
 102        return of_get_gpio_flags(np, index, NULL);
 103}
 104
 105#endif /* __LINUX_OF_GPIO_H */
 106