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#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        OF_GPIO_SINGLE_ENDED = 0x2,
  33};
  34
  35#ifdef CONFIG_OF_GPIO
  36
  37/*
  38 * OF GPIO chip for memory mapped banks
  39 */
  40struct of_mm_gpio_chip {
  41        struct gpio_chip gc;
  42        void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
  43        void __iomem *regs;
  44};
  45
  46static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
  47{
  48        return container_of(gc, struct of_mm_gpio_chip, gc);
  49}
  50
  51extern int of_get_named_gpio_flags(struct device_node *np,
  52                const char *list_name, int index, enum of_gpio_flags *flags);
  53
  54extern int of_mm_gpiochip_add_data(struct device_node *np,
  55                                   struct of_mm_gpio_chip *mm_gc,
  56                                   void *data);
  57static inline int of_mm_gpiochip_add(struct device_node *np,
  58                                     struct of_mm_gpio_chip *mm_gc)
  59{
  60        return of_mm_gpiochip_add_data(np, mm_gc, NULL);
  61}
  62extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
  63
  64extern int of_gpio_simple_xlate(struct gpio_chip *gc,
  65                                const struct of_phandle_args *gpiospec,
  66                                u32 *flags);
  67
  68#else /* CONFIG_OF_GPIO */
  69
  70/* Drivers may not strictly depend on the GPIO support, so let them link. */
  71static inline int of_get_named_gpio_flags(struct device_node *np,
  72                const char *list_name, int index, enum of_gpio_flags *flags)
  73{
  74        if (flags)
  75                *flags = 0;
  76
  77        return -ENOSYS;
  78}
  79
  80static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
  81                                       const struct of_phandle_args *gpiospec,
  82                                       u32 *flags)
  83{
  84        return -ENOSYS;
  85}
  86
  87#endif /* CONFIG_OF_GPIO */
  88
  89/**
  90 * of_gpio_named_count() - Count GPIOs for a device
  91 * @np:         device node to count GPIOs for
  92 * @propname:   property name containing gpio specifier(s)
  93 *
  94 * The function returns the count of GPIOs specified for a node.
  95 * Note that the empty GPIO specifiers count too. Returns either
  96 *   Number of gpios defined in property,
  97 *   -EINVAL for an incorrectly formed gpios property, or
  98 *   -ENOENT for a missing gpios property
  99 *
 100 * Example:
 101 * gpios = <0
 102 *          &gpio1 1 2
 103 *          0
 104 *          &gpio2 3 4>;
 105 *
 106 * The above example defines four GPIOs, two of which are not specified.
 107 * This function will return '4'
 108 */
 109static inline int of_gpio_named_count(struct device_node *np, const char* propname)
 110{
 111        return of_count_phandle_with_args(np, propname, "#gpio-cells");
 112}
 113
 114/**
 115 * of_gpio_count() - Count GPIOs for a device
 116 * @np:         device node to count GPIOs for
 117 *
 118 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 119 */
 120static inline int of_gpio_count(struct device_node *np)
 121{
 122        return of_gpio_named_count(np, "gpios");
 123}
 124
 125static inline int of_get_gpio_flags(struct device_node *np, int index,
 126                      enum of_gpio_flags *flags)
 127{
 128        return of_get_named_gpio_flags(np, "gpios", index, flags);
 129}
 130
 131/**
 132 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 133 * @np:         device node to get GPIO from
 134 * @propname:   Name of property containing gpio specifier(s)
 135 * @index:      index of the GPIO
 136 *
 137 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 138 * value on the error condition.
 139 */
 140static inline int of_get_named_gpio(struct device_node *np,
 141                                   const char *propname, int index)
 142{
 143        return of_get_named_gpio_flags(np, propname, index, NULL);
 144}
 145
 146/**
 147 * of_get_gpio() - Get a GPIO number to use with GPIO API
 148 * @np:         device node to get GPIO from
 149 * @index:      index of the GPIO
 150 *
 151 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 152 * value on the error condition.
 153 */
 154static inline int of_get_gpio(struct device_node *np, int index)
 155{
 156        return of_get_gpio_flags(np, index, NULL);
 157}
 158
 159#endif /* __LINUX_OF_GPIO_H */
 160