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_gpiochip_add(struct gpio_chip *gc);
  65extern void of_gpiochip_remove(struct gpio_chip *gc);
  66extern int of_gpio_simple_xlate(struct gpio_chip *gc,
  67                                const struct of_phandle_args *gpiospec,
  68                                u32 *flags);
  69
  70#else /* CONFIG_OF_GPIO */
  71
  72/* Drivers may not strictly depend on the GPIO support, so let them link. */
  73static inline int of_get_named_gpio_flags(struct device_node *np,
  74                const char *list_name, int index, enum of_gpio_flags *flags)
  75{
  76        if (flags)
  77                *flags = 0;
  78
  79        return -ENOSYS;
  80}
  81
  82static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
  83                                       const struct of_phandle_args *gpiospec,
  84                                       u32 *flags)
  85{
  86        return -ENOSYS;
  87}
  88
  89static inline int of_gpiochip_add(struct gpio_chip *gc) { return 0; }
  90static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
  91
  92#endif /* CONFIG_OF_GPIO */
  93
  94/**
  95 * of_gpio_named_count() - Count GPIOs for a device
  96 * @np:         device node to count GPIOs for
  97 * @propname:   property name containing gpio specifier(s)
  98 *
  99 * The function returns the count of GPIOs specified for a node.
 100 * Note that the empty GPIO specifiers count too. Returns either
 101 *   Number of gpios defined in property,
 102 *   -EINVAL for an incorrectly formed gpios property, or
 103 *   -ENOENT for a missing gpios property
 104 *
 105 * Example:
 106 * gpios = <0
 107 *          &gpio1 1 2
 108 *          0
 109 *          &gpio2 3 4>;
 110 *
 111 * The above example defines four GPIOs, two of which are not specified.
 112 * This function will return '4'
 113 */
 114static inline int of_gpio_named_count(struct device_node *np, const char* propname)
 115{
 116        return of_count_phandle_with_args(np, propname, "#gpio-cells");
 117}
 118
 119/**
 120 * of_gpio_count() - Count GPIOs for a device
 121 * @np:         device node to count GPIOs for
 122 *
 123 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 124 */
 125static inline int of_gpio_count(struct device_node *np)
 126{
 127        return of_gpio_named_count(np, "gpios");
 128}
 129
 130static inline int of_get_gpio_flags(struct device_node *np, int index,
 131                      enum of_gpio_flags *flags)
 132{
 133        return of_get_named_gpio_flags(np, "gpios", index, flags);
 134}
 135
 136/**
 137 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 138 * @np:         device node to get GPIO from
 139 * @propname:   Name of property containing gpio specifier(s)
 140 * @index:      index of the GPIO
 141 *
 142 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 143 * value on the error condition.
 144 */
 145static inline int of_get_named_gpio(struct device_node *np,
 146                                   const char *propname, int index)
 147{
 148        return of_get_named_gpio_flags(np, propname, index, NULL);
 149}
 150
 151/**
 152 * of_get_gpio() - Get a GPIO number to use with GPIO API
 153 * @np:         device node to get GPIO from
 154 * @index:      index of the GPIO
 155 *
 156 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 157 * value on the error condition.
 158 */
 159static inline int of_get_gpio(struct device_node *np, int index)
 160{
 161        return of_get_gpio_flags(np, index, NULL);
 162}
 163
 164#endif /* __LINUX_OF_GPIO_H */
 165