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        OF_GPIO_OPEN_DRAIN = 0x4,
  34        OF_GPIO_SLEEP_MAY_LOOSE_VALUE = 0x8,
  35};
  36
  37#ifdef CONFIG_OF_GPIO
  38
  39/*
  40 * OF GPIO chip for memory mapped banks
  41 */
  42struct of_mm_gpio_chip {
  43        struct gpio_chip gc;
  44        void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
  45        void __iomem *regs;
  46};
  47
  48static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
  49{
  50        return container_of(gc, struct of_mm_gpio_chip, gc);
  51}
  52
  53extern int of_get_named_gpio_flags(struct device_node *np,
  54                const char *list_name, int index, enum of_gpio_flags *flags);
  55
  56extern int of_mm_gpiochip_add_data(struct device_node *np,
  57                                   struct of_mm_gpio_chip *mm_gc,
  58                                   void *data);
  59static inline int of_mm_gpiochip_add(struct device_node *np,
  60                                     struct of_mm_gpio_chip *mm_gc)
  61{
  62        return of_mm_gpiochip_add_data(np, mm_gc, NULL);
  63}
  64extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
  65
  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
  89#endif /* CONFIG_OF_GPIO */
  90
  91/**
  92 * of_gpio_named_count() - Count GPIOs for a device
  93 * @np:         device node to count GPIOs for
  94 * @propname:   property name containing gpio specifier(s)
  95 *
  96 * The function returns the count of GPIOs specified for a node.
  97 * Note that the empty GPIO specifiers count too. Returns either
  98 *   Number of gpios defined in property,
  99 *   -EINVAL for an incorrectly formed gpios property, or
 100 *   -ENOENT for a missing gpios property
 101 *
 102 * Example:
 103 * gpios = <0
 104 *          &gpio1 1 2
 105 *          0
 106 *          &gpio2 3 4>;
 107 *
 108 * The above example defines four GPIOs, two of which are not specified.
 109 * This function will return '4'
 110 */
 111static inline int of_gpio_named_count(struct device_node *np, const char* propname)
 112{
 113        return of_count_phandle_with_args(np, propname, "#gpio-cells");
 114}
 115
 116/**
 117 * of_gpio_count() - Count GPIOs for a device
 118 * @np:         device node to count GPIOs for
 119 *
 120 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 121 */
 122static inline int of_gpio_count(struct device_node *np)
 123{
 124        return of_gpio_named_count(np, "gpios");
 125}
 126
 127static inline int of_get_gpio_flags(struct device_node *np, int index,
 128                      enum of_gpio_flags *flags)
 129{
 130        return of_get_named_gpio_flags(np, "gpios", index, flags);
 131}
 132
 133/**
 134 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 135 * @np:         device node to get GPIO from
 136 * @propname:   Name of property containing gpio specifier(s)
 137 * @index:      index of the GPIO
 138 *
 139 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 140 * value on the error condition.
 141 */
 142static inline int of_get_named_gpio(struct device_node *np,
 143                                   const char *propname, int index)
 144{
 145        return of_get_named_gpio_flags(np, propname, index, NULL);
 146}
 147
 148/**
 149 * of_get_gpio() - Get a GPIO number to use with GPIO API
 150 * @np:         device node to get GPIO from
 151 * @index:      index of the GPIO
 152 *
 153 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 154 * value on the error condition.
 155 */
 156static inline int of_get_gpio(struct device_node *np, int index)
 157{
 158        return of_get_gpio_flags(np, index, NULL);
 159}
 160
 161#endif /* __LINUX_OF_GPIO_H */
 162