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 * 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_named_gpio_flags(struct device_node *np,
  50                const char *list_name, int index, enum of_gpio_flags *flags);
  51
  52extern unsigned int of_gpio_count(struct device_node *np);
  53
  54extern int of_mm_gpiochip_add(struct device_node *np,
  55                              struct of_mm_gpio_chip *mm_gc);
  56
  57extern void of_gpiochip_add(struct gpio_chip *gc);
  58extern void of_gpiochip_remove(struct gpio_chip *gc);
  59extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np);
  60extern int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
  61                                const void *gpio_spec, u32 *flags);
  62
  63#else /* CONFIG_OF_GPIO */
  64
  65/* Drivers may not strictly depend on the GPIO support, so let them link. */
  66static inline int of_get_named_gpio_flags(struct device_node *np,
  67                const char *list_name, int index, enum of_gpio_flags *flags)
  68{
  69        return -ENOSYS;
  70}
  71
  72static inline unsigned int of_gpio_count(struct device_node *np)
  73{
  74        return 0;
  75}
  76
  77static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
  78                                       struct device_node *np,
  79                                       const void *gpio_spec, u32 *flags)
  80{
  81        return -ENOSYS;
  82}
  83
  84static inline void of_gpiochip_add(struct gpio_chip *gc) { }
  85static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
  86
  87#endif /* CONFIG_OF_GPIO */
  88
  89/**
  90 * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API
  91 * @np:         device node to get GPIO from
  92 * @index:      index of the GPIO
  93 * @flags:      a flags pointer to fill in
  94 *
  95 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
  96 * value on the error condition. If @flags is not NULL the function also fills
  97 * in flags for the GPIO.
  98 */
  99static inline int of_get_gpio_flags(struct device_node *np, int index,
 100                      enum of_gpio_flags *flags)
 101{
 102        return of_get_named_gpio_flags(np, "gpios", index, flags);
 103}
 104
 105/**
 106 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 107 * @np:         device node to get GPIO from
 108 * @propname:   Name of property containing gpio specifier(s)
 109 * @index:      index of the GPIO
 110 *
 111 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 112 * value on the error condition.
 113 */
 114static inline int of_get_named_gpio(struct device_node *np,
 115                                   const char *propname, int index)
 116{
 117        return of_get_named_gpio_flags(np, propname, index, NULL);
 118}
 119
 120/**
 121 * of_get_gpio() - Get a GPIO number to use with GPIO API
 122 * @np:         device node to get GPIO from
 123 * @index:      index of the GPIO
 124 *
 125 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 126 * value on the error condition.
 127 */
 128static inline int of_get_gpio(struct device_node *np, int index)
 129{
 130        return of_get_gpio_flags(np, index, NULL);
 131}
 132
 133#endif /* __LINUX_OF_GPIO_H */
 134