LXR linux/include/linux/of

   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * OF helpers for the GPIO API
   4 *
   5 * Copyright (c) 2007-2008  MontaVista Software, Inc.
   6 *
   7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
   8 */
   9
  10#ifndef __LINUX_OF_GPIO_H
  11#define __LINUX_OF_GPIO_H
  12
  13#include <linux/compiler.h>
  14#include <linux/gpio/driver.h>
  15#include <linux/gpio.h>         /* FIXME: Shouldn't be here */
  16#include <linux/of.h>
  17
  18struct device_node;
  19
  20/*
  21 * This is Linux-specific flags. By default controllers' and Linux' mapping
  22 * match, but GPIO controllers are free to translate their own flags to
  23 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
  24 */
  25enum of_gpio_flags {
  26        OF_GPIO_ACTIVE_LOW = 0x1,
  27        OF_GPIO_SINGLE_ENDED = 0x2,
  28        OF_GPIO_OPEN_DRAIN = 0x4,
  29        OF_GPIO_TRANSITORY = 0x8,
  30        OF_GPIO_PULL_UP = 0x10,
  31        OF_GPIO_PULL_DOWN = 0x20,
  32};
  33
  34#ifdef CONFIG_OF_GPIO
  35
  36#include <linux/kernel.h>
  37
  38/*
  39 * OF GPIO chip for memory mapped banks
  40 */
  41struct of_mm_gpio_chip {
  42        struct gpio_chip gc;
  43        void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
  44        void __iomem *regs;
  45};
  46
  47static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
  48{
  49        return container_of(gc, struct of_mm_gpio_chip, gc);
  50}
  51
  52extern int of_get_named_gpio_flags(const struct device_node *np,
  53                const char *list_name, int index, enum of_gpio_flags *flags);
  54
  55extern int of_mm_gpiochip_add_data(struct device_node *np,
  56                                   struct of_mm_gpio_chip *mm_gc,
  57                                   void *data);
  58static inline int of_mm_gpiochip_add(struct device_node *np,
  59                                     struct of_mm_gpio_chip *mm_gc)
  60{
  61        return of_mm_gpiochip_add_data(np, mm_gc, NULL);
  62}
  63extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
  64
  65#else /* CONFIG_OF_GPIO */
  66
  67#include <linux/errno.h>
  68
  69/* Drivers may not strictly depend on the GPIO support, so let them link. */
  70static inline int of_get_named_gpio_flags(const struct device_node *np,
  71                const char *list_name, int index, enum of_gpio_flags *flags)
  72{
  73        if (flags)
  74                *flags = 0;
  75
  76        return -ENOSYS;
  77}
  78
  79#endif /* CONFIG_OF_GPIO */
  80
  81/**
  82 * of_gpio_named_count() - Count GPIOs for a device
  83 * @np:         device node to count GPIOs for
  84 * @propname:   property name containing gpio specifier(s)
  85 *
  86 * The function returns the count of GPIOs specified for a node.
  87 * Note that the empty GPIO specifiers count too. Returns either
  88 *   Number of gpios defined in property,
  89 *   -EINVAL for an incorrectly formed gpios property, or
  90 *   -ENOENT for a missing gpios property
  91 *
  92 * Example:
  93 * gpios = <0
  94 *          &gpio1 1 2
  95 *          0
  96 *          &gpio2 3 4>;
  97 *
  98 * The above example defines four GPIOs, two of which are not specified.
  99 * This function will return '4'
 100 */
 101static inline int of_gpio_named_count(const struct device_node *np,
 102                                      const char *propname)
 103{
 104        return of_count_phandle_with_args(np, propname, "#gpio-cells");
 105}
 106
 107/**
 108 * of_gpio_count() - Count GPIOs for a device
 109 * @np:         device node to count GPIOs for
 110 *
 111 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 112 */
 113static inline int of_gpio_count(const struct device_node *np)
 114{
 115        return of_gpio_named_count(np, "gpios");
 116}
 117
 118static inline int of_get_gpio_flags(const struct device_node *np, int index,
 119                      enum of_gpio_flags *flags)
 120{
 121        return of_get_named_gpio_flags(np, "gpios", index, flags);
 122}
 123
 124/**
 125 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 126 * @np:         device node to get GPIO from
 127 * @propname:   Name of property containing gpio specifier(s)
 128 * @index:      index of the GPIO
 129 *
 130 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 131 * value on the error condition.
 132 */
 133static inline int of_get_named_gpio(const struct device_node *np,
 134                                   const char *propname, int index)
 135{
 136        return of_get_named_gpio_flags(np, propname, index, NULL);
 137}
 138
 139/**
 140 * of_get_gpio() - Get a GPIO number to use with GPIO API
 141 * @np:         device node to get GPIO from
 142 * @index:      index of the GPIO
 143 *
 144 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 145 * value on the error condition.
 146 */
 147static inline int of_get_gpio(const struct device_node *np, int index)
 148{
 149        return of_get_gpio_flags(np, index, NULL);
 150}
 151
 152#endif /* __LINUX_OF_GPIO_H */
 153