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/kernel.h>
  15#include <linux/errno.h>
  16#include <linux/gpio.h>
  17#include <linux/of.h>
  18
  19struct device_node;
  20
  21/*
  22 * This is Linux-specific flags. By default controllers' and Linux' mapping
  23 * match, but GPIO controllers are free to translate their own flags to
  24 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
  25 */
  26enum of_gpio_flags {
  27        OF_GPIO_ACTIVE_LOW = 0x1,
  28        OF_GPIO_SINGLE_ENDED = 0x2,
  29        OF_GPIO_OPEN_DRAIN = 0x4,
  30        OF_GPIO_TRANSITORY = 0x8,
  31        OF_GPIO_PULL_UP = 0x10,
  32        OF_GPIO_PULL_DOWN = 0x20,
  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
  64#else /* CONFIG_OF_GPIO */
  65
  66/* Drivers may not strictly depend on the GPIO support, so let them link. */
  67static inline int of_get_named_gpio_flags(struct device_node *np,
  68                const char *list_name, int index, enum of_gpio_flags *flags)
  69{
  70        if (flags)
  71                *flags = 0;
  72
  73        return -ENOSYS;
  74}
  75
  76#endif /* CONFIG_OF_GPIO */
  77
  78/**
  79 * of_gpio_named_count() - Count GPIOs for a device
  80 * @np:         device node to count GPIOs for
  81 * @propname:   property name containing gpio specifier(s)
  82 *
  83 * The function returns the count of GPIOs specified for a node.
  84 * Note that the empty GPIO specifiers count too. Returns either
  85 *   Number of gpios defined in property,
  86 *   -EINVAL for an incorrectly formed gpios property, or
  87 *   -ENOENT for a missing gpios property
  88 *
  89 * Example:
  90 * gpios = <0
  91 *          &gpio1 1 2
  92 *          0
  93 *          &gpio2 3 4>;
  94 *
  95 * The above example defines four GPIOs, two of which are not specified.
  96 * This function will return '4'
  97 */
  98static inline int of_gpio_named_count(struct device_node *np, const char* propname)
  99{
 100        return of_count_phandle_with_args(np, propname, "#gpio-cells");
 101}
 102
 103/**
 104 * of_gpio_count() - Count GPIOs for a device
 105 * @np:         device node to count GPIOs for
 106 *
 107 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 108 */
 109static inline int of_gpio_count(struct device_node *np)
 110{
 111        return of_gpio_named_count(np, "gpios");
 112}
 113
 114static inline int of_get_gpio_flags(struct device_node *np, int index,
 115                      enum of_gpio_flags *flags)
 116{
 117        return of_get_named_gpio_flags(np, "gpios", index, flags);
 118}
 119
 120/**
 121 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 122 * @np:         device node to get GPIO from
 123 * @propname:   Name of property containing gpio specifier(s)
 124 * @index:      index of the GPIO
 125 *
 126 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 127 * value on the error condition.
 128 */
 129static inline int of_get_named_gpio(struct device_node *np,
 130                                   const char *propname, int index)
 131{
 132        return of_get_named_gpio_flags(np, propname, index, NULL);
 133}
 134
 135/**
 136 * of_get_gpio() - Get a GPIO number to use with GPIO API
 137 * @np:         device node to get GPIO from
 138 * @index:      index of the GPIO
 139 *
 140 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 141 * value on the error condition.
 142 */
 143static inline int of_get_gpio(struct device_node *np, int index)
 144{
 145        return of_get_gpio_flags(np, index, NULL);
 146}
 147
 148#endif /* __LINUX_OF_GPIO_H */
 149