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};
  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 int of_mm_gpiochip_add_data(struct device_node *np,
  53                                   struct of_mm_gpio_chip *mm_gc,
  54                                   void *data);
  55static inline int of_mm_gpiochip_add(struct device_node *np,
  56                                     struct of_mm_gpio_chip *mm_gc)
  57{
  58        return of_mm_gpiochip_add_data(np, mm_gc, NULL);
  59}
  60extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
  61
  62extern int of_gpio_simple_xlate(struct gpio_chip *gc,
  63                                const struct of_phandle_args *gpiospec,
  64                                u32 *flags);
  65
  66#else /* CONFIG_OF_GPIO */
  67
  68/* Drivers may not strictly depend on the GPIO support, so let them link. */
  69static inline int of_get_named_gpio_flags(struct device_node *np,
  70                const char *list_name, int index, enum of_gpio_flags *flags)
  71{
  72        if (flags)
  73                *flags = 0;
  74
  75        return -ENOSYS;
  76}
  77
  78static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
  79                                       const struct of_phandle_args *gpiospec,
  80                                       u32 *flags)
  81{
  82        return -ENOSYS;
  83}
  84
  85#endif /* CONFIG_OF_GPIO */
  86
  87/**
  88 * of_gpio_named_count() - Count GPIOs for a device
  89 * @np:         device node to count GPIOs for
  90 * @propname:   property name containing gpio specifier(s)
  91 *
  92 * The function returns the count of GPIOs specified for a node.
  93 * Note that the empty GPIO specifiers count too. Returns either
  94 *   Number of gpios defined in property,
  95 *   -EINVAL for an incorrectly formed gpios property, or
  96 *   -ENOENT for a missing gpios property
  97 *
  98 * Example:
  99 * gpios = <0
 100 *          &gpio1 1 2
 101 *          0
 102 *          &gpio2 3 4>;
 103 *
 104 * The above example defines four GPIOs, two of which are not specified.
 105 * This function will return '4'
 106 */
 107static inline int of_gpio_named_count(struct device_node *np, const char* propname)
 108{
 109        return of_count_phandle_with_args(np, propname, "#gpio-cells");
 110}
 111
 112/**
 113 * of_gpio_count() - Count GPIOs for a device
 114 * @np:         device node to count GPIOs for
 115 *
 116 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 117 */
 118static inline int of_gpio_count(struct device_node *np)
 119{
 120        return of_gpio_named_count(np, "gpios");
 121}
 122
 123static inline int of_get_gpio_flags(struct device_node *np, int index,
 124                      enum of_gpio_flags *flags)
 125{
 126        return of_get_named_gpio_flags(np, "gpios", index, flags);
 127}
 128
 129/**
 130 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 131 * @np:         device node to get GPIO from
 132 * @propname:   Name of property containing gpio specifier(s)
 133 * @index:      index of the GPIO
 134 *
 135 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 136 * value on the error condition.
 137 */
 138static inline int of_get_named_gpio(struct device_node *np,
 139                                   const char *propname, int index)
 140{
 141        return of_get_named_gpio_flags(np, propname, index, NULL);
 142}
 143
 144/**
 145 * of_get_gpio() - Get a GPIO number to use with GPIO API
 146 * @np:         device node to get GPIO from
 147 * @index:      index of the GPIO
 148 *
 149 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 150 * value on the error condition.
 151 */
 152static inline int of_get_gpio(struct device_node *np, int index)
 153{
 154        return of_get_gpio_flags(np, index, NULL);
 155}
 156
 157#endif /* __LINUX_OF_GPIO_H */
 158