include/linux/of_gpio.h

   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
  18 struct 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  */
  25 enum 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  */
  41 struct 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
  47 static 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
  52 extern int of_get_named_gpio_flags(struct device_node *np,
  53                 const char *list_name, int index, enum of_gpio_flags *flags);
  54
  55 extern int of_mm_gpiochip_add_data(struct device_node *np,
  56                                    struct of_mm_gpio_chip *mm_gc,
  57                                    void *data);
  58 static 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 }
  63 extern 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. */
  70 static inline int of_get_named_gpio_flags(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  */
 101 static inline int of_gpio_named_count(struct device_node *np, const char* propname)
 102 {
 103         return of_count_phandle_with_args(np, propname, "#gpio-cells");
 104 }
 105
 106 /**
 107  * of_gpio_count() - Count GPIOs for a device
 108  * @np:         device node to count GPIOs for
 109  *
 110  * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 111  */
 112 static inline int of_gpio_count(struct device_node *np)
 113 {
 114         return of_gpio_named_count(np, "gpios");
 115 }
 116
 117 static inline int of_get_gpio_flags(struct device_node *np, int index,
 118                       enum of_gpio_flags *flags)
 119 {
 120         return of_get_named_gpio_flags(np, "gpios", index, flags);
 121 }
 122
 123 /**
 124  * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 125  * @np:         device node to get GPIO from
 126  * @propname:   Name of property containing gpio specifier(s)
 127  * @index:      index of the GPIO
 128  *
 129  * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 130  * value on the error condition.
 131  */
 132 static inline int of_get_named_gpio(struct device_node *np,
 133                                    const char *propname, int index)
 134 {
 135         return of_get_named_gpio_flags(np, propname, index, NULL);
 136 }
 137
 138 /**
 139  * of_get_gpio() - Get a GPIO number to use with GPIO API
 140  * @np:         device node to get GPIO from
 141  * @index:      index of the GPIO
 142  *
 143  * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 144  * value on the error condition.
 145  */
 146 static inline int of_get_gpio(struct device_node *np, int index)
 147 {
 148         return of_get_gpio_flags(np, index, NULL);
 149 }
 150
 151 #endif /* __LINUX_OF_GPIO_H */