root/include/linux/of_gpio.h

INCLUDED FROM

DEFINITIONS

1. to_of_mm_gpio_chip
2. of_mm_gpiochip_add
3. of_get_named_gpio_flags
4. of_gpio_named_count
5. of_gpio_count
6. of_get_gpio_flags
7. of_get_named_gpio
8. of_get_gpio

   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 
  19 struct 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  */
  26 enum 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  */
  40 struct 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 
  46 static 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 
  51 extern int of_get_named_gpio_flags(struct device_node *np,
  52                 const char *list_name, int index, enum of_gpio_flags *flags);
  53 
  54 extern int of_mm_gpiochip_add_data(struct device_node *np,
  55                                    struct of_mm_gpio_chip *mm_gc,
  56                                    void *data);
  57 static 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 }
  62 extern 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. */
  67 static 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  */
  98 static 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  */
 109 static inline int of_gpio_count(struct device_node *np)
 110 {
 111         return of_gpio_named_count(np, "gpios");
 112 }
 113 
 114 static 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  */
 129 static 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  */
 143 static 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 */