Linux kernel mirror (for testing)
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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 */