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/gpio/driver.h>
15#include <linux/gpio.h> /* FIXME: Shouldn't be here */
16#include <linux/of.h>
17
18struct 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 */
25enum 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 */
41struct 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
47static 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
52extern int of_get_named_gpio_flags(const struct device_node *np,
53 const char *list_name, int index, enum of_gpio_flags *flags);
54
55extern int of_mm_gpiochip_add_data(struct device_node *np,
56 struct of_mm_gpio_chip *mm_gc,
57 void *data);
58static 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}
63extern 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. */
70static inline int of_get_named_gpio_flags(const 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 */
101static inline int of_gpio_named_count(const struct device_node *np,
102 const char *propname)
103{
104 return of_count_phandle_with_args(np, propname, "#gpio-cells");
105}
106
107/**
108 * of_gpio_count() - Count GPIOs for a device
109 * @np: device node to count GPIOs for
110 *
111 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
112 */
113static inline int of_gpio_count(const struct device_node *np)
114{
115 return of_gpio_named_count(np, "gpios");
116}
117
118static inline int of_get_gpio_flags(const struct device_node *np, int index,
119 enum of_gpio_flags *flags)
120{
121 return of_get_named_gpio_flags(np, "gpios", index, flags);
122}
123
124/**
125 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
126 * @np: device node to get GPIO from
127 * @propname: Name of property containing gpio specifier(s)
128 * @index: index of the GPIO
129 *
130 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
131 * value on the error condition.
132 */
133static inline int of_get_named_gpio(const struct device_node *np,
134 const char *propname, int index)
135{
136 return of_get_named_gpio_flags(np, propname, index, NULL);
137}
138
139/**
140 * of_get_gpio() - Get a GPIO number to use with GPIO API
141 * @np: device node to get GPIO from
142 * @index: index of the GPIO
143 *
144 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
145 * value on the error condition.
146 */
147static inline int of_get_gpio(const struct device_node *np, int index)
148{
149 return of_get_gpio_flags(np, index, NULL);
150}
151
152#endif /* __LINUX_OF_GPIO_H */