Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
os
linux
1/*
2 * OF helpers for the GPIO API
3 *
4 * Copyright (c) 2007-2008 MontaVista Software, Inc.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14#ifndef __LINUX_OF_GPIO_H
15#define __LINUX_OF_GPIO_H
16
17#include <linux/compiler.h>
18#include <linux/kernel.h>
19#include <linux/errno.h>
20#include <linux/gpio.h>
21
22struct device_node;
23
24/*
25 * This is Linux-specific flags. By default controllers' and Linux' mapping
26 * match, but GPIO controllers are free to translate their own flags to
27 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
28 */
29enum of_gpio_flags {
30 OF_GPIO_ACTIVE_LOW = 0x1,
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 unsigned int of_gpio_count(struct device_node *np);
53
54extern int of_mm_gpiochip_add(struct device_node *np,
55 struct of_mm_gpio_chip *mm_gc);
56
57extern void of_gpiochip_add(struct gpio_chip *gc);
58extern void of_gpiochip_remove(struct gpio_chip *gc);
59extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np);
60extern int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
61 const void *gpio_spec, u32 *flags);
62
63#else /* CONFIG_OF_GPIO */
64
65/* Drivers may not strictly depend on the GPIO support, so let them link. */
66static inline int of_get_named_gpio_flags(struct device_node *np,
67 const char *list_name, int index, enum of_gpio_flags *flags)
68{
69 return -ENOSYS;
70}
71
72static inline unsigned int of_gpio_count(struct device_node *np)
73{
74 return 0;
75}
76
77static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
78 struct device_node *np,
79 const void *gpio_spec, u32 *flags)
80{
81 return -ENOSYS;
82}
83
84static inline void of_gpiochip_add(struct gpio_chip *gc) { }
85static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
86
87#endif /* CONFIG_OF_GPIO */
88
89/**
90 * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API
91 * @np: device node to get GPIO from
92 * @index: index of the GPIO
93 * @flags: a flags pointer to fill in
94 *
95 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
96 * value on the error condition. If @flags is not NULL the function also fills
97 * in flags for the GPIO.
98 */
99static inline int of_get_gpio_flags(struct device_node *np, int index,
100 enum of_gpio_flags *flags)
101{
102 return of_get_named_gpio_flags(np, "gpios", index, flags);
103}
104
105/**
106 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
107 * @np: device node to get GPIO from
108 * @propname: Name of property containing gpio specifier(s)
109 * @index: index of the GPIO
110 *
111 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
112 * value on the error condition.
113 */
114static inline int of_get_named_gpio(struct device_node *np,
115 const char *propname, int index)
116{
117 return of_get_named_gpio_flags(np, propname, index, NULL);
118}
119
120/**
121 * of_get_gpio() - Get a GPIO number to use with GPIO API
122 * @np: device node to get GPIO from
123 * @index: index of the GPIO
124 *
125 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
126 * value on the error condition.
127 */
128static inline int of_get_gpio(struct device_node *np, int index)
129{
130 return of_get_gpio_flags(np, index, NULL);
131}
132
133#endif /* __LINUX_OF_GPIO_H */