Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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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#include <linux/of.h>
22
23struct device_node;
24
25/*
26 * This is Linux-specific flags. By default controllers' and Linux' mapping
27 * match, but GPIO controllers are free to translate their own flags to
28 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
29 */
30enum of_gpio_flags {
31 OF_GPIO_ACTIVE_LOW = 0x1,
32};
33
34#ifdef CONFIG_OF_GPIO
35
36/*
37 * OF GPIO chip for memory mapped banks
38 */
39struct of_mm_gpio_chip {
40 struct gpio_chip gc;
41 void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
42 void __iomem *regs;
43};
44
45static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
46{
47 return container_of(gc, struct of_mm_gpio_chip, gc);
48}
49
50extern int of_get_named_gpio_flags(struct device_node *np,
51 const char *list_name, int index, enum of_gpio_flags *flags);
52
53extern unsigned int of_gpio_named_count(struct device_node *np,
54 const char* propname);
55
56extern int of_mm_gpiochip_add(struct device_node *np,
57 struct of_mm_gpio_chip *mm_gc);
58
59extern void of_gpiochip_add(struct gpio_chip *gc);
60extern void of_gpiochip_remove(struct gpio_chip *gc);
61extern int of_gpio_simple_xlate(struct gpio_chip *gc,
62 const struct of_phandle_args *gpiospec,
63 u32 *flags);
64
65#else /* CONFIG_OF_GPIO */
66
67/* Drivers may not strictly depend on the GPIO support, so let them link. */
68static inline int of_get_named_gpio_flags(struct device_node *np,
69 const char *list_name, int index, enum of_gpio_flags *flags)
70{
71 return -ENOSYS;
72}
73
74static inline unsigned int of_gpio_named_count(struct device_node *np,
75 const char* propname)
76{
77 return 0;
78}
79
80static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
81 const struct of_phandle_args *gpiospec,
82 u32 *flags)
83{
84 return -ENOSYS;
85}
86
87static inline void of_gpiochip_add(struct gpio_chip *gc) { }
88static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
89
90#endif /* CONFIG_OF_GPIO */
91
92/**
93 * of_gpio_count - Count GPIOs for a device
94 * @np: device node to count GPIOs for
95 *
96 * The function returns the count of GPIOs specified for a node.
97 *
98 * Note that the empty GPIO specifiers counts too. For example,
99 *
100 * gpios = <0
101 * &pio1 1 2
102 * 0
103 * &pio2 3 4>;
104 *
105 * defines four GPIOs (so this function will return 4), two of which
106 * are not specified.
107 */
108static inline unsigned int of_gpio_count(struct device_node *np)
109{
110 return of_gpio_named_count(np, "gpios");
111}
112
113/**
114 * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API
115 * @np: device node to get GPIO from
116 * @index: index of the GPIO
117 * @flags: a flags pointer to fill in
118 *
119 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
120 * value on the error condition. If @flags is not NULL the function also fills
121 * in flags for the GPIO.
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 */