summaryrefslogtreecommitdiff
path: root/include/linux/of_gpio.h
blob: d71f2cc141ae3f6607da4940441643ee1ab8e7fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
/*
 * OF helpers for the GPIO API
 *
 * Copyright (c) 2007-2008  MontaVista Software, Inc.
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#ifndef __LINUX_OF_GPIO_H
#define __LINUX_OF_GPIO_H

#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/of.h>

struct device_node;
struct gpio_desc;

/*
 * This is Linux-specific flags. By default controllers' and Linux' mapping
 * match, but GPIO controllers are free to translate their own flags to
 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
 */
enum of_gpio_flags {
	OF_GPIO_ACTIVE_LOW = 0x1,
};

#ifdef CONFIG_OF_GPIO

/*
 * OF GPIO chip for memory mapped banks
 */
struct of_mm_gpio_chip {
	struct gpio_chip gc;
	void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
	void __iomem *regs;
};

static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
{
	return container_of(gc, struct of_mm_gpio_chip, gc);
}

extern struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
		const char *list_name, int index, enum of_gpio_flags *flags);

extern int of_mm_gpiochip_add(struct device_node *np,
			      struct of_mm_gpio_chip *mm_gc);

extern void of_gpiochip_add(struct gpio_chip *gc);
extern void of_gpiochip_remove(struct gpio_chip *gc);
extern int of_gpio_simple_xlate(struct gpio_chip *gc,
				const struct of_phandle_args *gpiospec,
				u32 *flags);

#else /* CONFIG_OF_GPIO */

/* Drivers may not strictly depend on the GPIO support, so let them link. */
static inline struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
		const char *list_name, int index, enum of_gpio_flags *flags)
{
	return ERR_PTR(-ENOSYS);
}

static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
				       const struct of_phandle_args *gpiospec,
				       u32 *flags)
{
	return -ENOSYS;
}

static inline void of_gpiochip_add(struct gpio_chip *gc) { }
static inline void of_gpiochip_remove(struct gpio_chip *gc) { }

#endif /* CONFIG_OF_GPIO */

static inline int of_get_named_gpio_flags(struct device_node *np,
		const char *list_name, int index, enum of_gpio_flags *flags)
{
	struct gpio_desc *desc;
	desc = of_get_named_gpiod_flags(np, list_name, index, flags);

	if (IS_ERR(desc))
		return PTR_ERR(desc);
	else
		return desc_to_gpio(desc);
}

/**
 * of_gpio_named_count() - Count GPIOs for a device
 * @np:		device node to count GPIOs for
 * @propname:	property name containing gpio specifier(s)
 *
 * The function returns the count of GPIOs specified for a node.
 * Note that the empty GPIO specifiers count too. Returns either
 *   Number of gpios defined in property,
 *   -EINVAL for an incorrectly formed gpios property, or
 *   -ENOENT for a missing gpios property
 *
 * Example:
 * gpios = <0
 *          &gpio1 1 2
 *          0
 *          &gpio2 3 4>;
 *
 * The above example defines four GPIOs, two of which are not specified.
 * This function will return '4'
 */
static inline int of_gpio_named_count(struct device_node *np, const char* propname)
{
	return of_count_phandle_with_args(np, propname, "#gpio-cells");
}

/**
 * of_gpio_count() - Count GPIOs for a device
 * @np:		device node to count GPIOs for
 *
 * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
 */
static inline int of_gpio_count(struct device_node *np)
{
	return of_gpio_named_count(np, "gpios");
}

/**
 * of_get_gpiod_flags() - Get a GPIO descriptor and flags to use with GPIO API
 * @np:		device node to get GPIO from
 * @index:	index of the GPIO
 * @flags:	a flags pointer to fill in
 *
 * Returns GPIO descriptor to use with Linux generic GPIO API, or a errno
 * value on the error condition. If @flags is not NULL the function also fills
 * in flags for the GPIO.
 */
static inline struct gpio_desc *of_get_gpiod_flags(struct device_node *np,
					int index, enum of_gpio_flags *flags)
{
	return of_get_named_gpiod_flags(np, "gpios", index, flags);
}

static inline int of_get_gpio_flags(struct device_node *np, int index,
		      enum of_gpio_flags *flags)
{
	return of_get_named_gpio_flags(np, "gpios", index, flags);
}

/**
 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 * @np:		device node to get GPIO from
 * @propname:	Name of property containing gpio specifier(s)
 * @index:	index of the GPIO
 *
 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 * value on the error condition.
 */
static inline int of_get_named_gpio(struct device_node *np,
                                   const char *propname, int index)
{
	return of_get_named_gpio_flags(np, propname, index, NULL);
}

/**
 * of_get_gpio() - Get a GPIO number to use with GPIO API
 * @np:		device node to get GPIO from
 * @index:	index of the GPIO
 *
 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 * value on the error condition.
 */
static inline int of_get_gpio(struct device_node *np, int index)
{
	return of_get_gpio_flags(np, index, NULL);
}

#endif /* __LINUX_OF_GPIO_H */