summaryrefslogtreecommitdiff
path: root/include/asm-generic/gpio.h
blob: 40ec1433f05de25d15cedaeaf2388b2cc8d0298c (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
#ifndef _ASM_GENERIC_GPIO_H
#define _ASM_GENERIC_GPIO_H

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/of.h>

#ifdef CONFIG_GPIOLIB

#include <linux/compiler.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h>

/* Platforms may implement their GPIO interface with library code,
 * at a small performance cost for non-inlined operations and some
 * extra memory (for code and for per-GPIO table entries).
 *
 * While the GPIO programming interface defines valid GPIO numbers
 * to be in the range 0..MAX_INT, this library restricts them to the
 * smaller range 0..ARCH_NR_GPIOS-1.
 *
 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
 * actually an estimate of a board-specific value.
 */

#ifndef ARCH_NR_GPIOS
#define ARCH_NR_GPIOS		512
#endif

/*
 * "valid" GPIO numbers are nonnegative and may be passed to
 * setup routines like gpio_request().  only some valid numbers
 * can successfully be requested and used.
 *
 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
 * platform data and other tables.
 */

static inline bool gpio_is_valid(int number)
{
	return number >= 0 && number < ARCH_NR_GPIOS;
}

struct device;
struct gpio;
struct seq_file;
struct module;
struct device_node;
struct gpio_desc;

/* caller holds gpio_lock *OR* gpio is marked as requested */
static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
{
	return gpiod_to_chip(gpio_to_desc(gpio));
}

/* Always use the library code for GPIO management calls,
 * or when sleeping may be involved.
 */
extern int gpio_request(unsigned gpio, const char *label);
extern void gpio_free(unsigned gpio);

static inline int gpio_direction_input(unsigned gpio)
{
	return gpiod_direction_input(gpio_to_desc(gpio));
}
static inline int gpio_direction_output(unsigned gpio, int value)
{
	return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
}

static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
{
	return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
}

static inline int gpio_get_value_cansleep(unsigned gpio)
{
	return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
}
static inline void gpio_set_value_cansleep(unsigned gpio, int value)
{
	return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
}


/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
 * the GPIO is constant and refers to some always-present controller,
 * giving direct access to chip registers and tight bitbanging loops.
 */
static inline int __gpio_get_value(unsigned gpio)
{
	return gpiod_get_raw_value(gpio_to_desc(gpio));
}
static inline void __gpio_set_value(unsigned gpio, int value)
{
	return gpiod_set_raw_value(gpio_to_desc(gpio), value);
}

static inline int __gpio_cansleep(unsigned gpio)
{
	return gpiod_cansleep(gpio_to_desc(gpio));
}

static inline int __gpio_to_irq(unsigned gpio)
{
	return gpiod_to_irq(gpio_to_desc(gpio));
}

extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
extern int gpio_request_array(const struct gpio *array, size_t num);
extern void gpio_free_array(const struct gpio *array, size_t num);

/*
 * A sysfs interface can be exported by individual drivers if they want,
 * but more typically is configured entirely from userspace.
 */
static inline int gpio_export(unsigned gpio, bool direction_may_change)
{
	return gpiod_export(gpio_to_desc(gpio), direction_may_change);
}

static inline int gpio_export_link(struct device *dev, const char *name,
				   unsigned gpio)
{
	return gpiod_export_link(dev, name, gpio_to_desc(gpio));
}

static inline void gpio_unexport(unsigned gpio)
{
	gpiod_unexport(gpio_to_desc(gpio));
}

#else	/* !CONFIG_GPIOLIB */

static inline bool gpio_is_valid(int number)
{
	/* only non-negative numbers are valid */
	return number >= 0;
}

/* platforms that don't directly support access to GPIOs through I2C, SPI,
 * or other blocking infrastructure can use these wrappers.
 */

static inline int gpio_cansleep(unsigned gpio)
{
	return 0;
}

static inline int gpio_get_value_cansleep(unsigned gpio)
{
	might_sleep();
	return __gpio_get_value(gpio);
}

static inline void gpio_set_value_cansleep(unsigned gpio, int value)
{
	might_sleep();
	__gpio_set_value(gpio, value);
}

#endif /* !CONFIG_GPIOLIB */

#endif /* _ASM_GENERIC_GPIO_H */