Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_GENERIC_GPIO_H
3#define _ASM_GENERIC_GPIO_H
4
5#include <linux/kernel.h>
6#include <linux/types.h>
7#include <linux/errno.h>
8#include <linux/of.h>
9
10#ifdef CONFIG_GPIOLIB
11
12#include <linux/compiler.h>
13#include <linux/gpio/driver.h>
14#include <linux/gpio/consumer.h>
15
16/* Platforms may implement their GPIO interface with library code,
17 * at a small performance cost for non-inlined operations and some
18 * extra memory (for code and for per-GPIO table entries).
19 *
20 * While the GPIO programming interface defines valid GPIO numbers
21 * to be in the range 0..MAX_INT, this library restricts them to the
22 * smaller range 0..ARCH_NR_GPIOS-1.
23 *
24 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
25 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
26 * actually an estimate of a board-specific value.
27 */
28
29#ifndef ARCH_NR_GPIOS
30#if defined(CONFIG_ARCH_NR_GPIO) && CONFIG_ARCH_NR_GPIO > 0
31#define ARCH_NR_GPIOS CONFIG_ARCH_NR_GPIO
32#else
33#define ARCH_NR_GPIOS 512
34#endif
35#endif
36
37/*
38 * "valid" GPIO numbers are nonnegative and may be passed to
39 * setup routines like gpio_request(). only some valid numbers
40 * can successfully be requested and used.
41 *
42 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
43 * platform data and other tables.
44 */
45
46static inline bool gpio_is_valid(int number)
47{
48 return number >= 0 && number < ARCH_NR_GPIOS;
49}
50
51struct device;
52struct gpio;
53struct seq_file;
54struct module;
55struct device_node;
56struct gpio_desc;
57
58/* caller holds gpio_lock *OR* gpio is marked as requested */
59static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
60{
61 return gpiod_to_chip(gpio_to_desc(gpio));
62}
63
64/* Always use the library code for GPIO management calls,
65 * or when sleeping may be involved.
66 */
67extern int gpio_request(unsigned gpio, const char *label);
68extern void gpio_free(unsigned gpio);
69
70static inline int gpio_direction_input(unsigned gpio)
71{
72 return gpiod_direction_input(gpio_to_desc(gpio));
73}
74static inline int gpio_direction_output(unsigned gpio, int value)
75{
76 return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
77}
78
79static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
80{
81 return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
82}
83
84static inline int gpio_get_value_cansleep(unsigned gpio)
85{
86 return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
87}
88static inline void gpio_set_value_cansleep(unsigned gpio, int value)
89{
90 return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
91}
92
93
94/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
95 * the GPIO is constant and refers to some always-present controller,
96 * giving direct access to chip registers and tight bitbanging loops.
97 */
98static inline int __gpio_get_value(unsigned gpio)
99{
100 return gpiod_get_raw_value(gpio_to_desc(gpio));
101}
102static inline void __gpio_set_value(unsigned gpio, int value)
103{
104 return gpiod_set_raw_value(gpio_to_desc(gpio), value);
105}
106
107static inline int __gpio_cansleep(unsigned gpio)
108{
109 return gpiod_cansleep(gpio_to_desc(gpio));
110}
111
112static inline int __gpio_to_irq(unsigned gpio)
113{
114 return gpiod_to_irq(gpio_to_desc(gpio));
115}
116
117extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
118extern int gpio_request_array(const struct gpio *array, size_t num);
119extern void gpio_free_array(const struct gpio *array, size_t num);
120
121/*
122 * A sysfs interface can be exported by individual drivers if they want,
123 * but more typically is configured entirely from userspace.
124 */
125static inline int gpio_export(unsigned gpio, bool direction_may_change)
126{
127 return gpiod_export(gpio_to_desc(gpio), direction_may_change);
128}
129
130static inline int gpio_export_link(struct device *dev, const char *name,
131 unsigned gpio)
132{
133 return gpiod_export_link(dev, name, gpio_to_desc(gpio));
134}
135
136static inline void gpio_unexport(unsigned gpio)
137{
138 gpiod_unexport(gpio_to_desc(gpio));
139}
140
141#else /* !CONFIG_GPIOLIB */
142
143static inline bool gpio_is_valid(int number)
144{
145 /* only non-negative numbers are valid */
146 return number >= 0;
147}
148
149/* platforms that don't directly support access to GPIOs through I2C, SPI,
150 * or other blocking infrastructure can use these wrappers.
151 */
152
153static inline int gpio_cansleep(unsigned gpio)
154{
155 return 0;
156}
157
158static inline int gpio_get_value_cansleep(unsigned gpio)
159{
160 might_sleep();
161 return __gpio_get_value(gpio);
162}
163
164static inline void gpio_set_value_cansleep(unsigned gpio, int value)
165{
166 might_sleep();
167 __gpio_set_value(gpio, value);
168}
169
170#endif /* !CONFIG_GPIOLIB */
171
172#endif /* _ASM_GENERIC_GPIO_H */