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