1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * <linux/gpio.h>
4 *
5 * This is the LEGACY GPIO bulk include file, including legacy APIs. It is
6 * used for GPIO drivers still referencing the global GPIO numberspace,
7 * and should not be included in new code.
8 *
9 * If you're implementing a GPIO driver, only include <linux/gpio/driver.h>
10 * If you're implementing a GPIO consumer, only include <linux/gpio/consumer.h>
11 */
12#ifndef __LINUX_GPIO_H
13#define __LINUX_GPIO_H
14
15#include <linux/types.h>
16
17struct device;
18
19/* see Documentation/driver-api/gpio/legacy.rst */
20
21/* make these flag values available regardless of GPIO kconfig options */
22#define GPIOF_DIR_OUT (0 << 0)
23#define GPIOF_DIR_IN (1 << 0)
24
25#define GPIOF_INIT_LOW (0 << 1)
26#define GPIOF_INIT_HIGH (1 << 1)
27
28#define GPIOF_IN (GPIOF_DIR_IN)
29#define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW)
30#define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
31
32/* Gpio pin is active-low */
33#define GPIOF_ACTIVE_LOW (1 << 2)
34
35/**
36 * struct gpio - a structure describing a GPIO with configuration
37 * @gpio: the GPIO number
38 * @flags: GPIO configuration as specified by GPIOF_*
39 * @label: a literal description string of this GPIO
40 */
41struct gpio {
42 unsigned gpio;
43 unsigned long flags;
44 const char *label;
45};
46
47#ifdef CONFIG_GPIOLIB
48
49#include <linux/gpio/consumer.h>
50
51/*
52 * "valid" GPIO numbers are nonnegative and may be passed to
53 * setup routines like gpio_request(). Only some valid numbers
54 * can successfully be requested and used.
55 *
56 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
57 * platform data and other tables.
58 */
59static inline bool gpio_is_valid(int number)
60{
61 /* only non-negative numbers are valid */
62 return number >= 0;
63}
64
65/*
66 * Platforms may implement their GPIO interface with library code,
67 * at a small performance cost for non-inlined operations and some
68 * extra memory (for code and for per-GPIO table entries).
69 */
70
71/*
72 * At the end we want all GPIOs to be dynamically allocated from 0.
73 * However, some legacy drivers still perform fixed allocation.
74 * Until they are all fixed, leave 0-512 space for them.
75 */
76#define GPIO_DYNAMIC_BASE 512
77
78/* Always use the library code for GPIO management calls,
79 * or when sleeping may be involved.
80 */
81int gpio_request(unsigned gpio, const char *label);
82void gpio_free(unsigned gpio);
83
84static inline int gpio_direction_input(unsigned gpio)
85{
86 return gpiod_direction_input(desc: gpio_to_desc(gpio));
87}
88static inline int gpio_direction_output(unsigned gpio, int value)
89{
90 return gpiod_direction_output_raw(desc: gpio_to_desc(gpio), value);
91}
92
93static inline int gpio_get_value_cansleep(unsigned gpio)
94{
95 return gpiod_get_raw_value_cansleep(desc: gpio_to_desc(gpio));
96}
97static inline void gpio_set_value_cansleep(unsigned gpio, int value)
98{
99 return gpiod_set_raw_value_cansleep(desc: gpio_to_desc(gpio), value);
100}
101
102static inline int gpio_get_value(unsigned gpio)
103{
104 return gpiod_get_raw_value(desc: gpio_to_desc(gpio));
105}
106static inline void gpio_set_value(unsigned gpio, int value)
107{
108 return gpiod_set_raw_value(desc: gpio_to_desc(gpio), value);
109}
110
111static inline int gpio_to_irq(unsigned gpio)
112{
113 return gpiod_to_irq(desc: gpio_to_desc(gpio));
114}
115
116int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
117int gpio_request_array(const struct gpio *array, size_t num);
118void gpio_free_array(const struct gpio *array, size_t num);
119
120/* CONFIG_GPIOLIB: bindings for managed devices that want to request gpios */
121
122int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
123int devm_gpio_request_one(struct device *dev, unsigned gpio,
124 unsigned long flags, const char *label);
125
126#else /* ! CONFIG_GPIOLIB */
127
128#include <linux/kernel.h>
129
130#include <asm/bug.h>
131#include <asm/errno.h>
132
133static inline bool gpio_is_valid(int number)
134{
135 return false;
136}
137
138static inline int gpio_request(unsigned gpio, const char *label)
139{
140 return -ENOSYS;
141}
142
143static inline int gpio_request_one(unsigned gpio,
144 unsigned long flags, const char *label)
145{
146 return -ENOSYS;
147}
148
149static inline int gpio_request_array(const struct gpio *array, size_t num)
150{
151 return -ENOSYS;
152}
153
154static inline void gpio_free(unsigned gpio)
155{
156 might_sleep();
157
158 /* GPIO can never have been requested */
159 WARN_ON(1);
160}
161
162static inline void gpio_free_array(const struct gpio *array, size_t num)
163{
164 might_sleep();
165
166 /* GPIO can never have been requested */
167 WARN_ON(1);
168}
169
170static inline int gpio_direction_input(unsigned gpio)
171{
172 return -ENOSYS;
173}
174
175static inline int gpio_direction_output(unsigned gpio, int value)
176{
177 return -ENOSYS;
178}
179
180static inline int gpio_get_value(unsigned gpio)
181{
182 /* GPIO can never have been requested or set as {in,out}put */
183 WARN_ON(1);
184 return 0;
185}
186
187static inline void gpio_set_value(unsigned gpio, int value)
188{
189 /* GPIO can never have been requested or set as output */
190 WARN_ON(1);
191}
192
193static inline int gpio_get_value_cansleep(unsigned gpio)
194{
195 /* GPIO can never have been requested or set as {in,out}put */
196 WARN_ON(1);
197 return 0;
198}
199
200static inline void gpio_set_value_cansleep(unsigned gpio, int value)
201{
202 /* GPIO can never have been requested or set as output */
203 WARN_ON(1);
204}
205
206static inline int gpio_to_irq(unsigned gpio)
207{
208 /* GPIO can never have been requested or set as input */
209 WARN_ON(1);
210 return -EINVAL;
211}
212
213static inline int devm_gpio_request(struct device *dev, unsigned gpio,
214 const char *label)
215{
216 WARN_ON(1);
217 return -EINVAL;
218}
219
220static inline int devm_gpio_request_one(struct device *dev, unsigned gpio,
221 unsigned long flags, const char *label)
222{
223 WARN_ON(1);
224 return -EINVAL;
225}
226
227#endif /* ! CONFIG_GPIOLIB */
228
229#endif /* __LINUX_GPIO_H */
230

source code of linux/include/linux/gpio.h