Linux kernel mirror (for testing)
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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 * Define the maximum of the possible GPIO in the global numberspace.
79 * While the GPIO base and numbers are positive, we limit it with signed
80 * maximum as a lot of code is using negative values for special cases.
81 */
82#define GPIO_DYNAMIC_MAX INT_MAX
83
84/* Always use the library code for GPIO management calls,
85 * or when sleeping may be involved.
86 */
87int gpio_request(unsigned gpio, const char *label);
88void gpio_free(unsigned gpio);
89
90static inline int gpio_direction_input(unsigned gpio)
91{
92 return gpiod_direction_input(gpio_to_desc(gpio));
93}
94static inline int gpio_direction_output(unsigned gpio, int value)
95{
96 return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
97}
98
99static inline int gpio_get_value_cansleep(unsigned gpio)
100{
101 return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
102}
103static inline void gpio_set_value_cansleep(unsigned gpio, int value)
104{
105 return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
106}
107
108static inline int gpio_get_value(unsigned gpio)
109{
110 return gpiod_get_raw_value(gpio_to_desc(gpio));
111}
112static inline void gpio_set_value(unsigned gpio, int value)
113{
114 return gpiod_set_raw_value(gpio_to_desc(gpio), value);
115}
116
117static inline int gpio_to_irq(unsigned gpio)
118{
119 return gpiod_to_irq(gpio_to_desc(gpio));
120}
121
122int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
123
124/* CONFIG_GPIOLIB: bindings for managed devices that want to request gpios */
125
126int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
127int devm_gpio_request_one(struct device *dev, unsigned gpio,
128 unsigned long flags, const char *label);
129
130#else /* ! CONFIG_GPIOLIB */
131
132#include <linux/kernel.h>
133
134#include <asm/bug.h>
135#include <asm/errno.h>
136
137static inline bool gpio_is_valid(int number)
138{
139 return false;
140}
141
142static inline int gpio_request(unsigned gpio, const char *label)
143{
144 return -ENOSYS;
145}
146
147static inline int gpio_request_one(unsigned gpio,
148 unsigned long flags, const char *label)
149{
150 return -ENOSYS;
151}
152
153static inline void gpio_free(unsigned gpio)
154{
155 might_sleep();
156
157 /* GPIO can never have been requested */
158 WARN_ON(1);
159}
160
161static inline int gpio_direction_input(unsigned gpio)
162{
163 return -ENOSYS;
164}
165
166static inline int gpio_direction_output(unsigned gpio, int value)
167{
168 return -ENOSYS;
169}
170
171static inline int gpio_get_value(unsigned gpio)
172{
173 /* GPIO can never have been requested or set as {in,out}put */
174 WARN_ON(1);
175 return 0;
176}
177
178static inline void gpio_set_value(unsigned gpio, int value)
179{
180 /* GPIO can never have been requested or set as output */
181 WARN_ON(1);
182}
183
184static inline int gpio_get_value_cansleep(unsigned gpio)
185{
186 /* GPIO can never have been requested or set as {in,out}put */
187 WARN_ON(1);
188 return 0;
189}
190
191static inline void gpio_set_value_cansleep(unsigned gpio, int value)
192{
193 /* GPIO can never have been requested or set as output */
194 WARN_ON(1);
195}
196
197static inline int gpio_to_irq(unsigned gpio)
198{
199 /* GPIO can never have been requested or set as input */
200 WARN_ON(1);
201 return -EINVAL;
202}
203
204static inline int devm_gpio_request(struct device *dev, unsigned gpio,
205 const char *label)
206{
207 WARN_ON(1);
208 return -EINVAL;
209}
210
211static inline int devm_gpio_request_one(struct device *dev, unsigned gpio,
212 unsigned long flags, const char *label)
213{
214 WARN_ON(1);
215 return -EINVAL;
216}
217
218#endif /* ! CONFIG_GPIOLIB */
219
220#endif /* __LINUX_GPIO_H */