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
gpio_is_valid(int number)46 static inline bool gpio_is_valid(int number)
47 {
48 return number >= 0 && number < ARCH_NR_GPIOS;
49 }
50
51 struct device;
52 struct gpio;
53 struct seq_file;
54 struct module;
55 struct device_node;
56 struct gpio_desc;
57
58 /* caller holds gpio_lock *OR* gpio is marked as requested */
gpio_to_chip(unsigned gpio)59 static 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 */
67 extern int gpio_request(unsigned gpio, const char *label);
68 extern void gpio_free(unsigned gpio);
69
gpio_direction_input(unsigned gpio)70 static inline int gpio_direction_input(unsigned gpio)
71 {
72 return gpiod_direction_input(gpio_to_desc(gpio));
73 }
gpio_direction_output(unsigned gpio,int value)74 static inline int gpio_direction_output(unsigned gpio, int value)
75 {
76 return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
77 }
78
gpio_set_debounce(unsigned gpio,unsigned debounce)79 static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
80 {
81 return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
82 }
83
gpio_get_value_cansleep(unsigned gpio)84 static inline int gpio_get_value_cansleep(unsigned gpio)
85 {
86 return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
87 }
gpio_set_value_cansleep(unsigned gpio,int value)88 static 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 */
__gpio_get_value(unsigned gpio)98 static inline int __gpio_get_value(unsigned gpio)
99 {
100 return gpiod_get_raw_value(gpio_to_desc(gpio));
101 }
__gpio_set_value(unsigned gpio,int value)102 static inline void __gpio_set_value(unsigned gpio, int value)
103 {
104 return gpiod_set_raw_value(gpio_to_desc(gpio), value);
105 }
106
__gpio_cansleep(unsigned gpio)107 static inline int __gpio_cansleep(unsigned gpio)
108 {
109 return gpiod_cansleep(gpio_to_desc(gpio));
110 }
111
__gpio_to_irq(unsigned gpio)112 static inline int __gpio_to_irq(unsigned gpio)
113 {
114 return gpiod_to_irq(gpio_to_desc(gpio));
115 }
116
117 extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
118 extern int gpio_request_array(const struct gpio *array, size_t num);
119 extern 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 */
gpio_export(unsigned gpio,bool direction_may_change)125 static inline int gpio_export(unsigned gpio, bool direction_may_change)
126 {
127 return gpiod_export(gpio_to_desc(gpio), direction_may_change);
128 }
129
gpio_export_link(struct device * dev,const char * name,unsigned gpio)130 static 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
gpio_unexport(unsigned gpio)136 static inline void gpio_unexport(unsigned gpio)
137 {
138 gpiod_unexport(gpio_to_desc(gpio));
139 }
140
141 #else /* !CONFIG_GPIOLIB */
142
gpio_is_valid(int number)143 static 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
gpio_cansleep(unsigned gpio)153 static inline int gpio_cansleep(unsigned gpio)
154 {
155 return 0;
156 }
157
gpio_get_value_cansleep(unsigned gpio)158 static inline int gpio_get_value_cansleep(unsigned gpio)
159 {
160 might_sleep();
161 return __gpio_get_value(gpio);
162 }
163
gpio_set_value_cansleep(unsigned gpio,int value)164 static 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 */
173