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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 */
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
8#ifdef CONFIG_GPIOLIB
9
10#include <linux/compiler.h>
11
12/* Platforms may implement their GPIO interface with library code,
13 * at a small performance cost for non-inlined operations and some
14 * extra memory (for code and for per-GPIO table entries).
15 *
16 * While the GPIO programming interface defines valid GPIO numbers
17 * to be in the range 0..MAX_INT, this library restricts them to the
18 * smaller range 0..ARCH_NR_GPIOS-1.
19 *
20 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
21 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
22 * actually an estimate of a board-specific value.
23 */
24
25#ifndef ARCH_NR_GPIOS
26#define ARCH_NR_GPIOS 256
27#endif
28
29/*
30 * "valid" GPIO numbers are nonnegative and may be passed to
31 * setup routines like gpio_request(). only some valid numbers
32 * can successfully be requested and used.
33 *
34 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
35 * platform data and other tables.
36 */
37
38static inline bool gpio_is_valid(int number)
39{
40 return number >= 0 && number < ARCH_NR_GPIOS;
41}
42
43struct device;
44struct seq_file;
45struct module;
46struct device_node;
47
48/**
49 * struct gpio_chip - abstract a GPIO controller
50 * @label: for diagnostics
51 * @dev: optional device providing the GPIOs
52 * @owner: helps prevent removal of modules exporting active GPIOs
53 * @request: optional hook for chip-specific activation, such as
54 * enabling module power and clock; may sleep
55 * @free: optional hook for chip-specific deactivation, such as
56 * disabling module power and clock; may sleep
57 * @direction_input: configures signal "offset" as input, or returns error
58 * @get: returns value for signal "offset"; for output signals this
59 * returns either the value actually sensed, or zero
60 * @direction_output: configures signal "offset" as output, or returns error
61 * @set: assigns output value for signal "offset"
62 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
63 * implementation may not sleep
64 * @dbg_show: optional routine to show contents in debugfs; default code
65 * will be used when this is omitted, but custom code can show extra
66 * state (such as pullup/pulldown configuration).
67 * @base: identifies the first GPIO number handled by this chip; or, if
68 * negative during registration, requests dynamic ID allocation.
69 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
70 * handled is (base + ngpio - 1).
71 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
72 * must while accessing GPIO expander chips over I2C or SPI
73 * @names: if set, must be an array of strings to use as alternative
74 * names for the GPIOs in this chip. Any entry in the array
75 * may be NULL if there is no alias for the GPIO, however the
76 * array must be @ngpio entries long. A name can include a single printk
77 * format specifier for an unsigned int. It is substituted by the actual
78 * number of the gpio.
79 *
80 * A gpio_chip can help platforms abstract various sources of GPIOs so
81 * they can all be accessed through a common programing interface.
82 * Example sources would be SOC controllers, FPGAs, multifunction
83 * chips, dedicated GPIO expanders, and so on.
84 *
85 * Each chip controls a number of signals, identified in method calls
86 * by "offset" values in the range 0..(@ngpio - 1). When those signals
87 * are referenced through calls like gpio_get_value(gpio), the offset
88 * is calculated by subtracting @base from the gpio number.
89 */
90struct gpio_chip {
91 const char *label;
92 struct device *dev;
93 struct module *owner;
94
95 int (*request)(struct gpio_chip *chip,
96 unsigned offset);
97 void (*free)(struct gpio_chip *chip,
98 unsigned offset);
99
100 int (*direction_input)(struct gpio_chip *chip,
101 unsigned offset);
102 int (*get)(struct gpio_chip *chip,
103 unsigned offset);
104 int (*direction_output)(struct gpio_chip *chip,
105 unsigned offset, int value);
106 int (*set_debounce)(struct gpio_chip *chip,
107 unsigned offset, unsigned debounce);
108
109 void (*set)(struct gpio_chip *chip,
110 unsigned offset, int value);
111
112 int (*to_irq)(struct gpio_chip *chip,
113 unsigned offset);
114
115 void (*dbg_show)(struct seq_file *s,
116 struct gpio_chip *chip);
117 int base;
118 u16 ngpio;
119 const char *const *names;
120 unsigned can_sleep:1;
121 unsigned exported:1;
122
123#if defined(CONFIG_OF_GPIO)
124 /*
125 * If CONFIG_OF is enabled, then all GPIO controllers described in the
126 * device tree automatically may have an OF translation
127 */
128 struct device_node *of_node;
129 int of_gpio_n_cells;
130 int (*of_xlate)(struct gpio_chip *gc, struct device_node *np,
131 const void *gpio_spec, u32 *flags);
132#endif
133};
134
135extern const char *gpiochip_is_requested(struct gpio_chip *chip,
136 unsigned offset);
137extern int __must_check gpiochip_reserve(int start, int ngpio);
138
139/* add/remove chips */
140extern int gpiochip_add(struct gpio_chip *chip);
141extern int __must_check gpiochip_remove(struct gpio_chip *chip);
142extern struct gpio_chip *gpiochip_find(void *data,
143 int (*match)(struct gpio_chip *chip,
144 void *data));
145
146
147/* Always use the library code for GPIO management calls,
148 * or when sleeping may be involved.
149 */
150extern int gpio_request(unsigned gpio, const char *label);
151extern void gpio_free(unsigned gpio);
152
153extern int gpio_direction_input(unsigned gpio);
154extern int gpio_direction_output(unsigned gpio, int value);
155
156extern int gpio_set_debounce(unsigned gpio, unsigned debounce);
157
158extern int gpio_get_value_cansleep(unsigned gpio);
159extern void gpio_set_value_cansleep(unsigned gpio, int value);
160
161
162/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
163 * the GPIO is constant and refers to some always-present controller,
164 * giving direct access to chip registers and tight bitbanging loops.
165 */
166extern int __gpio_get_value(unsigned gpio);
167extern void __gpio_set_value(unsigned gpio, int value);
168
169extern int __gpio_cansleep(unsigned gpio);
170
171extern int __gpio_to_irq(unsigned gpio);
172
173/**
174 * struct gpio - a structure describing a GPIO with configuration
175 * @gpio: the GPIO number
176 * @flags: GPIO configuration as specified by GPIOF_*
177 * @label: a literal description string of this GPIO
178 */
179struct gpio {
180 unsigned gpio;
181 unsigned long flags;
182 const char *label;
183};
184
185extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
186extern int gpio_request_array(const struct gpio *array, size_t num);
187extern void gpio_free_array(const struct gpio *array, size_t num);
188
189#ifdef CONFIG_GPIO_SYSFS
190
191/*
192 * A sysfs interface can be exported by individual drivers if they want,
193 * but more typically is configured entirely from userspace.
194 */
195extern int gpio_export(unsigned gpio, bool direction_may_change);
196extern int gpio_export_link(struct device *dev, const char *name,
197 unsigned gpio);
198extern int gpio_sysfs_set_active_low(unsigned gpio, int value);
199extern void gpio_unexport(unsigned gpio);
200
201#endif /* CONFIG_GPIO_SYSFS */
202
203#else /* !CONFIG_GPIOLIB */
204
205static inline bool gpio_is_valid(int number)
206{
207 /* only non-negative numbers are valid */
208 return number >= 0;
209}
210
211/* platforms that don't directly support access to GPIOs through I2C, SPI,
212 * or other blocking infrastructure can use these wrappers.
213 */
214
215static inline int gpio_cansleep(unsigned gpio)
216{
217 return 0;
218}
219
220static inline int gpio_get_value_cansleep(unsigned gpio)
221{
222 might_sleep();
223 return gpio_get_value(gpio);
224}
225
226static inline void gpio_set_value_cansleep(unsigned gpio, int value)
227{
228 might_sleep();
229 gpio_set_value(gpio, value);
230}
231
232#endif /* !CONFIG_GPIOLIB */
233
234#ifndef CONFIG_GPIO_SYSFS
235
236struct device;
237
238/* sysfs support is only available with gpiolib, where it's optional */
239
240static inline int gpio_export(unsigned gpio, bool direction_may_change)
241{
242 return -ENOSYS;
243}
244
245static inline int gpio_export_link(struct device *dev, const char *name,
246 unsigned gpio)
247{
248 return -ENOSYS;
249}
250
251static inline int gpio_sysfs_set_active_low(unsigned gpio, int value)
252{
253 return -ENOSYS;
254}
255
256static inline void gpio_unexport(unsigned gpio)
257{
258}
259#endif /* CONFIG_GPIO_SYSFS */
260
261#endif /* _ASM_GENERIC_GPIO_H */