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4c20386c DB |
1 | #ifndef _ASM_GENERIC_GPIO_H |
2 | #define _ASM_GENERIC_GPIO_H | |
3 | ||
b3db4a8a | 4 | #include <linux/kernel.h> |
6ea0205b | 5 | #include <linux/types.h> |
25947d5a | 6 | #include <linux/errno.h> |
15c9a0ac | 7 | #include <linux/of.h> |
6ea0205b | 8 | |
7444a72e | 9 | #ifdef CONFIG_GPIOLIB |
d2876d08 | 10 | |
6ea0205b DB |
11 | #include <linux/compiler.h> |
12 | ||
d2876d08 DB |
13 | /* Platforms may implement their GPIO interface with library code, |
14 | * at a small performance cost for non-inlined operations and some | |
15 | * extra memory (for code and for per-GPIO table entries). | |
16 | * | |
17 | * While the GPIO programming interface defines valid GPIO numbers | |
18 | * to be in the range 0..MAX_INT, this library restricts them to the | |
6a9436d0 | 19 | * smaller range 0..ARCH_NR_GPIOS-1. |
c956126c DB |
20 | * |
21 | * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of | |
22 | * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is | |
23 | * actually an estimate of a board-specific value. | |
d2876d08 DB |
24 | */ |
25 | ||
26 | #ifndef ARCH_NR_GPIOS | |
27 | #define ARCH_NR_GPIOS 256 | |
28 | #endif | |
29 | ||
c956126c DB |
30 | /* |
31 | * "valid" GPIO numbers are nonnegative and may be passed to | |
32 | * setup routines like gpio_request(). only some valid numbers | |
33 | * can successfully be requested and used. | |
34 | * | |
35 | * Invalid GPIO numbers are useful for indicating no-such-GPIO in | |
36 | * platform data and other tables. | |
37 | */ | |
38 | ||
3474cb3c | 39 | static inline bool gpio_is_valid(int number) |
e6de1808 | 40 | { |
3474cb3c | 41 | return number >= 0 && number < ARCH_NR_GPIOS; |
e6de1808 GL |
42 | } |
43 | ||
1f018c8d | 44 | struct device; |
feb83699 | 45 | struct gpio; |
d2876d08 | 46 | struct seq_file; |
438d8908 | 47 | struct module; |
a19e3da5 | 48 | struct device_node; |
d2876d08 DB |
49 | |
50 | /** | |
51 | * struct gpio_chip - abstract a GPIO controller | |
52 | * @label: for diagnostics | |
d8f388d8 DB |
53 | * @dev: optional device providing the GPIOs |
54 | * @owner: helps prevent removal of modules exporting active GPIOs | |
35e8bb51 DB |
55 | * @request: optional hook for chip-specific activation, such as |
56 | * enabling module power and clock; may sleep | |
57 | * @free: optional hook for chip-specific deactivation, such as | |
58 | * disabling module power and clock; may sleep | |
d2876d08 DB |
59 | * @direction_input: configures signal "offset" as input, or returns error |
60 | * @get: returns value for signal "offset"; for output signals this | |
61 | * returns either the value actually sensed, or zero | |
62 | * @direction_output: configures signal "offset" as output, or returns error | |
63 | * @set: assigns output value for signal "offset" | |
0f6d504e DB |
64 | * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; |
65 | * implementation may not sleep | |
d2876d08 DB |
66 | * @dbg_show: optional routine to show contents in debugfs; default code |
67 | * will be used when this is omitted, but custom code can show extra | |
68 | * state (such as pullup/pulldown configuration). | |
69 | * @base: identifies the first GPIO number handled by this chip; or, if | |
70 | * negative during registration, requests dynamic ID allocation. | |
71 | * @ngpio: the number of GPIOs handled by this controller; the last GPIO | |
72 | * handled is (base + ngpio - 1). | |
73 | * @can_sleep: flag must be set iff get()/set() methods sleep, as they | |
74 | * must while accessing GPIO expander chips over I2C or SPI | |
926b663c DS |
75 | * @names: if set, must be an array of strings to use as alternative |
76 | * names for the GPIOs in this chip. Any entry in the array | |
77 | * may be NULL if there is no alias for the GPIO, however the | |
7839ec78 UKK |
78 | * array must be @ngpio entries long. A name can include a single printk |
79 | * format specifier for an unsigned int. It is substituted by the actual | |
80 | * number of the gpio. | |
d2876d08 DB |
81 | * |
82 | * A gpio_chip can help platforms abstract various sources of GPIOs so | |
83 | * they can all be accessed through a common programing interface. | |
84 | * Example sources would be SOC controllers, FPGAs, multifunction | |
85 | * chips, dedicated GPIO expanders, and so on. | |
86 | * | |
87 | * Each chip controls a number of signals, identified in method calls | |
88 | * by "offset" values in the range 0..(@ngpio - 1). When those signals | |
89 | * are referenced through calls like gpio_get_value(gpio), the offset | |
90 | * is calculated by subtracting @base from the gpio number. | |
91 | */ | |
92 | struct gpio_chip { | |
4fd5463c | 93 | const char *label; |
d8f388d8 | 94 | struct device *dev; |
438d8908 | 95 | struct module *owner; |
d2876d08 | 96 | |
35e8bb51 DB |
97 | int (*request)(struct gpio_chip *chip, |
98 | unsigned offset); | |
99 | void (*free)(struct gpio_chip *chip, | |
100 | unsigned offset); | |
101 | ||
d2876d08 DB |
102 | int (*direction_input)(struct gpio_chip *chip, |
103 | unsigned offset); | |
104 | int (*get)(struct gpio_chip *chip, | |
105 | unsigned offset); | |
106 | int (*direction_output)(struct gpio_chip *chip, | |
107 | unsigned offset, int value); | |
c4b5be98 FB |
108 | int (*set_debounce)(struct gpio_chip *chip, |
109 | unsigned offset, unsigned debounce); | |
110 | ||
d2876d08 DB |
111 | void (*set)(struct gpio_chip *chip, |
112 | unsigned offset, int value); | |
0f6d504e DB |
113 | |
114 | int (*to_irq)(struct gpio_chip *chip, | |
115 | unsigned offset); | |
116 | ||
d2876d08 DB |
117 | void (*dbg_show)(struct seq_file *s, |
118 | struct gpio_chip *chip); | |
119 | int base; | |
120 | u16 ngpio; | |
62154991 | 121 | const char *const *names; |
d2876d08 | 122 | unsigned can_sleep:1; |
d8f388d8 | 123 | unsigned exported:1; |
a19e3da5 AV |
124 | |
125 | #if defined(CONFIG_OF_GPIO) | |
126 | /* | |
127 | * If CONFIG_OF is enabled, then all GPIO controllers described in the | |
128 | * device tree automatically may have an OF translation | |
129 | */ | |
130 | struct device_node *of_node; | |
131 | int of_gpio_n_cells; | |
15c9a0ac GL |
132 | int (*of_xlate)(struct gpio_chip *gc, |
133 | const struct of_phandle_args *gpiospec, u32 *flags); | |
a19e3da5 | 134 | #endif |
d2876d08 DB |
135 | }; |
136 | ||
137 | extern const char *gpiochip_is_requested(struct gpio_chip *chip, | |
138 | unsigned offset); | |
1a2d397a | 139 | extern struct gpio_chip *gpio_to_chip(unsigned gpio); |
6ea0205b | 140 | extern int __must_check gpiochip_reserve(int start, int ngpio); |
d2876d08 DB |
141 | |
142 | /* add/remove chips */ | |
143 | extern int gpiochip_add(struct gpio_chip *chip); | |
144 | extern int __must_check gpiochip_remove(struct gpio_chip *chip); | |
594fa265 GL |
145 | extern struct gpio_chip *gpiochip_find(void *data, |
146 | int (*match)(struct gpio_chip *chip, | |
147 | void *data)); | |
d2876d08 DB |
148 | |
149 | ||
150 | /* Always use the library code for GPIO management calls, | |
151 | * or when sleeping may be involved. | |
152 | */ | |
d8a3515e | 153 | extern int gpio_request(unsigned gpio, const char *label); |
d2876d08 DB |
154 | extern void gpio_free(unsigned gpio); |
155 | ||
d8a3515e LT |
156 | extern int gpio_direction_input(unsigned gpio); |
157 | extern int gpio_direction_output(unsigned gpio, int value); | |
d2876d08 | 158 | |
c4b5be98 FB |
159 | extern int gpio_set_debounce(unsigned gpio, unsigned debounce); |
160 | ||
d2876d08 DB |
161 | extern int gpio_get_value_cansleep(unsigned gpio); |
162 | extern void gpio_set_value_cansleep(unsigned gpio, int value); | |
163 | ||
164 | ||
165 | /* A platform's <asm/gpio.h> code may want to inline the I/O calls when | |
166 | * the GPIO is constant and refers to some always-present controller, | |
167 | * giving direct access to chip registers and tight bitbanging loops. | |
168 | */ | |
169 | extern int __gpio_get_value(unsigned gpio); | |
170 | extern void __gpio_set_value(unsigned gpio, int value); | |
171 | ||
172 | extern int __gpio_cansleep(unsigned gpio); | |
173 | ||
0f6d504e | 174 | extern int __gpio_to_irq(unsigned gpio); |
d2876d08 | 175 | |
d8a3515e | 176 | extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); |
7c295975 LPC |
177 | extern int gpio_request_array(const struct gpio *array, size_t num); |
178 | extern void gpio_free_array(const struct gpio *array, size_t num); | |
3e45f1d1 | 179 | |
1a0703ed JC |
180 | /* bindings for managed devices that want to request gpios */ |
181 | int devm_gpio_request(struct device *dev, unsigned gpio, const char *label); | |
182 | void devm_gpio_free(struct device *dev, unsigned int gpio); | |
183 | ||
d8f388d8 DB |
184 | #ifdef CONFIG_GPIO_SYSFS |
185 | ||
186 | /* | |
187 | * A sysfs interface can be exported by individual drivers if they want, | |
188 | * but more typically is configured entirely from userspace. | |
189 | */ | |
190 | extern int gpio_export(unsigned gpio, bool direction_may_change); | |
a4177ee7 JN |
191 | extern int gpio_export_link(struct device *dev, const char *name, |
192 | unsigned gpio); | |
07697461 | 193 | extern int gpio_sysfs_set_active_low(unsigned gpio, int value); |
d8f388d8 DB |
194 | extern void gpio_unexport(unsigned gpio); |
195 | ||
196 | #endif /* CONFIG_GPIO_SYSFS */ | |
197 | ||
09cd9527 | 198 | #else /* !CONFIG_GPIOLIB */ |
d2876d08 | 199 | |
3474cb3c | 200 | static inline bool gpio_is_valid(int number) |
e6de1808 GL |
201 | { |
202 | /* only non-negative numbers are valid */ | |
203 | return number >= 0; | |
204 | } | |
205 | ||
4c20386c DB |
206 | /* platforms that don't directly support access to GPIOs through I2C, SPI, |
207 | * or other blocking infrastructure can use these wrappers. | |
208 | */ | |
209 | ||
210 | static inline int gpio_cansleep(unsigned gpio) | |
211 | { | |
212 | return 0; | |
213 | } | |
214 | ||
215 | static inline int gpio_get_value_cansleep(unsigned gpio) | |
216 | { | |
217 | might_sleep(); | |
eb9ae7f2 | 218 | return __gpio_get_value(gpio); |
4c20386c DB |
219 | } |
220 | ||
221 | static inline void gpio_set_value_cansleep(unsigned gpio, int value) | |
222 | { | |
223 | might_sleep(); | |
eb9ae7f2 | 224 | __gpio_set_value(gpio, value); |
4c20386c DB |
225 | } |
226 | ||
09cd9527 | 227 | #endif /* !CONFIG_GPIOLIB */ |
d8f388d8 DB |
228 | |
229 | #ifndef CONFIG_GPIO_SYSFS | |
230 | ||
1f018c8d MF |
231 | struct device; |
232 | ||
d8f388d8 DB |
233 | /* sysfs support is only available with gpiolib, where it's optional */ |
234 | ||
235 | static inline int gpio_export(unsigned gpio, bool direction_may_change) | |
236 | { | |
237 | return -ENOSYS; | |
238 | } | |
239 | ||
a4177ee7 JN |
240 | static inline int gpio_export_link(struct device *dev, const char *name, |
241 | unsigned gpio) | |
242 | { | |
243 | return -ENOSYS; | |
244 | } | |
245 | ||
07697461 JN |
246 | static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) |
247 | { | |
248 | return -ENOSYS; | |
249 | } | |
250 | ||
d8f388d8 DB |
251 | static inline void gpio_unexport(unsigned gpio) |
252 | { | |
253 | } | |
254 | #endif /* CONFIG_GPIO_SYSFS */ | |
d2876d08 | 255 | |
4c20386c | 256 | #endif /* _ASM_GENERIC_GPIO_H */ |