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