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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. |
d2876d08 DB |
19 | */ |
20 | ||
21 | #ifndef ARCH_NR_GPIOS | |
22 | #define ARCH_NR_GPIOS 256 | |
23 | #endif | |
24 | ||
e6de1808 GL |
25 | static inline int gpio_is_valid(int number) |
26 | { | |
27 | /* only some non-negative numbers are valid */ | |
28 | return ((unsigned)number) < ARCH_NR_GPIOS; | |
29 | } | |
30 | ||
1f018c8d | 31 | struct device; |
d2876d08 | 32 | struct seq_file; |
438d8908 | 33 | struct module; |
a19e3da5 | 34 | struct device_node; |
d2876d08 DB |
35 | |
36 | /** | |
37 | * struct gpio_chip - abstract a GPIO controller | |
38 | * @label: for diagnostics | |
d8f388d8 DB |
39 | * @dev: optional device providing the GPIOs |
40 | * @owner: helps prevent removal of modules exporting active GPIOs | |
35e8bb51 DB |
41 | * @request: optional hook for chip-specific activation, such as |
42 | * enabling module power and clock; may sleep | |
43 | * @free: optional hook for chip-specific deactivation, such as | |
44 | * disabling module power and clock; may sleep | |
d2876d08 DB |
45 | * @direction_input: configures signal "offset" as input, or returns error |
46 | * @get: returns value for signal "offset"; for output signals this | |
47 | * returns either the value actually sensed, or zero | |
48 | * @direction_output: configures signal "offset" as output, or returns error | |
49 | * @set: assigns output value for signal "offset" | |
0f6d504e DB |
50 | * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; |
51 | * implementation may not sleep | |
d2876d08 DB |
52 | * @dbg_show: optional routine to show contents in debugfs; default code |
53 | * will be used when this is omitted, but custom code can show extra | |
54 | * state (such as pullup/pulldown configuration). | |
55 | * @base: identifies the first GPIO number handled by this chip; or, if | |
56 | * negative during registration, requests dynamic ID allocation. | |
57 | * @ngpio: the number of GPIOs handled by this controller; the last GPIO | |
58 | * handled is (base + ngpio - 1). | |
59 | * @can_sleep: flag must be set iff get()/set() methods sleep, as they | |
60 | * must while accessing GPIO expander chips over I2C or SPI | |
926b663c DS |
61 | * @names: if set, must be an array of strings to use as alternative |
62 | * names for the GPIOs in this chip. Any entry in the array | |
63 | * may be NULL if there is no alias for the GPIO, however the | |
7839ec78 UKK |
64 | * array must be @ngpio entries long. A name can include a single printk |
65 | * format specifier for an unsigned int. It is substituted by the actual | |
66 | * number of the gpio. | |
d2876d08 DB |
67 | * |
68 | * A gpio_chip can help platforms abstract various sources of GPIOs so | |
69 | * they can all be accessed through a common programing interface. | |
70 | * Example sources would be SOC controllers, FPGAs, multifunction | |
71 | * chips, dedicated GPIO expanders, and so on. | |
72 | * | |
73 | * Each chip controls a number of signals, identified in method calls | |
74 | * by "offset" values in the range 0..(@ngpio - 1). When those signals | |
75 | * are referenced through calls like gpio_get_value(gpio), the offset | |
76 | * is calculated by subtracting @base from the gpio number. | |
77 | */ | |
78 | struct gpio_chip { | |
4fd5463c | 79 | const char *label; |
d8f388d8 | 80 | struct device *dev; |
438d8908 | 81 | struct module *owner; |
d2876d08 | 82 | |
35e8bb51 DB |
83 | int (*request)(struct gpio_chip *chip, |
84 | unsigned offset); | |
85 | void (*free)(struct gpio_chip *chip, | |
86 | unsigned offset); | |
87 | ||
d2876d08 DB |
88 | int (*direction_input)(struct gpio_chip *chip, |
89 | unsigned offset); | |
90 | int (*get)(struct gpio_chip *chip, | |
91 | unsigned offset); | |
92 | int (*direction_output)(struct gpio_chip *chip, | |
93 | unsigned offset, int value); | |
c4b5be98 FB |
94 | int (*set_debounce)(struct gpio_chip *chip, |
95 | unsigned offset, unsigned debounce); | |
96 | ||
d2876d08 DB |
97 | void (*set)(struct gpio_chip *chip, |
98 | unsigned offset, int value); | |
0f6d504e DB |
99 | |
100 | int (*to_irq)(struct gpio_chip *chip, | |
101 | unsigned offset); | |
102 | ||
d2876d08 DB |
103 | void (*dbg_show)(struct seq_file *s, |
104 | struct gpio_chip *chip); | |
105 | int base; | |
106 | u16 ngpio; | |
62154991 | 107 | const char *const *names; |
d2876d08 | 108 | unsigned can_sleep:1; |
d8f388d8 | 109 | unsigned exported:1; |
a19e3da5 AV |
110 | |
111 | #if defined(CONFIG_OF_GPIO) | |
112 | /* | |
113 | * If CONFIG_OF is enabled, then all GPIO controllers described in the | |
114 | * device tree automatically may have an OF translation | |
115 | */ | |
116 | struct device_node *of_node; | |
117 | int of_gpio_n_cells; | |
118 | int (*of_xlate)(struct gpio_chip *gc, struct device_node *np, | |
119 | const void *gpio_spec, u32 *flags); | |
120 | #endif | |
d2876d08 DB |
121 | }; |
122 | ||
123 | extern const char *gpiochip_is_requested(struct gpio_chip *chip, | |
124 | unsigned offset); | |
6ea0205b | 125 | extern int __must_check gpiochip_reserve(int start, int ngpio); |
d2876d08 DB |
126 | |
127 | /* add/remove chips */ | |
128 | extern int gpiochip_add(struct gpio_chip *chip); | |
129 | extern int __must_check gpiochip_remove(struct gpio_chip *chip); | |
130 | ||
131 | ||
132 | /* Always use the library code for GPIO management calls, | |
133 | * or when sleeping may be involved. | |
134 | */ | |
135 | extern int gpio_request(unsigned gpio, const char *label); | |
136 | extern void gpio_free(unsigned gpio); | |
137 | ||
138 | extern int gpio_direction_input(unsigned gpio); | |
139 | extern int gpio_direction_output(unsigned gpio, int value); | |
140 | ||
c4b5be98 FB |
141 | extern int gpio_set_debounce(unsigned gpio, unsigned debounce); |
142 | ||
d2876d08 DB |
143 | extern int gpio_get_value_cansleep(unsigned gpio); |
144 | extern void gpio_set_value_cansleep(unsigned gpio, int value); | |
145 | ||
146 | ||
147 | /* A platform's <asm/gpio.h> code may want to inline the I/O calls when | |
148 | * the GPIO is constant and refers to some always-present controller, | |
149 | * giving direct access to chip registers and tight bitbanging loops. | |
150 | */ | |
151 | extern int __gpio_get_value(unsigned gpio); | |
152 | extern void __gpio_set_value(unsigned gpio, int value); | |
153 | ||
154 | extern int __gpio_cansleep(unsigned gpio); | |
155 | ||
0f6d504e | 156 | extern int __gpio_to_irq(unsigned gpio); |
d2876d08 | 157 | |
3e45f1d1 EM |
158 | #define GPIOF_DIR_OUT (0 << 0) |
159 | #define GPIOF_DIR_IN (1 << 0) | |
160 | ||
161 | #define GPIOF_INIT_LOW (0 << 1) | |
162 | #define GPIOF_INIT_HIGH (1 << 1) | |
163 | ||
164 | #define GPIOF_IN (GPIOF_DIR_IN) | |
165 | #define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW) | |
166 | #define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH) | |
167 | ||
168 | /** | |
169 | * struct gpio - a structure describing a GPIO with configuration | |
170 | * @gpio: the GPIO number | |
171 | * @flags: GPIO configuration as specified by GPIOF_* | |
172 | * @label: a literal description string of this GPIO | |
173 | */ | |
174 | struct gpio { | |
175 | unsigned gpio; | |
176 | unsigned long flags; | |
177 | const char *label; | |
178 | }; | |
179 | ||
180 | extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); | |
181 | extern int gpio_request_array(struct gpio *array, size_t num); | |
182 | extern void gpio_free_array(struct gpio *array, size_t num); | |
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 | ||
198 | #else /* !CONFIG_HAVE_GPIO_LIB */ | |
d2876d08 | 199 | |
e6de1808 GL |
200 | static inline int gpio_is_valid(int number) |
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(); | |
218 | return gpio_get_value(gpio); | |
219 | } | |
220 | ||
221 | static inline void gpio_set_value_cansleep(unsigned gpio, int value) | |
222 | { | |
223 | might_sleep(); | |
224 | gpio_set_value(gpio, value); | |
225 | } | |
226 | ||
d8f388d8 DB |
227 | #endif /* !CONFIG_HAVE_GPIO_LIB */ |
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 */ |