Boot Linux faster!

Check our new training course

Boot Linux faster!

Check our new training course
and Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
/*
 * Copyright (c) 2015-2016 Intel Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * @file
 * @brief Public APIs for GPIO drivers
 */

#ifndef __GPIO_H__
#define __GPIO_H__

#include <misc/__assert.h>
#include <misc/slist.h>

#include <stdint.h>
#include <stddef.h>
#include <device.h>

/**
 * @brief GPIO Driver APIs
 * @defgroup gpio_interface GPIO Driver APIs
 * @ingroup io_interfaces
 * @{
 */
#ifdef __cplusplus
extern "C" {
#endif

/** @cond INTERNAL_HIDDEN */
#define GPIO_ACCESS_BY_PIN 0
#define GPIO_ACCESS_BY_PORT 1
/** @endcond */

/** GPIO pin to be input. */
#define GPIO_DIR_IN		(0 << 0)

/** GPIO pin to be output. */
#define GPIO_DIR_OUT		(1 << 0)

/** For internal use. */
#define GPIO_DIR_MASK		0x1

/** GPIO pin to trigger interrupt. */
#define GPIO_INT		(1 << 1)

/** GPIO pin trigger on level low or falling edge. */
#define GPIO_INT_ACTIVE_LOW	(0 << 2)

/** GPIO pin trigger on level high or rising edge. */
#define GPIO_INT_ACTIVE_HIGH	(1 << 2)

/** GPIO pin trggier to be synchronized to clock pulses. */
#define GPIO_INT_CLOCK_SYNC     (1 << 3)

/** Enable GPIO pin debounce. */
#define GPIO_INT_DEBOUNCE       (1 << 4)

/** Do Level trigger. */
#define GPIO_INT_LEVEL		(0 << 5)

/** Do Edge trigger. */
#define GPIO_INT_EDGE		(1 << 5)

/** Interrupt triggers on both rising and falling edge. */
#define GPIO_INT_DOUBLE_EDGE	(1 << 6)

/*
 * GPIO_POL_* define the polarity of the GPIO (1 bit).
 */

/** For internal use. */
#define GPIO_POL_POS		7

/** GPIO pin polarity is normal. */
#define GPIO_POL_NORMAL		(0 << GPIO_POL_POS)

/** GPIO pin polarity is inverted. */
#define GPIO_POL_INV		(1 << GPIO_POL_POS)

/** For internal use. */
#define GPIO_POL_MASK		(1 << GPIO_POL_POS)

/*
 * GPIO_PUD_* are related to pull-up/pull-down.
 */

/** For internal use. */
#define GPIO_PUD_POS		8

/** GPIO pin to have no pull-up or pull-down. */
#define GPIO_PUD_NORMAL		(0 << GPIO_PUD_POS)

/** Enable GPIO pin pull-up. */
#define GPIO_PUD_PULL_UP	(1 << GPIO_PUD_POS)

/** Enable GPIO pin pull-down. */
#define GPIO_PUD_PULL_DOWN	(2 << GPIO_PUD_POS)

/** For internal use. */
#define GPIO_PUD_MASK		(3 << GPIO_PUD_POS)

/*
 * GPIO_PIN_(EN-/DIS-)ABLE are for pin enable / disable.
 *
 * Individual pins can be enabled or disabled
 * if the controller supports this operation.
 */

/** Enable GPIO pin. */
#define GPIO_PIN_ENABLE		(1 << 10)

/** Disable GPIO pin. */
#define GPIO_PIN_DISABLE	(1 << 11)

/**
 * @brief Define the application callback function signature.
 *
 * @param port Device struct for the GPIO device.
 * @param pin The pin that triggers the callback.
 *
 * Note: This is the former callback signature used to set a unique
 *       callback (API v1.0) through gpio_set_callback(). The new
 *       struct gpio_callback below is now the preferred way.
 */
typedef void (*gpio_callback_t)(struct device *port, uint32_t pin);


struct gpio_callback;

/**
 * @brief Define the application callback handler function signature
 *
 * @param port Device struct for the GPIO device.
 * @param cb Original struct gpio_callback owning this handler
 * @param pins Mask of pins that triggers the callback handler
 *
 * Note: cb pointer can be used to retrieve private data through
 * CONTAINER_OF() if original struct gpio_callback is stored in
 * another private structure.
 */
typedef void (*gpio_callback_handler_t)(struct device *port,
					struct gpio_callback *cb,
					uint32_t pins);

/**
 * @brief GPIO callback structure
 *
 * Used to register a callback in the driver instance callback list.
 * As many callbacks as needed can be added as long as each of them
 * are unique pointers of struct gpio_callback.
 * Beware such structure should not be allocated on stack.
 *
 * Note: To help setting it, see gpio_init_callback() below
 */
struct gpio_callback {
	/** This is meant to be used in the driver and the user should not
	 * mess with it (see drivers/gpio/gpio_utils.h)
	 */
	sys_snode_t node;

	/** Actual callback function being called when relevant. */
	gpio_callback_handler_t handler;

	/** A mask of pins the callback is interested in, if 0 the callback
	 * will never be called. Such pin_mask can be modified whenever
	 * necessary by the owner, and thus will affect the handler being
	 * called or not. The selected pins must be configured to trigger
	 * an interrupt.
	 */
	uint32_t pin_mask;
};

/**
 * @cond INTERNAL_HIDDEN
 *
 * GPIO driver API definition.
 *
 * (Internal use only.)
 */
typedef int (*gpio_config_t)(struct device *port, int access_op,
			     uint32_t pin, int flags);
typedef int (*gpio_write_t)(struct device *port, int access_op,
			    uint32_t pin, uint32_t value);
typedef int (*gpio_read_t)(struct device *port, int access_op,
			   uint32_t pin, uint32_t *value);
typedef int (*gpio_manage_callback_t)(struct device *port,
				      struct gpio_callback *callback,
				      bool set);
typedef int (*gpio_enable_callback_t)(struct device *port,
				      int access_op,
				      uint32_t pin);
typedef int (*gpio_disable_callback_t)(struct device *port,
				       int access_op,
				       uint32_t pin);

struct gpio_driver_api {
	gpio_config_t config;
	gpio_write_t write;
	gpio_read_t read;
	gpio_manage_callback_t manage_callback;
	gpio_enable_callback_t enable_callback;
	gpio_disable_callback_t disable_callback;
};
/**
 * @endcond
 */

/**
 * @brief Configure a single pin.
 * @param port Pointer to device structure for the driver instance.
 * @param pin Pin number to configure.
 * @param flags Flags for pin configuration. IN/OUT, interrupt ...
 */
static inline int gpio_pin_configure(struct device *port, uint8_t pin,
				     int flags)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->config(port, GPIO_ACCESS_BY_PIN, pin, flags);
}

/**
 * @brief Write the data value to a single pin.
 * @param port Pointer to the device structure for the driver instance.
 * @param pin Pin number where the data is written.
 * @param value Value set on the pin.
 */
static inline int gpio_pin_write(struct device *port, uint32_t pin,
				 uint32_t value)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->write(port, GPIO_ACCESS_BY_PIN, pin, value);
}

/**
 * @brief Read the data value of a single pin.
 * @param port Pointer to the device structure for the driver instance.
 * @param pin Pin number where data is read.
 * @param value Integer pointer to receive the data vales from the pin.
 */
static inline int gpio_pin_read(struct device *port, uint32_t pin,
				uint32_t *value)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->read(port, GPIO_ACCESS_BY_PIN, pin, value);
}

/**
 * @brief Former way of setting the application's callback.
 * @param port Pointer to the device structure for the driver instance.
 * @param callback Application's callback (or NULL to unset).
 *
 * Note: This function sets a unique callback for the driver instance,
 *       i.e. another call to this function will overwrite it. This is
 *       the old way of doing things (API v1.0) and should be replaced
 *       by gpio_add_callback() and gpio_remove_callback().
 *       Using this function will not collide with the new ones.
 */
int __deprecated gpio_set_callback(struct device *port,
				   gpio_callback_t callback);

/**
 * @brief Helper to initialize a struct gpio_callback properly
 * @param callback A valid Application's callback structure pointer.
 * @param handler A valid handler function pointer.
 * @param pin_mask A bit mask of relevant pins for the handler
 */
static inline void gpio_init_callback(struct gpio_callback *callback,
				      gpio_callback_handler_t handler,
				      uint32_t pin_mask)
{
	__ASSERT(callback, "Callback pointer should not be NULL");
	__ASSERT(handler, "Callback handler pointer should not be NULL");

	callback->handler = handler;
	callback->pin_mask = pin_mask;
}

/**
 * @brief Add an application callback.
 * @param port Pointer to the device structure for the driver instance.
 * @param callback A valid Application's callback structure pointer.
 *
 * Note: enables to add as many callback as needed on the same port.
 *       This is the preferred way and is replacing gpio_set_callback().
 */
static inline int gpio_add_callback(struct device *port,
				    struct gpio_callback *callback)
{
	struct gpio_driver_api *api;

	__ASSERT(callback, "Callback pointer should not be NULL");

	api = (struct gpio_driver_api *) port->driver_api;
	return api->manage_callback(port, callback, true);
}

/**
 * @brief Remove an application callback.
 * @param port Pointer to the device structure for the driver instance.
 * @param callback A valid application's callback structure pointer.
 *
 * Note: enables to remove as many callacks as added through
 *       gpio_add_callback(). This is the preferred way and it's
 *       replacing gpio_set_callback() with a NULL pointer as a callback.
 */
static inline int gpio_remove_callback(struct device *port,
				       struct gpio_callback *callback)
{
	struct gpio_driver_api *api;

	__ASSERT(callback, "Callback pointer should not be NULL");

	api = (struct gpio_driver_api *) port->driver_api;
	return api->manage_callback(port, callback, false);
}

/**
 * @brief Enable callback(s) for a single pin.
 * @param port Pointer to the device structure for the driver instance.
 * @param pin Pin number where the callback function is enabled.
 *
 * Note: Depending on the driver implementation, this function will enable
 *       the pin to trigger an interruption. So as a semantic detail, if no
 *       callback is registered, of course none will be called.
 */
static inline int gpio_pin_enable_callback(struct device *port, uint32_t pin)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->enable_callback(port, GPIO_ACCESS_BY_PIN, pin);
}

/**
 * @brief Disable callback(s) for a single pin.
 * @param port Pointer to the device structure for the driver instance.
 * @param pin Pin number where the callback function is disabled.
 */
static inline int gpio_pin_disable_callback(struct device *port, uint32_t pin)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->disable_callback(port, GPIO_ACCESS_BY_PIN, pin);
}

/**
 * @brief Configure all the pins the same way in the port.
 *        List out all flags on the detailed description.
 *
 * @param port Pointer to the device structure for the driver instance.
 * @param flags Flags for the port configuration. IN/OUT, interrupt ...
 */
static inline int gpio_port_configure(struct device *port, int flags)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->config(port, GPIO_ACCESS_BY_PORT, 0, flags);
}

/**
 * @brief Write a data value to the port.
 * @param port Pointer to the device structure for the driver instance.
 * @param value Value to set on the port.
 */
static inline int gpio_port_write(struct device *port, uint32_t value)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->write(port, GPIO_ACCESS_BY_PORT, 0, value);
}

/**
 * @brief Read data value from the port.
 * @param port Pointer to the device structure for the driver instance.
 * @param value Integer pointer to receive the data value from the port.
 */
static inline int gpio_port_read(struct device *port, uint32_t *value)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->read(port, GPIO_ACCESS_BY_PORT, 0, value);
}

/**
 * @brief Enable callback(s) for the port.
 * @param port Pointer to the device structure for the driver instance.
 *
 * Note: Depending on the driver implementation, this function will enable
 *       the port to trigger an interruption on all pins, as long as these
 *       are configured properly. So as a semantic detail, if no callback
 *       is registered, of course none will be called.
 */
static inline int gpio_port_enable_callback(struct device *port)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->enable_callback(port, GPIO_ACCESS_BY_PORT, 0);
}

/**
 * @brief Disable callback(s) for the port.
 * @param port Pointer to the device structure for the driver instance.
 */
static inline int gpio_port_disable_callback(struct device *port)
{
	struct gpio_driver_api *api;

	api = (struct gpio_driver_api *) port->driver_api;
	return api->disable_callback(port, GPIO_ACCESS_BY_PORT, 0);
}

#ifdef __cplusplus
}
#endif

/**
 * @}
 */

#endif /* __GPIO_H__ */