Linux Audio

Check our new training course

Embedded Linux Audio

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

Bootlin logo

Elixir Cross Referencer

Loading...
  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
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
/**
 * @file sensor.h
 *
 * @brief Public APIs for the sensor driver.
 */

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#ifndef __SENSOR_H__
#define __SENSOR_H__

/**
 * @brief Sensor Interface
 * @defgroup sensor_interface Sensor Interface
 * @ingroup io_interfaces
 * @{
 */

#ifdef __cplusplus
extern "C" {
#endif

#include <zephyr/types.h>
#include <device.h>
#include <errno.h>

/**
 * @brief Representation of a sensor readout value.
 *
 * The value is represented as having an integer and a fractional part,
 * and can be obtained using the formula val1 + val2 * 10^(-6).
 */
struct sensor_value {
	/** Integer part of the value. */
	s32_t val1;
	/** Fractional part of the value. */
	s32_t val2;
};

/**
 * @brief Sensor channels.
 */
enum sensor_channel {
	/** Acceleration on the X axis, in m/s^2. */
	SENSOR_CHAN_ACCEL_X,
	/** Acceleration on the Y axis, in m/s^2. */
	SENSOR_CHAN_ACCEL_Y,
	/** Acceleration on the Z axis, in m/s^2. */
	SENSOR_CHAN_ACCEL_Z,
	/** Acceleration on the X, Y and Z axes. */
	SENSOR_CHAN_ACCEL_XYZ,
	/**
	 * This enum value will be deprecated.
	 * Please use SENSOR_CHAN_ACCEL_XYZ instead.
	 *
	 * Acceleration on any axis.
	 */
	SENSOR_CHAN_ACCEL_ANY = SENSOR_CHAN_ACCEL_XYZ,
	/** Angular velocity around the X axis, in radians/s. */
	SENSOR_CHAN_GYRO_X,
	/** Angular velocity around the Y axis, in radians/s. */
	SENSOR_CHAN_GYRO_Y,
	/** Angular velocity around the Z axis, in radians/s. */
	SENSOR_CHAN_GYRO_Z,
	/** Angular velocity around the X, Y and Z axes. */
	SENSOR_CHAN_GYRO_XYZ,
	/**
	 * This enum value will be deprecated.
	 * Please use SENSOR_CHAN_GYRO_XYZ instead.
	 *
	 * Angular velocity on any axis.
	 */
	SENSOR_CHAN_GYRO_ANY = SENSOR_CHAN_GYRO_XYZ,
	/** Magnetic field on the X axis, in Gauss. */
	SENSOR_CHAN_MAGN_X,
	/** Magnetic field on the Y axis, in Gauss. */
	SENSOR_CHAN_MAGN_Y,
	/** Magnetic field on the Z axis, in Gauss. */
	SENSOR_CHAN_MAGN_Z,
	/** Magnetic field on the X, Y and Z axes. */
	SENSOR_CHAN_MAGN_XYZ,
	/**
	 * This enum value will be deprecated.
	 * Please use SENSOR_CHAN_MAGN_XYZ instead.
	 *
	 * Magnetic field on any axis.
	 */
	SENSOR_CHAN_MAGN_ANY = SENSOR_CHAN_MAGN_XYZ,
	/** Temperature in degrees Celsius. */
	SENSOR_CHAN_TEMP,
	/** Pressure in kilopascal. */
	SENSOR_CHAN_PRESS,
	/**
	 * Proximity.  Adimensional.  A value of 1 indicates that an
	 * object is close.
	 */
	SENSOR_CHAN_PROX,
	/** Humidity, in milli percent. */
	SENSOR_CHAN_HUMIDITY,
	/** Illuminance in visible spectrum, in lux. */
	SENSOR_CHAN_LIGHT,
	/** Illuminance in infra-red spectrum, in lux. */
	SENSOR_CHAN_IR,
	/** Illuminance in red spectrum, in lux. */
	SENSOR_CHAN_RED,
	/** Illuminance in green spectrum, in lux. */
	SENSOR_CHAN_GREEN,
	/** Illuminance in blue spectrum, in lux. */
	SENSOR_CHAN_BLUE,
	/** Altitude, in meters */
	SENSOR_CHAN_ALTITUDE,

	/** 1.0 micro-meters Particulate Matter, in ug/m^3 */
	SENSOR_CHAN_PM_1_0,
	/** 2.5 micro-meters Particulate Matter, in ug/m^3 */
	SENSOR_CHAN_PM_2_5,
	/** 10 micro-meters Particulate Matter, in ug/m^3 */
	SENSOR_CHAN_PM_10,
	/** All channels. */
	SENSOR_CHAN_ALL,
};

/**
 * @brief Sensor trigger types.
 */
enum sensor_trigger_type {
	/**
	 * Timer-based trigger, useful when the sensor does not have an
	 * interrupt line.
	 */
	SENSOR_TRIG_TIMER,
	/** Trigger fires whenever new data is ready. */
	SENSOR_TRIG_DATA_READY,
	/**
	 * Trigger fires when the selected channel varies significantly.
	 * This includes any-motion detection when the channel is
	 * acceleration or gyro. If detection is based on slope between
	 * successive channel readings, the slope threshold is configured
	 * via the @ref SENSOR_ATTR_SLOPE_TH and @ref SENSOR_ATTR_SLOPE_DUR
	 * attributes.
	 */
	SENSOR_TRIG_DELTA,
	/** Trigger fires when a near/far event is detected. */
	SENSOR_TRIG_NEAR_FAR,
	/**
	 * Trigger fires when channel reading transitions configured
	 * thresholds.  The thresholds are configured via the @ref
	 * SENSOR_ATTR_LOWER_THRESH and @ref SENSOR_ATTR_UPPER_THRESH
	 * attributes.
	 */
	SENSOR_TRIG_THRESHOLD,

	/** Trigger fires when a single tap is detected. */
	SENSOR_TRIG_TAP,

	/** Trigger fires when a double tap is detected. */
	SENSOR_TRIG_DOUBLE_TAP,
};

/**
 * @brief Sensor trigger spec.
 */
struct sensor_trigger {
	/** Trigger type. */
	enum sensor_trigger_type type;
	/** Channel the trigger is set on. */
	enum sensor_channel chan;
};

/**
 * @brief Sensor attribute types.
 */
enum sensor_attribute {
	/**
	 * Sensor sampling frequency, i.e. how many times a second the
	 * sensor takes a measurement.
	 */
	SENSOR_ATTR_SAMPLING_FREQUENCY,
	/** Lower threshold for trigger. */
	SENSOR_ATTR_LOWER_THRESH,
	/** Upper threshold for trigger. */
	SENSOR_ATTR_UPPER_THRESH,
	/** Threshold for any-motion (slope) trigger. */
	SENSOR_ATTR_SLOPE_TH,
	/**
	 * Duration for which the slope values needs to be
	 * outside the threshold for the trigger to fire.
	 */
	SENSOR_ATTR_SLOPE_DUR,
	/** Oversampling factor */
	SENSOR_ATTR_OVERSAMPLING,
	/** Sensor range, in SI units. */
	SENSOR_ATTR_FULL_SCALE,
	/**
	 * The sensor value returned will be altered by the amount indicated by
	 * offset: final_value = sensor_value + offset.
	 */
	SENSOR_ATTR_OFFSET,
	/**
	 * Calibration target. This will be used by the internal chip's
	 * algorithms to calibrate itself on a certain axis, or all of them.
	 */
	SENSOR_ATTR_CALIB_TARGET,
};

/**
 * @typedef sensor_trigger_handler_t
 * @brief Callback API upon firing of a trigger
 *
 * @param "struct device *dev" Pointer to the sensor device
 * @param "struct sensor_trigger *trigger" The trigger
 */
typedef void (*sensor_trigger_handler_t)(struct device *dev,
					 struct sensor_trigger *trigger);

/**
 * @typedef sensor_attr_set_t
 * @brief Callback API upon setting a sensor's attributes
 *
 * See sensor_attr_set() for argument description
 */
typedef int (*sensor_attr_set_t)(struct device *dev,
				 enum sensor_channel chan,
				 enum sensor_attribute attr,
				 const struct sensor_value *val);
/**
 * @typedef sensor_trigger_set_t
 * @brief Callback API for setting a sensor's trigger and handler
 *
 * See sensor_trigger_set() for argument description
 */
typedef int (*sensor_trigger_set_t)(struct device *dev,
				    const struct sensor_trigger *trig,
				    sensor_trigger_handler_t handler);
/**
 * @typedef sensor_sample_fetch_t
 * @brief Callback API for fetching data from a sensor
 *
 * See sensor_sample_fetch() for argument description
 */
typedef int (*sensor_sample_fetch_t)(struct device *dev,
				     enum sensor_channel chan);
/**
 * @typedef sensor_channel_get_t
 * @brief Callback API for getting a reading from a sensor
 *
 * See sensor_channel_get() for argument description
 */
typedef int (*sensor_channel_get_t)(struct device *dev,
				    enum sensor_channel chan,
				    struct sensor_value *val);

struct sensor_driver_api {
	sensor_attr_set_t attr_set;
	sensor_trigger_set_t trigger_set;
	sensor_sample_fetch_t sample_fetch;
	sensor_channel_get_t channel_get;
};

/**
 * @brief Set an attribute for a sensor
 *
 * @param dev Pointer to the sensor device
 * @param chan The channel the attribute belongs to, if any.  Some
 * attributes may only be set for all channels of a device, depending on
 * device capabilities.
 * @param attr The attribute to set
 * @param val The value to set the attribute to
 *
 * @return 0 if successful, negative errno code if failure.
 */
__syscall int sensor_attr_set(struct device *dev,
			      enum sensor_channel chan,
			      enum sensor_attribute attr,
			      const struct sensor_value *val);

static inline int _impl_sensor_attr_set(struct device *dev,
					enum sensor_channel chan,
					enum sensor_attribute attr,
					const struct sensor_value *val)
{
	const struct sensor_driver_api *api = dev->driver_api;

	if (!api->attr_set) {
		return -ENOTSUP;
	}

	return api->attr_set(dev, chan, attr, val);
}

/**
 * @brief Activate a sensor's trigger and set the trigger handler
 *
 * The handler will be called from a thread, so I2C or SPI operations are
 * safe.  However, the thread's stack is limited and defined by the
 * driver.  It is currently up to the caller to ensure that the handler
 * does not overflow the stack.
 *
 * This API is not permitted for user threads.
 *
 * @param dev Pointer to the sensor device
 * @param trig The trigger to activate
 * @param handler The function that should be called when the trigger
 * fires
 *
 * @return 0 if successful, negative errno code if failure.
 */
static inline int sensor_trigger_set(struct device *dev,
				     struct sensor_trigger *trig,
				     sensor_trigger_handler_t handler)
{
	const struct sensor_driver_api *api = dev->driver_api;

	if (!api->trigger_set) {
		return -ENOTSUP;
	}

	return api->trigger_set(dev, trig, handler);
}

/**
 * @brief Fetch a sample from the sensor and store it in an internal
 * driver buffer
 *
 * Read all of a sensor's active channels and, if necessary, perform any
 * additional operations necessary to make the values useful.  The user
 * may then get individual channel values by calling @ref
 * sensor_channel_get.
 *
 * Since the function communicates with the sensor device, it is unsafe
 * to call it in an ISR if the device is connected via I2C or SPI.
 *
 * @param dev Pointer to the sensor device
 *
 * @return 0 if successful, negative errno code if failure.
 */
__syscall int sensor_sample_fetch(struct device *dev);

static inline int _impl_sensor_sample_fetch(struct device *dev)
{
	const struct sensor_driver_api *api = dev->driver_api;

	return api->sample_fetch(dev, SENSOR_CHAN_ALL);
}

/**
 * @brief Fetch a sample from the sensor and store it in an internal
 * driver buffer
 *
 * Read and compute compensation for one type of sensor data (magnetometer,
 * accelerometer, etc). The user may then get individual channel values by
 * calling @ref sensor_channel_get.
 *
 * This is mostly implemented by multi function devices enabling reading at
 * different sampling rates.
 *
 * Since the function communicates with the sensor device, it is unsafe
 * to call it in an ISR if the device is connected via I2C or SPI.
 *
 * @param dev Pointer to the sensor device
 * @param type The channel that needs updated
 *
 * @return 0 if successful, negative errno code if failure.
 */
__syscall int sensor_sample_fetch_chan(struct device *dev,
				       enum sensor_channel type);

static inline int _impl_sensor_sample_fetch_chan(struct device *dev,
						 enum sensor_channel type)
{
	const struct sensor_driver_api *api = dev->driver_api;

	return api->sample_fetch(dev, type);
}

/**
 * @brief Get a reading from a sensor device
 *
 * Return a useful value for a particular channel, from the driver's
 * internal data.  Before calling this function, a sample must be
 * obtained by calling @ref sensor_sample_fetch or
 * @ref sensor_sample_fetch_chan. It is guaranteed that two subsequent
 * calls of this function for the same channels will yield the same
 * value, if @ref sensor_sample_fetch or @ref sensor_sample_fetch_chan
 * has not been called in the meantime.
 *
 * For vectorial data samples you can request all axes in just one call
 * by passing the specific channel with _XYZ suffix. The sample will be
 * returned at val[0], val[1] and val[2] (X, Y and Z in that order).
 *
 * @param dev Pointer to the sensor device
 * @param chan The channel to read
 * @param val Where to store the value
 *
 * @return 0 if successful, negative errno code if failure.
 */
__syscall int sensor_channel_get(struct device *dev,
				 enum sensor_channel chan,
				 struct sensor_value *val);

static inline int _impl_sensor_channel_get(struct device *dev,
					   enum sensor_channel chan,
					   struct sensor_value *val)
{
	const struct sensor_driver_api *api = dev->driver_api;

	return api->channel_get(dev, chan, val);
}

/**
 * @brief The value of gravitational constant in micro m/s^2.
 */
#define SENSOR_G		9806650LL

/**
 * @brief The value of constant PI in micros.
 */
#define SENSOR_PI		3141592LL

/**
 * @brief Helper function to convert acceleration from m/s^2 to Gs
 *
 * @param ms2 A pointer to a sensor_value struct holding the acceleration,
 *            in m/s^2.
 *
 * @return The converted value, in Gs.
 */
static inline s32_t sensor_ms2_to_g(const struct sensor_value *ms2)
{
	s64_t micro_ms2 = ms2->val1 * 1000000LL + ms2->val2;

	if (micro_ms2 > 0) {
		return (micro_ms2 + SENSOR_G / 2) / SENSOR_G;
	} else {
		return (micro_ms2 - SENSOR_G / 2) / SENSOR_G;
	}
}

/**
 * @brief Helper function to convert acceleration from Gs to m/s^2
 *
 * @param g The G value to be converted.
 * @param ms2 A pointer to a sensor_value struct, where the result is stored.
 */
static inline void sensor_g_to_ms2(s32_t g, struct sensor_value *ms2)
{
	ms2->val1 = ((s64_t)g * SENSOR_G) / 1000000LL;
	ms2->val2 = ((s64_t)g * SENSOR_G) % 1000000LL;
}

/**
 * @brief Helper function for converting radians to degrees.
 *
 * @param rad A pointer to a sensor_value struct, holding the value in radians.
 *
 * @return The converted value, in degrees.
 */
static inline s32_t sensor_rad_to_degrees(const struct sensor_value *rad)
{
	s64_t micro_rad_s = rad->val1 * 1000000LL + rad->val2;

	if (micro_rad_s > 0) {
		return (micro_rad_s * 180LL + SENSOR_PI / 2) / SENSOR_PI;
	} else {
		return (micro_rad_s * 180LL - SENSOR_PI / 2) / SENSOR_PI;
	}
}

/**
 * @brief Helper function for converting degrees to radians.
 *
 * @param d The value (in degrees) to be converted.
 * @param rad A pointer to a sensor_value struct, where the result is stored.
 */
static inline void sensor_degrees_to_rad(s32_t d, struct sensor_value *rad)
{
	rad->val1 = ((s64_t)d * SENSOR_PI / 180LL) / 1000000LL;
	rad->val2 = ((s64_t)d * SENSOR_PI / 180LL) % 1000000LL;
}

/**
 * @brief Helper function for converting struct sensor_value to double.
 *
 * @param val A pointer to a sensor_value struct.
 * @return The converted value.
 */
static inline double sensor_value_to_double(struct sensor_value *val)
{
	return (double)val->val1 + (double)val->val2 / 1000000;
}

#include <syscalls/sensor.h>

#ifdef __cplusplus
}
#endif

/**
 * @}
 */

#endif /* __SENSOR_H__ */