Linux preempt-rt

Check our new training course

Real-Time Linux with PREEMPT_RT

Check our new training course
with 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
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
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
/*
 * Copyright (c) 2018 Peter Bigot Consulting, LLC
 * Copyright (c) 2018 Linaro Ltd.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <device.h>
#include <drivers/gpio.h>
#include <drivers/i2c.h>
#include <kernel.h>
#include <sys/byteorder.h>
#include <sys/util.h>
#include <drivers/sensor.h>
#include <sys/__assert.h>
#include <logging/log.h>

#include "ccs811.h"

#define WAKE_PIN DT_INST_0_AMS_CCS811_WAKE_GPIOS_PIN
#define RESET_PIN DT_INST_0_AMS_CCS811_RESET_GPIOS_PIN

LOG_MODULE_REGISTER(CCS811, CONFIG_SENSOR_LOG_LEVEL);

#ifdef DT_INST_0_AMS_CCS811_WAKE_GPIOS_CONTROLLER
static void set_wake(struct ccs811_data *drv_data, bool enable)
{
	gpio_pin_set(drv_data->wake_gpio, WAKE_PIN, enable);
	if (enable) {
		k_busy_wait(50);        /* t_WAKE = 50 us */
	} else {
		k_busy_wait(20);        /* t_DWAKE = 20 us */
	}
}
#else
#define set_wake(...)
#endif

/* Get STATUS register in low 8 bits, and if ERROR is set put ERROR_ID
 * in bits 8..15.  These registers are available in both boot and
 * application mode.
 */
static int fetch_status(struct device *i2c)
{
	u8_t status;
	int rv;

	if (i2c_reg_read_byte(i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
			      CCS811_REG_STATUS, &status) < 0) {
		LOG_ERR("Failed to read Status register");
		return -EIO;
	}

	rv = status;
	if (status & CCS811_STATUS_ERROR) {
		u8_t error_id;

		if (i2c_reg_read_byte(i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
				      CCS811_REG_ERROR_ID, &error_id) < 0) {
			LOG_ERR("Failed to read ERROR_ID register");
			return -EIO;
		}

		rv |= (error_id << 8);
	}

	return rv;
}

static inline u8_t error_from_status(int status)
{
	return status >> 8;
}

const struct ccs811_result_type *ccs811_result(struct device *dev)
{
	struct ccs811_data *drv_data = dev->driver_data;

	return &drv_data->result;
}

int ccs811_configver_fetch(struct device *dev,
			   struct ccs811_configver_type *ptr)
{
	struct ccs811_data *drv_data = dev->driver_data;
	u8_t cmd;
	int rc;

	if (!ptr) {
		return -EINVAL;
	}

	set_wake(drv_data, true);
	cmd = CCS811_REG_HW_VERSION;
	rc = i2c_write_read(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
			    &cmd, sizeof(cmd),
			    &ptr->hw_version, sizeof(ptr->hw_version));
	if (rc == 0) {
		cmd = CCS811_REG_FW_BOOT_VERSION;
		rc = i2c_write_read(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
				    &cmd, sizeof(cmd),
				    (u8_t *)&ptr->fw_boot_version,
				    sizeof(ptr->fw_boot_version));
		ptr->fw_boot_version = sys_be16_to_cpu(ptr->fw_boot_version);
	}

	if (rc == 0) {
		cmd = CCS811_REG_FW_APP_VERSION;
		rc = i2c_write_read(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
				    &cmd, sizeof(cmd),
				    (u8_t *)&ptr->fw_app_version,
				    sizeof(ptr->fw_app_version));
		ptr->fw_app_version = sys_be16_to_cpu(ptr->fw_app_version);
	}
	if (rc == 0) {
		LOG_INF("HW %x FW %x APP %x",
			ptr->hw_version, ptr->fw_boot_version,
			ptr->fw_app_version);
	}

	set_wake(drv_data, false);
	ptr->mode = drv_data->mode & CCS811_MODE_MSK;

	return rc;
}

int ccs811_baseline_fetch(struct device *dev)
{
	const u8_t cmd = CCS811_REG_BASELINE;
	struct ccs811_data *drv_data = dev->driver_data;
	int rc;
	u16_t baseline;

	set_wake(drv_data, true);

	rc = i2c_write_read(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
			    &cmd, sizeof(cmd),
			    (u8_t *)&baseline, sizeof(baseline));
	set_wake(drv_data, false);
	if (rc <= 0) {
		rc = baseline;
	}

	return rc;
}

int ccs811_baseline_update(struct device *dev,
			   u16_t baseline)
{
	struct ccs811_data *drv_data = dev->driver_data;
	u8_t buf[1 + sizeof(baseline)];
	int rc;

	buf[0] = CCS811_REG_BASELINE;
	memcpy(buf + 1, &baseline, sizeof(baseline));
	set_wake(drv_data, true);
	rc = i2c_write(drv_data->i2c, buf, sizeof(buf), DT_INST_0_AMS_CCS811_BASE_ADDRESS);
	set_wake(drv_data, false);
	return rc;
}

int ccs811_envdata_update(struct device *dev,
			  const struct sensor_value *temperature,
			  const struct sensor_value *humidity)
{
	struct ccs811_data *drv_data = dev->driver_data;
	int rc;
	u8_t buf[5] = { CCS811_REG_ENV_DATA };

	/*
	 * Environment data are represented in a broken whole/fraction
	 * system that specified a 9-bit fractional part to represent
	 * milli-units.  Since 1000 is greater than 512, the device
	 * actually only pays attention to the top bit, treating it as
	 * indicating 0.5.  So we only write the first octet (7-bit
	 * while plus 1-bit half).
	 *
	 * Humidity is simple: scale it by two and round to the
	 * nearest half.  Assume the fractional part is not
	 * negative.
	 */
	if (humidity) {
		int value = 2 * humidity->val1;

		value += (250000 + humidity->val2) / 500000;
		if (value < 0) {
			value = 0;
		} else if (value > (2 * 100)) {
			value = 2 * 100;
		}
		LOG_DBG("HUM %d.%06d becomes %d",
			humidity->val1, humidity->val2, value);
		buf[1] = value;
	} else {
		buf[1] = 2 * 50;
	}

	/*
	 * Temperature is offset from -25 Cel.  Values below minimum
	 * store as zero.  Default is 25 Cel.  Again we round to the
	 * nearest half, complicated by Zephyr's signed representation
	 * of the fractional part.
	 */
	if (temperature) {
		int value = 2 * temperature->val1;

		if (temperature->val2 < 0) {
			value += (250000 + temperature->val2) / 500000;
		} else {
			value += (-250000 + temperature->val2) / 500000;
		}
		if (value < (2 * -25)) {
			value = 0;
		} else {
			value += 2 * 25;
		}
		LOG_DBG("TEMP %d.%06d becomes %d",
			temperature->val1, temperature->val2, value);
		buf[3] = value;
	} else {
		buf[3] = 2 * (25 + 25);
	}

	set_wake(drv_data, true);
	rc = i2c_write(drv_data->i2c, buf, sizeof(buf), DT_INST_0_AMS_CCS811_BASE_ADDRESS);
	set_wake(drv_data, false);
	return rc;
}

static int ccs811_sample_fetch(struct device *dev, enum sensor_channel chan)
{
	struct ccs811_data *drv_data = dev->driver_data;
	struct ccs811_result_type *rp = &drv_data->result;
	const u8_t cmd = CCS811_REG_ALG_RESULT_DATA;
	int rc;
	u16_t buf[4] = { 0 };
	unsigned int status;

	set_wake(drv_data, true);
	rc = i2c_write_read(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
			    &cmd, sizeof(cmd),
			    (u8_t *)buf, sizeof(buf));
	set_wake(drv_data, false);
	if (rc < 0) {
		return -EIO;
	}

	rp->co2 = sys_be16_to_cpu(buf[0]);
	rp->voc = sys_be16_to_cpu(buf[1]);
	status = sys_le16_to_cpu(buf[2]); /* sic */
	rp->status = status;
	rp->error = error_from_status(status);
	rp->raw = sys_be16_to_cpu(buf[3]);

	/* APP FW 1.1 does not set DATA_READY, but it does set CO2 to
	 * zero while it's starting up.  Assume a non-zero CO2 with
	 * old firmware is valid for the purposes of claiming the
	 * fetch was fresh.
	 */
	if ((drv_data->app_fw_ver <= 0x11)
	    && (rp->co2 != 0)) {
		status |= CCS811_STATUS_DATA_READY;
	}
	return (status & CCS811_STATUS_DATA_READY) ? 0 : -EAGAIN;
}

static int ccs811_channel_get(struct device *dev,
			      enum sensor_channel chan,
			      struct sensor_value *val)
{
	struct ccs811_data *drv_data = dev->driver_data;
	const struct ccs811_result_type *rp = &drv_data->result;
	u32_t uval;

	switch (chan) {
	case SENSOR_CHAN_CO2:
		val->val1 = rp->co2;
		val->val2 = 0;

		break;
	case SENSOR_CHAN_VOC:
		val->val1 = rp->voc;
		val->val2 = 0;

		break;
	case SENSOR_CHAN_VOLTAGE:
		/*
		 * Raw ADC readings are contained in least significant 10 bits
		 */
		uval = ((rp->raw & CCS811_RAW_VOLTAGE_MSK)
			>> CCS811_RAW_VOLTAGE_POS) * CCS811_RAW_VOLTAGE_SCALE;
		val->val1 = uval / 1000000U;
		val->val2 = uval % 1000000;

		break;
	case SENSOR_CHAN_CURRENT:
		/*
		 * Current readings are contained in most
		 * significant 6 bits in microAmps
		 */
		uval = ((rp->raw & CCS811_RAW_CURRENT_MSK)
			>> CCS811_RAW_CURRENT_POS) * CCS811_RAW_CURRENT_SCALE;
		val->val1 = uval / 1000000U;
		val->val2 = uval % 1000000;

		break;
	default:
		return -ENOTSUP;
	}

	return 0;
}

static const struct sensor_driver_api ccs811_driver_api = {
#ifdef CONFIG_CCS811_TRIGGER
	.attr_set = ccs811_attr_set,
	.trigger_set = ccs811_trigger_set,
#endif
	.sample_fetch = ccs811_sample_fetch,
	.channel_get = ccs811_channel_get,
};

static int switch_to_app_mode(struct device *i2c)
{
	u8_t buf;
	int status;

	LOG_DBG("Switching to Application mode...");

	status = fetch_status(i2c);
	if (status < 0) {
		return -EIO;
	}

	/* Check for the application firmware */
	if (!(status & CCS811_STATUS_APP_VALID)) {
		LOG_ERR("No Application firmware loaded");
		return -EINVAL;
	}

	/* Check if already in application mode */
	if (status & CCS811_STATUS_FW_MODE) {
		LOG_DBG("CCS811 Already in application mode");
		return 0;
	}

	buf = CCS811_REG_APP_START;
	/* Set the device to application mode */
	if (i2c_write(i2c, &buf, 1, DT_INST_0_AMS_CCS811_BASE_ADDRESS) < 0) {
		LOG_ERR("Failed to set Application mode");
		return -EIO;
	}

	k_sleep(1);             /* t_APP_START */
	status = fetch_status(i2c);
	if (status < 0) {
		return -EIO;
	}

	/* Check for application mode */
	if (!(status & CCS811_STATUS_FW_MODE)) {
		LOG_ERR("Failed to start Application firmware");
		return -EINVAL;
	}

	LOG_DBG("CCS811 Application firmware started!");

	return 0;
}

#ifdef CONFIG_CCS811_TRIGGER

int ccs811_mutate_meas_mode(struct device *dev,
			    u8_t set,
			    u8_t clear)
{
	struct ccs811_data *drv_data = dev->driver_data;
	int rc = 0;
	u8_t mode = set | (drv_data->mode & ~clear);

	/*
	 * Changing drive mode of a running system has preconditions.
	 * Only allow changing the interrupt generation.
	 */
	if ((set | clear) & ~(CCS811_MODE_DATARDY | CCS811_MODE_THRESH)) {
		return -EINVAL;
	}

	if (mode != drv_data->mode) {
		set_wake(drv_data, true);
		rc = i2c_reg_write_byte(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
					CCS811_REG_MEAS_MODE,
					mode);
		LOG_DBG("CCS811 meas mode change %02x to %02x got %d",
			drv_data->mode, mode, rc);
		if (rc < 0) {
			LOG_ERR("Failed to set mode");
			rc = -EIO;
		} else {
			drv_data->mode = mode;
			rc = 0;
		}

		set_wake(drv_data, false);
	}

	return rc;
}

int ccs811_set_thresholds(struct device *dev)
{
	struct ccs811_data *drv_data = dev->driver_data;
	const u8_t buf[5] = {
		CCS811_REG_THRESHOLDS,
		drv_data->co2_l2m >> 8,
		drv_data->co2_l2m,
		drv_data->co2_m2h >> 8,
		drv_data->co2_m2h,
	};
	int rc;

	set_wake(drv_data, true);
	rc = i2c_write(drv_data->i2c, buf, sizeof(buf), DT_INST_0_AMS_CCS811_BASE_ADDRESS);
	set_wake(drv_data, false);
	return rc;
}

#endif /* CONFIG_CCS811_TRIGGER */

static int ccs811_init(struct device *dev)
{
	struct ccs811_data *drv_data = dev->driver_data;
	int ret = 0;
	int status;
	u16_t fw_ver;
	u8_t cmd;
	u8_t hw_id;

	*drv_data = (struct ccs811_data){ 0 };
	drv_data->i2c = device_get_binding(DT_INST_0_AMS_CCS811_BUS_NAME);
	if (drv_data->i2c == NULL) {
		LOG_ERR("Failed to get pointer to %s device!",
			DT_INST_0_AMS_CCS811_BUS_NAME);
		return -EINVAL;
	}

#ifdef DT_INST_0_AMS_CCS811_WAKE_GPIOS_CONTROLLER
	drv_data->wake_gpio = device_get_binding(DT_INST_0_AMS_CCS811_WAKE_GPIOS_CONTROLLER);
	if (drv_data->wake_gpio == NULL) {
		LOG_ERR("Failed to get pointer to WAKE device: %s",
			DT_INST_0_AMS_CCS811_WAKE_GPIOS_CONTROLLER);
		return -EINVAL;
	}

	/*
	 * Wakeup pin should be pulled low before initiating
	 * any I2C transfer.  If it has been tied to GND by
	 * default, skip this part.
	 */
	gpio_pin_configure(drv_data->wake_gpio, WAKE_PIN,
			   GPIO_OUTPUT_INACTIVE
			   | DT_INST_0_AMS_CCS811_WAKE_GPIOS_FLAGS);

	set_wake(drv_data, true);
	k_sleep(1);
#endif
#ifdef DT_INST_0_AMS_CCS811_RESET_GPIOS_CONTROLLER
	drv_data->reset_gpio = device_get_binding(DT_INST_0_AMS_CCS811_RESET_GPIOS_CONTROLLER);
	if (drv_data->reset_gpio == NULL) {
		LOG_ERR("Failed to get pointer to RESET device: %s",
			DT_INST_0_AMS_CCS811_RESET_GPIOS_CONTROLLER);
		return -EINVAL;
	}
	gpio_pin_configure(drv_data->reset_gpio, RESET_PIN,
			   GPIO_OUTPUT_ACTIVE
			   | DT_INST_0_AMS_CCS811_RESET_GPIOS_FLAGS);

	k_sleep(1);
#endif

#ifdef DT_INST_0_AMS_CCS811_IRQ_GPIOS_CONTROLLER
	drv_data->irq_gpio = device_get_binding(DT_INST_0_AMS_CCS811_IRQ_GPIOS_CONTROLLER);
	if (drv_data->irq_gpio == NULL) {
		LOG_ERR("Failed to get pointer to INT device: %s",
			DT_INST_0_AMS_CCS811_IRQ_GPIOS_CONTROLLER);
		return -EINVAL;
	}
#endif

	/* Reset the device.  This saves having to deal with detecting
	 * and validating any errors or configuration inconsistencies
	 * after a reset that left the device running.
	 */
#ifdef DT_INST_0_AMS_CCS811_RESET_GPIOS_CONTROLLER
	gpio_pin_set(drv_data->reset_gpio, RESET_PIN, 1);
	k_busy_wait(15);        /* t_RESET */
	gpio_pin_set(drv_data->reset_gpio, RESET_PIN, 0);
#else
	{
		static u8_t const reset_seq[] = {
			0xFF, 0x11, 0xE5, 0x72, 0x8A,
		};

		if (i2c_write(drv_data->i2c, reset_seq, sizeof(reset_seq),
			      DT_INST_0_AMS_CCS811_BASE_ADDRESS) < 0) {
			LOG_ERR("Failed to issue SW reset");
			ret = -EIO;
			goto out;
		}
	}
#endif
	k_sleep(20);            /* t_START assuming recent power-on */

	/* Switch device to application mode */
	ret = switch_to_app_mode(drv_data->i2c);
	if (ret) {
		goto out;
	}

	/* Check Hardware ID */
	if (i2c_reg_read_byte(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
			      CCS811_REG_HW_ID, &hw_id) < 0) {
		LOG_ERR("Failed to read Hardware ID register");
		ret = -EIO;
		goto out;
	}

	if (hw_id != CCS881_HW_ID) {
		LOG_ERR("Hardware ID mismatch!");
		ret = -EINVAL;
		goto out;
	}

	/* Check application firmware version (first byte) */
	cmd = CCS811_REG_FW_APP_VERSION;
	if (i2c_write_read(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
			   &cmd, sizeof(cmd),
			   &fw_ver, sizeof(fw_ver)) < 0) {
		LOG_ERR("Failed to read App Firmware Version register");
		ret = -EIO;
		goto out;
	}
	fw_ver = sys_be16_to_cpu(fw_ver);
	LOG_INF("App FW %04x", fw_ver);
	drv_data->app_fw_ver = fw_ver >> 8U;

	/* Configure measurement mode */
	u8_t meas_mode = CCS811_MODE_IDLE;
#ifdef CONFIG_CCS811_DRIVE_MODE_1
	meas_mode = CCS811_MODE_IAQ_1SEC;
#elif defined(CONFIG_CCS811_DRIVE_MODE_2)
	meas_mode = CCS811_MODE_IAQ_10SEC;
#elif defined(CONFIG_CCS811_DRIVE_MODE_3)
	meas_mode = CCS811_MODE_IAQ_60SEC;
#elif defined(CONFIG_CCS811_DRIVE_MODE_4)
	meas_mode = CCS811_MODE_IAQ_250MSEC;
#endif
	if (i2c_reg_write_byte(drv_data->i2c, DT_INST_0_AMS_CCS811_BASE_ADDRESS,
			       CCS811_REG_MEAS_MODE,
			       meas_mode) < 0) {
		LOG_ERR("Failed to set Measurement mode");
		ret = -EIO;
		goto out;
	}
	drv_data->mode = meas_mode;

	/* Check for error */
	status = fetch_status(drv_data->i2c);
	if (status < 0) {
		ret = -EIO;
		goto out;
	}

	if (status & CCS811_STATUS_ERROR) {
		LOG_ERR("CCS811 Error %02x during sensor configuration",
			error_from_status(status));
		ret = -EINVAL;
		goto out;
	}

#ifdef CONFIG_CCS811_TRIGGER
	ret = ccs811_init_interrupt(dev);
	LOG_DBG("CCS811 interrupt init got %d", ret);
#endif

out:
	set_wake(drv_data, false);
	return ret;
}

static struct ccs811_data ccs811_driver;

DEVICE_AND_API_INIT(ccs811, DT_INST_0_AMS_CCS811_LABEL, ccs811_init, &ccs811_driver,
		    NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,
		    &ccs811_driver_api);