xref: /linux/drivers/iio/chemical/scd30_core.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Sensirion SCD30 carbon dioxide sensor core driver
4  *
5  * Copyright (c) 2020 Tomasz Duszynski <tduszyns@gmail.com>
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/bits.h>
10 #include <linux/cleanup.h>
11 #include <linux/completion.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/errno.h>
15 #include <linux/export.h>
16 #include <linux/iio/buffer.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19 #include <linux/iio/trigger.h>
20 #include <linux/iio/trigger_consumer.h>
21 #include <linux/iio/triggered_buffer.h>
22 #include <linux/iio/types.h>
23 #include <linux/interrupt.h>
24 #include <linux/irqreturn.h>
25 #include <linux/jiffies.h>
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/mutex.h>
29 #include <linux/regulator/consumer.h>
30 #include <linux/string.h>
31 #include <linux/sysfs.h>
32 #include <linux/types.h>
33 #include <asm/byteorder.h>
34 
35 #include "scd30.h"
36 
37 #define SCD30_PRESSURE_COMP_MIN_MBAR 700
38 #define SCD30_PRESSURE_COMP_MAX_MBAR 1400
39 #define SCD30_PRESSURE_COMP_DEFAULT 1013
40 #define SCD30_MEAS_INTERVAL_MIN_S 2
41 #define SCD30_MEAS_INTERVAL_MAX_S 1800
42 #define SCD30_MEAS_INTERVAL_DEFAULT SCD30_MEAS_INTERVAL_MIN_S
43 #define SCD30_FRC_MIN_PPM 400
44 #define SCD30_FRC_MAX_PPM 2000
45 #define SCD30_TEMP_OFFSET_MAX 655360
46 #define SCD30_EXTRA_TIMEOUT_PER_S 250
47 
48 /* Floating point arithmetic macros */
49 #define SCD30_FLOAT_MANTISSA_MSK GENMASK(22, 0)
50 #define SCD30_FLOAT_EXP_MSK GENMASK(30, 23)
51 #define SCD30_FLOAT_SIGN_MSK BIT(31)
52 
53 enum {
54 	SCD30_CONC,
55 	SCD30_TEMP,
56 	SCD30_HR,
57 };
58 
59 static int scd30_command_write(struct scd30_state *state, enum scd30_cmd cmd, u16 arg)
60 {
61 	return state->command(state, cmd, arg, NULL, 0);
62 }
63 
64 static int scd30_command_read(struct scd30_state *state, enum scd30_cmd cmd, u16 *val)
65 {
66 	__be16 tmp;
67 	int ret;
68 
69 	ret = state->command(state, cmd, 0, &tmp, sizeof(tmp));
70 	*val = be16_to_cpup(&tmp);
71 
72 	return ret;
73 }
74 
75 static int scd30_reset(struct scd30_state *state)
76 {
77 	int ret;
78 	u16 val;
79 
80 	ret = scd30_command_write(state, CMD_RESET, 0);
81 	if (ret)
82 		return ret;
83 
84 	/* sensor boots up within 2 secs */
85 	msleep(2000);
86 	/*
87 	 * Power-on-reset causes sensor to produce some glitch on i2c bus and
88 	 * some controllers end up in error state. Try to recover by placing
89 	 * any data on the bus.
90 	 */
91 	scd30_command_read(state, CMD_MEAS_READY, &val);
92 
93 	return 0;
94 }
95 
96 /* simplified float to fixed point conversion with a scaling factor of 0.01 */
97 static int scd30_float_to_fp(int float32)
98 {
99 	int fraction, shift, sign;
100 	int mantissa = FIELD_GET(SCD30_FLOAT_MANTISSA_MSK, float32);
101 	int exp = FIELD_GET(SCD30_FLOAT_EXP_MSK, float32);
102 
103 	if (float32 & SCD30_FLOAT_SIGN_MSK)
104 		sign = -1;
105 	else
106 		sign = 1;
107 
108 	/* special case 0 */
109 	if (!exp && !mantissa)
110 		return 0;
111 
112 	exp -= 127;
113 	if (exp < 0) {
114 		exp = -exp;
115 		/* return values ranging from 1 to 99 */
116 		return sign * ((((BIT(23) + mantissa) * 100) >> 23) >> exp);
117 	}
118 
119 	/* return values starting at 100 */
120 	shift = 23 - exp;
121 	float32 = BIT(exp) + (mantissa >> shift);
122 	fraction = mantissa & GENMASK(shift - 1, 0);
123 
124 	return sign * (float32 * 100 + ((fraction * 100) >> shift));
125 }
126 
127 static int scd30_read_meas(struct scd30_state *state)
128 {
129 	int i, ret;
130 
131 	ret = state->command(state, CMD_READ_MEAS, 0, state->meas, sizeof(state->meas));
132 	if (ret)
133 		return ret;
134 
135 	be32_to_cpu_array(state->meas, (__be32 *)state->meas, ARRAY_SIZE(state->meas));
136 
137 	for (i = 0; i < ARRAY_SIZE(state->meas); i++)
138 		state->meas[i] = scd30_float_to_fp(state->meas[i]);
139 
140 	/*
141 	 * co2 is left unprocessed while temperature and humidity are scaled
142 	 * to milli deg C and milli percent respectively.
143 	 */
144 	state->meas[SCD30_TEMP] *= 10;
145 	state->meas[SCD30_HR] *= 10;
146 
147 	return 0;
148 }
149 
150 static int scd30_wait_meas_irq(struct scd30_state *state)
151 {
152 	int ret, timeout;
153 
154 	reinit_completion(&state->meas_ready);
155 	enable_irq(state->irq);
156 	timeout = msecs_to_jiffies(state->meas_interval * (1000 + SCD30_EXTRA_TIMEOUT_PER_S));
157 	ret = wait_for_completion_interruptible_timeout(&state->meas_ready, timeout);
158 	if (ret > 0)
159 		ret = 0;
160 	else if (!ret)
161 		ret = -ETIMEDOUT;
162 
163 	disable_irq(state->irq);
164 
165 	return ret;
166 }
167 
168 static int scd30_wait_meas_poll(struct scd30_state *state)
169 {
170 	int timeout = state->meas_interval * SCD30_EXTRA_TIMEOUT_PER_S, tries = 5;
171 
172 	do {
173 		int ret;
174 		u16 val;
175 
176 		ret = scd30_command_read(state, CMD_MEAS_READY, &val);
177 		if (ret)
178 			return -EIO;
179 
180 		/* new measurement available */
181 		if (val)
182 			break;
183 
184 		msleep_interruptible(timeout);
185 	} while (--tries);
186 
187 	return tries ? 0 : -ETIMEDOUT;
188 }
189 
190 static int scd30_read_poll(struct scd30_state *state)
191 {
192 	int ret;
193 
194 	ret = scd30_wait_meas_poll(state);
195 	if (ret)
196 		return ret;
197 
198 	return scd30_read_meas(state);
199 }
200 
201 static int scd30_read(struct scd30_state *state)
202 {
203 	if (state->irq > 0)
204 		return scd30_wait_meas_irq(state);
205 
206 	return scd30_read_poll(state);
207 }
208 
209 static int scd30_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
210 			  int *val, int *val2, long mask)
211 {
212 	struct scd30_state *state = iio_priv(indio_dev);
213 	int ret;
214 	u16 tmp;
215 
216 	guard(mutex)(&state->lock);
217 	switch (mask) {
218 	case IIO_CHAN_INFO_RAW:
219 	case IIO_CHAN_INFO_PROCESSED:
220 		if (chan->output) {
221 			*val = state->pressure_comp;
222 			return IIO_VAL_INT;
223 		}
224 
225 		if (!iio_device_claim_direct(indio_dev))
226 			return -EBUSY;
227 
228 		ret = scd30_read(state);
229 		if (ret) {
230 			iio_device_release_direct(indio_dev);
231 			return ret;
232 		}
233 
234 		*val = state->meas[chan->address];
235 		iio_device_release_direct(indio_dev);
236 		return IIO_VAL_INT;
237 	case IIO_CHAN_INFO_SCALE:
238 		*val = 0;
239 		*val2 = 1;
240 		return IIO_VAL_INT_PLUS_MICRO;
241 	case IIO_CHAN_INFO_SAMP_FREQ:
242 		ret = scd30_command_read(state, CMD_MEAS_INTERVAL, &tmp);
243 		if (ret)
244 			return ret;
245 
246 		*val = 0;
247 		*val2 = 1000000000 / tmp;
248 		return IIO_VAL_INT_PLUS_NANO;
249 	case IIO_CHAN_INFO_CALIBBIAS:
250 		ret = scd30_command_read(state, CMD_TEMP_OFFSET, &tmp);
251 		if (ret)
252 			return ret;
253 
254 		*val = tmp;
255 		return IIO_VAL_INT;
256 	default:
257 		return -EINVAL;
258 	}
259 }
260 
261 static int scd30_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
262 			   int val, int val2, long mask)
263 {
264 	struct scd30_state *state = iio_priv(indio_dev);
265 	int ret;
266 
267 	guard(mutex)(&state->lock);
268 	switch (mask) {
269 	case IIO_CHAN_INFO_SAMP_FREQ:
270 		if (val || !val2)
271 			return -EINVAL;
272 
273 		val = 1000000000 / val2;
274 		if (val < SCD30_MEAS_INTERVAL_MIN_S || val > SCD30_MEAS_INTERVAL_MAX_S)
275 			return -EINVAL;
276 
277 		ret = scd30_command_write(state, CMD_MEAS_INTERVAL, val);
278 		if (ret)
279 			return ret;
280 
281 		state->meas_interval = val;
282 		return 0;
283 	case IIO_CHAN_INFO_RAW:
284 		switch (chan->type) {
285 		case IIO_PRESSURE:
286 			if (val < SCD30_PRESSURE_COMP_MIN_MBAR ||
287 			    val > SCD30_PRESSURE_COMP_MAX_MBAR)
288 				return -EINVAL;
289 
290 			ret = scd30_command_write(state, CMD_START_MEAS, val);
291 			if (ret)
292 				return ret;
293 
294 			state->pressure_comp = val;
295 			return 0;
296 		default:
297 			return -EINVAL;
298 		}
299 	case IIO_CHAN_INFO_CALIBBIAS:
300 		if (val < 0 || val > SCD30_TEMP_OFFSET_MAX)
301 			return -EINVAL;
302 		/*
303 		 * Manufacturer does not explicitly specify min/max sensible
304 		 * values hence check is omitted for simplicity.
305 		 */
306 		return scd30_command_write(state, CMD_TEMP_OFFSET / 10, val);
307 	default:
308 		return -EINVAL;
309 	}
310 }
311 
312 static int scd30_write_raw_get_fmt(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
313 				   long mask)
314 {
315 	switch (mask) {
316 	case IIO_CHAN_INFO_SAMP_FREQ:
317 		return IIO_VAL_INT_PLUS_NANO;
318 	case IIO_CHAN_INFO_RAW:
319 	case IIO_CHAN_INFO_CALIBBIAS:
320 		return IIO_VAL_INT;
321 	}
322 
323 	return -EINVAL;
324 }
325 
326 static const int scd30_pressure_raw_available[] = {
327 	SCD30_PRESSURE_COMP_MIN_MBAR, 1, SCD30_PRESSURE_COMP_MAX_MBAR,
328 };
329 
330 static const int scd30_temp_calibbias_available[] = {
331 	0, 10, SCD30_TEMP_OFFSET_MAX,
332 };
333 
334 static int scd30_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
335 			    const int **vals, int *type, int *length, long mask)
336 {
337 	switch (mask) {
338 	case IIO_CHAN_INFO_RAW:
339 		*vals = scd30_pressure_raw_available;
340 		*type = IIO_VAL_INT;
341 
342 		return IIO_AVAIL_RANGE;
343 	case IIO_CHAN_INFO_CALIBBIAS:
344 		*vals = scd30_temp_calibbias_available;
345 		*type = IIO_VAL_INT;
346 
347 		return IIO_AVAIL_RANGE;
348 	}
349 
350 	return -EINVAL;
351 }
352 
353 static ssize_t sampling_frequency_available_show(struct device *dev, struct device_attribute *attr,
354 						 char *buf)
355 {
356 	int i = SCD30_MEAS_INTERVAL_MIN_S;
357 	ssize_t len = 0;
358 
359 	do {
360 		len += sysfs_emit_at(buf, len, "0.%09u ", 1000000000 / i);
361 		/*
362 		 * Not all values fit PAGE_SIZE buffer hence print every 6th
363 		 * (each frequency differs by 6s in time domain from the
364 		 * adjacent). Unlisted but valid ones are still accepted.
365 		 */
366 		i += 6;
367 	} while (i <= SCD30_MEAS_INTERVAL_MAX_S);
368 
369 	buf[len - 1] = '\n';
370 
371 	return len;
372 }
373 
374 static ssize_t calibration_auto_enable_show(struct device *dev, struct device_attribute *attr,
375 					    char *buf)
376 {
377 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
378 	struct scd30_state *state = iio_priv(indio_dev);
379 	int ret;
380 	u16 val;
381 
382 	guard(mutex)(&state->lock);
383 
384 	ret = scd30_command_read(state, CMD_ASC, &val);
385 	if (ret)
386 		return ret;
387 
388 	return sysfs_emit(buf, "%d\n", val);
389 }
390 
391 static ssize_t calibration_auto_enable_store(struct device *dev, struct device_attribute *attr,
392 					     const char *buf, size_t len)
393 {
394 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
395 	struct scd30_state *state = iio_priv(indio_dev);
396 	bool val;
397 	int ret;
398 
399 	ret = kstrtobool(buf, &val);
400 	if (ret)
401 		return ret;
402 
403 	guard(mutex)(&state->lock);
404 
405 	ret = scd30_command_write(state, CMD_ASC, val);
406 	if (ret)
407 		return ret;
408 
409 	return len;
410 }
411 
412 static ssize_t calibration_forced_value_show(struct device *dev, struct device_attribute *attr,
413 					     char *buf)
414 {
415 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
416 	struct scd30_state *state = iio_priv(indio_dev);
417 	int ret;
418 	u16 val;
419 
420 	guard(mutex)(&state->lock);
421 
422 	ret = scd30_command_read(state, CMD_FRC, &val);
423 	if (ret)
424 		return ret;
425 
426 	return sysfs_emit(buf, "%d\n", val);
427 }
428 
429 static ssize_t calibration_forced_value_store(struct device *dev, struct device_attribute *attr,
430 					      const char *buf, size_t len)
431 {
432 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
433 	struct scd30_state *state = iio_priv(indio_dev);
434 	int ret;
435 	u16 val;
436 
437 	ret = kstrtou16(buf, 0, &val);
438 	if (ret)
439 		return ret;
440 
441 	if (val < SCD30_FRC_MIN_PPM || val > SCD30_FRC_MAX_PPM)
442 		return -EINVAL;
443 
444 	guard(mutex)(&state->lock);
445 
446 	ret = scd30_command_write(state, CMD_FRC, val);
447 	if (ret)
448 		return ret;
449 
450 	return len;
451 }
452 
453 static IIO_DEVICE_ATTR_RO(sampling_frequency_available, 0);
454 static IIO_DEVICE_ATTR_RW(calibration_auto_enable, 0);
455 static IIO_DEVICE_ATTR_RW(calibration_forced_value, 0);
456 
457 static struct attribute *scd30_attrs[] = {
458 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
459 	&iio_dev_attr_calibration_auto_enable.dev_attr.attr,
460 	&iio_dev_attr_calibration_forced_value.dev_attr.attr,
461 	NULL
462 };
463 
464 static const struct attribute_group scd30_attr_group = {
465 	.attrs = scd30_attrs,
466 };
467 
468 static const struct iio_info scd30_info = {
469 	.attrs = &scd30_attr_group,
470 	.read_raw = scd30_read_raw,
471 	.write_raw = scd30_write_raw,
472 	.write_raw_get_fmt = scd30_write_raw_get_fmt,
473 	.read_avail = scd30_read_avail,
474 };
475 
476 #define SCD30_CHAN_SCAN_TYPE(_sign, _realbits) .scan_type = { \
477 	.sign = _sign, \
478 	.realbits = _realbits, \
479 	.storagebits = 32, \
480 	.endianness = IIO_CPU, \
481 }
482 
483 static const struct iio_chan_spec scd30_channels[] = {
484 	{
485 		/*
486 		 * this channel is special in a sense we are pretending that
487 		 * sensor is able to change measurement chamber pressure but in
488 		 * fact we're just setting pressure compensation value
489 		 */
490 		.type = IIO_PRESSURE,
491 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
492 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
493 		.output = 1,
494 		.scan_index = -1,
495 	},
496 	{
497 		.type = IIO_CONCENTRATION,
498 		.channel2 = IIO_MOD_CO2,
499 		.address = SCD30_CONC,
500 		.scan_index = SCD30_CONC,
501 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
502 				      BIT(IIO_CHAN_INFO_SCALE),
503 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
504 		.modified = 1,
505 
506 		SCD30_CHAN_SCAN_TYPE('u', 20),
507 	},
508 	{
509 		.type = IIO_TEMP,
510 		.address = SCD30_TEMP,
511 		.scan_index = SCD30_TEMP,
512 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
513 				      BIT(IIO_CHAN_INFO_CALIBBIAS),
514 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS),
515 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
516 
517 		SCD30_CHAN_SCAN_TYPE('s', 18),
518 	},
519 	{
520 		.type = IIO_HUMIDITYRELATIVE,
521 		.address = SCD30_HR,
522 		.scan_index = SCD30_HR,
523 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
524 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
525 
526 		SCD30_CHAN_SCAN_TYPE('u', 17),
527 	},
528 	IIO_CHAN_SOFT_TIMESTAMP(3),
529 };
530 
531 static int scd30_suspend(struct device *dev)
532 {
533 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
534 	struct scd30_state *state  = iio_priv(indio_dev);
535 	int ret;
536 
537 	ret = scd30_command_write(state, CMD_STOP_MEAS, 0);
538 	if (ret)
539 		return ret;
540 
541 	return regulator_disable(state->vdd);
542 }
543 
544 static int scd30_resume(struct device *dev)
545 {
546 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
547 	struct scd30_state *state = iio_priv(indio_dev);
548 	int ret;
549 
550 	ret = regulator_enable(state->vdd);
551 	if (ret)
552 		return ret;
553 
554 	return scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
555 }
556 
557 EXPORT_NS_SIMPLE_DEV_PM_OPS(scd30_pm_ops, scd30_suspend, scd30_resume, IIO_SCD30);
558 
559 static void scd30_stop_meas(void *data)
560 {
561 	struct scd30_state *state = data;
562 
563 	scd30_command_write(state, CMD_STOP_MEAS, 0);
564 }
565 
566 static void scd30_disable_regulator(void *data)
567 {
568 	struct scd30_state *state = data;
569 
570 	regulator_disable(state->vdd);
571 }
572 
573 static irqreturn_t scd30_irq_handler(int irq, void *priv)
574 {
575 	struct iio_dev *indio_dev = priv;
576 
577 	if (iio_buffer_enabled(indio_dev)) {
578 		iio_trigger_poll(indio_dev->trig);
579 
580 		return IRQ_HANDLED;
581 	}
582 
583 	return IRQ_WAKE_THREAD;
584 }
585 
586 static irqreturn_t scd30_irq_thread_handler(int irq, void *priv)
587 {
588 	struct iio_dev *indio_dev = priv;
589 	struct scd30_state *state = iio_priv(indio_dev);
590 	int ret;
591 
592 	ret = scd30_read_meas(state);
593 	if (ret)
594 		goto out;
595 
596 	complete_all(&state->meas_ready);
597 out:
598 	return IRQ_HANDLED;
599 }
600 
601 static int scd30_trigger_handler_helper(struct iio_dev *indio_dev, int *scan_data,
602 					size_t scan_data_size)
603 {
604 	struct scd30_state *state = iio_priv(indio_dev);
605 	int ret;
606 
607 	guard(mutex)(&state->lock);
608 
609 	if (!iio_trigger_using_own(indio_dev))
610 		ret = scd30_read_poll(state);
611 	else
612 		ret = scd30_read_meas(state);
613 	memcpy(scan_data, state->meas, scan_data_size);
614 
615 	return ret;
616 }
617 
618 static irqreturn_t scd30_trigger_handler(int irq, void *p)
619 {
620 	struct iio_poll_func *pf = p;
621 	struct iio_dev *indio_dev = pf->indio_dev;
622 	struct {
623 		int data[SCD30_MEAS_COUNT];
624 		aligned_s64 ts;
625 	} scan = { };
626 	int ret;
627 
628 	ret = scd30_trigger_handler_helper(indio_dev, scan.data, sizeof(scan.data));
629 	if (ret)
630 		goto out;
631 
632 	iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
633 				    iio_get_time_ns(indio_dev));
634 out:
635 	iio_trigger_notify_done(indio_dev->trig);
636 	return IRQ_HANDLED;
637 }
638 
639 static int scd30_set_trigger_state(struct iio_trigger *trig, bool state)
640 {
641 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
642 	struct scd30_state *st = iio_priv(indio_dev);
643 
644 	if (state)
645 		enable_irq(st->irq);
646 	else
647 		disable_irq(st->irq);
648 
649 	return 0;
650 }
651 
652 static const struct iio_trigger_ops scd30_trigger_ops = {
653 	.set_trigger_state = scd30_set_trigger_state,
654 	.validate_device = iio_trigger_validate_own_device,
655 };
656 
657 static int scd30_setup_trigger(struct iio_dev *indio_dev)
658 {
659 	struct scd30_state *state = iio_priv(indio_dev);
660 	struct device *dev = indio_dev->dev.parent;
661 	struct iio_trigger *trig;
662 	int ret;
663 
664 	trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
665 				      iio_device_id(indio_dev));
666 	if (!trig)
667 		return -ENOMEM;
668 
669 	trig->ops = &scd30_trigger_ops;
670 	iio_trigger_set_drvdata(trig, indio_dev);
671 
672 	ret = devm_iio_trigger_register(dev, trig);
673 	if (ret)
674 		return ret;
675 
676 	indio_dev->trig = iio_trigger_get(trig);
677 
678 	/*
679 	 * Interrupt is enabled just before taking a fresh measurement
680 	 * and disabled afterwards. This means we need to ensure it is not
681 	 * enabled here to keep calls to enable/disable balanced.
682 	 */
683 	ret = devm_request_threaded_irq(dev, state->irq, scd30_irq_handler,
684 					scd30_irq_thread_handler,
685 					IRQF_TRIGGER_HIGH | IRQF_ONESHOT |
686 					IRQF_NO_AUTOEN,
687 					indio_dev->name, indio_dev);
688 	if (ret)
689 		return ret;
690 
691 	return 0;
692 }
693 
694 int scd30_probe(struct device *dev, int irq, const char *name, void *priv,
695 		scd30_command_t command)
696 {
697 	static const unsigned long scd30_scan_masks[] = { 0x07, 0x00 };
698 	struct scd30_state *state;
699 	struct iio_dev *indio_dev;
700 	int ret;
701 	u16 val;
702 
703 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
704 	if (!indio_dev)
705 		return -ENOMEM;
706 
707 	state = iio_priv(indio_dev);
708 	state->dev = dev;
709 	state->priv = priv;
710 	state->irq = irq;
711 	state->pressure_comp = SCD30_PRESSURE_COMP_DEFAULT;
712 	state->meas_interval = SCD30_MEAS_INTERVAL_DEFAULT;
713 	state->command = command;
714 
715 	ret = devm_mutex_init(dev, &state->lock);
716 	if (ret)
717 		return ret;
718 
719 	init_completion(&state->meas_ready);
720 
721 	dev_set_drvdata(dev, indio_dev);
722 
723 	indio_dev->info = &scd30_info;
724 	indio_dev->name = name;
725 	indio_dev->channels = scd30_channels;
726 	indio_dev->num_channels = ARRAY_SIZE(scd30_channels);
727 	indio_dev->modes = INDIO_DIRECT_MODE;
728 	indio_dev->available_scan_masks = scd30_scan_masks;
729 
730 	state->vdd = devm_regulator_get(dev, "vdd");
731 	if (IS_ERR(state->vdd))
732 		return dev_err_probe(dev, PTR_ERR(state->vdd), "failed to get regulator\n");
733 
734 	ret = regulator_enable(state->vdd);
735 	if (ret)
736 		return ret;
737 
738 	ret = devm_add_action_or_reset(dev, scd30_disable_regulator, state);
739 	if (ret)
740 		return ret;
741 
742 	ret = scd30_reset(state);
743 	if (ret)
744 		return dev_err_probe(dev, ret, "failed to reset device\n");
745 
746 	if (state->irq > 0) {
747 		ret = scd30_setup_trigger(indio_dev);
748 		if (ret)
749 			return dev_err_probe(dev, ret, "failed to setup trigger\n");
750 	}
751 
752 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, scd30_trigger_handler, NULL);
753 	if (ret)
754 		return ret;
755 
756 	ret = scd30_command_read(state, CMD_FW_VERSION, &val);
757 	if (ret)
758 		return dev_err_probe(dev, ret, "failed to read firmware version\n");
759 	dev_info(dev, "firmware version: %d.%d\n", val >> 8, (char)val);
760 
761 	ret = scd30_command_write(state, CMD_MEAS_INTERVAL, state->meas_interval);
762 	if (ret)
763 		return dev_err_probe(dev, ret, "failed to set measurement interval\n");
764 
765 	ret = scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
766 	if (ret)
767 		return dev_err_probe(dev, ret, "failed to start measurement\n");
768 
769 	ret = devm_add_action_or_reset(dev, scd30_stop_meas, state);
770 	if (ret)
771 		return ret;
772 
773 	return devm_iio_device_register(dev, indio_dev);
774 }
775 EXPORT_SYMBOL_NS(scd30_probe, "IIO_SCD30");
776 
777 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
778 MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor core driver");
779 MODULE_LICENSE("GPL v2");
780