1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Sensirion SCD30 carbon dioxide sensor core driver
4  *
5  * Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@octakon.com>
6  */
7 #include <linux/bits.h>
8 #include <linux/completion.h>
9 #include <linux/delay.h>
10 #include <linux/device.h>
11 #include <linux/errno.h>
12 #include <linux/export.h>
13 #include <linux/iio/buffer.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/sysfs.h>
16 #include <linux/iio/trigger.h>
17 #include <linux/iio/trigger_consumer.h>
18 #include <linux/iio/triggered_buffer.h>
19 #include <linux/iio/types.h>
20 #include <linux/interrupt.h>
21 #include <linux/irqreturn.h>
22 #include <linux/jiffies.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/regulator/consumer.h>
27 #include <linux/string.h>
28 #include <linux/sysfs.h>
29 #include <linux/types.h>
30 #include <asm/byteorder.h>
31 
32 #include "scd30.h"
33 
34 #define SCD30_PRESSURE_COMP_MIN_MBAR 700
35 #define SCD30_PRESSURE_COMP_MAX_MBAR 1400
36 #define SCD30_PRESSURE_COMP_DEFAULT 1013
37 #define SCD30_MEAS_INTERVAL_MIN_S 2
38 #define SCD30_MEAS_INTERVAL_MAX_S 1800
39 #define SCD30_MEAS_INTERVAL_DEFAULT SCD30_MEAS_INTERVAL_MIN_S
40 #define SCD30_FRC_MIN_PPM 400
41 #define SCD30_FRC_MAX_PPM 2000
42 #define SCD30_TEMP_OFFSET_MAX 655360
43 #define SCD30_EXTRA_TIMEOUT_PER_S 250
44 
45 enum {
46 	SCD30_CONC,
47 	SCD30_TEMP,
48 	SCD30_HR,
49 };
50 
scd30_command_write(struct scd30_state * state,enum scd30_cmd cmd,u16 arg)51 static int scd30_command_write(struct scd30_state *state, enum scd30_cmd cmd, u16 arg)
52 {
53 	return state->command(state, cmd, arg, NULL, 0);
54 }
55 
scd30_command_read(struct scd30_state * state,enum scd30_cmd cmd,u16 * val)56 static int scd30_command_read(struct scd30_state *state, enum scd30_cmd cmd, u16 *val)
57 {
58 	__be16 tmp;
59 	int ret;
60 
61 	ret = state->command(state, cmd, 0, &tmp, sizeof(tmp));
62 	*val = be16_to_cpup(&tmp);
63 
64 	return ret;
65 }
66 
scd30_reset(struct scd30_state * state)67 static int scd30_reset(struct scd30_state *state)
68 {
69 	int ret;
70 	u16 val;
71 
72 	ret = scd30_command_write(state, CMD_RESET, 0);
73 	if (ret)
74 		return ret;
75 
76 	/* sensor boots up within 2 secs */
77 	msleep(2000);
78 	/*
79 	 * Power-on-reset causes sensor to produce some glitch on i2c bus and
80 	 * some controllers end up in error state. Try to recover by placing
81 	 * any data on the bus.
82 	 */
83 	scd30_command_read(state, CMD_MEAS_READY, &val);
84 
85 	return 0;
86 }
87 
88 /* simplified float to fixed point conversion with a scaling factor of 0.01 */
scd30_float_to_fp(int float32)89 static int scd30_float_to_fp(int float32)
90 {
91 	int fraction, shift,
92 	    mantissa = float32 & GENMASK(22, 0),
93 	    sign = (float32 & BIT(31)) ? -1 : 1,
94 	    exp = (float32 & ~BIT(31)) >> 23;
95 
96 	/* special case 0 */
97 	if (!exp && !mantissa)
98 		return 0;
99 
100 	exp -= 127;
101 	if (exp < 0) {
102 		exp = -exp;
103 		/* return values ranging from 1 to 99 */
104 		return sign * ((((BIT(23) + mantissa) * 100) >> 23) >> exp);
105 	}
106 
107 	/* return values starting at 100 */
108 	shift = 23 - exp;
109 	float32 = BIT(exp) + (mantissa >> shift);
110 	fraction = mantissa & GENMASK(shift - 1, 0);
111 
112 	return sign * (float32 * 100 + ((fraction * 100) >> shift));
113 }
114 
scd30_read_meas(struct scd30_state * state)115 static int scd30_read_meas(struct scd30_state *state)
116 {
117 	int i, ret;
118 
119 	ret = state->command(state, CMD_READ_MEAS, 0, state->meas, sizeof(state->meas));
120 	if (ret)
121 		return ret;
122 
123 	be32_to_cpu_array(state->meas, (__be32 *)state->meas, ARRAY_SIZE(state->meas));
124 
125 	for (i = 0; i < ARRAY_SIZE(state->meas); i++)
126 		state->meas[i] = scd30_float_to_fp(state->meas[i]);
127 
128 	/*
129 	 * co2 is left unprocessed while temperature and humidity are scaled
130 	 * to milli deg C and milli percent respectively.
131 	 */
132 	state->meas[SCD30_TEMP] *= 10;
133 	state->meas[SCD30_HR] *= 10;
134 
135 	return 0;
136 }
137 
scd30_wait_meas_irq(struct scd30_state * state)138 static int scd30_wait_meas_irq(struct scd30_state *state)
139 {
140 	int ret, timeout;
141 
142 	reinit_completion(&state->meas_ready);
143 	enable_irq(state->irq);
144 	timeout = msecs_to_jiffies(state->meas_interval * (1000 + SCD30_EXTRA_TIMEOUT_PER_S));
145 	ret = wait_for_completion_interruptible_timeout(&state->meas_ready, timeout);
146 	if (ret > 0)
147 		ret = 0;
148 	else if (!ret)
149 		ret = -ETIMEDOUT;
150 
151 	disable_irq(state->irq);
152 
153 	return ret;
154 }
155 
scd30_wait_meas_poll(struct scd30_state * state)156 static int scd30_wait_meas_poll(struct scd30_state *state)
157 {
158 	int timeout = state->meas_interval * SCD30_EXTRA_TIMEOUT_PER_S, tries = 5;
159 
160 	do {
161 		int ret;
162 		u16 val;
163 
164 		ret = scd30_command_read(state, CMD_MEAS_READY, &val);
165 		if (ret)
166 			return -EIO;
167 
168 		/* new measurement available */
169 		if (val)
170 			break;
171 
172 		msleep_interruptible(timeout);
173 	} while (--tries);
174 
175 	return tries ? 0 : -ETIMEDOUT;
176 }
177 
scd30_read_poll(struct scd30_state * state)178 static int scd30_read_poll(struct scd30_state *state)
179 {
180 	int ret;
181 
182 	ret = scd30_wait_meas_poll(state);
183 	if (ret)
184 		return ret;
185 
186 	return scd30_read_meas(state);
187 }
188 
scd30_read(struct scd30_state * state)189 static int scd30_read(struct scd30_state *state)
190 {
191 	if (state->irq > 0)
192 		return scd30_wait_meas_irq(state);
193 
194 	return scd30_read_poll(state);
195 }
196 
scd30_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)197 static int scd30_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
198 			  int *val, int *val2, long mask)
199 {
200 	struct scd30_state *state = iio_priv(indio_dev);
201 	int ret = -EINVAL;
202 	u16 tmp;
203 
204 	mutex_lock(&state->lock);
205 	switch (mask) {
206 	case IIO_CHAN_INFO_RAW:
207 	case IIO_CHAN_INFO_PROCESSED:
208 		if (chan->output) {
209 			*val = state->pressure_comp;
210 			ret = IIO_VAL_INT;
211 			break;
212 		}
213 
214 		ret = iio_device_claim_direct_mode(indio_dev);
215 		if (ret)
216 			break;
217 
218 		ret = scd30_read(state);
219 		if (ret) {
220 			iio_device_release_direct_mode(indio_dev);
221 			break;
222 		}
223 
224 		*val = state->meas[chan->address];
225 		iio_device_release_direct_mode(indio_dev);
226 		ret = IIO_VAL_INT;
227 		break;
228 	case IIO_CHAN_INFO_SCALE:
229 		*val = 0;
230 		*val2 = 1;
231 		ret = IIO_VAL_INT_PLUS_MICRO;
232 		break;
233 	case IIO_CHAN_INFO_SAMP_FREQ:
234 		ret = scd30_command_read(state, CMD_MEAS_INTERVAL, &tmp);
235 		if (ret)
236 			break;
237 
238 		*val = 0;
239 		*val2 = 1000000000 / tmp;
240 		ret = IIO_VAL_INT_PLUS_NANO;
241 		break;
242 	case IIO_CHAN_INFO_CALIBBIAS:
243 		ret = scd30_command_read(state, CMD_TEMP_OFFSET, &tmp);
244 		if (ret)
245 			break;
246 
247 		*val = tmp;
248 		ret = IIO_VAL_INT;
249 		break;
250 	}
251 	mutex_unlock(&state->lock);
252 
253 	return ret;
254 }
255 
scd30_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)256 static int scd30_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
257 			   int val, int val2, long mask)
258 {
259 	struct scd30_state *state = iio_priv(indio_dev);
260 	int ret = -EINVAL;
261 
262 	mutex_lock(&state->lock);
263 	switch (mask) {
264 	case IIO_CHAN_INFO_SAMP_FREQ:
265 		if (val)
266 			break;
267 
268 		val = 1000000000 / val2;
269 		if (val < SCD30_MEAS_INTERVAL_MIN_S || val > SCD30_MEAS_INTERVAL_MAX_S)
270 			break;
271 
272 		ret = scd30_command_write(state, CMD_MEAS_INTERVAL, val);
273 		if (ret)
274 			break;
275 
276 		state->meas_interval = val;
277 		break;
278 	case IIO_CHAN_INFO_RAW:
279 		switch (chan->type) {
280 		case IIO_PRESSURE:
281 			if (val < SCD30_PRESSURE_COMP_MIN_MBAR ||
282 			    val > SCD30_PRESSURE_COMP_MAX_MBAR)
283 				break;
284 
285 			ret = scd30_command_write(state, CMD_START_MEAS, val);
286 			if (ret)
287 				break;
288 
289 			state->pressure_comp = val;
290 			break;
291 		default:
292 			break;
293 		}
294 		break;
295 	case IIO_CHAN_INFO_CALIBBIAS:
296 		if (val < 0 || val > SCD30_TEMP_OFFSET_MAX)
297 			break;
298 		/*
299 		 * Manufacturer does not explicitly specify min/max sensible
300 		 * values hence check is omitted for simplicity.
301 		 */
302 		ret = scd30_command_write(state, CMD_TEMP_OFFSET / 10, val);
303 	}
304 	mutex_unlock(&state->lock);
305 
306 	return ret;
307 }
308 
scd30_write_raw_get_fmt(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,long mask)309 static int scd30_write_raw_get_fmt(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
310 				   long mask)
311 {
312 	switch (mask) {
313 	case IIO_CHAN_INFO_SAMP_FREQ:
314 		return IIO_VAL_INT_PLUS_NANO;
315 	case IIO_CHAN_INFO_RAW:
316 	case IIO_CHAN_INFO_CALIBBIAS:
317 		return IIO_VAL_INT;
318 	}
319 
320 	return -EINVAL;
321 }
322 
323 static const int scd30_pressure_raw_available[] = {
324 	SCD30_PRESSURE_COMP_MIN_MBAR, 1, SCD30_PRESSURE_COMP_MAX_MBAR,
325 };
326 
327 static const int scd30_temp_calibbias_available[] = {
328 	0, 10, SCD30_TEMP_OFFSET_MAX,
329 };
330 
scd30_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)331 static int scd30_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
332 			    const int **vals, int *type, int *length, long mask)
333 {
334 	switch (mask) {
335 	case IIO_CHAN_INFO_RAW:
336 		*vals = scd30_pressure_raw_available;
337 		*type = IIO_VAL_INT;
338 
339 		return IIO_AVAIL_RANGE;
340 	case IIO_CHAN_INFO_CALIBBIAS:
341 		*vals = scd30_temp_calibbias_available;
342 		*type = IIO_VAL_INT;
343 
344 		return IIO_AVAIL_RANGE;
345 	}
346 
347 	return -EINVAL;
348 }
349 
sampling_frequency_available_show(struct device * dev,struct device_attribute * attr,char * buf)350 static ssize_t sampling_frequency_available_show(struct device *dev, struct device_attribute *attr,
351 						 char *buf)
352 {
353 	int i = SCD30_MEAS_INTERVAL_MIN_S;
354 	ssize_t len = 0;
355 
356 	do {
357 		len += sysfs_emit_at(buf, len, "0.%09u ", 1000000000 / i);
358 		/*
359 		 * Not all values fit PAGE_SIZE buffer hence print every 6th
360 		 * (each frequency differs by 6s in time domain from the
361 		 * adjacent). Unlisted but valid ones are still accepted.
362 		 */
363 		i += 6;
364 	} while (i <= SCD30_MEAS_INTERVAL_MAX_S);
365 
366 	buf[len - 1] = '\n';
367 
368 	return len;
369 }
370 
calibration_auto_enable_show(struct device * dev,struct device_attribute * attr,char * buf)371 static ssize_t calibration_auto_enable_show(struct device *dev, struct device_attribute *attr,
372 					    char *buf)
373 {
374 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
375 	struct scd30_state *state = iio_priv(indio_dev);
376 	int ret;
377 	u16 val;
378 
379 	mutex_lock(&state->lock);
380 	ret = scd30_command_read(state, CMD_ASC, &val);
381 	mutex_unlock(&state->lock);
382 
383 	return ret ?: sysfs_emit(buf, "%d\n", val);
384 }
385 
calibration_auto_enable_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)386 static ssize_t calibration_auto_enable_store(struct device *dev, struct device_attribute *attr,
387 					     const char *buf, size_t len)
388 {
389 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
390 	struct scd30_state *state = iio_priv(indio_dev);
391 	bool val;
392 	int ret;
393 
394 	ret = kstrtobool(buf, &val);
395 	if (ret)
396 		return ret;
397 
398 	mutex_lock(&state->lock);
399 	ret = scd30_command_write(state, CMD_ASC, val);
400 	mutex_unlock(&state->lock);
401 
402 	return ret ?: len;
403 }
404 
calibration_forced_value_show(struct device * dev,struct device_attribute * attr,char * buf)405 static ssize_t calibration_forced_value_show(struct device *dev, struct device_attribute *attr,
406 					     char *buf)
407 {
408 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
409 	struct scd30_state *state = iio_priv(indio_dev);
410 	int ret;
411 	u16 val;
412 
413 	mutex_lock(&state->lock);
414 	ret = scd30_command_read(state, CMD_FRC, &val);
415 	mutex_unlock(&state->lock);
416 
417 	return ret ?: sysfs_emit(buf, "%d\n", val);
418 }
419 
calibration_forced_value_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)420 static ssize_t calibration_forced_value_store(struct device *dev, struct device_attribute *attr,
421 					      const char *buf, size_t len)
422 {
423 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
424 	struct scd30_state *state = iio_priv(indio_dev);
425 	int ret;
426 	u16 val;
427 
428 	ret = kstrtou16(buf, 0, &val);
429 	if (ret)
430 		return ret;
431 
432 	if (val < SCD30_FRC_MIN_PPM || val > SCD30_FRC_MAX_PPM)
433 		return -EINVAL;
434 
435 	mutex_lock(&state->lock);
436 	ret = scd30_command_write(state, CMD_FRC, val);
437 	mutex_unlock(&state->lock);
438 
439 	return ret ?: len;
440 }
441 
442 static IIO_DEVICE_ATTR_RO(sampling_frequency_available, 0);
443 static IIO_DEVICE_ATTR_RW(calibration_auto_enable, 0);
444 static IIO_DEVICE_ATTR_RW(calibration_forced_value, 0);
445 
446 static struct attribute *scd30_attrs[] = {
447 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
448 	&iio_dev_attr_calibration_auto_enable.dev_attr.attr,
449 	&iio_dev_attr_calibration_forced_value.dev_attr.attr,
450 	NULL
451 };
452 
453 static const struct attribute_group scd30_attr_group = {
454 	.attrs = scd30_attrs,
455 };
456 
457 static const struct iio_info scd30_info = {
458 	.attrs = &scd30_attr_group,
459 	.read_raw = scd30_read_raw,
460 	.write_raw = scd30_write_raw,
461 	.write_raw_get_fmt = scd30_write_raw_get_fmt,
462 	.read_avail = scd30_read_avail,
463 };
464 
465 #define SCD30_CHAN_SCAN_TYPE(_sign, _realbits) .scan_type = { \
466 	.sign = _sign, \
467 	.realbits = _realbits, \
468 	.storagebits = 32, \
469 	.endianness = IIO_CPU, \
470 }
471 
472 static const struct iio_chan_spec scd30_channels[] = {
473 	{
474 		/*
475 		 * this channel is special in a sense we are pretending that
476 		 * sensor is able to change measurement chamber pressure but in
477 		 * fact we're just setting pressure compensation value
478 		 */
479 		.type = IIO_PRESSURE,
480 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
481 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
482 		.output = 1,
483 		.scan_index = -1,
484 	},
485 	{
486 		.type = IIO_CONCENTRATION,
487 		.channel2 = IIO_MOD_CO2,
488 		.address = SCD30_CONC,
489 		.scan_index = SCD30_CONC,
490 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
491 				      BIT(IIO_CHAN_INFO_SCALE),
492 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
493 		.modified = 1,
494 
495 		SCD30_CHAN_SCAN_TYPE('u', 20),
496 	},
497 	{
498 		.type = IIO_TEMP,
499 		.address = SCD30_TEMP,
500 		.scan_index = SCD30_TEMP,
501 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
502 				      BIT(IIO_CHAN_INFO_CALIBBIAS),
503 		.info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS),
504 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
505 
506 		SCD30_CHAN_SCAN_TYPE('s', 18),
507 	},
508 	{
509 		.type = IIO_HUMIDITYRELATIVE,
510 		.address = SCD30_HR,
511 		.scan_index = SCD30_HR,
512 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
513 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
514 
515 		SCD30_CHAN_SCAN_TYPE('u', 17),
516 	},
517 	IIO_CHAN_SOFT_TIMESTAMP(3),
518 };
519 
scd30_suspend(struct device * dev)520 static int scd30_suspend(struct device *dev)
521 {
522 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
523 	struct scd30_state *state  = iio_priv(indio_dev);
524 	int ret;
525 
526 	ret = scd30_command_write(state, CMD_STOP_MEAS, 0);
527 	if (ret)
528 		return ret;
529 
530 	return regulator_disable(state->vdd);
531 }
532 
scd30_resume(struct device * dev)533 static int scd30_resume(struct device *dev)
534 {
535 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
536 	struct scd30_state *state = iio_priv(indio_dev);
537 	int ret;
538 
539 	ret = regulator_enable(state->vdd);
540 	if (ret)
541 		return ret;
542 
543 	return scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
544 }
545 
546 EXPORT_NS_SIMPLE_DEV_PM_OPS(scd30_pm_ops, scd30_suspend, scd30_resume, IIO_SCD30);
547 
scd30_stop_meas(void * data)548 static void scd30_stop_meas(void *data)
549 {
550 	struct scd30_state *state = data;
551 
552 	scd30_command_write(state, CMD_STOP_MEAS, 0);
553 }
554 
scd30_disable_regulator(void * data)555 static void scd30_disable_regulator(void *data)
556 {
557 	struct scd30_state *state = data;
558 
559 	regulator_disable(state->vdd);
560 }
561 
scd30_irq_handler(int irq,void * priv)562 static irqreturn_t scd30_irq_handler(int irq, void *priv)
563 {
564 	struct iio_dev *indio_dev = priv;
565 
566 	if (iio_buffer_enabled(indio_dev)) {
567 		iio_trigger_poll(indio_dev->trig);
568 
569 		return IRQ_HANDLED;
570 	}
571 
572 	return IRQ_WAKE_THREAD;
573 }
574 
scd30_irq_thread_handler(int irq,void * priv)575 static irqreturn_t scd30_irq_thread_handler(int irq, void *priv)
576 {
577 	struct iio_dev *indio_dev = priv;
578 	struct scd30_state *state = iio_priv(indio_dev);
579 	int ret;
580 
581 	ret = scd30_read_meas(state);
582 	if (ret)
583 		goto out;
584 
585 	complete_all(&state->meas_ready);
586 out:
587 	return IRQ_HANDLED;
588 }
589 
scd30_trigger_handler(int irq,void * p)590 static irqreturn_t scd30_trigger_handler(int irq, void *p)
591 {
592 	struct iio_poll_func *pf = p;
593 	struct iio_dev *indio_dev = pf->indio_dev;
594 	struct scd30_state *state = iio_priv(indio_dev);
595 	struct {
596 		int data[SCD30_MEAS_COUNT];
597 		s64 ts __aligned(8);
598 	} scan;
599 	int ret;
600 
601 	mutex_lock(&state->lock);
602 	if (!iio_trigger_using_own(indio_dev))
603 		ret = scd30_read_poll(state);
604 	else
605 		ret = scd30_read_meas(state);
606 	memset(&scan, 0, sizeof(scan));
607 	memcpy(scan.data, state->meas, sizeof(state->meas));
608 	mutex_unlock(&state->lock);
609 	if (ret)
610 		goto out;
611 
612 	iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev));
613 out:
614 	iio_trigger_notify_done(indio_dev->trig);
615 	return IRQ_HANDLED;
616 }
617 
scd30_set_trigger_state(struct iio_trigger * trig,bool state)618 static int scd30_set_trigger_state(struct iio_trigger *trig, bool state)
619 {
620 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
621 	struct scd30_state *st = iio_priv(indio_dev);
622 
623 	if (state)
624 		enable_irq(st->irq);
625 	else
626 		disable_irq(st->irq);
627 
628 	return 0;
629 }
630 
631 static const struct iio_trigger_ops scd30_trigger_ops = {
632 	.set_trigger_state = scd30_set_trigger_state,
633 	.validate_device = iio_trigger_validate_own_device,
634 };
635 
scd30_setup_trigger(struct iio_dev * indio_dev)636 static int scd30_setup_trigger(struct iio_dev *indio_dev)
637 {
638 	struct scd30_state *state = iio_priv(indio_dev);
639 	struct device *dev = indio_dev->dev.parent;
640 	struct iio_trigger *trig;
641 	int ret;
642 
643 	trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
644 				      iio_device_id(indio_dev));
645 	if (!trig)
646 		return dev_err_probe(dev, -ENOMEM, "failed to allocate trigger\n");
647 
648 	trig->ops = &scd30_trigger_ops;
649 	iio_trigger_set_drvdata(trig, indio_dev);
650 
651 	ret = devm_iio_trigger_register(dev, trig);
652 	if (ret)
653 		return ret;
654 
655 	indio_dev->trig = iio_trigger_get(trig);
656 
657 	/*
658 	 * Interrupt is enabled just before taking a fresh measurement
659 	 * and disabled afterwards. This means we need to ensure it is not
660 	 * enabled here to keep calls to enable/disable balanced.
661 	 */
662 	ret = devm_request_threaded_irq(dev, state->irq, scd30_irq_handler,
663 					scd30_irq_thread_handler,
664 					IRQF_TRIGGER_HIGH | IRQF_ONESHOT |
665 					IRQF_NO_AUTOEN,
666 					indio_dev->name, indio_dev);
667 	if (ret)
668 		return dev_err_probe(dev, ret, "failed to request irq\n");
669 
670 	return 0;
671 }
672 
scd30_probe(struct device * dev,int irq,const char * name,void * priv,scd30_command_t command)673 int scd30_probe(struct device *dev, int irq, const char *name, void *priv,
674 		scd30_command_t command)
675 {
676 	static const unsigned long scd30_scan_masks[] = { 0x07, 0x00 };
677 	struct scd30_state *state;
678 	struct iio_dev *indio_dev;
679 	int ret;
680 	u16 val;
681 
682 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
683 	if (!indio_dev)
684 		return -ENOMEM;
685 
686 	state = iio_priv(indio_dev);
687 	state->dev = dev;
688 	state->priv = priv;
689 	state->irq = irq;
690 	state->pressure_comp = SCD30_PRESSURE_COMP_DEFAULT;
691 	state->meas_interval = SCD30_MEAS_INTERVAL_DEFAULT;
692 	state->command = command;
693 	mutex_init(&state->lock);
694 	init_completion(&state->meas_ready);
695 
696 	dev_set_drvdata(dev, indio_dev);
697 
698 	indio_dev->info = &scd30_info;
699 	indio_dev->name = name;
700 	indio_dev->channels = scd30_channels;
701 	indio_dev->num_channels = ARRAY_SIZE(scd30_channels);
702 	indio_dev->modes = INDIO_DIRECT_MODE;
703 	indio_dev->available_scan_masks = scd30_scan_masks;
704 
705 	state->vdd = devm_regulator_get(dev, "vdd");
706 	if (IS_ERR(state->vdd))
707 		return dev_err_probe(dev, PTR_ERR(state->vdd), "failed to get regulator\n");
708 
709 	ret = regulator_enable(state->vdd);
710 	if (ret)
711 		return ret;
712 
713 	ret = devm_add_action_or_reset(dev, scd30_disable_regulator, state);
714 	if (ret)
715 		return ret;
716 
717 	ret = scd30_reset(state);
718 	if (ret)
719 		return dev_err_probe(dev, ret, "failed to reset device\n");
720 
721 	if (state->irq > 0) {
722 		ret = scd30_setup_trigger(indio_dev);
723 		if (ret)
724 			return dev_err_probe(dev, ret, "failed to setup trigger\n");
725 	}
726 
727 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, scd30_trigger_handler, NULL);
728 	if (ret)
729 		return ret;
730 
731 	ret = scd30_command_read(state, CMD_FW_VERSION, &val);
732 	if (ret)
733 		return dev_err_probe(dev, ret, "failed to read firmware version\n");
734 	dev_info(dev, "firmware version: %d.%d\n", val >> 8, (char)val);
735 
736 	ret = scd30_command_write(state, CMD_MEAS_INTERVAL, state->meas_interval);
737 	if (ret)
738 		return dev_err_probe(dev, ret, "failed to set measurement interval\n");
739 
740 	ret = scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
741 	if (ret)
742 		return dev_err_probe(dev, ret, "failed to start measurement\n");
743 
744 	ret = devm_add_action_or_reset(dev, scd30_stop_meas, state);
745 	if (ret)
746 		return ret;
747 
748 	return devm_iio_device_register(dev, indio_dev);
749 }
750 EXPORT_SYMBOL_NS(scd30_probe, IIO_SCD30);
751 
752 MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>");
753 MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor core driver");
754 MODULE_LICENSE("GPL v2");
755