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
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
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Support for AMS AS73211 JENCOLOR(R) Digital XYZ Sensor
 *
 * Author: Christian Eggers <ceggers@arri.de>
 *
 * Copyright (c) 2020 ARRI Lighting
 *
 * Color light sensor with 16-bit channels for x, y, z and temperature);
 * 7-bit I2C slave address 0x74 .. 0x77.
 *
 * Datasheet: https://ams.com/documents/20143/36005/AS73211_DS000556_3-01.pdf
 */

#include <linux/bitfield.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/units.h>

#define AS73211_DRV_NAME "as73211"

/* AS73211 configuration registers */
#define AS73211_REG_OSR    0x0
#define AS73211_REG_AGEN   0x2
#define AS73211_REG_CREG1  0x6
#define AS73211_REG_CREG2  0x7
#define AS73211_REG_CREG3  0x8

/* AS73211 output register bank */
#define AS73211_OUT_OSR_STATUS    0
#define AS73211_OUT_TEMP          1
#define AS73211_OUT_MRES1         2
#define AS73211_OUT_MRES2         3
#define AS73211_OUT_MRES3         4

#define AS73211_OSR_SS            BIT(7)
#define AS73211_OSR_PD            BIT(6)
#define AS73211_OSR_SW_RES        BIT(3)
#define AS73211_OSR_DOS_MASK      GENMASK(2, 0)
#define AS73211_OSR_DOS_CONFIG    FIELD_PREP(AS73211_OSR_DOS_MASK, 0x2)
#define AS73211_OSR_DOS_MEASURE   FIELD_PREP(AS73211_OSR_DOS_MASK, 0x3)

#define AS73211_AGEN_DEVID_MASK   GENMASK(7, 4)
#define AS73211_AGEN_DEVID(x)     FIELD_PREP(AS73211_AGEN_DEVID_MASK, (x))
#define AS73211_AGEN_MUT_MASK     GENMASK(3, 0)
#define AS73211_AGEN_MUT(x)       FIELD_PREP(AS73211_AGEN_MUT_MASK, (x))

#define AS73211_CREG1_GAIN_MASK   GENMASK(7, 4)
#define AS73211_CREG1_GAIN_1      11
#define AS73211_CREG1_TIME_MASK   GENMASK(3, 0)

#define AS73211_CREG3_CCLK_MASK   GENMASK(1, 0)

#define AS73211_OSR_STATUS_OUTCONVOF  BIT(15)
#define AS73211_OSR_STATUS_MRESOF     BIT(14)
#define AS73211_OSR_STATUS_ADCOF      BIT(13)
#define AS73211_OSR_STATUS_LDATA      BIT(12)
#define AS73211_OSR_STATUS_NDATA      BIT(11)
#define AS73211_OSR_STATUS_NOTREADY   BIT(10)

#define AS73211_SAMPLE_FREQ_BASE      1024000

#define AS73211_SAMPLE_TIME_NUM       15
#define AS73211_SAMPLE_TIME_MAX_MS    BIT(AS73211_SAMPLE_TIME_NUM - 1)

/* Available sample frequencies are 1.024MHz multiplied by powers of two. */
static const int as73211_samp_freq_avail[] = {
	AS73211_SAMPLE_FREQ_BASE * 1,
	AS73211_SAMPLE_FREQ_BASE * 2,
	AS73211_SAMPLE_FREQ_BASE * 4,
	AS73211_SAMPLE_FREQ_BASE * 8,
};

static const int as73211_hardwaregain_avail[] = {
	1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048,
};

/**
 * struct as73211_data - Instance data for one AS73211
 * @client: I2C client.
 * @osr:    Cached Operational State Register.
 * @creg1:  Cached Configuration Register 1.
 * @creg2:  Cached Configuration Register 2.
 * @creg3:  Cached Configuration Register 3.
 * @mutex:  Keeps cached registers in sync with the device.
 * @completion: Completion to wait for interrupt.
 * @int_time_avail: Available integration times (depend on sampling frequency).
 */
struct as73211_data {
	struct i2c_client *client;
	u8 osr;
	u8 creg1;
	u8 creg2;
	u8 creg3;
	struct mutex mutex;
	struct completion completion;
	int int_time_avail[AS73211_SAMPLE_TIME_NUM * 2];
};

#define AS73211_COLOR_CHANNEL(_color, _si, _addr) { \
	.type = IIO_INTENSITY, \
	.modified = 1, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
	.info_mask_shared_by_type = \
		BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
		BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
		BIT(IIO_CHAN_INFO_INT_TIME), \
	.info_mask_shared_by_type_available = \
		BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
		BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \
		BIT(IIO_CHAN_INFO_INT_TIME), \
	.channel2 = IIO_MOD_##_color, \
	.address = _addr, \
	.scan_index = _si, \
	.scan_type = { \
		.sign = 'u', \
		.realbits = 16, \
		.storagebits = 16, \
		.endianness = IIO_LE, \
	}, \
}

#define AS73211_OFFSET_TEMP_INT    (-66)
#define AS73211_OFFSET_TEMP_MICRO  900000
#define AS73211_SCALE_TEMP_INT     0
#define AS73211_SCALE_TEMP_MICRO   50000

#define AS73211_SCALE_X 277071108  /* nW/m^2 */
#define AS73211_SCALE_Y 298384270  /* nW/m^2 */
#define AS73211_SCALE_Z 160241927  /* nW/m^2 */

/* Channel order MUST match devices result register order */
#define AS73211_SCAN_INDEX_TEMP 0
#define AS73211_SCAN_INDEX_X    1
#define AS73211_SCAN_INDEX_Y    2
#define AS73211_SCAN_INDEX_Z    3
#define AS73211_SCAN_INDEX_TS   4

#define AS73211_SCAN_MASK_COLOR ( \
	BIT(AS73211_SCAN_INDEX_X) |   \
	BIT(AS73211_SCAN_INDEX_Y) |   \
	BIT(AS73211_SCAN_INDEX_Z))

#define AS73211_SCAN_MASK_ALL (    \
	BIT(AS73211_SCAN_INDEX_TEMP) | \
	AS73211_SCAN_MASK_COLOR)

static const struct iio_chan_spec as73211_channels[] = {
	{
		.type = IIO_TEMP,
		.info_mask_separate =
			BIT(IIO_CHAN_INFO_RAW) |
			BIT(IIO_CHAN_INFO_OFFSET) |
			BIT(IIO_CHAN_INFO_SCALE),
		.address = AS73211_OUT_TEMP,
		.scan_index = AS73211_SCAN_INDEX_TEMP,
		.scan_type = {
			.sign = 'u',
			.realbits = 16,
			.storagebits = 16,
			.endianness = IIO_LE,
		}
	},
	AS73211_COLOR_CHANNEL(X, AS73211_SCAN_INDEX_X, AS73211_OUT_MRES1),
	AS73211_COLOR_CHANNEL(Y, AS73211_SCAN_INDEX_Y, AS73211_OUT_MRES2),
	AS73211_COLOR_CHANNEL(Z, AS73211_SCAN_INDEX_Z, AS73211_OUT_MRES3),
	IIO_CHAN_SOFT_TIMESTAMP(AS73211_SCAN_INDEX_TS),
};

static unsigned int as73211_integration_time_1024cyc(struct as73211_data *data)
{
	/*
	 * Return integration time in units of 1024 clock cycles. Integration time
	 * in CREG1 is in powers of 2 (x 1024 cycles).
	 */
	return BIT(FIELD_GET(AS73211_CREG1_TIME_MASK, data->creg1));
}

static unsigned int as73211_integration_time_us(struct as73211_data *data,
						 unsigned int integration_time_1024cyc)
{
	/*
	 * f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz)
	 * t_cycl is configured in CREG1 in powers of 2 (x 1024 cycles)
	 * t_int_us = 1 / (f_samp) * t_cycl * US_PER_SEC
	 *          = 1 / (2^CREG3_CCLK * 1,024,000) * 2^CREG1_CYCLES * 1,024 * US_PER_SEC
	 *          = 2^(-CREG3_CCLK) * 2^CREG1_CYCLES * 1,000
	 * In order to get rid of negative exponents, we extend the "fraction"
	 * by 2^3 (CREG3_CCLK,max = 3)
	 * t_int_us = 2^(3-CREG3_CCLK) * 2^CREG1_CYCLES * 125
	 */
	return BIT(3 - FIELD_GET(AS73211_CREG3_CCLK_MASK, data->creg3)) *
		integration_time_1024cyc * 125;
}

static void as73211_integration_time_calc_avail(struct as73211_data *data)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(data->int_time_avail) / 2; i++) {
		unsigned int time_us = as73211_integration_time_us(data, BIT(i));

		data->int_time_avail[i * 2 + 0] = time_us / USEC_PER_SEC;
		data->int_time_avail[i * 2 + 1] = time_us % USEC_PER_SEC;
	}
}

static unsigned int as73211_gain(struct as73211_data *data)
{
	/* gain can be calculated from CREG1 as 2^(11 - CREG1_GAIN) */
	return BIT(AS73211_CREG1_GAIN_1 - FIELD_GET(AS73211_CREG1_GAIN_MASK, data->creg1));
}

/* must be called with as73211_data::mutex held. */
static int as73211_req_data(struct as73211_data *data)
{
	unsigned int time_us = as73211_integration_time_us(data,
							    as73211_integration_time_1024cyc(data));
	struct device *dev = &data->client->dev;
	union i2c_smbus_data smbus_data;
	u16 osr_status;
	int ret;

	if (data->client->irq)
		reinit_completion(&data->completion);

	/*
	 * During measurement, there should be no traffic on the i2c bus as the
	 * electrical noise would disturb the measurement process.
	 */
	i2c_lock_bus(data->client->adapter, I2C_LOCK_SEGMENT);

	data->osr &= ~AS73211_OSR_DOS_MASK;
	data->osr |= AS73211_OSR_DOS_MEASURE | AS73211_OSR_SS;

	smbus_data.byte = data->osr;
	ret = __i2c_smbus_xfer(data->client->adapter, data->client->addr,
			data->client->flags, I2C_SMBUS_WRITE,
			AS73211_REG_OSR, I2C_SMBUS_BYTE_DATA, &smbus_data);
	if (ret < 0) {
		i2c_unlock_bus(data->client->adapter, I2C_LOCK_SEGMENT);
		return ret;
	}

	/*
	 * Reset AS73211_OSR_SS (is self clearing) in order to avoid unintentional
	 * triggering of further measurements later.
	 */
	data->osr &= ~AS73211_OSR_SS;

	/*
	 * Add 33% extra margin for the timeout. fclk,min = fclk,typ - 27%.
	 */
	time_us += time_us / 3;
	if (data->client->irq) {
		ret = wait_for_completion_timeout(&data->completion, usecs_to_jiffies(time_us));
		if (!ret) {
			dev_err(dev, "timeout waiting for READY IRQ\n");
			i2c_unlock_bus(data->client->adapter, I2C_LOCK_SEGMENT);
			return -ETIMEDOUT;
		}
	} else {
		/* Wait integration time */
		usleep_range(time_us, 2 * time_us);
	}

	i2c_unlock_bus(data->client->adapter, I2C_LOCK_SEGMENT);

	ret = i2c_smbus_read_word_data(data->client, AS73211_OUT_OSR_STATUS);
	if (ret < 0)
		return ret;

	osr_status = ret;
	if (osr_status != (AS73211_OSR_DOS_MEASURE | AS73211_OSR_STATUS_NDATA)) {
		if (osr_status & AS73211_OSR_SS) {
			dev_err(dev, "%s() Measurement has not stopped\n", __func__);
			return -ETIME;
		}
		if (osr_status & AS73211_OSR_STATUS_NOTREADY) {
			dev_err(dev, "%s() Data is not ready\n", __func__);
			return -ENODATA;
		}
		if (!(osr_status & AS73211_OSR_STATUS_NDATA)) {
			dev_err(dev, "%s() No new data available\n", __func__);
			return -ENODATA;
		}
		if (osr_status & AS73211_OSR_STATUS_LDATA) {
			dev_err(dev, "%s() Result buffer overrun\n", __func__);
			return -ENOBUFS;
		}
		if (osr_status & AS73211_OSR_STATUS_ADCOF) {
			dev_err(dev, "%s() ADC overflow\n", __func__);
			return -EOVERFLOW;
		}
		if (osr_status & AS73211_OSR_STATUS_MRESOF) {
			dev_err(dev, "%s() Measurement result overflow\n", __func__);
			return -EOVERFLOW;
		}
		if (osr_status & AS73211_OSR_STATUS_OUTCONVOF) {
			dev_err(dev, "%s() Timer overflow\n", __func__);
			return -EOVERFLOW;
		}
		dev_err(dev, "%s() Unexpected status value\n", __func__);
		return -EIO;
	}

	return 0;
}

static int as73211_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
			     int *val, int *val2, long mask)
{
	struct as73211_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW: {
		int ret;

		ret = iio_device_claim_direct_mode(indio_dev);
		if (ret < 0)
			return ret;

		ret = as73211_req_data(data);
		if (ret < 0) {
			iio_device_release_direct_mode(indio_dev);
			return ret;
		}

		ret = i2c_smbus_read_word_data(data->client, chan->address);
		iio_device_release_direct_mode(indio_dev);
		if (ret < 0)
			return ret;

		*val = ret;
		return IIO_VAL_INT;
	}
	case IIO_CHAN_INFO_OFFSET:
		*val = AS73211_OFFSET_TEMP_INT;
		*val2 = AS73211_OFFSET_TEMP_MICRO;
		return IIO_VAL_INT_PLUS_MICRO;

	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_TEMP:
			*val = AS73211_SCALE_TEMP_INT;
			*val2 = AS73211_SCALE_TEMP_MICRO;
			return IIO_VAL_INT_PLUS_MICRO;

		case IIO_INTENSITY: {
			unsigned int scale;

			switch (chan->channel2) {
			case IIO_MOD_X:
				scale = AS73211_SCALE_X;
				break;
			case IIO_MOD_Y:
				scale = AS73211_SCALE_Y;
				break;
			case IIO_MOD_Z:
				scale = AS73211_SCALE_Z;
				break;
			default:
				return -EINVAL;
			}
			scale /= as73211_gain(data);
			scale /= as73211_integration_time_1024cyc(data);
			*val = scale;
			return IIO_VAL_INT;

		default:
			return -EINVAL;
		}}

	case IIO_CHAN_INFO_SAMP_FREQ:
		/* f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz) */
		*val = BIT(FIELD_GET(AS73211_CREG3_CCLK_MASK, data->creg3)) *
			AS73211_SAMPLE_FREQ_BASE;
		return IIO_VAL_INT;

	case IIO_CHAN_INFO_HARDWAREGAIN:
		*val = as73211_gain(data);
		return IIO_VAL_INT;

	case IIO_CHAN_INFO_INT_TIME: {
		unsigned int time_us;

		mutex_lock(&data->mutex);
		time_us = as73211_integration_time_us(data, as73211_integration_time_1024cyc(data));
		mutex_unlock(&data->mutex);
		*val = time_us / USEC_PER_SEC;
		*val2 = time_us % USEC_PER_SEC;
		return IIO_VAL_INT_PLUS_MICRO;

	default:
		return -EINVAL;
	}}
}

static int as73211_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
			       const int **vals, int *type, int *length, long mask)
{
	struct as73211_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		*length = ARRAY_SIZE(as73211_samp_freq_avail);
		*vals = as73211_samp_freq_avail;
		*type = IIO_VAL_INT;
		return IIO_AVAIL_LIST;

	case IIO_CHAN_INFO_HARDWAREGAIN:
		*length = ARRAY_SIZE(as73211_hardwaregain_avail);
		*vals = as73211_hardwaregain_avail;
		*type = IIO_VAL_INT;
		return IIO_AVAIL_LIST;

	case IIO_CHAN_INFO_INT_TIME:
		*length = ARRAY_SIZE(data->int_time_avail);
		*vals = data->int_time_avail;
		*type = IIO_VAL_INT_PLUS_MICRO;
		return IIO_AVAIL_LIST;

	default:
		return -EINVAL;
	}
}

static int _as73211_write_raw(struct iio_dev *indio_dev,
			       struct iio_chan_spec const *chan __always_unused,
			       int val, int val2, long mask)
{
	struct as73211_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ: {
		int reg_bits, freq_kHz = val / HZ_PER_KHZ;  /* 1024, 2048, ... */

		/* val must be 1024 * 2^x */
		if (val < 0 || (freq_kHz * HZ_PER_KHZ) != val ||
				!is_power_of_2(freq_kHz) || val2)
			return -EINVAL;

		/* f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz (=2^10)) */
		reg_bits = ilog2(freq_kHz) - 10;
		if (!FIELD_FIT(AS73211_CREG3_CCLK_MASK, reg_bits))
			return -EINVAL;

		data->creg3 &= ~AS73211_CREG3_CCLK_MASK;
		data->creg3 |= FIELD_PREP(AS73211_CREG3_CCLK_MASK, reg_bits);
		as73211_integration_time_calc_avail(data);

		ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_CREG3, data->creg3);
		if (ret < 0)
			return ret;

		return 0;
	}
	case IIO_CHAN_INFO_HARDWAREGAIN: {
		unsigned int reg_bits;

		if (val < 0 || !is_power_of_2(val) || val2)
			return -EINVAL;

		/* gain can be calculated from CREG1 as 2^(11 - CREG1_GAIN) */
		reg_bits = AS73211_CREG1_GAIN_1 - ilog2(val);
		if (!FIELD_FIT(AS73211_CREG1_GAIN_MASK, reg_bits))
			return -EINVAL;

		data->creg1 &= ~AS73211_CREG1_GAIN_MASK;
		data->creg1 |= FIELD_PREP(AS73211_CREG1_GAIN_MASK, reg_bits);

		ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_CREG1, data->creg1);
		if (ret < 0)
			return ret;

		return 0;
	}
	case IIO_CHAN_INFO_INT_TIME: {
		int val_us = val * USEC_PER_SEC + val2;
		int time_ms;
		int reg_bits;

		/* f_samp is configured in CREG3 in powers of 2 (x 1.024 MHz) */
		int f_samp_1_024mhz = BIT(FIELD_GET(AS73211_CREG3_CCLK_MASK, data->creg3));

		/*
		 * time_ms = time_us * US_PER_MS * f_samp_1_024mhz / MHZ_PER_HZ
		 *         = time_us * f_samp_1_024mhz / 1000
		 */
		time_ms = (val_us * f_samp_1_024mhz) / 1000;  /* 1 ms, 2 ms, ... (power of two) */
		if (time_ms < 0 || !is_power_of_2(time_ms) || time_ms > AS73211_SAMPLE_TIME_MAX_MS)
			return -EINVAL;

		reg_bits = ilog2(time_ms);
		if (!FIELD_FIT(AS73211_CREG1_TIME_MASK, reg_bits))
			return -EINVAL;  /* not possible due to previous tests */

		data->creg1 &= ~AS73211_CREG1_TIME_MASK;
		data->creg1 |= FIELD_PREP(AS73211_CREG1_TIME_MASK, reg_bits);

		ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_CREG1, data->creg1);
		if (ret < 0)
			return ret;

		return 0;

	default:
		return -EINVAL;
	}}
}

static int as73211_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
			      int val, int val2, long mask)
{
	struct as73211_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);

	ret = iio_device_claim_direct_mode(indio_dev);
	if (ret < 0)
		goto error_unlock;

	/* Need to switch to config mode ... */
	if ((data->osr & AS73211_OSR_DOS_MASK) != AS73211_OSR_DOS_CONFIG) {
		data->osr &= ~AS73211_OSR_DOS_MASK;
		data->osr |= AS73211_OSR_DOS_CONFIG;

		ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_OSR, data->osr);
		if (ret < 0)
			goto error_release;
	}

	ret = _as73211_write_raw(indio_dev, chan, val, val2, mask);

error_release:
	iio_device_release_direct_mode(indio_dev);
error_unlock:
	mutex_unlock(&data->mutex);
	return ret;
}

static irqreturn_t as73211_ready_handler(int irq __always_unused, void *priv)
{
	struct as73211_data *data = iio_priv(priv);

	complete(&data->completion);

	return IRQ_HANDLED;
}

static irqreturn_t as73211_trigger_handler(int irq __always_unused, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct as73211_data *data = iio_priv(indio_dev);
	struct {
		__le16 chan[4];
		s64 ts __aligned(8);
	} scan;
	int data_result, ret;

	mutex_lock(&data->mutex);

	data_result = as73211_req_data(data);
	if (data_result < 0 && data_result != -EOVERFLOW)
		goto done;  /* don't push any data for errors other than EOVERFLOW */

	if (*indio_dev->active_scan_mask == AS73211_SCAN_MASK_ALL) {
		/* Optimization for reading all (color + temperature) channels */
		u8 addr = as73211_channels[0].address;
		struct i2c_msg msgs[] = {
			{
				.addr = data->client->addr,
				.flags = 0,
				.len = 1,
				.buf = &addr,
			},
			{
				.addr = data->client->addr,
				.flags = I2C_M_RD,
				.len = sizeof(scan.chan),
				.buf = (u8 *)&scan.chan,
			},
		};

		ret = i2c_transfer(data->client->adapter, msgs, ARRAY_SIZE(msgs));
		if (ret < 0)
			goto done;
	} else {
		/* Optimization for reading only color channels */

		/* AS73211 starts reading at address 2 */
		ret = i2c_master_recv(data->client,
				(char *)&scan.chan[1], 3 * sizeof(scan.chan[1]));
		if (ret < 0)
			goto done;
	}

	if (data_result) {
		/*
		 * Saturate all channels (in case of overflows). Temperature channel
		 * is not affected by overflows.
		 */
		scan.chan[1] = cpu_to_le16(U16_MAX);
		scan.chan[2] = cpu_to_le16(U16_MAX);
		scan.chan[3] = cpu_to_le16(U16_MAX);
	}

	iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev));

done:
	mutex_unlock(&data->mutex);
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static const struct iio_info as73211_info = {
	.read_raw = as73211_read_raw,
	.read_avail = as73211_read_avail,
	.write_raw = as73211_write_raw,
};

static int as73211_power(struct iio_dev *indio_dev, bool state)
{
	struct as73211_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);

	if (state)
		data->osr &= ~AS73211_OSR_PD;
	else
		data->osr |= AS73211_OSR_PD;

	ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_OSR, data->osr);

	mutex_unlock(&data->mutex);

	if (ret < 0)
		return ret;

	return 0;
}

static void as73211_power_disable(void *data)
{
	struct iio_dev *indio_dev = data;

	as73211_power(indio_dev, false);
}

static int as73211_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct as73211_data *data;
	struct iio_dev *indio_dev;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	data->client = client;

	mutex_init(&data->mutex);
	init_completion(&data->completion);

	indio_dev->info = &as73211_info;
	indio_dev->name = AS73211_DRV_NAME;
	indio_dev->channels = as73211_channels;
	indio_dev->num_channels = ARRAY_SIZE(as73211_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_OSR);
	if (ret < 0)
		return ret;
	data->osr = ret;

	/* reset device */
	data->osr |= AS73211_OSR_SW_RES;
	ret = i2c_smbus_write_byte_data(data->client, AS73211_REG_OSR, data->osr);
	if (ret < 0)
		return ret;

	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_OSR);
	if (ret < 0)
		return ret;
	data->osr = ret;

	/*
	 * Reading AGEN is only possible after reset (AGEN is not available if
	 * device is in measurement mode).
	 */
	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_AGEN);
	if (ret < 0)
		return ret;

	/* At the time of writing this driver, only DEVID 2 and MUT 1 are known. */
	if ((ret & AS73211_AGEN_DEVID_MASK) != AS73211_AGEN_DEVID(2) ||
	    (ret & AS73211_AGEN_MUT_MASK) != AS73211_AGEN_MUT(1))
		return -ENODEV;

	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_CREG1);
	if (ret < 0)
		return ret;
	data->creg1 = ret;

	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_CREG2);
	if (ret < 0)
		return ret;
	data->creg2 = ret;

	ret = i2c_smbus_read_byte_data(data->client, AS73211_REG_CREG3);
	if (ret < 0)
		return ret;
	data->creg3 = ret;
	as73211_integration_time_calc_avail(data);

	ret = as73211_power(indio_dev, true);
	if (ret < 0)
		return ret;

	ret = devm_add_action_or_reset(dev, as73211_power_disable, indio_dev);
	if (ret)
		return ret;

	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, as73211_trigger_handler, NULL);
	if (ret)
		return ret;

	if (client->irq) {
		ret = devm_request_threaded_irq(&client->dev, client->irq,
				NULL,
				as73211_ready_handler,
				IRQF_ONESHOT,
				client->name, indio_dev);
		if (ret)
			return ret;
	}

	return devm_iio_device_register(dev, indio_dev);
}

static int as73211_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));

	return as73211_power(indio_dev, false);
}

static int as73211_resume(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));

	return as73211_power(indio_dev, true);
}

static DEFINE_SIMPLE_DEV_PM_OPS(as73211_pm_ops, as73211_suspend,
				as73211_resume);

static const struct of_device_id as73211_of_match[] = {
	{ .compatible = "ams,as73211" },
	{ }
};
MODULE_DEVICE_TABLE(of, as73211_of_match);

static const struct i2c_device_id as73211_id[] = {
	{ "as73211", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, as73211_id);

static struct i2c_driver as73211_driver = {
	.driver = {
		.name           = AS73211_DRV_NAME,
		.of_match_table = as73211_of_match,
		.pm             = pm_sleep_ptr(&as73211_pm_ops),
	},
	.probe      = as73211_probe,
	.id_table   = as73211_id,
};
module_i2c_driver(as73211_driver);

MODULE_AUTHOR("Christian Eggers <ceggers@arri.de>");
MODULE_DESCRIPTION("AS73211 XYZ True Color Sensor driver");
MODULE_LICENSE("GPL");