summaryrefslogtreecommitdiff
path: root/drivers/iio/dac/ad5770r.c
blob: 2d7623b9b2c0ec8b88e46676a40086660c7d0cb7 (plain)
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
// SPDX-License-Identifier: GPL-2.0+
/*
 * AD5770R Digital to analog converters driver
 *
 * Copyright 2018 Analog Devices Inc.
 */

#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>

#define ADI_SPI_IF_CONFIG_A		0x00
#define ADI_SPI_IF_CONFIG_B		0x01
#define ADI_SPI_IF_DEVICE_CONFIG	0x02
#define ADI_SPI_IF_CHIP_TYPE		0x03
#define ADI_SPI_IF_PRODUCT_ID_L		0x04
#define ADI_SPI_IF_PRODUCT_ID_H		0x05
#define ADI_SPI_IF_CHIP_GRADE		0x06
#define ADI_SPI_IF_SCRACTH_PAD		0x0A
#define ADI_SPI_IF_SPI_REVISION		0x0B
#define ADI_SPI_IF_SPI_VENDOR_L		0x0C
#define ADI_SPI_IF_SPI_VENDOR_H		0x0D
#define ADI_SPI_IF_SPI_STREAM_MODE	0x0E
#define ADI_SPI_IF_CONFIG_C		0x10
#define ADI_SPI_IF_STATUS_A		0x11

/* ADI_SPI_IF_CONFIG_A */
#define ADI_SPI_IF_SW_RESET_MSK		(BIT(0) | BIT(7))
#define ADI_SPI_IF_SW_RESET_SEL(x)	((x) & ADI_SPI_IF_SW_RESET_MSK)
#define ADI_SPI_IF_ADDR_ASC_MSK		(BIT(2) | BIT(5))
#define ADI_SPI_IF_ADDR_ASC_SEL(x)	(((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)

/* ADI_SPI_IF_CONFIG_B */
#define ADI_SPI_IF_SINGLE_INS_MSK	BIT(7)
#define ADI_SPI_IF_SINGLE_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
#define ADI_SPI_IF_SHORT_INS_MSK	BIT(7)
#define ADI_SPI_IF_SHORT_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)

/* ADI_SPI_IF_CONFIG_C */
#define ADI_SPI_IF_STRICT_REG_MSK	BIT(5)
#define ADI_SPI_IF_STRICT_REG_GET(x)	FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)

/* AD5770R configuration registers */
#define AD5770R_CHANNEL_CONFIG		0x14
#define AD5770R_OUTPUT_RANGE(ch)	(0x15 + (ch))
#define AD5770R_FILTER_RESISTOR(ch)	(0x1D + (ch))
#define AD5770R_REFERENCE		0x1B
#define AD5770R_DAC_LSB(ch)		(0x26 + 2 * (ch))
#define AD5770R_DAC_MSB(ch)		(0x27 + 2 * (ch))
#define AD5770R_CH_SELECT		0x34
#define AD5770R_CH_ENABLE		0x44

/* AD5770R_CHANNEL_CONFIG */
#define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)
#define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))

/* AD5770R_OUTPUT_RANGE */
#define AD5770R_RANGE_OUTPUT_SCALING(x)		(((x) & GENMASK(5, 0)) << 2)
#define AD5770R_RANGE_MODE(x)			((x) & GENMASK(1, 0))

/* AD5770R_REFERENCE */
#define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)
#define AD5770R_REF_SEL(x)			((x) & GENMASK(1, 0))

/* AD5770R_CH_ENABLE */
#define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))

#define AD5770R_MAX_CHANNELS	6
#define AD5770R_MAX_CH_MODES	14
#define AD5770R_LOW_VREF_mV	1250
#define AD5770R_HIGH_VREF_mV	2500

enum ad5770r_ch0_modes {
	AD5770R_CH0_0_300 = 0,
	AD5770R_CH0_NEG_60_0,
	AD5770R_CH0_NEG_60_300
};

enum ad5770r_ch1_modes {
	AD5770R_CH1_0_140_LOW_HEAD = 1,
	AD5770R_CH1_0_140_LOW_NOISE,
	AD5770R_CH1_0_250
};

enum ad5770r_ch2_5_modes {
	AD5770R_CH_LOW_RANGE = 0,
	AD5770R_CH_HIGH_RANGE
};

enum ad5770r_ref_v {
	AD5770R_EXT_2_5_V = 0,
	AD5770R_INT_1_25_V_OUT_ON,
	AD5770R_EXT_1_25_V,
	AD5770R_INT_1_25_V_OUT_OFF
};

enum ad5770r_output_filter_resistor {
	AD5770R_FILTER_60_OHM = 0x0,
	AD5770R_FILTER_5_6_KOHM = 0x5,
	AD5770R_FILTER_11_2_KOHM,
	AD5770R_FILTER_22_2_KOHM,
	AD5770R_FILTER_44_4_KOHM,
	AD5770R_FILTER_104_KOHM,
};

struct ad5770r_out_range {
	u8	out_scale;
	u8	out_range_mode;
};

/**
 * struct ad5770R_state - driver instance specific data
 * @spi:		spi_device
 * @regmap:		regmap
 * @vref_reg:		fixed regulator for reference configuration
 * @gpio_reset:		gpio descriptor
 * @output_mode:	array contains channels output ranges
 * @vref:		reference value
 * @ch_pwr_down:	powerdown flags
 * @internal_ref:	internal reference flag
 * @external_res:	external 2.5k resistor flag
 * @transf_buf:		cache aligned buffer for spi read/write
 */
struct ad5770r_state {
	struct spi_device		*spi;
	struct regmap			*regmap;
	struct regulator		*vref_reg;
	struct gpio_desc		*gpio_reset;
	struct ad5770r_out_range	output_mode[AD5770R_MAX_CHANNELS];
	int				vref;
	bool				ch_pwr_down[AD5770R_MAX_CHANNELS];
	bool				internal_ref;
	bool				external_res;
	u8				transf_buf[2] ____cacheline_aligned;
};

static const struct regmap_config ad5770r_spi_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.read_flag_mask = BIT(7),
};

struct ad5770r_output_modes {
	unsigned int ch;
	u8 mode;
	int min;
	int max;
};

static struct ad5770r_output_modes ad5770r_rng_tbl[] = {
	{ 0, AD5770R_CH0_0_300, 0, 300 },
	{ 0, AD5770R_CH0_NEG_60_0, -60, 0 },
	{ 0, AD5770R_CH0_NEG_60_300, -60, 300 },
	{ 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },
	{ 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },
	{ 1, AD5770R_CH1_0_250, 0, 250 },
	{ 2, AD5770R_CH_LOW_RANGE, 0, 55 },
	{ 2, AD5770R_CH_HIGH_RANGE, 0, 150 },
	{ 3, AD5770R_CH_LOW_RANGE, 0, 45 },
	{ 3, AD5770R_CH_HIGH_RANGE, 0, 100 },
	{ 4, AD5770R_CH_LOW_RANGE, 0, 45 },
	{ 4, AD5770R_CH_HIGH_RANGE, 0, 100 },
	{ 5, AD5770R_CH_LOW_RANGE, 0, 45 },
	{ 5, AD5770R_CH_HIGH_RANGE, 0, 100 },
};

static const unsigned int ad5770r_filter_freqs[] = {
	153, 357, 715, 1400, 2800, 262000,
};

static const unsigned int ad5770r_filter_reg_vals[] = {
	AD5770R_FILTER_104_KOHM,
	AD5770R_FILTER_44_4_KOHM,
	AD5770R_FILTER_22_2_KOHM,
	AD5770R_FILTER_11_2_KOHM,
	AD5770R_FILTER_5_6_KOHM,
	AD5770R_FILTER_60_OHM
};

static int ad5770r_set_output_mode(struct ad5770r_state *st,
				   const struct ad5770r_out_range *out_mode,
				   int channel)
{
	unsigned int regval;

	regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |
		 AD5770R_RANGE_MODE(out_mode->out_range_mode);

	return regmap_write(st->regmap,
			    AD5770R_OUTPUT_RANGE(channel), regval);
}

static int ad5770r_set_reference(struct ad5770r_state *st)
{
	unsigned int regval;

	regval = AD5770R_REF_RESISTOR_SEL(st->external_res);

	if (st->internal_ref) {
		regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
	} else {
		switch (st->vref) {
		case AD5770R_LOW_VREF_mV:
			regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);
			break;
		case AD5770R_HIGH_VREF_mV:
			regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);
			break;
		default:
			regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
			break;
		}
	}

	return regmap_write(st->regmap, AD5770R_REFERENCE, regval);
}

static int ad5770r_soft_reset(struct ad5770r_state *st)
{
	return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,
			    ADI_SPI_IF_SW_RESET_SEL(1));
}

static int ad5770r_reset(struct ad5770r_state *st)
{
	/* Perform software reset if no GPIO provided */
	if (!st->gpio_reset)
		return ad5770r_soft_reset(st);

	gpiod_set_value_cansleep(st->gpio_reset, 0);
	usleep_range(10, 20);
	gpiod_set_value_cansleep(st->gpio_reset, 1);

	/* data must not be written during reset timeframe */
	usleep_range(100, 200);

	return 0;
}

static int ad5770r_get_range(struct ad5770r_state *st,
			     int ch, int *min, int *max)
{
	int i;
	u8 tbl_ch, tbl_mode, out_range;

	out_range = st->output_mode[ch].out_range_mode;

	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
		tbl_ch = ad5770r_rng_tbl[i].ch;
		tbl_mode = ad5770r_rng_tbl[i].mode;
		if (tbl_ch == ch && tbl_mode == out_range) {
			*min = ad5770r_rng_tbl[i].min;
			*max = ad5770r_rng_tbl[i].max;
			return 0;
		}
	}

	return -EINVAL;
}

static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,
				   const struct iio_chan_spec *chan, int *freq)
{
	struct ad5770r_state *st = iio_priv(indio_dev);
	int ret;
	unsigned int regval, i;

	ret = regmap_read(st->regmap,
			  AD5770R_FILTER_RESISTOR(chan->channel), &regval);
	if (ret < 0)
		return ret;

	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)
		if (regval == ad5770r_filter_reg_vals[i])
			break;
	if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))
		return -EINVAL;

	*freq = ad5770r_filter_freqs[i];

	return IIO_VAL_INT;
}

static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,
				   const struct iio_chan_spec *chan,
				   unsigned int freq)
{
	struct ad5770r_state *st = iio_priv(indio_dev);
	unsigned int regval, i;

	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)
		if (ad5770r_filter_freqs[i] >= freq)
			break;
	if (i == ARRAY_SIZE(ad5770r_filter_freqs))
		return -EINVAL;

	regval = ad5770r_filter_reg_vals[i];

	return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),
			    regval);
}

static int ad5770r_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long info)
{
	struct ad5770r_state *st = iio_priv(indio_dev);
	int max, min, ret;
	u16 buf16;

	switch (info) {
	case IIO_CHAN_INFO_RAW:
		ret = regmap_bulk_read(st->regmap,
				       chan->address,
				       st->transf_buf, 2);
		if (ret)
			return 0;

		buf16 = st->transf_buf[0] + (st->transf_buf[1] << 8);
		*val = buf16 >> 2;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		ret = ad5770r_get_range(st, chan->channel, &min, &max);
		if (ret < 0)
			return ret;
		*val = max - min;
		/* There is no sign bit. (negative current is mapped from 0)
		 * (sourced/sinked) current = raw * scale + offset
		 * where offset in case of CH0 can be negative.
		 */
		*val2 = 14;
		return IIO_VAL_FRACTIONAL_LOG2;
	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
		return ad5770r_get_filter_freq(indio_dev, chan, val);
	case IIO_CHAN_INFO_OFFSET:
		ret = ad5770r_get_range(st, chan->channel, &min, &max);
		if (ret < 0)
			return ret;
		*val = min;
		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}
}

static int ad5770r_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int val, int val2, long info)
{
	struct ad5770r_state *st = iio_priv(indio_dev);

	switch (info) {
	case IIO_CHAN_INFO_RAW:
		st->transf_buf[0] = ((u16)val >> 6);
		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
		return regmap_bulk_write(st->regmap, chan->address,
					 st->transf_buf, 2);
	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
		return ad5770r_set_filter_freq(indio_dev, chan, val);
	default:
		return -EINVAL;
	}
}

static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
				   struct iio_chan_spec const *chan,
				   const int **vals, int *type, int *length,
				   long mask)
{
	switch (mask) {
	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
		*type = IIO_VAL_INT;
		*vals = ad5770r_filter_freqs;
		*length = ARRAY_SIZE(ad5770r_filter_freqs);
		return IIO_AVAIL_LIST;
	}

	return -EINVAL;
}

static int ad5770r_reg_access(struct iio_dev *indio_dev,
			      unsigned int reg,
			      unsigned int writeval,
			      unsigned int *readval)
{
	struct ad5770r_state *st = iio_priv(indio_dev);

	if (readval)
		return regmap_read(st->regmap, reg, readval);
	else
		return regmap_write(st->regmap, reg, writeval);
}

static const struct iio_info ad5770r_info = {
	.read_raw = ad5770r_read_raw,
	.write_raw = ad5770r_write_raw,
	.read_avail = ad5770r_read_freq_avail,
	.debugfs_reg_access = &ad5770r_reg_access,
};

static int ad5770r_store_output_range(struct ad5770r_state *st,
				      int min, int max, int index)
{
	int i;

	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
		if (ad5770r_rng_tbl[i].ch != index)
			continue;
		if (ad5770r_rng_tbl[i].min != min ||
		    ad5770r_rng_tbl[i].max != max)
			continue;
		st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;

		return 0;
	}

	return -EINVAL;
}

static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,
					  uintptr_t private,
					  const struct iio_chan_spec *chan,
					  char *buf)
{
	struct ad5770r_state *st = iio_priv(indio_dev);

	return sprintf(buf, "%d\n", st->ch_pwr_down[chan->channel]);
}

static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,
					   uintptr_t private,
					   const struct iio_chan_spec *chan,
					   const char *buf, size_t len)
{
	struct ad5770r_state *st = iio_priv(indio_dev);
	unsigned int regval;
	unsigned int mask;
	bool readin;
	int ret;

	ret = kstrtobool(buf, &readin);
	if (ret)
		return ret;

	readin = !readin;

	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
	if (chan->channel == 0 &&
	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
		regval |= AD5770R_CFG_CH0_SINK_EN(readin);
		mask = BIT(chan->channel) + BIT(7);
	} else {
		mask = BIT(chan->channel);
	}
	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
				 regval);
	if (ret)
		return ret;

	regval = AD5770R_CH_SET(readin, chan->channel);
	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
				 BIT(chan->channel), regval);
	if (ret)
		return ret;

	st->ch_pwr_down[chan->channel] = !readin;

	return len;
}

static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {
	{
		.name = "powerdown",
		.read = ad5770r_read_dac_powerdown,
		.write = ad5770r_write_dac_powerdown,
		.shared = IIO_SEPARATE,
	},
	{ }
};

#define AD5770R_IDAC_CHANNEL(index, reg) {				\
	.type = IIO_CURRENT,						\
	.address = reg,							\
	.indexed = 1,							\
	.channel = index,						\
	.output = 1,							\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
		BIT(IIO_CHAN_INFO_SCALE) |				\
		BIT(IIO_CHAN_INFO_OFFSET) |				\
		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
	.info_mask_shared_by_type_available =				\
		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
	.ext_info = ad5770r_ext_info,					\
}

static const struct iio_chan_spec ad5770r_channels[] = {
	AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),
	AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),
	AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),
	AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),
	AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),
	AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),
};

static int ad5770r_channel_config(struct ad5770r_state *st)
{
	int ret, tmp[2], min, max;
	unsigned int num;
	struct fwnode_handle *child;

	num = device_get_child_node_count(&st->spi->dev);
	if (num != AD5770R_MAX_CHANNELS)
		return -EINVAL;

	device_for_each_child_node(&st->spi->dev, child) {
		ret = fwnode_property_read_u32(child, "num", &num);
		if (ret)
			return ret;
		if (num >= AD5770R_MAX_CHANNELS)
			return -EINVAL;

		ret = fwnode_property_read_u32_array(child,
						     "adi,range-microamp",
						     tmp, 2);
		if (ret)
			return ret;

		min = tmp[0] / 1000;
		max = tmp[1] / 1000;
		ret = ad5770r_store_output_range(st, min, max, num);
		if (ret)
			return ret;
	}

	return ret;
}

static int ad5770r_init(struct ad5770r_state *st)
{
	int ret, i;

	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
						 GPIOD_OUT_HIGH);
	if (IS_ERR(st->gpio_reset))
		return PTR_ERR(st->gpio_reset);

	/* Perform a reset */
	ret = ad5770r_reset(st);
	if (ret)
		return ret;

	/* Set output range */
	ret = ad5770r_channel_config(st);
	if (ret)
		return ret;

	for (i = 0; i < AD5770R_MAX_CHANNELS; i++) {
		ret = ad5770r_set_output_mode(st,  &st->output_mode[i], i);
		if (ret)
			return ret;
	}

	st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
						     "adi,external-resistor");

	ret = ad5770r_set_reference(st);
	if (ret)
		return ret;

	/* Set outputs off */
	ret = regmap_write(st->regmap, AD5770R_CHANNEL_CONFIG, 0x00);
	if (ret)
		return ret;

	ret = regmap_write(st->regmap, AD5770R_CH_ENABLE, 0x00);
	if (ret)
		return ret;

	for (i = 0; i < AD5770R_MAX_CHANNELS; i++)
		st->ch_pwr_down[i] = true;

	return ret;
}

static void ad5770r_disable_regulator(void *data)
{
	struct ad5770r_state *st = data;

	regulator_disable(st->vref_reg);
}

static int ad5770r_probe(struct spi_device *spi)
{
	struct ad5770r_state *st;
	struct iio_dev *indio_dev;
	struct regmap *regmap;
	int ret;

	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	if (!indio_dev)
		return -ENOMEM;

	st = iio_priv(indio_dev);
	spi_set_drvdata(spi, indio_dev);

	st->spi = spi;

	regmap = devm_regmap_init_spi(spi, &ad5770r_spi_regmap_config);
	if (IS_ERR(regmap)) {
		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
			PTR_ERR(regmap));
		return PTR_ERR(regmap);
	}
	st->regmap = regmap;

	st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
	if (!IS_ERR(st->vref_reg)) {
		ret = regulator_enable(st->vref_reg);
		if (ret) {
			dev_err(&spi->dev,
				"Failed to enable vref regulators: %d\n", ret);
			return ret;
		}

		ret = devm_add_action_or_reset(&spi->dev,
					       ad5770r_disable_regulator,
					       st);
		if (ret < 0)
			return ret;

		ret = regulator_get_voltage(st->vref_reg);
		if (ret < 0)
			return ret;

		st->vref = ret / 1000;
	} else {
		if (PTR_ERR(st->vref_reg) == -ENODEV) {
			st->vref = AD5770R_LOW_VREF_mV;
			st->internal_ref = true;
		} else {
			return PTR_ERR(st->vref_reg);
		}
	}

	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->info = &ad5770r_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = ad5770r_channels;
	indio_dev->num_channels = ARRAY_SIZE(ad5770r_channels);

	ret = ad5770r_init(st);
	if (ret < 0) {
		dev_err(&spi->dev, "AD5770R init failed\n");
		return ret;
	}

	return devm_iio_device_register(&st->spi->dev, indio_dev);
}

static const struct of_device_id ad5770r_of_id[] = {
	{ .compatible = "adi,ad5770r", },
	{},
};
MODULE_DEVICE_TABLE(of, ad5770r_of_id);

static const struct spi_device_id ad5770r_id[] = {
	{ "ad5770r", 0 },
	{},
};
MODULE_DEVICE_TABLE(spi, ad5770r_id);

static struct spi_driver ad5770r_driver = {
	.driver = {
		.name = KBUILD_MODNAME,
		.of_match_table = ad5770r_of_id,
	},
	.probe = ad5770r_probe,
	.id_table = ad5770r_id,
};

module_spi_driver(ad5770r_driver);

MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD5770R IDAC");
MODULE_LICENSE("GPL v2");