xref: /linux/drivers/iio/dac/ad5770r.c (revision d723c456ef5ad60d368e62791004fd152c4380aa)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * AD5770R Digital to analog converters driver
4  *
5  * Copyright 2018 Analog Devices Inc.
6  */
7 
8 #include <linux/bits.h>
9 #include <linux/delay.h>
10 #include <linux/device.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/iio/iio.h>
13 #include <linux/iio/sysfs.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/property.h>
17 #include <linux/regmap.h>
18 #include <linux/regulator/consumer.h>
19 #include <linux/spi/spi.h>
20 #include <linux/unaligned.h>
21 
22 #define ADI_SPI_IF_CONFIG_A		0x00
23 #define ADI_SPI_IF_CONFIG_B		0x01
24 #define ADI_SPI_IF_DEVICE_CONFIG	0x02
25 #define ADI_SPI_IF_CHIP_TYPE		0x03
26 #define ADI_SPI_IF_PRODUCT_ID_L		0x04
27 #define ADI_SPI_IF_PRODUCT_ID_H		0x05
28 #define ADI_SPI_IF_CHIP_GRADE		0x06
29 #define ADI_SPI_IF_SCRACTH_PAD		0x0A
30 #define ADI_SPI_IF_SPI_REVISION		0x0B
31 #define ADI_SPI_IF_SPI_VENDOR_L		0x0C
32 #define ADI_SPI_IF_SPI_VENDOR_H		0x0D
33 #define ADI_SPI_IF_SPI_STREAM_MODE	0x0E
34 #define ADI_SPI_IF_CONFIG_C		0x10
35 #define ADI_SPI_IF_STATUS_A		0x11
36 
37 /* ADI_SPI_IF_CONFIG_A */
38 #define ADI_SPI_IF_SW_RESET_MSK		(BIT(0) | BIT(7))
39 #define ADI_SPI_IF_SW_RESET_SEL(x)	((x) & ADI_SPI_IF_SW_RESET_MSK)
40 #define ADI_SPI_IF_ADDR_ASC_MSK		(BIT(2) | BIT(5))
41 #define ADI_SPI_IF_ADDR_ASC_SEL(x)	(((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)
42 
43 /* ADI_SPI_IF_CONFIG_B */
44 #define ADI_SPI_IF_SINGLE_INS_MSK	BIT(7)
45 #define ADI_SPI_IF_SINGLE_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
46 #define ADI_SPI_IF_SHORT_INS_MSK	BIT(7)
47 #define ADI_SPI_IF_SHORT_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
48 
49 /* ADI_SPI_IF_CONFIG_C */
50 #define ADI_SPI_IF_STRICT_REG_MSK	BIT(5)
51 #define ADI_SPI_IF_STRICT_REG_GET(x)	FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)
52 
53 /* AD5770R configuration registers */
54 #define AD5770R_CHANNEL_CONFIG		0x14
55 #define AD5770R_OUTPUT_RANGE(ch)	(0x15 + (ch))
56 #define AD5770R_FILTER_RESISTOR(ch)	(0x1D + (ch))
57 #define AD5770R_REFERENCE		0x1B
58 #define AD5770R_DAC_LSB(ch)		(0x26 + 2 * (ch))
59 #define AD5770R_DAC_MSB(ch)		(0x27 + 2 * (ch))
60 #define AD5770R_CH_SELECT		0x34
61 #define AD5770R_CH_ENABLE		0x44
62 
63 /* AD5770R_CHANNEL_CONFIG */
64 #define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)
65 #define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))
66 
67 /* AD5770R_OUTPUT_RANGE */
68 #define AD5770R_RANGE_OUTPUT_SCALING(x)		(((x) & GENMASK(5, 0)) << 2)
69 #define AD5770R_RANGE_MODE(x)			((x) & GENMASK(1, 0))
70 
71 /* AD5770R_REFERENCE */
72 #define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)
73 #define AD5770R_REF_SEL(x)			((x) & GENMASK(1, 0))
74 
75 /* AD5770R_CH_ENABLE */
76 #define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))
77 
78 #define AD5770R_MAX_CHANNELS	6
79 #define AD5770R_MAX_CH_MODES	14
80 #define AD5770R_LOW_VREF_mV	1250
81 #define AD5770R_HIGH_VREF_mV	2500
82 
83 enum ad5770r_ch0_modes {
84 	AD5770R_CH0_0_300 = 0,
85 	AD5770R_CH0_NEG_60_0,
86 	AD5770R_CH0_NEG_60_300
87 };
88 
89 enum ad5770r_ch1_modes {
90 	AD5770R_CH1_0_140_LOW_HEAD = 1,
91 	AD5770R_CH1_0_140_LOW_NOISE,
92 	AD5770R_CH1_0_250
93 };
94 
95 enum ad5770r_ch2_5_modes {
96 	AD5770R_CH_LOW_RANGE = 0,
97 	AD5770R_CH_HIGH_RANGE
98 };
99 
100 enum ad5770r_ref_v {
101 	AD5770R_EXT_2_5_V = 0,
102 	AD5770R_INT_1_25_V_OUT_ON,
103 	AD5770R_EXT_1_25_V,
104 	AD5770R_INT_1_25_V_OUT_OFF
105 };
106 
107 enum ad5770r_output_filter_resistor {
108 	AD5770R_FILTER_60_OHM = 0x0,
109 	AD5770R_FILTER_5_6_KOHM = 0x5,
110 	AD5770R_FILTER_11_2_KOHM,
111 	AD5770R_FILTER_22_2_KOHM,
112 	AD5770R_FILTER_44_4_KOHM,
113 	AD5770R_FILTER_104_KOHM,
114 };
115 
116 struct ad5770r_out_range {
117 	u8	out_scale;
118 	u8	out_range_mode;
119 };
120 
121 /**
122  * struct ad5770r_state - driver instance specific data
123  * @spi:		spi_device
124  * @regmap:		regmap
125  * @vref_reg:		fixed regulator for reference configuration
126  * @gpio_reset:		gpio descriptor
127  * @output_mode:	array contains channels output ranges
128  * @vref:		reference value
129  * @ch_pwr_down:	powerdown flags
130  * @internal_ref:	internal reference flag
131  * @external_res:	external 2.5k resistor flag
132  * @transf_buf:		cache aligned buffer for spi read/write
133  */
134 struct ad5770r_state {
135 	struct spi_device		*spi;
136 	struct regmap			*regmap;
137 	struct regulator		*vref_reg;
138 	struct gpio_desc		*gpio_reset;
139 	struct ad5770r_out_range	output_mode[AD5770R_MAX_CHANNELS];
140 	int				vref;
141 	bool				ch_pwr_down[AD5770R_MAX_CHANNELS];
142 	bool				internal_ref;
143 	bool				external_res;
144 	u8				transf_buf[2] __aligned(IIO_DMA_MINALIGN);
145 };
146 
147 static const struct regmap_config ad5770r_spi_regmap_config = {
148 	.reg_bits = 8,
149 	.val_bits = 8,
150 	.read_flag_mask = BIT(7),
151 };
152 
153 struct ad5770r_output_modes {
154 	unsigned int ch;
155 	u8 mode;
156 	int min;
157 	int max;
158 };
159 
160 static struct ad5770r_output_modes ad5770r_rng_tbl[] = {
161 	{ 0, AD5770R_CH0_0_300, 0, 300 },
162 	{ 0, AD5770R_CH0_NEG_60_0, -60, 0 },
163 	{ 0, AD5770R_CH0_NEG_60_300, -60, 300 },
164 	{ 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },
165 	{ 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },
166 	{ 1, AD5770R_CH1_0_250, 0, 250 },
167 	{ 2, AD5770R_CH_LOW_RANGE, 0, 55 },
168 	{ 2, AD5770R_CH_HIGH_RANGE, 0, 150 },
169 	{ 3, AD5770R_CH_LOW_RANGE, 0, 45 },
170 	{ 3, AD5770R_CH_HIGH_RANGE, 0, 100 },
171 	{ 4, AD5770R_CH_LOW_RANGE, 0, 45 },
172 	{ 4, AD5770R_CH_HIGH_RANGE, 0, 100 },
173 	{ 5, AD5770R_CH_LOW_RANGE, 0, 45 },
174 	{ 5, AD5770R_CH_HIGH_RANGE, 0, 100 },
175 };
176 
177 static const unsigned int ad5770r_filter_freqs[] = {
178 	153, 357, 715, 1400, 2800, 262000,
179 };
180 
181 static const unsigned int ad5770r_filter_reg_vals[] = {
182 	AD5770R_FILTER_104_KOHM,
183 	AD5770R_FILTER_44_4_KOHM,
184 	AD5770R_FILTER_22_2_KOHM,
185 	AD5770R_FILTER_11_2_KOHM,
186 	AD5770R_FILTER_5_6_KOHM,
187 	AD5770R_FILTER_60_OHM
188 };
189 
190 static int ad5770r_set_output_mode(struct ad5770r_state *st,
191 				   const struct ad5770r_out_range *out_mode,
192 				   int channel)
193 {
194 	unsigned int regval;
195 
196 	regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |
197 		 AD5770R_RANGE_MODE(out_mode->out_range_mode);
198 
199 	return regmap_write(st->regmap,
200 			    AD5770R_OUTPUT_RANGE(channel), regval);
201 }
202 
203 static int ad5770r_set_reference(struct ad5770r_state *st)
204 {
205 	unsigned int regval;
206 
207 	regval = AD5770R_REF_RESISTOR_SEL(st->external_res);
208 
209 	if (st->internal_ref) {
210 		regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
211 	} else {
212 		switch (st->vref) {
213 		case AD5770R_LOW_VREF_mV:
214 			regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);
215 			break;
216 		case AD5770R_HIGH_VREF_mV:
217 			regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);
218 			break;
219 		default:
220 			regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
221 			break;
222 		}
223 	}
224 
225 	return regmap_write(st->regmap, AD5770R_REFERENCE, regval);
226 }
227 
228 static int ad5770r_soft_reset(struct ad5770r_state *st)
229 {
230 	return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,
231 			    ADI_SPI_IF_SW_RESET_SEL(1));
232 }
233 
234 static int ad5770r_reset(struct ad5770r_state *st)
235 {
236 	/* Perform software reset if no GPIO provided */
237 	if (!st->gpio_reset)
238 		return ad5770r_soft_reset(st);
239 
240 	gpiod_set_value_cansleep(st->gpio_reset, 0);
241 	usleep_range(10, 20);
242 	gpiod_set_value_cansleep(st->gpio_reset, 1);
243 
244 	/* data must not be written during reset timeframe */
245 	usleep_range(100, 200);
246 
247 	return 0;
248 }
249 
250 static int ad5770r_get_range(struct ad5770r_state *st,
251 			     int ch, int *min, int *max)
252 {
253 	int i;
254 	u8 tbl_ch, tbl_mode, out_range;
255 
256 	out_range = st->output_mode[ch].out_range_mode;
257 
258 	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
259 		tbl_ch = ad5770r_rng_tbl[i].ch;
260 		tbl_mode = ad5770r_rng_tbl[i].mode;
261 		if (tbl_ch == ch && tbl_mode == out_range) {
262 			*min = ad5770r_rng_tbl[i].min;
263 			*max = ad5770r_rng_tbl[i].max;
264 			return 0;
265 		}
266 	}
267 
268 	return -EINVAL;
269 }
270 
271 static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,
272 				   const struct iio_chan_spec *chan, int *freq)
273 {
274 	struct ad5770r_state *st = iio_priv(indio_dev);
275 	int ret;
276 	unsigned int regval, i;
277 
278 	ret = regmap_read(st->regmap,
279 			  AD5770R_FILTER_RESISTOR(chan->channel), &regval);
280 	if (ret < 0)
281 		return ret;
282 
283 	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)
284 		if (regval == ad5770r_filter_reg_vals[i])
285 			break;
286 	if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))
287 		return -EINVAL;
288 
289 	*freq = ad5770r_filter_freqs[i];
290 
291 	return IIO_VAL_INT;
292 }
293 
294 static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,
295 				   const struct iio_chan_spec *chan,
296 				   unsigned int freq)
297 {
298 	struct ad5770r_state *st = iio_priv(indio_dev);
299 	unsigned int regval, i;
300 
301 	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)
302 		if (ad5770r_filter_freqs[i] >= freq)
303 			break;
304 	if (i == ARRAY_SIZE(ad5770r_filter_freqs))
305 		return -EINVAL;
306 
307 	regval = ad5770r_filter_reg_vals[i];
308 
309 	return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),
310 			    regval);
311 }
312 
313 static int ad5770r_read_raw(struct iio_dev *indio_dev,
314 			    struct iio_chan_spec const *chan,
315 			    int *val, int *val2, long info)
316 {
317 	struct ad5770r_state *st = iio_priv(indio_dev);
318 	int max, min, ret;
319 	u16 buf16;
320 
321 	switch (info) {
322 	case IIO_CHAN_INFO_RAW:
323 		ret = regmap_bulk_read(st->regmap,
324 				       chan->address,
325 				       st->transf_buf, 2);
326 		if (ret)
327 			return 0;
328 
329 		buf16 = get_unaligned_le16(st->transf_buf);
330 		*val = buf16 >> 2;
331 		return IIO_VAL_INT;
332 	case IIO_CHAN_INFO_SCALE:
333 		ret = ad5770r_get_range(st, chan->channel, &min, &max);
334 		if (ret < 0)
335 			return ret;
336 		*val = max - min;
337 		/* There is no sign bit. (negative current is mapped from 0)
338 		 * (sourced/sinked) current = raw * scale + offset
339 		 * where offset in case of CH0 can be negative.
340 		 */
341 		*val2 = 14;
342 		return IIO_VAL_FRACTIONAL_LOG2;
343 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
344 		return ad5770r_get_filter_freq(indio_dev, chan, val);
345 	case IIO_CHAN_INFO_OFFSET:
346 		ret = ad5770r_get_range(st, chan->channel, &min, &max);
347 		if (ret < 0)
348 			return ret;
349 		*val = min;
350 		return IIO_VAL_INT;
351 	default:
352 		return -EINVAL;
353 	}
354 }
355 
356 static int ad5770r_write_raw(struct iio_dev *indio_dev,
357 			     struct iio_chan_spec const *chan,
358 			     int val, int val2, long info)
359 {
360 	struct ad5770r_state *st = iio_priv(indio_dev);
361 
362 	switch (info) {
363 	case IIO_CHAN_INFO_RAW:
364 		st->transf_buf[0] = ((u16)val >> 6);
365 		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
366 		return regmap_bulk_write(st->regmap, chan->address,
367 					 st->transf_buf, 2);
368 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
369 		return ad5770r_set_filter_freq(indio_dev, chan, val);
370 	default:
371 		return -EINVAL;
372 	}
373 }
374 
375 static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
376 				   struct iio_chan_spec const *chan,
377 				   const int **vals, int *type, int *length,
378 				   long mask)
379 {
380 	switch (mask) {
381 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
382 		*type = IIO_VAL_INT;
383 		*vals = ad5770r_filter_freqs;
384 		*length = ARRAY_SIZE(ad5770r_filter_freqs);
385 		return IIO_AVAIL_LIST;
386 	}
387 
388 	return -EINVAL;
389 }
390 
391 static int ad5770r_reg_access(struct iio_dev *indio_dev,
392 			      unsigned int reg,
393 			      unsigned int writeval,
394 			      unsigned int *readval)
395 {
396 	struct ad5770r_state *st = iio_priv(indio_dev);
397 
398 	if (readval)
399 		return regmap_read(st->regmap, reg, readval);
400 	else
401 		return regmap_write(st->regmap, reg, writeval);
402 }
403 
404 static const struct iio_info ad5770r_info = {
405 	.read_raw = ad5770r_read_raw,
406 	.write_raw = ad5770r_write_raw,
407 	.read_avail = ad5770r_read_freq_avail,
408 	.debugfs_reg_access = &ad5770r_reg_access,
409 };
410 
411 static int ad5770r_store_output_range(struct ad5770r_state *st,
412 				      int min, int max, int index)
413 {
414 	int i;
415 
416 	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
417 		if (ad5770r_rng_tbl[i].ch != index)
418 			continue;
419 		if (ad5770r_rng_tbl[i].min != min ||
420 		    ad5770r_rng_tbl[i].max != max)
421 			continue;
422 		st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;
423 
424 		return 0;
425 	}
426 
427 	return -EINVAL;
428 }
429 
430 static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,
431 					  uintptr_t private,
432 					  const struct iio_chan_spec *chan,
433 					  char *buf)
434 {
435 	struct ad5770r_state *st = iio_priv(indio_dev);
436 
437 	return sysfs_emit(buf, "%d\n", st->ch_pwr_down[chan->channel]);
438 }
439 
440 static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,
441 					   uintptr_t private,
442 					   const struct iio_chan_spec *chan,
443 					   const char *buf, size_t len)
444 {
445 	struct ad5770r_state *st = iio_priv(indio_dev);
446 	unsigned int regval;
447 	unsigned int mask;
448 	bool readin;
449 	int ret;
450 
451 	ret = kstrtobool(buf, &readin);
452 	if (ret)
453 		return ret;
454 
455 	readin = !readin;
456 
457 	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
458 	if (chan->channel == 0 &&
459 	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
460 		regval |= AD5770R_CFG_CH0_SINK_EN(readin);
461 		mask = BIT(chan->channel) + BIT(7);
462 	} else {
463 		mask = BIT(chan->channel);
464 	}
465 	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
466 				 regval);
467 	if (ret)
468 		return ret;
469 
470 	regval = AD5770R_CH_SET(readin, chan->channel);
471 	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
472 				 BIT(chan->channel), regval);
473 	if (ret)
474 		return ret;
475 
476 	st->ch_pwr_down[chan->channel] = !readin;
477 
478 	return len;
479 }
480 
481 static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {
482 	{
483 		.name = "powerdown",
484 		.read = ad5770r_read_dac_powerdown,
485 		.write = ad5770r_write_dac_powerdown,
486 		.shared = IIO_SEPARATE,
487 	},
488 	{ }
489 };
490 
491 #define AD5770R_IDAC_CHANNEL(index, reg) {				\
492 	.type = IIO_CURRENT,						\
493 	.address = reg,							\
494 	.indexed = 1,							\
495 	.channel = index,						\
496 	.output = 1,							\
497 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
498 		BIT(IIO_CHAN_INFO_SCALE) |				\
499 		BIT(IIO_CHAN_INFO_OFFSET) |				\
500 		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
501 	.info_mask_shared_by_type_available =				\
502 		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
503 	.ext_info = ad5770r_ext_info,					\
504 }
505 
506 static const struct iio_chan_spec ad5770r_channels[] = {
507 	AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),
508 	AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),
509 	AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),
510 	AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),
511 	AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),
512 	AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),
513 };
514 
515 static int ad5770r_channel_config(struct ad5770r_state *st)
516 {
517 	int ret, tmp[2], min, max;
518 	unsigned int num;
519 
520 	num = device_get_child_node_count(&st->spi->dev);
521 	if (num != AD5770R_MAX_CHANNELS)
522 		return -EINVAL;
523 
524 	device_for_each_child_node_scoped(&st->spi->dev, child) {
525 		ret = fwnode_property_read_u32(child, "reg", &num);
526 		if (ret)
527 			return ret;
528 		if (num >= AD5770R_MAX_CHANNELS)
529 			return -EINVAL;
530 
531 		ret = fwnode_property_read_u32_array(child,
532 						     "adi,range-microamp",
533 						     tmp, 2);
534 		if (ret)
535 			return ret;
536 
537 		min = tmp[0] / 1000;
538 		max = tmp[1] / 1000;
539 		ret = ad5770r_store_output_range(st, min, max, num);
540 		if (ret)
541 			return ret;
542 	}
543 
544 	return 0;
545 }
546 
547 static int ad5770r_init(struct ad5770r_state *st)
548 {
549 	int ret, i;
550 
551 	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
552 						 GPIOD_OUT_HIGH);
553 	if (IS_ERR(st->gpio_reset))
554 		return PTR_ERR(st->gpio_reset);
555 
556 	/* Perform a reset */
557 	ret = ad5770r_reset(st);
558 	if (ret)
559 		return ret;
560 
561 	/* Set output range */
562 	ret = ad5770r_channel_config(st);
563 	if (ret)
564 		return ret;
565 
566 	for (i = 0; i < AD5770R_MAX_CHANNELS; i++) {
567 		ret = ad5770r_set_output_mode(st,  &st->output_mode[i], i);
568 		if (ret)
569 			return ret;
570 	}
571 
572 	st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
573 						     "adi,external-resistor");
574 
575 	ret = ad5770r_set_reference(st);
576 	if (ret)
577 		return ret;
578 
579 	/* Set outputs off */
580 	ret = regmap_write(st->regmap, AD5770R_CHANNEL_CONFIG, 0x00);
581 	if (ret)
582 		return ret;
583 
584 	ret = regmap_write(st->regmap, AD5770R_CH_ENABLE, 0x00);
585 	if (ret)
586 		return ret;
587 
588 	for (i = 0; i < AD5770R_MAX_CHANNELS; i++)
589 		st->ch_pwr_down[i] = true;
590 
591 	return ret;
592 }
593 
594 static void ad5770r_disable_regulator(void *data)
595 {
596 	struct ad5770r_state *st = data;
597 
598 	regulator_disable(st->vref_reg);
599 }
600 
601 static int ad5770r_probe(struct spi_device *spi)
602 {
603 	struct ad5770r_state *st;
604 	struct iio_dev *indio_dev;
605 	struct regmap *regmap;
606 	int ret;
607 
608 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
609 	if (!indio_dev)
610 		return -ENOMEM;
611 
612 	st = iio_priv(indio_dev);
613 	spi_set_drvdata(spi, indio_dev);
614 
615 	st->spi = spi;
616 
617 	regmap = devm_regmap_init_spi(spi, &ad5770r_spi_regmap_config);
618 	if (IS_ERR(regmap)) {
619 		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
620 			PTR_ERR(regmap));
621 		return PTR_ERR(regmap);
622 	}
623 	st->regmap = regmap;
624 
625 	st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
626 	if (!IS_ERR(st->vref_reg)) {
627 		ret = regulator_enable(st->vref_reg);
628 		if (ret) {
629 			dev_err(&spi->dev,
630 				"Failed to enable vref regulators: %d\n", ret);
631 			return ret;
632 		}
633 
634 		ret = devm_add_action_or_reset(&spi->dev,
635 					       ad5770r_disable_regulator,
636 					       st);
637 		if (ret < 0)
638 			return ret;
639 
640 		ret = regulator_get_voltage(st->vref_reg);
641 		if (ret < 0)
642 			return ret;
643 
644 		st->vref = ret / 1000;
645 	} else {
646 		if (PTR_ERR(st->vref_reg) == -ENODEV) {
647 			st->vref = AD5770R_LOW_VREF_mV;
648 			st->internal_ref = true;
649 		} else {
650 			return PTR_ERR(st->vref_reg);
651 		}
652 	}
653 
654 	indio_dev->name = spi_get_device_id(spi)->name;
655 	indio_dev->info = &ad5770r_info;
656 	indio_dev->modes = INDIO_DIRECT_MODE;
657 	indio_dev->channels = ad5770r_channels;
658 	indio_dev->num_channels = ARRAY_SIZE(ad5770r_channels);
659 
660 	ret = ad5770r_init(st);
661 	if (ret < 0) {
662 		dev_err(&spi->dev, "AD5770R init failed\n");
663 		return ret;
664 	}
665 
666 	return devm_iio_device_register(&st->spi->dev, indio_dev);
667 }
668 
669 static const struct of_device_id ad5770r_of_id[] = {
670 	{ .compatible = "adi,ad5770r", },
671 	{},
672 };
673 MODULE_DEVICE_TABLE(of, ad5770r_of_id);
674 
675 static const struct spi_device_id ad5770r_id[] = {
676 	{ "ad5770r", 0 },
677 	{},
678 };
679 MODULE_DEVICE_TABLE(spi, ad5770r_id);
680 
681 static struct spi_driver ad5770r_driver = {
682 	.driver = {
683 		.name = KBUILD_MODNAME,
684 		.of_match_table = ad5770r_of_id,
685 	},
686 	.probe = ad5770r_probe,
687 	.id_table = ad5770r_id,
688 };
689 
690 module_spi_driver(ad5770r_driver);
691 
692 MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
693 MODULE_DESCRIPTION("Analog Devices AD5770R IDAC");
694 MODULE_LICENSE("GPL v2");
695