xref: /openbmc/linux/drivers/iio/dac/ad5770r.c (revision 877013bc)
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 
21 #define ADI_SPI_IF_CONFIG_A		0x00
22 #define ADI_SPI_IF_CONFIG_B		0x01
23 #define ADI_SPI_IF_DEVICE_CONFIG	0x02
24 #define ADI_SPI_IF_CHIP_TYPE		0x03
25 #define ADI_SPI_IF_PRODUCT_ID_L		0x04
26 #define ADI_SPI_IF_PRODUCT_ID_H		0x05
27 #define ADI_SPI_IF_CHIP_GRADE		0x06
28 #define ADI_SPI_IF_SCRACTH_PAD		0x0A
29 #define ADI_SPI_IF_SPI_REVISION		0x0B
30 #define ADI_SPI_IF_SPI_VENDOR_L		0x0C
31 #define ADI_SPI_IF_SPI_VENDOR_H		0x0D
32 #define ADI_SPI_IF_SPI_STREAM_MODE	0x0E
33 #define ADI_SPI_IF_CONFIG_C		0x10
34 #define ADI_SPI_IF_STATUS_A		0x11
35 
36 /* ADI_SPI_IF_CONFIG_A */
37 #define ADI_SPI_IF_SW_RESET_MSK		(BIT(0) | BIT(7))
38 #define ADI_SPI_IF_SW_RESET_SEL(x)	((x) & ADI_SPI_IF_SW_RESET_MSK)
39 #define ADI_SPI_IF_ADDR_ASC_MSK		(BIT(2) | BIT(5))
40 #define ADI_SPI_IF_ADDR_ASC_SEL(x)	(((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)
41 
42 /* ADI_SPI_IF_CONFIG_B */
43 #define ADI_SPI_IF_SINGLE_INS_MSK	BIT(7)
44 #define ADI_SPI_IF_SINGLE_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
45 #define ADI_SPI_IF_SHORT_INS_MSK	BIT(7)
46 #define ADI_SPI_IF_SHORT_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
47 
48 /* ADI_SPI_IF_CONFIG_C */
49 #define ADI_SPI_IF_STRICT_REG_MSK	BIT(5)
50 #define ADI_SPI_IF_STRICT_REG_GET(x)	FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)
51 
52 /* AD5770R configuration registers */
53 #define AD5770R_CHANNEL_CONFIG		0x14
54 #define AD5770R_OUTPUT_RANGE(ch)	(0x15 + (ch))
55 #define AD5770R_FILTER_RESISTOR(ch)	(0x1D + (ch))
56 #define AD5770R_REFERENCE		0x1B
57 #define AD5770R_DAC_LSB(ch)		(0x26 + 2 * (ch))
58 #define AD5770R_DAC_MSB(ch)		(0x27 + 2 * (ch))
59 #define AD5770R_CH_SELECT		0x34
60 #define AD5770R_CH_ENABLE		0x44
61 
62 /* AD5770R_CHANNEL_CONFIG */
63 #define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)
64 #define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))
65 
66 /* AD5770R_OUTPUT_RANGE */
67 #define AD5770R_RANGE_OUTPUT_SCALING(x)		(((x) & GENMASK(5, 0)) << 2)
68 #define AD5770R_RANGE_MODE(x)			((x) & GENMASK(1, 0))
69 
70 /* AD5770R_REFERENCE */
71 #define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)
72 #define AD5770R_REF_SEL(x)			((x) & GENMASK(1, 0))
73 
74 /* AD5770R_CH_ENABLE */
75 #define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))
76 
77 #define AD5770R_MAX_CHANNELS	6
78 #define AD5770R_MAX_CH_MODES	14
79 #define AD5770R_LOW_VREF_mV	1250
80 #define AD5770R_HIGH_VREF_mV	2500
81 
82 enum ad5770r_ch0_modes {
83 	AD5770R_CH0_0_300 = 0,
84 	AD5770R_CH0_NEG_60_0,
85 	AD5770R_CH0_NEG_60_300
86 };
87 
88 enum ad5770r_ch1_modes {
89 	AD5770R_CH1_0_140_LOW_HEAD = 1,
90 	AD5770R_CH1_0_140_LOW_NOISE,
91 	AD5770R_CH1_0_250
92 };
93 
94 enum ad5770r_ch2_5_modes {
95 	AD5770R_CH_LOW_RANGE = 0,
96 	AD5770R_CH_HIGH_RANGE
97 };
98 
99 enum ad5770r_ref_v {
100 	AD5770R_EXT_2_5_V = 0,
101 	AD5770R_INT_1_25_V_OUT_ON,
102 	AD5770R_EXT_1_25_V,
103 	AD5770R_INT_1_25_V_OUT_OFF
104 };
105 
106 enum ad5770r_output_filter_resistor {
107 	AD5770R_FILTER_60_OHM = 0x0,
108 	AD5770R_FILTER_5_6_KOHM = 0x5,
109 	AD5770R_FILTER_11_2_KOHM,
110 	AD5770R_FILTER_22_2_KOHM,
111 	AD5770R_FILTER_44_4_KOHM,
112 	AD5770R_FILTER_104_KOHM,
113 };
114 
115 struct ad5770r_out_range {
116 	u8	out_scale;
117 	u8	out_range_mode;
118 };
119 
120 /**
121  * struct ad5770r_state - driver instance specific data
122  * @spi:		spi_device
123  * @regmap:		regmap
124  * @vref_reg:		fixed regulator for reference configuration
125  * @gpio_reset:		gpio descriptor
126  * @output_mode:	array contains channels output ranges
127  * @vref:		reference value
128  * @ch_pwr_down:	powerdown flags
129  * @internal_ref:	internal reference flag
130  * @external_res:	external 2.5k resistor flag
131  * @transf_buf:		cache aligned buffer for spi read/write
132  */
133 struct ad5770r_state {
134 	struct spi_device		*spi;
135 	struct regmap			*regmap;
136 	struct regulator		*vref_reg;
137 	struct gpio_desc		*gpio_reset;
138 	struct ad5770r_out_range	output_mode[AD5770R_MAX_CHANNELS];
139 	int				vref;
140 	bool				ch_pwr_down[AD5770R_MAX_CHANNELS];
141 	bool				internal_ref;
142 	bool				external_res;
143 	u8				transf_buf[2] ____cacheline_aligned;
144 };
145 
146 static const struct regmap_config ad5770r_spi_regmap_config = {
147 	.reg_bits = 8,
148 	.val_bits = 8,
149 	.read_flag_mask = BIT(7),
150 };
151 
152 struct ad5770r_output_modes {
153 	unsigned int ch;
154 	u8 mode;
155 	int min;
156 	int max;
157 };
158 
159 static struct ad5770r_output_modes ad5770r_rng_tbl[] = {
160 	{ 0, AD5770R_CH0_0_300, 0, 300 },
161 	{ 0, AD5770R_CH0_NEG_60_0, -60, 0 },
162 	{ 0, AD5770R_CH0_NEG_60_300, -60, 300 },
163 	{ 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },
164 	{ 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },
165 	{ 1, AD5770R_CH1_0_250, 0, 250 },
166 	{ 2, AD5770R_CH_LOW_RANGE, 0, 55 },
167 	{ 2, AD5770R_CH_HIGH_RANGE, 0, 150 },
168 	{ 3, AD5770R_CH_LOW_RANGE, 0, 45 },
169 	{ 3, AD5770R_CH_HIGH_RANGE, 0, 100 },
170 	{ 4, AD5770R_CH_LOW_RANGE, 0, 45 },
171 	{ 4, AD5770R_CH_HIGH_RANGE, 0, 100 },
172 	{ 5, AD5770R_CH_LOW_RANGE, 0, 45 },
173 	{ 5, AD5770R_CH_HIGH_RANGE, 0, 100 },
174 };
175 
176 static const unsigned int ad5770r_filter_freqs[] = {
177 	153, 357, 715, 1400, 2800, 262000,
178 };
179 
180 static const unsigned int ad5770r_filter_reg_vals[] = {
181 	AD5770R_FILTER_104_KOHM,
182 	AD5770R_FILTER_44_4_KOHM,
183 	AD5770R_FILTER_22_2_KOHM,
184 	AD5770R_FILTER_11_2_KOHM,
185 	AD5770R_FILTER_5_6_KOHM,
186 	AD5770R_FILTER_60_OHM
187 };
188 
189 static int ad5770r_set_output_mode(struct ad5770r_state *st,
190 				   const struct ad5770r_out_range *out_mode,
191 				   int channel)
192 {
193 	unsigned int regval;
194 
195 	regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |
196 		 AD5770R_RANGE_MODE(out_mode->out_range_mode);
197 
198 	return regmap_write(st->regmap,
199 			    AD5770R_OUTPUT_RANGE(channel), regval);
200 }
201 
202 static int ad5770r_set_reference(struct ad5770r_state *st)
203 {
204 	unsigned int regval;
205 
206 	regval = AD5770R_REF_RESISTOR_SEL(st->external_res);
207 
208 	if (st->internal_ref) {
209 		regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
210 	} else {
211 		switch (st->vref) {
212 		case AD5770R_LOW_VREF_mV:
213 			regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);
214 			break;
215 		case AD5770R_HIGH_VREF_mV:
216 			regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);
217 			break;
218 		default:
219 			regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
220 			break;
221 		}
222 	}
223 
224 	return regmap_write(st->regmap, AD5770R_REFERENCE, regval);
225 }
226 
227 static int ad5770r_soft_reset(struct ad5770r_state *st)
228 {
229 	return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,
230 			    ADI_SPI_IF_SW_RESET_SEL(1));
231 }
232 
233 static int ad5770r_reset(struct ad5770r_state *st)
234 {
235 	/* Perform software reset if no GPIO provided */
236 	if (!st->gpio_reset)
237 		return ad5770r_soft_reset(st);
238 
239 	gpiod_set_value_cansleep(st->gpio_reset, 0);
240 	usleep_range(10, 20);
241 	gpiod_set_value_cansleep(st->gpio_reset, 1);
242 
243 	/* data must not be written during reset timeframe */
244 	usleep_range(100, 200);
245 
246 	return 0;
247 }
248 
249 static int ad5770r_get_range(struct ad5770r_state *st,
250 			     int ch, int *min, int *max)
251 {
252 	int i;
253 	u8 tbl_ch, tbl_mode, out_range;
254 
255 	out_range = st->output_mode[ch].out_range_mode;
256 
257 	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
258 		tbl_ch = ad5770r_rng_tbl[i].ch;
259 		tbl_mode = ad5770r_rng_tbl[i].mode;
260 		if (tbl_ch == ch && tbl_mode == out_range) {
261 			*min = ad5770r_rng_tbl[i].min;
262 			*max = ad5770r_rng_tbl[i].max;
263 			return 0;
264 		}
265 	}
266 
267 	return -EINVAL;
268 }
269 
270 static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,
271 				   const struct iio_chan_spec *chan, int *freq)
272 {
273 	struct ad5770r_state *st = iio_priv(indio_dev);
274 	int ret;
275 	unsigned int regval, i;
276 
277 	ret = regmap_read(st->regmap,
278 			  AD5770R_FILTER_RESISTOR(chan->channel), &regval);
279 	if (ret < 0)
280 		return ret;
281 
282 	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)
283 		if (regval == ad5770r_filter_reg_vals[i])
284 			break;
285 	if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))
286 		return -EINVAL;
287 
288 	*freq = ad5770r_filter_freqs[i];
289 
290 	return IIO_VAL_INT;
291 }
292 
293 static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,
294 				   const struct iio_chan_spec *chan,
295 				   unsigned int freq)
296 {
297 	struct ad5770r_state *st = iio_priv(indio_dev);
298 	unsigned int regval, i;
299 
300 	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)
301 		if (ad5770r_filter_freqs[i] >= freq)
302 			break;
303 	if (i == ARRAY_SIZE(ad5770r_filter_freqs))
304 		return -EINVAL;
305 
306 	regval = ad5770r_filter_reg_vals[i];
307 
308 	return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),
309 			    regval);
310 }
311 
312 static int ad5770r_read_raw(struct iio_dev *indio_dev,
313 			    struct iio_chan_spec const *chan,
314 			    int *val, int *val2, long info)
315 {
316 	struct ad5770r_state *st = iio_priv(indio_dev);
317 	int max, min, ret;
318 	u16 buf16;
319 
320 	switch (info) {
321 	case IIO_CHAN_INFO_RAW:
322 		ret = regmap_bulk_read(st->regmap,
323 				       chan->address,
324 				       st->transf_buf, 2);
325 		if (ret)
326 			return 0;
327 
328 		buf16 = st->transf_buf[0] + (st->transf_buf[1] << 8);
329 		*val = buf16 >> 2;
330 		return IIO_VAL_INT;
331 	case IIO_CHAN_INFO_SCALE:
332 		ret = ad5770r_get_range(st, chan->channel, &min, &max);
333 		if (ret < 0)
334 			return ret;
335 		*val = max - min;
336 		/* There is no sign bit. (negative current is mapped from 0)
337 		 * (sourced/sinked) current = raw * scale + offset
338 		 * where offset in case of CH0 can be negative.
339 		 */
340 		*val2 = 14;
341 		return IIO_VAL_FRACTIONAL_LOG2;
342 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
343 		return ad5770r_get_filter_freq(indio_dev, chan, val);
344 	case IIO_CHAN_INFO_OFFSET:
345 		ret = ad5770r_get_range(st, chan->channel, &min, &max);
346 		if (ret < 0)
347 			return ret;
348 		*val = min;
349 		return IIO_VAL_INT;
350 	default:
351 		return -EINVAL;
352 	}
353 }
354 
355 static int ad5770r_write_raw(struct iio_dev *indio_dev,
356 			     struct iio_chan_spec const *chan,
357 			     int val, int val2, long info)
358 {
359 	struct ad5770r_state *st = iio_priv(indio_dev);
360 
361 	switch (info) {
362 	case IIO_CHAN_INFO_RAW:
363 		st->transf_buf[0] = ((u16)val >> 6);
364 		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
365 		return regmap_bulk_write(st->regmap, chan->address,
366 					 st->transf_buf, 2);
367 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
368 		return ad5770r_set_filter_freq(indio_dev, chan, val);
369 	default:
370 		return -EINVAL;
371 	}
372 }
373 
374 static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
375 				   struct iio_chan_spec const *chan,
376 				   const int **vals, int *type, int *length,
377 				   long mask)
378 {
379 	switch (mask) {
380 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
381 		*type = IIO_VAL_INT;
382 		*vals = ad5770r_filter_freqs;
383 		*length = ARRAY_SIZE(ad5770r_filter_freqs);
384 		return IIO_AVAIL_LIST;
385 	}
386 
387 	return -EINVAL;
388 }
389 
390 static int ad5770r_reg_access(struct iio_dev *indio_dev,
391 			      unsigned int reg,
392 			      unsigned int writeval,
393 			      unsigned int *readval)
394 {
395 	struct ad5770r_state *st = iio_priv(indio_dev);
396 
397 	if (readval)
398 		return regmap_read(st->regmap, reg, readval);
399 	else
400 		return regmap_write(st->regmap, reg, writeval);
401 }
402 
403 static const struct iio_info ad5770r_info = {
404 	.read_raw = ad5770r_read_raw,
405 	.write_raw = ad5770r_write_raw,
406 	.read_avail = ad5770r_read_freq_avail,
407 	.debugfs_reg_access = &ad5770r_reg_access,
408 };
409 
410 static int ad5770r_store_output_range(struct ad5770r_state *st,
411 				      int min, int max, int index)
412 {
413 	int i;
414 
415 	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
416 		if (ad5770r_rng_tbl[i].ch != index)
417 			continue;
418 		if (ad5770r_rng_tbl[i].min != min ||
419 		    ad5770r_rng_tbl[i].max != max)
420 			continue;
421 		st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;
422 
423 		return 0;
424 	}
425 
426 	return -EINVAL;
427 }
428 
429 static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,
430 					  uintptr_t private,
431 					  const struct iio_chan_spec *chan,
432 					  char *buf)
433 {
434 	struct ad5770r_state *st = iio_priv(indio_dev);
435 
436 	return sysfs_emit(buf, "%d\n", st->ch_pwr_down[chan->channel]);
437 }
438 
439 static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,
440 					   uintptr_t private,
441 					   const struct iio_chan_spec *chan,
442 					   const char *buf, size_t len)
443 {
444 	struct ad5770r_state *st = iio_priv(indio_dev);
445 	unsigned int regval;
446 	unsigned int mask;
447 	bool readin;
448 	int ret;
449 
450 	ret = kstrtobool(buf, &readin);
451 	if (ret)
452 		return ret;
453 
454 	readin = !readin;
455 
456 	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
457 	if (chan->channel == 0 &&
458 	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
459 		regval |= AD5770R_CFG_CH0_SINK_EN(readin);
460 		mask = BIT(chan->channel) + BIT(7);
461 	} else {
462 		mask = BIT(chan->channel);
463 	}
464 	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
465 				 regval);
466 	if (ret)
467 		return ret;
468 
469 	regval = AD5770R_CH_SET(readin, chan->channel);
470 	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
471 				 BIT(chan->channel), regval);
472 	if (ret)
473 		return ret;
474 
475 	st->ch_pwr_down[chan->channel] = !readin;
476 
477 	return len;
478 }
479 
480 static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {
481 	{
482 		.name = "powerdown",
483 		.read = ad5770r_read_dac_powerdown,
484 		.write = ad5770r_write_dac_powerdown,
485 		.shared = IIO_SEPARATE,
486 	},
487 	{ }
488 };
489 
490 #define AD5770R_IDAC_CHANNEL(index, reg) {				\
491 	.type = IIO_CURRENT,						\
492 	.address = reg,							\
493 	.indexed = 1,							\
494 	.channel = index,						\
495 	.output = 1,							\
496 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
497 		BIT(IIO_CHAN_INFO_SCALE) |				\
498 		BIT(IIO_CHAN_INFO_OFFSET) |				\
499 		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
500 	.info_mask_shared_by_type_available =				\
501 		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
502 	.ext_info = ad5770r_ext_info,					\
503 }
504 
505 static const struct iio_chan_spec ad5770r_channels[] = {
506 	AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),
507 	AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),
508 	AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),
509 	AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),
510 	AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),
511 	AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),
512 };
513 
514 static int ad5770r_channel_config(struct ad5770r_state *st)
515 {
516 	int ret, tmp[2], min, max;
517 	unsigned int num;
518 	struct fwnode_handle *child;
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(&st->spi->dev, child) {
525 		ret = fwnode_property_read_u32(child, "num", &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 ret;
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