xref: /linux/drivers/iio/adc/ad7124.c (revision f8e17c17b81070f38062dce79ca7f4541851dadd)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * AD7124 SPI ADC driver
4  *
5  * Copyright 2018 Analog Devices Inc.
6  */
7 #include <linux/bitfield.h>
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/spi/spi.h>
17 
18 #include <linux/iio/iio.h>
19 #include <linux/iio/adc/ad_sigma_delta.h>
20 #include <linux/iio/sysfs.h>
21 
22 /* AD7124 registers */
23 #define AD7124_COMMS			0x00
24 #define AD7124_STATUS			0x00
25 #define AD7124_ADC_CONTROL		0x01
26 #define AD7124_DATA			0x02
27 #define AD7124_IO_CONTROL_1		0x03
28 #define AD7124_IO_CONTROL_2		0x04
29 #define AD7124_ID			0x05
30 #define AD7124_ERROR			0x06
31 #define AD7124_ERROR_EN		0x07
32 #define AD7124_MCLK_COUNT		0x08
33 #define AD7124_CHANNEL(x)		(0x09 + (x))
34 #define AD7124_CONFIG(x)		(0x19 + (x))
35 #define AD7124_FILTER(x)		(0x21 + (x))
36 #define AD7124_OFFSET(x)		(0x29 + (x))
37 #define AD7124_GAIN(x)			(0x31 + (x))
38 
39 /* AD7124_STATUS */
40 #define AD7124_STATUS_POR_FLAG_MSK	BIT(4)
41 
42 /* AD7124_ADC_CONTROL */
43 #define AD7124_ADC_CTRL_REF_EN_MSK	BIT(8)
44 #define AD7124_ADC_CTRL_REF_EN(x)	FIELD_PREP(AD7124_ADC_CTRL_REF_EN_MSK, x)
45 #define AD7124_ADC_CTRL_PWR_MSK	GENMASK(7, 6)
46 #define AD7124_ADC_CTRL_PWR(x)		FIELD_PREP(AD7124_ADC_CTRL_PWR_MSK, x)
47 #define AD7124_ADC_CTRL_MODE_MSK	GENMASK(5, 2)
48 #define AD7124_ADC_CTRL_MODE(x)	FIELD_PREP(AD7124_ADC_CTRL_MODE_MSK, x)
49 
50 /* AD7124_CHANNEL_X */
51 #define AD7124_CHANNEL_EN_MSK		BIT(15)
52 #define AD7124_CHANNEL_EN(x)		FIELD_PREP(AD7124_CHANNEL_EN_MSK, x)
53 #define AD7124_CHANNEL_SETUP_MSK	GENMASK(14, 12)
54 #define AD7124_CHANNEL_SETUP(x)	FIELD_PREP(AD7124_CHANNEL_SETUP_MSK, x)
55 #define AD7124_CHANNEL_AINP_MSK	GENMASK(9, 5)
56 #define AD7124_CHANNEL_AINP(x)		FIELD_PREP(AD7124_CHANNEL_AINP_MSK, x)
57 #define AD7124_CHANNEL_AINM_MSK	GENMASK(4, 0)
58 #define AD7124_CHANNEL_AINM(x)		FIELD_PREP(AD7124_CHANNEL_AINM_MSK, x)
59 
60 /* AD7124_CONFIG_X */
61 #define AD7124_CONFIG_BIPOLAR_MSK	BIT(11)
62 #define AD7124_CONFIG_BIPOLAR(x)	FIELD_PREP(AD7124_CONFIG_BIPOLAR_MSK, x)
63 #define AD7124_CONFIG_REF_SEL_MSK	GENMASK(4, 3)
64 #define AD7124_CONFIG_REF_SEL(x)	FIELD_PREP(AD7124_CONFIG_REF_SEL_MSK, x)
65 #define AD7124_CONFIG_PGA_MSK		GENMASK(2, 0)
66 #define AD7124_CONFIG_PGA(x)		FIELD_PREP(AD7124_CONFIG_PGA_MSK, x)
67 #define AD7124_CONFIG_IN_BUFF_MSK	GENMASK(7, 6)
68 #define AD7124_CONFIG_IN_BUFF(x)	FIELD_PREP(AD7124_CONFIG_IN_BUFF_MSK, x)
69 
70 /* AD7124_FILTER_X */
71 #define AD7124_FILTER_FS_MSK		GENMASK(10, 0)
72 #define AD7124_FILTER_FS(x)		FIELD_PREP(AD7124_FILTER_FS_MSK, x)
73 
74 enum ad7124_ids {
75 	ID_AD7124_4,
76 	ID_AD7124_8,
77 };
78 
79 enum ad7124_ref_sel {
80 	AD7124_REFIN1,
81 	AD7124_REFIN2,
82 	AD7124_INT_REF,
83 	AD7124_AVDD_REF,
84 };
85 
86 enum ad7124_power_mode {
87 	AD7124_LOW_POWER,
88 	AD7124_MID_POWER,
89 	AD7124_FULL_POWER,
90 };
91 
92 static const unsigned int ad7124_gain[8] = {
93 	1, 2, 4, 8, 16, 32, 64, 128
94 };
95 
96 static const int ad7124_master_clk_freq_hz[3] = {
97 	[AD7124_LOW_POWER] = 76800,
98 	[AD7124_MID_POWER] = 153600,
99 	[AD7124_FULL_POWER] = 614400,
100 };
101 
102 static const char * const ad7124_ref_names[] = {
103 	[AD7124_REFIN1] = "refin1",
104 	[AD7124_REFIN2] = "refin2",
105 	[AD7124_INT_REF] = "int",
106 	[AD7124_AVDD_REF] = "avdd",
107 };
108 
109 struct ad7124_chip_info {
110 	unsigned int num_inputs;
111 };
112 
113 struct ad7124_channel_config {
114 	enum ad7124_ref_sel refsel;
115 	bool bipolar;
116 	bool buf_positive;
117 	bool buf_negative;
118 	unsigned int ain;
119 	unsigned int vref_mv;
120 	unsigned int pga_bits;
121 	unsigned int odr;
122 };
123 
124 struct ad7124_state {
125 	const struct ad7124_chip_info *chip_info;
126 	struct ad_sigma_delta sd;
127 	struct ad7124_channel_config *channel_config;
128 	struct regulator *vref[4];
129 	struct clk *mclk;
130 	unsigned int adc_control;
131 	unsigned int num_channels;
132 };
133 
134 static const struct iio_chan_spec ad7124_channel_template = {
135 	.type = IIO_VOLTAGE,
136 	.indexed = 1,
137 	.differential = 1,
138 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
139 		BIT(IIO_CHAN_INFO_SCALE) |
140 		BIT(IIO_CHAN_INFO_OFFSET) |
141 		BIT(IIO_CHAN_INFO_SAMP_FREQ),
142 	.scan_type = {
143 		.sign = 'u',
144 		.realbits = 24,
145 		.storagebits = 32,
146 		.shift = 8,
147 		.endianness = IIO_BE,
148 	},
149 };
150 
151 static struct ad7124_chip_info ad7124_chip_info_tbl[] = {
152 	[ID_AD7124_4] = {
153 		.num_inputs = 8,
154 	},
155 	[ID_AD7124_8] = {
156 		.num_inputs = 16,
157 	},
158 };
159 
160 static int ad7124_find_closest_match(const int *array,
161 				     unsigned int size, int val)
162 {
163 	int i, idx;
164 	unsigned int diff_new, diff_old;
165 
166 	diff_old = U32_MAX;
167 	idx = 0;
168 
169 	for (i = 0; i < size; i++) {
170 		diff_new = abs(val - array[i]);
171 		if (diff_new < diff_old) {
172 			diff_old = diff_new;
173 			idx = i;
174 		}
175 	}
176 
177 	return idx;
178 }
179 
180 static int ad7124_spi_write_mask(struct ad7124_state *st,
181 				 unsigned int addr,
182 				 unsigned long mask,
183 				 unsigned int val,
184 				 unsigned int bytes)
185 {
186 	unsigned int readval;
187 	int ret;
188 
189 	ret = ad_sd_read_reg(&st->sd, addr, bytes, &readval);
190 	if (ret < 0)
191 		return ret;
192 
193 	readval &= ~mask;
194 	readval |= val;
195 
196 	return ad_sd_write_reg(&st->sd, addr, bytes, readval);
197 }
198 
199 static int ad7124_set_mode(struct ad_sigma_delta *sd,
200 			   enum ad_sigma_delta_mode mode)
201 {
202 	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
203 
204 	st->adc_control &= ~AD7124_ADC_CTRL_MODE_MSK;
205 	st->adc_control |= AD7124_ADC_CTRL_MODE(mode);
206 
207 	return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control);
208 }
209 
210 static int ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
211 {
212 	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
213 	unsigned int val;
214 
215 	val = st->channel_config[channel].ain | AD7124_CHANNEL_EN(1) |
216 	      AD7124_CHANNEL_SETUP(channel);
217 
218 	return ad_sd_write_reg(&st->sd, AD7124_CHANNEL(channel), 2, val);
219 }
220 
221 static const struct ad_sigma_delta_info ad7124_sigma_delta_info = {
222 	.set_channel = ad7124_set_channel,
223 	.set_mode = ad7124_set_mode,
224 	.has_registers = true,
225 	.addr_shift = 0,
226 	.read_mask = BIT(6),
227 	.data_reg = AD7124_DATA,
228 	.irq_flags = IRQF_TRIGGER_FALLING,
229 };
230 
231 static int ad7124_set_channel_odr(struct ad7124_state *st,
232 				  unsigned int channel,
233 				  unsigned int odr)
234 {
235 	unsigned int fclk, odr_sel_bits;
236 	int ret;
237 
238 	fclk = clk_get_rate(st->mclk);
239 	/*
240 	 * FS[10:0] = fCLK / (fADC x 32) where:
241 	 * fADC is the output data rate
242 	 * fCLK is the master clock frequency
243 	 * FS[10:0] are the bits in the filter register
244 	 * FS[10:0] can have a value from 1 to 2047
245 	 */
246 	odr_sel_bits = DIV_ROUND_CLOSEST(fclk, odr * 32);
247 	if (odr_sel_bits < 1)
248 		odr_sel_bits = 1;
249 	else if (odr_sel_bits > 2047)
250 		odr_sel_bits = 2047;
251 
252 	ret = ad7124_spi_write_mask(st, AD7124_FILTER(channel),
253 				    AD7124_FILTER_FS_MSK,
254 				    AD7124_FILTER_FS(odr_sel_bits), 3);
255 	if (ret < 0)
256 		return ret;
257 	/* fADC = fCLK / (FS[10:0] x 32) */
258 	st->channel_config[channel].odr =
259 		DIV_ROUND_CLOSEST(fclk, odr_sel_bits * 32);
260 
261 	return 0;
262 }
263 
264 static int ad7124_set_channel_gain(struct ad7124_state *st,
265 				   unsigned int channel,
266 				   unsigned int gain)
267 {
268 	unsigned int res;
269 	int ret;
270 
271 	res = ad7124_find_closest_match(ad7124_gain,
272 					ARRAY_SIZE(ad7124_gain), gain);
273 	ret = ad7124_spi_write_mask(st, AD7124_CONFIG(channel),
274 				    AD7124_CONFIG_PGA_MSK,
275 				    AD7124_CONFIG_PGA(res), 2);
276 	if (ret < 0)
277 		return ret;
278 
279 	st->channel_config[channel].pga_bits = res;
280 
281 	return 0;
282 }
283 
284 static int ad7124_read_raw(struct iio_dev *indio_dev,
285 			   struct iio_chan_spec const *chan,
286 			   int *val, int *val2, long info)
287 {
288 	struct ad7124_state *st = iio_priv(indio_dev);
289 	int idx, ret;
290 
291 	switch (info) {
292 	case IIO_CHAN_INFO_RAW:
293 		ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
294 		if (ret < 0)
295 			return ret;
296 
297 		/* After the conversion is performed, disable the channel */
298 		ret = ad_sd_write_reg(&st->sd,
299 				      AD7124_CHANNEL(chan->address), 2,
300 				      st->channel_config[chan->address].ain |
301 				      AD7124_CHANNEL_EN(0));
302 		if (ret < 0)
303 			return ret;
304 
305 		return IIO_VAL_INT;
306 	case IIO_CHAN_INFO_SCALE:
307 		idx = st->channel_config[chan->address].pga_bits;
308 		*val = st->channel_config[chan->address].vref_mv;
309 		if (st->channel_config[chan->address].bipolar)
310 			*val2 = chan->scan_type.realbits - 1 + idx;
311 		else
312 			*val2 = chan->scan_type.realbits + idx;
313 
314 		return IIO_VAL_FRACTIONAL_LOG2;
315 	case IIO_CHAN_INFO_OFFSET:
316 		if (st->channel_config[chan->address].bipolar)
317 			*val = -(1 << (chan->scan_type.realbits - 1));
318 		else
319 			*val = 0;
320 
321 		return IIO_VAL_INT;
322 	case IIO_CHAN_INFO_SAMP_FREQ:
323 		*val = st->channel_config[chan->address].odr;
324 
325 		return IIO_VAL_INT;
326 	default:
327 		return -EINVAL;
328 	}
329 }
330 
331 static int ad7124_write_raw(struct iio_dev *indio_dev,
332 			    struct iio_chan_spec const *chan,
333 			    int val, int val2, long info)
334 {
335 	struct ad7124_state *st = iio_priv(indio_dev);
336 	unsigned int res, gain, full_scale, vref;
337 
338 	switch (info) {
339 	case IIO_CHAN_INFO_SAMP_FREQ:
340 		if (val2 != 0)
341 			return -EINVAL;
342 
343 		return ad7124_set_channel_odr(st, chan->address, val);
344 	case IIO_CHAN_INFO_SCALE:
345 		if (val != 0)
346 			return -EINVAL;
347 
348 		if (st->channel_config[chan->address].bipolar)
349 			full_scale = 1 << (chan->scan_type.realbits - 1);
350 		else
351 			full_scale = 1 << chan->scan_type.realbits;
352 
353 		vref = st->channel_config[chan->address].vref_mv * 1000000LL;
354 		res = DIV_ROUND_CLOSEST(vref, full_scale);
355 		gain = DIV_ROUND_CLOSEST(res, val2);
356 
357 		return ad7124_set_channel_gain(st, chan->address, gain);
358 	default:
359 		return -EINVAL;
360 	}
361 }
362 
363 static IIO_CONST_ATTR(in_voltage_scale_available,
364 	"0.000001164 0.000002328 0.000004656 0.000009313 0.000018626 0.000037252 0.000074505 0.000149011 0.000298023");
365 
366 static struct attribute *ad7124_attributes[] = {
367 	&iio_const_attr_in_voltage_scale_available.dev_attr.attr,
368 	NULL,
369 };
370 
371 static const struct attribute_group ad7124_attrs_group = {
372 	.attrs = ad7124_attributes,
373 };
374 
375 static const struct iio_info ad7124_info = {
376 	.read_raw = ad7124_read_raw,
377 	.write_raw = ad7124_write_raw,
378 	.validate_trigger = ad_sd_validate_trigger,
379 	.attrs = &ad7124_attrs_group,
380 };
381 
382 static int ad7124_soft_reset(struct ad7124_state *st)
383 {
384 	unsigned int readval, timeout;
385 	int ret;
386 
387 	ret = ad_sd_reset(&st->sd, 64);
388 	if (ret < 0)
389 		return ret;
390 
391 	timeout = 100;
392 	do {
393 		ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval);
394 		if (ret < 0)
395 			return ret;
396 
397 		if (!(readval & AD7124_STATUS_POR_FLAG_MSK))
398 			return 0;
399 
400 		/* The AD7124 requires typically 2ms to power up and settle */
401 		usleep_range(100, 2000);
402 	} while (--timeout);
403 
404 	dev_err(&st->sd.spi->dev, "Soft reset failed\n");
405 
406 	return -EIO;
407 }
408 
409 static int ad7124_init_channel_vref(struct ad7124_state *st,
410 				    unsigned int channel_number)
411 {
412 	unsigned int refsel = st->channel_config[channel_number].refsel;
413 
414 	switch (refsel) {
415 	case AD7124_REFIN1:
416 	case AD7124_REFIN2:
417 	case AD7124_AVDD_REF:
418 		if (IS_ERR(st->vref[refsel])) {
419 			dev_err(&st->sd.spi->dev,
420 				"Error, trying to use external voltage reference without a %s regulator.\n",
421 				ad7124_ref_names[refsel]);
422 			return PTR_ERR(st->vref[refsel]);
423 		}
424 		st->channel_config[channel_number].vref_mv =
425 			regulator_get_voltage(st->vref[refsel]);
426 		/* Conversion from uV to mV */
427 		st->channel_config[channel_number].vref_mv /= 1000;
428 		break;
429 	case AD7124_INT_REF:
430 		st->channel_config[channel_number].vref_mv = 2500;
431 		st->adc_control &= ~AD7124_ADC_CTRL_REF_EN_MSK;
432 		st->adc_control |= AD7124_ADC_CTRL_REF_EN(1);
433 		return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL,
434 				      2, st->adc_control);
435 	default:
436 		dev_err(&st->sd.spi->dev, "Invalid reference %d\n", refsel);
437 		return -EINVAL;
438 	}
439 
440 	return 0;
441 }
442 
443 static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev,
444 					  struct device_node *np)
445 {
446 	struct ad7124_state *st = iio_priv(indio_dev);
447 	struct device_node *child;
448 	struct iio_chan_spec *chan;
449 	struct ad7124_channel_config *chan_config;
450 	unsigned int ain[2], channel = 0, tmp;
451 	int ret;
452 
453 	st->num_channels = of_get_available_child_count(np);
454 	if (!st->num_channels) {
455 		dev_err(indio_dev->dev.parent, "no channel children\n");
456 		return -ENODEV;
457 	}
458 
459 	chan = devm_kcalloc(indio_dev->dev.parent, st->num_channels,
460 			    sizeof(*chan), GFP_KERNEL);
461 	if (!chan)
462 		return -ENOMEM;
463 
464 	chan_config = devm_kcalloc(indio_dev->dev.parent, st->num_channels,
465 				   sizeof(*chan_config), GFP_KERNEL);
466 	if (!chan_config)
467 		return -ENOMEM;
468 
469 	indio_dev->channels = chan;
470 	indio_dev->num_channels = st->num_channels;
471 	st->channel_config = chan_config;
472 
473 	for_each_available_child_of_node(np, child) {
474 		ret = of_property_read_u32(child, "reg", &channel);
475 		if (ret)
476 			goto err;
477 
478 		ret = of_property_read_u32_array(child, "diff-channels",
479 						 ain, 2);
480 		if (ret)
481 			goto err;
482 
483 		st->channel_config[channel].ain = AD7124_CHANNEL_AINP(ain[0]) |
484 						  AD7124_CHANNEL_AINM(ain[1]);
485 		st->channel_config[channel].bipolar =
486 			of_property_read_bool(child, "bipolar");
487 
488 		ret = of_property_read_u32(child, "adi,reference-select", &tmp);
489 		if (ret)
490 			st->channel_config[channel].refsel = AD7124_INT_REF;
491 		else
492 			st->channel_config[channel].refsel = tmp;
493 
494 		st->channel_config[channel].buf_positive =
495 			of_property_read_bool(child, "adi,buffered-positive");
496 		st->channel_config[channel].buf_negative =
497 			of_property_read_bool(child, "adi,buffered-negative");
498 
499 		chan[channel] = ad7124_channel_template;
500 		chan[channel].address = channel;
501 		chan[channel].scan_index = channel;
502 		chan[channel].channel = ain[0];
503 		chan[channel].channel2 = ain[1];
504 	}
505 
506 	return 0;
507 err:
508 	of_node_put(child);
509 
510 	return ret;
511 }
512 
513 static int ad7124_setup(struct ad7124_state *st)
514 {
515 	unsigned int val, fclk, power_mode;
516 	int i, ret, tmp;
517 
518 	fclk = clk_get_rate(st->mclk);
519 	if (!fclk)
520 		return -EINVAL;
521 
522 	/* The power mode changes the master clock frequency */
523 	power_mode = ad7124_find_closest_match(ad7124_master_clk_freq_hz,
524 					ARRAY_SIZE(ad7124_master_clk_freq_hz),
525 					fclk);
526 	if (fclk != ad7124_master_clk_freq_hz[power_mode]) {
527 		ret = clk_set_rate(st->mclk, fclk);
528 		if (ret)
529 			return ret;
530 	}
531 
532 	/* Set the power mode */
533 	st->adc_control &= ~AD7124_ADC_CTRL_PWR_MSK;
534 	st->adc_control |= AD7124_ADC_CTRL_PWR(power_mode);
535 	ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control);
536 	if (ret < 0)
537 		return ret;
538 
539 	for (i = 0; i < st->num_channels; i++) {
540 		val = st->channel_config[i].ain | AD7124_CHANNEL_SETUP(i);
541 		ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(i), 2, val);
542 		if (ret < 0)
543 			return ret;
544 
545 		ret = ad7124_init_channel_vref(st, i);
546 		if (ret < 0)
547 			return ret;
548 
549 		tmp = (st->channel_config[i].buf_positive << 1)  +
550 			st->channel_config[i].buf_negative;
551 
552 		val = AD7124_CONFIG_BIPOLAR(st->channel_config[i].bipolar) |
553 		      AD7124_CONFIG_REF_SEL(st->channel_config[i].refsel) |
554 		      AD7124_CONFIG_IN_BUFF(tmp);
555 		ret = ad_sd_write_reg(&st->sd, AD7124_CONFIG(i), 2, val);
556 		if (ret < 0)
557 			return ret;
558 		/*
559 		 * 9.38 SPS is the minimum output data rate supported
560 		 * regardless of the selected power mode. Round it up to 10 and
561 		 * set all the enabled channels to this default value.
562 		 */
563 		ret = ad7124_set_channel_odr(st, i, 10);
564 	}
565 
566 	return ret;
567 }
568 
569 static int ad7124_probe(struct spi_device *spi)
570 {
571 	const struct spi_device_id *id;
572 	struct ad7124_state *st;
573 	struct iio_dev *indio_dev;
574 	int i, ret;
575 
576 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
577 	if (!indio_dev)
578 		return -ENOMEM;
579 
580 	st = iio_priv(indio_dev);
581 
582 	id = spi_get_device_id(spi);
583 	st->chip_info = &ad7124_chip_info_tbl[id->driver_data];
584 
585 	ad_sd_init(&st->sd, indio_dev, spi, &ad7124_sigma_delta_info);
586 
587 	spi_set_drvdata(spi, indio_dev);
588 
589 	indio_dev->dev.parent = &spi->dev;
590 	indio_dev->name = spi_get_device_id(spi)->name;
591 	indio_dev->modes = INDIO_DIRECT_MODE;
592 	indio_dev->info = &ad7124_info;
593 
594 	ret = ad7124_of_parse_channel_config(indio_dev, spi->dev.of_node);
595 	if (ret < 0)
596 		return ret;
597 
598 	for (i = 0; i < ARRAY_SIZE(st->vref); i++) {
599 		if (i == AD7124_INT_REF)
600 			continue;
601 
602 		st->vref[i] = devm_regulator_get_optional(&spi->dev,
603 						ad7124_ref_names[i]);
604 		if (PTR_ERR(st->vref[i]) == -ENODEV)
605 			continue;
606 		else if (IS_ERR(st->vref[i]))
607 			return PTR_ERR(st->vref[i]);
608 
609 		ret = regulator_enable(st->vref[i]);
610 		if (ret)
611 			return ret;
612 	}
613 
614 	st->mclk = devm_clk_get(&spi->dev, "mclk");
615 	if (IS_ERR(st->mclk)) {
616 		ret = PTR_ERR(st->mclk);
617 		goto error_regulator_disable;
618 	}
619 
620 	ret = clk_prepare_enable(st->mclk);
621 	if (ret < 0)
622 		goto error_regulator_disable;
623 
624 	ret = ad7124_soft_reset(st);
625 	if (ret < 0)
626 		goto error_clk_disable_unprepare;
627 
628 	ret = ad7124_setup(st);
629 	if (ret < 0)
630 		goto error_clk_disable_unprepare;
631 
632 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
633 	if (ret < 0)
634 		goto error_clk_disable_unprepare;
635 
636 	ret = iio_device_register(indio_dev);
637 	if (ret < 0) {
638 		dev_err(&spi->dev, "Failed to register iio device\n");
639 		goto error_remove_trigger;
640 	}
641 
642 	return 0;
643 
644 error_remove_trigger:
645 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
646 error_clk_disable_unprepare:
647 	clk_disable_unprepare(st->mclk);
648 error_regulator_disable:
649 	for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) {
650 		if (!IS_ERR_OR_NULL(st->vref[i]))
651 			regulator_disable(st->vref[i]);
652 	}
653 
654 	return ret;
655 }
656 
657 static int ad7124_remove(struct spi_device *spi)
658 {
659 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
660 	struct ad7124_state *st = iio_priv(indio_dev);
661 	int i;
662 
663 	iio_device_unregister(indio_dev);
664 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
665 	clk_disable_unprepare(st->mclk);
666 
667 	for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) {
668 		if (!IS_ERR_OR_NULL(st->vref[i]))
669 			regulator_disable(st->vref[i]);
670 	}
671 
672 	return 0;
673 }
674 
675 static const struct spi_device_id ad7124_id_table[] = {
676 	{ "ad7124-4", ID_AD7124_4 },
677 	{ "ad7124-8", ID_AD7124_8 },
678 	{}
679 };
680 MODULE_DEVICE_TABLE(spi, ad7124_id_table);
681 
682 static const struct of_device_id ad7124_of_match[] = {
683 	{ .compatible = "adi,ad7124-4" },
684 	{ .compatible = "adi,ad7124-8" },
685 	{ },
686 };
687 MODULE_DEVICE_TABLE(of, ad7124_of_match);
688 
689 static struct spi_driver ad71124_driver = {
690 	.driver = {
691 		.name = "ad7124",
692 		.of_match_table = ad7124_of_match,
693 	},
694 	.probe = ad7124_probe,
695 	.remove	= ad7124_remove,
696 	.id_table = ad7124_id_table,
697 };
698 module_spi_driver(ad71124_driver);
699 
700 MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
701 MODULE_DESCRIPTION("Analog Devices AD7124 SPI driver");
702 MODULE_LICENSE("GPL");
703