xref: /openbmc/linux/drivers/iio/adc/ad7124.c (revision 3fc41476)
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/kernel.h>
13 #include <linux/module.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/spi/spi.h>
16 
17 #include <linux/iio/iio.h>
18 #include <linux/iio/adc/ad_sigma_delta.h>
19 #include <linux/iio/sysfs.h>
20 
21 /* AD7124 registers */
22 #define AD7124_COMMS			0x00
23 #define AD7124_STATUS			0x00
24 #define AD7124_ADC_CONTROL		0x01
25 #define AD7124_DATA			0x02
26 #define AD7124_IO_CONTROL_1		0x03
27 #define AD7124_IO_CONTROL_2		0x04
28 #define AD7124_ID			0x05
29 #define AD7124_ERROR			0x06
30 #define AD7124_ERROR_EN		0x07
31 #define AD7124_MCLK_COUNT		0x08
32 #define AD7124_CHANNEL(x)		(0x09 + (x))
33 #define AD7124_CONFIG(x)		(0x19 + (x))
34 #define AD7124_FILTER(x)		(0x21 + (x))
35 #define AD7124_OFFSET(x)		(0x29 + (x))
36 #define AD7124_GAIN(x)			(0x31 + (x))
37 
38 /* AD7124_STATUS */
39 #define AD7124_STATUS_POR_FLAG_MSK	BIT(4)
40 
41 /* AD7124_ADC_CONTROL */
42 #define AD7124_ADC_CTRL_PWR_MSK	GENMASK(7, 6)
43 #define AD7124_ADC_CTRL_PWR(x)		FIELD_PREP(AD7124_ADC_CTRL_PWR_MSK, x)
44 #define AD7124_ADC_CTRL_MODE_MSK	GENMASK(5, 2)
45 #define AD7124_ADC_CTRL_MODE(x)	FIELD_PREP(AD7124_ADC_CTRL_MODE_MSK, x)
46 
47 /* AD7124_CHANNEL_X */
48 #define AD7124_CHANNEL_EN_MSK		BIT(15)
49 #define AD7124_CHANNEL_EN(x)		FIELD_PREP(AD7124_CHANNEL_EN_MSK, x)
50 #define AD7124_CHANNEL_SETUP_MSK	GENMASK(14, 12)
51 #define AD7124_CHANNEL_SETUP(x)	FIELD_PREP(AD7124_CHANNEL_SETUP_MSK, x)
52 #define AD7124_CHANNEL_AINP_MSK	GENMASK(9, 5)
53 #define AD7124_CHANNEL_AINP(x)		FIELD_PREP(AD7124_CHANNEL_AINP_MSK, x)
54 #define AD7124_CHANNEL_AINM_MSK	GENMASK(4, 0)
55 #define AD7124_CHANNEL_AINM(x)		FIELD_PREP(AD7124_CHANNEL_AINM_MSK, x)
56 
57 /* AD7124_CONFIG_X */
58 #define AD7124_CONFIG_BIPOLAR_MSK	BIT(11)
59 #define AD7124_CONFIG_BIPOLAR(x)	FIELD_PREP(AD7124_CONFIG_BIPOLAR_MSK, x)
60 #define AD7124_CONFIG_REF_SEL_MSK	GENMASK(4, 3)
61 #define AD7124_CONFIG_REF_SEL(x)	FIELD_PREP(AD7124_CONFIG_REF_SEL_MSK, x)
62 #define AD7124_CONFIG_PGA_MSK		GENMASK(2, 0)
63 #define AD7124_CONFIG_PGA(x)		FIELD_PREP(AD7124_CONFIG_PGA_MSK, x)
64 
65 /* AD7124_FILTER_X */
66 #define AD7124_FILTER_FS_MSK		GENMASK(10, 0)
67 #define AD7124_FILTER_FS(x)		FIELD_PREP(AD7124_FILTER_FS_MSK, x)
68 
69 enum ad7124_ids {
70 	ID_AD7124_4,
71 	ID_AD7124_8,
72 };
73 
74 enum ad7124_ref_sel {
75 	AD7124_REFIN1,
76 	AD7124_REFIN2,
77 	AD7124_INT_REF,
78 	AD7124_AVDD_REF,
79 };
80 
81 enum ad7124_power_mode {
82 	AD7124_LOW_POWER,
83 	AD7124_MID_POWER,
84 	AD7124_FULL_POWER,
85 };
86 
87 static const unsigned int ad7124_gain[8] = {
88 	1, 2, 4, 8, 16, 32, 64, 128
89 };
90 
91 static const int ad7124_master_clk_freq_hz[3] = {
92 	[AD7124_LOW_POWER] = 76800,
93 	[AD7124_MID_POWER] = 153600,
94 	[AD7124_FULL_POWER] = 614400,
95 };
96 
97 static const char * const ad7124_ref_names[] = {
98 	[AD7124_REFIN1] = "refin1",
99 	[AD7124_REFIN2] = "refin2",
100 	[AD7124_INT_REF] = "int",
101 	[AD7124_AVDD_REF] = "avdd",
102 };
103 
104 struct ad7124_chip_info {
105 	unsigned int num_inputs;
106 };
107 
108 struct ad7124_channel_config {
109 	enum ad7124_ref_sel refsel;
110 	bool bipolar;
111 	unsigned int ain;
112 	unsigned int vref_mv;
113 	unsigned int pga_bits;
114 	unsigned int odr;
115 };
116 
117 struct ad7124_state {
118 	const struct ad7124_chip_info *chip_info;
119 	struct ad_sigma_delta sd;
120 	struct ad7124_channel_config channel_config[4];
121 	struct regulator *vref[4];
122 	struct clk *mclk;
123 	unsigned int adc_control;
124 	unsigned int num_channels;
125 };
126 
127 static const struct iio_chan_spec ad7124_channel_template = {
128 	.type = IIO_VOLTAGE,
129 	.indexed = 1,
130 	.differential = 1,
131 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
132 		BIT(IIO_CHAN_INFO_SCALE) |
133 		BIT(IIO_CHAN_INFO_OFFSET) |
134 		BIT(IIO_CHAN_INFO_SAMP_FREQ),
135 	.scan_type = {
136 		.sign = 'u',
137 		.realbits = 24,
138 		.storagebits = 32,
139 		.shift = 8,
140 		.endianness = IIO_BE,
141 	},
142 };
143 
144 static struct ad7124_chip_info ad7124_chip_info_tbl[] = {
145 	[ID_AD7124_4] = {
146 		.num_inputs = 8,
147 	},
148 	[ID_AD7124_8] = {
149 		.num_inputs = 16,
150 	},
151 };
152 
153 static int ad7124_find_closest_match(const int *array,
154 				     unsigned int size, int val)
155 {
156 	int i, idx;
157 	unsigned int diff_new, diff_old;
158 
159 	diff_old = U32_MAX;
160 	idx = 0;
161 
162 	for (i = 0; i < size; i++) {
163 		diff_new = abs(val - array[i]);
164 		if (diff_new < diff_old) {
165 			diff_old = diff_new;
166 			idx = i;
167 		}
168 	}
169 
170 	return idx;
171 }
172 
173 static int ad7124_spi_write_mask(struct ad7124_state *st,
174 				 unsigned int addr,
175 				 unsigned long mask,
176 				 unsigned int val,
177 				 unsigned int bytes)
178 {
179 	unsigned int readval;
180 	int ret;
181 
182 	ret = ad_sd_read_reg(&st->sd, addr, bytes, &readval);
183 	if (ret < 0)
184 		return ret;
185 
186 	readval &= ~mask;
187 	readval |= val;
188 
189 	return ad_sd_write_reg(&st->sd, addr, bytes, readval);
190 }
191 
192 static int ad7124_set_mode(struct ad_sigma_delta *sd,
193 			   enum ad_sigma_delta_mode mode)
194 {
195 	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
196 
197 	st->adc_control &= ~AD7124_ADC_CTRL_MODE_MSK;
198 	st->adc_control |= AD7124_ADC_CTRL_MODE(mode);
199 
200 	return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control);
201 }
202 
203 static int ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
204 {
205 	struct ad7124_state *st = container_of(sd, struct ad7124_state, sd);
206 	unsigned int val;
207 
208 	val = st->channel_config[channel].ain | AD7124_CHANNEL_EN(1) |
209 	      AD7124_CHANNEL_SETUP(channel);
210 
211 	return ad_sd_write_reg(&st->sd, AD7124_CHANNEL(channel), 2, val);
212 }
213 
214 static const struct ad_sigma_delta_info ad7124_sigma_delta_info = {
215 	.set_channel = ad7124_set_channel,
216 	.set_mode = ad7124_set_mode,
217 	.has_registers = true,
218 	.addr_shift = 0,
219 	.read_mask = BIT(6),
220 	.data_reg = AD7124_DATA,
221 };
222 
223 static int ad7124_set_channel_odr(struct ad7124_state *st,
224 				  unsigned int channel,
225 				  unsigned int odr)
226 {
227 	unsigned int fclk, odr_sel_bits;
228 	int ret;
229 
230 	fclk = clk_get_rate(st->mclk);
231 	/*
232 	 * FS[10:0] = fCLK / (fADC x 32) where:
233 	 * fADC is the output data rate
234 	 * fCLK is the master clock frequency
235 	 * FS[10:0] are the bits in the filter register
236 	 * FS[10:0] can have a value from 1 to 2047
237 	 */
238 	odr_sel_bits = DIV_ROUND_CLOSEST(fclk, odr * 32);
239 	if (odr_sel_bits < 1)
240 		odr_sel_bits = 1;
241 	else if (odr_sel_bits > 2047)
242 		odr_sel_bits = 2047;
243 
244 	ret = ad7124_spi_write_mask(st, AD7124_FILTER(channel),
245 				    AD7124_FILTER_FS_MSK,
246 				    AD7124_FILTER_FS(odr_sel_bits), 3);
247 	if (ret < 0)
248 		return ret;
249 	/* fADC = fCLK / (FS[10:0] x 32) */
250 	st->channel_config[channel].odr =
251 		DIV_ROUND_CLOSEST(fclk, odr_sel_bits * 32);
252 
253 	return 0;
254 }
255 
256 static int ad7124_set_channel_gain(struct ad7124_state *st,
257 				   unsigned int channel,
258 				   unsigned int gain)
259 {
260 	unsigned int res;
261 	int ret;
262 
263 	res = ad7124_find_closest_match(ad7124_gain,
264 					ARRAY_SIZE(ad7124_gain), gain);
265 	ret = ad7124_spi_write_mask(st, AD7124_CONFIG(channel),
266 				    AD7124_CONFIG_PGA_MSK,
267 				    AD7124_CONFIG_PGA(res), 2);
268 	if (ret < 0)
269 		return ret;
270 
271 	st->channel_config[channel].pga_bits = res;
272 
273 	return 0;
274 }
275 
276 static int ad7124_read_raw(struct iio_dev *indio_dev,
277 			   struct iio_chan_spec const *chan,
278 			   int *val, int *val2, long info)
279 {
280 	struct ad7124_state *st = iio_priv(indio_dev);
281 	int idx, ret;
282 
283 	switch (info) {
284 	case IIO_CHAN_INFO_RAW:
285 		ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
286 		if (ret < 0)
287 			return ret;
288 
289 		/* After the conversion is performed, disable the channel */
290 		ret = ad_sd_write_reg(&st->sd,
291 				      AD7124_CHANNEL(chan->address), 2,
292 				      st->channel_config[chan->address].ain |
293 				      AD7124_CHANNEL_EN(0));
294 		if (ret < 0)
295 			return ret;
296 
297 		return IIO_VAL_INT;
298 	case IIO_CHAN_INFO_SCALE:
299 		idx = st->channel_config[chan->address].pga_bits;
300 		*val = st->channel_config[chan->address].vref_mv;
301 		if (st->channel_config[chan->address].bipolar)
302 			*val2 = chan->scan_type.realbits - 1 + idx;
303 		else
304 			*val2 = chan->scan_type.realbits + idx;
305 
306 		return IIO_VAL_FRACTIONAL_LOG2;
307 	case IIO_CHAN_INFO_OFFSET:
308 		if (st->channel_config[chan->address].bipolar)
309 			*val = -(1 << (chan->scan_type.realbits - 1));
310 		else
311 			*val = 0;
312 
313 		return IIO_VAL_INT;
314 	case IIO_CHAN_INFO_SAMP_FREQ:
315 		*val = st->channel_config[chan->address].odr;
316 
317 		return IIO_VAL_INT;
318 	default:
319 		return -EINVAL;
320 	}
321 }
322 
323 static int ad7124_write_raw(struct iio_dev *indio_dev,
324 			    struct iio_chan_spec const *chan,
325 			    int val, int val2, long info)
326 {
327 	struct ad7124_state *st = iio_priv(indio_dev);
328 	unsigned int res, gain, full_scale, vref;
329 
330 	switch (info) {
331 	case IIO_CHAN_INFO_SAMP_FREQ:
332 		if (val2 != 0)
333 			return -EINVAL;
334 
335 		return ad7124_set_channel_odr(st, chan->address, val);
336 	case IIO_CHAN_INFO_SCALE:
337 		if (val != 0)
338 			return -EINVAL;
339 
340 		if (st->channel_config[chan->address].bipolar)
341 			full_scale = 1 << (chan->scan_type.realbits - 1);
342 		else
343 			full_scale = 1 << chan->scan_type.realbits;
344 
345 		vref = st->channel_config[chan->address].vref_mv * 1000000LL;
346 		res = DIV_ROUND_CLOSEST(vref, full_scale);
347 		gain = DIV_ROUND_CLOSEST(res, val2);
348 
349 		return ad7124_set_channel_gain(st, chan->address, gain);
350 	default:
351 		return -EINVAL;
352 	}
353 }
354 
355 static IIO_CONST_ATTR(in_voltage_scale_available,
356 	"0.000001164 0.000002328 0.000004656 0.000009313 0.000018626 0.000037252 0.000074505 0.000149011 0.000298023");
357 
358 static struct attribute *ad7124_attributes[] = {
359 	&iio_const_attr_in_voltage_scale_available.dev_attr.attr,
360 	NULL,
361 };
362 
363 static const struct attribute_group ad7124_attrs_group = {
364 	.attrs = ad7124_attributes,
365 };
366 
367 static const struct iio_info ad7124_info = {
368 	.read_raw = ad7124_read_raw,
369 	.write_raw = ad7124_write_raw,
370 	.validate_trigger = ad_sd_validate_trigger,
371 	.attrs = &ad7124_attrs_group,
372 };
373 
374 static int ad7124_soft_reset(struct ad7124_state *st)
375 {
376 	unsigned int readval, timeout;
377 	int ret;
378 
379 	ret = ad_sd_reset(&st->sd, 64);
380 	if (ret < 0)
381 		return ret;
382 
383 	timeout = 100;
384 	do {
385 		ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval);
386 		if (ret < 0)
387 			return ret;
388 
389 		if (!(readval & AD7124_STATUS_POR_FLAG_MSK))
390 			return 0;
391 
392 		/* The AD7124 requires typically 2ms to power up and settle */
393 		usleep_range(100, 2000);
394 	} while (--timeout);
395 
396 	dev_err(&st->sd.spi->dev, "Soft reset failed\n");
397 
398 	return -EIO;
399 }
400 
401 static int ad7124_init_channel_vref(struct ad7124_state *st,
402 				    unsigned int channel_number)
403 {
404 	unsigned int refsel = st->channel_config[channel_number].refsel;
405 
406 	switch (refsel) {
407 	case AD7124_REFIN1:
408 	case AD7124_REFIN2:
409 	case AD7124_AVDD_REF:
410 		if (IS_ERR(st->vref[refsel])) {
411 			dev_err(&st->sd.spi->dev,
412 				"Error, trying to use external voltage reference without a %s regulator.\n",
413 				ad7124_ref_names[refsel]);
414 			return PTR_ERR(st->vref[refsel]);
415 		}
416 		st->channel_config[channel_number].vref_mv =
417 			regulator_get_voltage(st->vref[refsel]);
418 		/* Conversion from uV to mV */
419 		st->channel_config[channel_number].vref_mv /= 1000;
420 		break;
421 	case AD7124_INT_REF:
422 		st->channel_config[channel_number].vref_mv = 2500;
423 		break;
424 	default:
425 		dev_err(&st->sd.spi->dev, "Invalid reference %d\n", refsel);
426 		return -EINVAL;
427 	}
428 
429 	return 0;
430 }
431 
432 static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev,
433 					  struct device_node *np)
434 {
435 	struct ad7124_state *st = iio_priv(indio_dev);
436 	struct device_node *child;
437 	struct iio_chan_spec *chan;
438 	unsigned int ain[2], channel = 0, tmp;
439 	int ret;
440 
441 	st->num_channels = of_get_available_child_count(np);
442 	if (!st->num_channels) {
443 		dev_err(indio_dev->dev.parent, "no channel children\n");
444 		return -ENODEV;
445 	}
446 
447 	chan = devm_kcalloc(indio_dev->dev.parent, st->num_channels,
448 			    sizeof(*chan), GFP_KERNEL);
449 	if (!chan)
450 		return -ENOMEM;
451 
452 	indio_dev->channels = chan;
453 	indio_dev->num_channels = st->num_channels;
454 
455 	for_each_available_child_of_node(np, child) {
456 		ret = of_property_read_u32(child, "reg", &channel);
457 		if (ret)
458 			goto err;
459 
460 		ret = of_property_read_u32_array(child, "diff-channels",
461 						 ain, 2);
462 		if (ret)
463 			goto err;
464 
465 		if (ain[0] >= st->chip_info->num_inputs ||
466 		    ain[1] >= st->chip_info->num_inputs) {
467 			dev_err(indio_dev->dev.parent,
468 				"Input pin number out of range.\n");
469 			ret = -EINVAL;
470 			goto err;
471 		}
472 		st->channel_config[channel].ain = AD7124_CHANNEL_AINP(ain[0]) |
473 						  AD7124_CHANNEL_AINM(ain[1]);
474 		st->channel_config[channel].bipolar =
475 			of_property_read_bool(child, "bipolar");
476 
477 		ret = of_property_read_u32(child, "adi,reference-select", &tmp);
478 		if (ret)
479 			st->channel_config[channel].refsel = AD7124_INT_REF;
480 		else
481 			st->channel_config[channel].refsel = tmp;
482 
483 		*chan = ad7124_channel_template;
484 		chan->address = channel;
485 		chan->scan_index = channel;
486 		chan->channel = ain[0];
487 		chan->channel2 = ain[1];
488 
489 		chan++;
490 	}
491 
492 	return 0;
493 err:
494 	of_node_put(child);
495 
496 	return ret;
497 }
498 
499 static int ad7124_setup(struct ad7124_state *st)
500 {
501 	unsigned int val, fclk, power_mode;
502 	int i, ret;
503 
504 	fclk = clk_get_rate(st->mclk);
505 	if (!fclk)
506 		return -EINVAL;
507 
508 	/* The power mode changes the master clock frequency */
509 	power_mode = ad7124_find_closest_match(ad7124_master_clk_freq_hz,
510 					ARRAY_SIZE(ad7124_master_clk_freq_hz),
511 					fclk);
512 	if (fclk != ad7124_master_clk_freq_hz[power_mode]) {
513 		ret = clk_set_rate(st->mclk, fclk);
514 		if (ret)
515 			return ret;
516 	}
517 
518 	/* Set the power mode */
519 	st->adc_control &= ~AD7124_ADC_CTRL_PWR_MSK;
520 	st->adc_control |= AD7124_ADC_CTRL_PWR(power_mode);
521 	ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control);
522 	if (ret < 0)
523 		return ret;
524 
525 	for (i = 0; i < st->num_channels; i++) {
526 		val = st->channel_config[i].ain | AD7124_CHANNEL_SETUP(i);
527 		ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(i), 2, val);
528 		if (ret < 0)
529 			return ret;
530 
531 		ret = ad7124_init_channel_vref(st, i);
532 		if (ret < 0)
533 			return ret;
534 
535 		val = AD7124_CONFIG_BIPOLAR(st->channel_config[i].bipolar) |
536 		      AD7124_CONFIG_REF_SEL(st->channel_config[i].refsel);
537 		ret = ad_sd_write_reg(&st->sd, AD7124_CONFIG(i), 2, val);
538 		if (ret < 0)
539 			return ret;
540 		/*
541 		 * 9.38 SPS is the minimum output data rate supported
542 		 * regardless of the selected power mode. Round it up to 10 and
543 		 * set all the enabled channels to this default value.
544 		 */
545 		ret = ad7124_set_channel_odr(st, i, 10);
546 	}
547 
548 	return ret;
549 }
550 
551 static int ad7124_probe(struct spi_device *spi)
552 {
553 	const struct spi_device_id *id;
554 	struct ad7124_state *st;
555 	struct iio_dev *indio_dev;
556 	int i, ret;
557 
558 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
559 	if (!indio_dev)
560 		return -ENOMEM;
561 
562 	st = iio_priv(indio_dev);
563 
564 	id = spi_get_device_id(spi);
565 	st->chip_info = &ad7124_chip_info_tbl[id->driver_data];
566 
567 	ad_sd_init(&st->sd, indio_dev, spi, &ad7124_sigma_delta_info);
568 
569 	spi_set_drvdata(spi, indio_dev);
570 
571 	indio_dev->dev.parent = &spi->dev;
572 	indio_dev->name = spi_get_device_id(spi)->name;
573 	indio_dev->modes = INDIO_DIRECT_MODE;
574 	indio_dev->info = &ad7124_info;
575 
576 	ret = ad7124_of_parse_channel_config(indio_dev, spi->dev.of_node);
577 	if (ret < 0)
578 		return ret;
579 
580 	for (i = 0; i < ARRAY_SIZE(st->vref); i++) {
581 		if (i == AD7124_INT_REF)
582 			continue;
583 
584 		st->vref[i] = devm_regulator_get_optional(&spi->dev,
585 						ad7124_ref_names[i]);
586 		if (PTR_ERR(st->vref[i]) == -ENODEV)
587 			continue;
588 		else if (IS_ERR(st->vref[i]))
589 			return PTR_ERR(st->vref[i]);
590 
591 		ret = regulator_enable(st->vref[i]);
592 		if (ret)
593 			return ret;
594 	}
595 
596 	st->mclk = devm_clk_get(&spi->dev, "mclk");
597 	if (IS_ERR(st->mclk)) {
598 		ret = PTR_ERR(st->mclk);
599 		goto error_regulator_disable;
600 	}
601 
602 	ret = clk_prepare_enable(st->mclk);
603 	if (ret < 0)
604 		goto error_regulator_disable;
605 
606 	ret = ad7124_soft_reset(st);
607 	if (ret < 0)
608 		goto error_clk_disable_unprepare;
609 
610 	ret = ad7124_setup(st);
611 	if (ret < 0)
612 		goto error_clk_disable_unprepare;
613 
614 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
615 	if (ret < 0)
616 		goto error_clk_disable_unprepare;
617 
618 	ret = iio_device_register(indio_dev);
619 	if (ret < 0) {
620 		dev_err(&spi->dev, "Failed to register iio device\n");
621 		goto error_remove_trigger;
622 	}
623 
624 	return 0;
625 
626 error_remove_trigger:
627 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
628 error_clk_disable_unprepare:
629 	clk_disable_unprepare(st->mclk);
630 error_regulator_disable:
631 	for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) {
632 		if (!IS_ERR_OR_NULL(st->vref[i]))
633 			regulator_disable(st->vref[i]);
634 	}
635 
636 	return ret;
637 }
638 
639 static int ad7124_remove(struct spi_device *spi)
640 {
641 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
642 	struct ad7124_state *st = iio_priv(indio_dev);
643 	int i;
644 
645 	iio_device_unregister(indio_dev);
646 	ad_sd_cleanup_buffer_and_trigger(indio_dev);
647 	clk_disable_unprepare(st->mclk);
648 
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 0;
655 }
656 
657 static const struct spi_device_id ad7124_id_table[] = {
658 	{ "ad7124-4", ID_AD7124_4 },
659 	{ "ad7124-8", ID_AD7124_8 },
660 	{}
661 };
662 MODULE_DEVICE_TABLE(spi, ad7124_id_table);
663 
664 static const struct of_device_id ad7124_of_match[] = {
665 	{ .compatible = "adi,ad7124-4" },
666 	{ .compatible = "adi,ad7124-8" },
667 	{ },
668 };
669 MODULE_DEVICE_TABLE(of, ad7124_of_match);
670 
671 static struct spi_driver ad71124_driver = {
672 	.driver = {
673 		.name = "ad7124",
674 		.of_match_table = ad7124_of_match,
675 	},
676 	.probe = ad7124_probe,
677 	.remove	= ad7124_remove,
678 	.id_table = ad7124_id_table,
679 };
680 module_spi_driver(ad71124_driver);
681 
682 MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
683 MODULE_DESCRIPTION("Analog Devices AD7124 SPI driver");
684 MODULE_LICENSE("GPL");
685