xref: /linux/drivers/iio/adc/ad4851.c (revision ab93e0dd72c37d378dd936f031ffb83ff2bd87ce)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Analog Devices AD4851 DAS driver
4  *
5  * Copyright 2024 Analog Devices Inc.
6  */
7 
8 #include <linux/array_size.h>
9 #include <linux/bitfield.h>
10 #include <linux/bits.h>
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/minmax.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/pwm.h>
19 #include <linux/regmap.h>
20 #include <linux/regulator/consumer.h>
21 #include <linux/spi/spi.h>
22 #include <linux/types.h>
23 #include <linux/unaligned.h>
24 #include <linux/units.h>
25 
26 #include <linux/iio/backend.h>
27 #include <linux/iio/iio.h>
28 
29 #define AD4851_REG_INTERFACE_CONFIG_A	0x00
30 #define AD4851_REG_INTERFACE_CONFIG_B	0x01
31 #define AD4851_REG_PRODUCT_ID_L		0x04
32 #define AD4851_REG_PRODUCT_ID_H		0x05
33 #define AD4851_REG_DEVICE_CTRL		0x25
34 #define AD4851_REG_PACKET		0x26
35 #define AD4851_REG_OVERSAMPLE		0x27
36 
37 #define AD4851_REG_CH_CONFIG_BASE	0x2A
38 #define AD4851_REG_CHX_SOFTSPAN(ch)	((0x12 * (ch)) + AD4851_REG_CH_CONFIG_BASE)
39 #define AD4851_REG_CHX_OFFSET(ch)	(AD4851_REG_CHX_SOFTSPAN(ch) + 0x01)
40 #define AD4851_REG_CHX_OFFSET_LSB(ch)	AD4851_REG_CHX_OFFSET(ch)
41 #define AD4851_REG_CHX_OFFSET_MID(ch)	(AD4851_REG_CHX_OFFSET_LSB(ch) + 0x01)
42 #define AD4851_REG_CHX_OFFSET_MSB(ch)	(AD4851_REG_CHX_OFFSET_MID(ch) + 0x01)
43 #define AD4851_REG_CHX_GAIN(ch)		(AD4851_REG_CHX_OFFSET(ch) + 0x03)
44 #define AD4851_REG_CHX_GAIN_LSB(ch)	AD4851_REG_CHX_GAIN(ch)
45 #define AD4851_REG_CHX_GAIN_MSB(ch)	(AD4851_REG_CHX_GAIN(ch) + 0x01)
46 #define AD4851_REG_CHX_PHASE(ch)	(AD4851_REG_CHX_GAIN(ch) + 0x02)
47 #define AD4851_REG_CHX_PHASE_LSB(ch)	AD4851_REG_CHX_PHASE(ch)
48 #define AD4851_REG_CHX_PHASE_MSB(ch)	(AD4851_REG_CHX_PHASE_LSB(ch) + 0x01)
49 
50 #define AD4851_REG_TESTPAT_0(c)		(0x38 + (c) * 0x12)
51 #define AD4851_REG_TESTPAT_1(c)		(0x39 + (c) * 0x12)
52 #define AD4851_REG_TESTPAT_2(c)		(0x3A + (c) * 0x12)
53 #define AD4851_REG_TESTPAT_3(c)		(0x3B + (c) * 0x12)
54 
55 #define AD4851_SW_RESET			(BIT(7) | BIT(0))
56 #define AD4851_SDO_ENABLE		BIT(4)
57 #define AD4851_SINGLE_INSTRUCTION	BIT(7)
58 #define AD4851_REFBUF			BIT(2)
59 #define AD4851_REFSEL			BIT(1)
60 #define AD4851_ECHO_CLOCK_MODE		BIT(0)
61 
62 #define AD4851_PACKET_FORMAT_0		0
63 #define AD4851_PACKET_FORMAT_1		1
64 #define AD4851_PACKET_FORMAT_MASK	GENMASK(1, 0)
65 
66 #define AD4851_OS_EN_MSK		BIT(7)
67 #define AD4851_OS_RATIO_MSK		GENMASK(3, 0)
68 
69 #define AD4851_TEST_PAT			BIT(2)
70 
71 #define AD4858_PACKET_SIZE_20		0
72 #define AD4858_PACKET_SIZE_24		1
73 #define AD4858_PACKET_SIZE_32		2
74 
75 #define AD4857_PACKET_SIZE_16		0
76 #define AD4857_PACKET_SIZE_24		1
77 
78 #define AD4851_TESTPAT_0_DEFAULT	0x2A
79 #define AD4851_TESTPAT_1_DEFAULT	0x3C
80 #define AD4851_TESTPAT_2_DEFAULT	0xCE
81 #define AD4851_TESTPAT_3_DEFAULT(c)	(0x0A + (0x10 * (c)))
82 
83 #define AD4851_SOFTSPAN_0V_2V5		0
84 #define AD4851_SOFTSPAN_N2V5_2V5	1
85 #define AD4851_SOFTSPAN_0V_5V		2
86 #define AD4851_SOFTSPAN_N5V_5V		3
87 #define AD4851_SOFTSPAN_0V_6V25		4
88 #define AD4851_SOFTSPAN_N6V25_6V25	5
89 #define AD4851_SOFTSPAN_0V_10V		6
90 #define AD4851_SOFTSPAN_N10V_10V	7
91 #define AD4851_SOFTSPAN_0V_12V5		8
92 #define AD4851_SOFTSPAN_N12V5_12V5	9
93 #define AD4851_SOFTSPAN_0V_20V		10
94 #define AD4851_SOFTSPAN_N20V_20V	11
95 #define AD4851_SOFTSPAN_0V_25V		12
96 #define AD4851_SOFTSPAN_N25V_25V	13
97 #define AD4851_SOFTSPAN_0V_40V		14
98 #define AD4851_SOFTSPAN_N40V_40V	15
99 
100 #define AD4851_MAX_LANES		8
101 #define AD4851_MAX_IODELAY		32
102 
103 #define AD4851_T_CNVH_NS		40
104 #define AD4851_T_CNVH_NS_MARGIN		10
105 
106 #define AD4841_MAX_SCALE_AVAIL		8
107 
108 #define AD4851_MAX_CH_NR		8
109 #define AD4851_CH_START			0
110 
111 struct ad4851_scale {
112 	unsigned int scale_val;
113 	u8 reg_val;
114 };
115 
116 static const struct ad4851_scale ad4851_scale_table_unipolar[] = {
117 	{ 2500, 0x0 },
118 	{ 5000, 0x2 },
119 	{ 6250, 0x4 },
120 	{ 10000, 0x6 },
121 	{ 12500, 0x8 },
122 	{ 20000, 0xA },
123 	{ 25000, 0xC },
124 	{ 40000, 0xE },
125 };
126 
127 static const struct ad4851_scale ad4851_scale_table_bipolar[] = {
128 	{ 5000, 0x1 },
129 	{ 10000, 0x3 },
130 	{ 12500, 0x5 },
131 	{ 20000, 0x7 },
132 	{ 25000, 0x9 },
133 	{ 40000, 0xB },
134 	{ 50000, 0xD },
135 	{ 80000, 0xF },
136 };
137 
138 static const unsigned int ad4851_scale_avail_unipolar[] = {
139 	2500,
140 	5000,
141 	6250,
142 	10000,
143 	12500,
144 	20000,
145 	25000,
146 	40000,
147 };
148 
149 static const unsigned int ad4851_scale_avail_bipolar[] = {
150 	5000,
151 	10000,
152 	12500,
153 	20000,
154 	25000,
155 	40000,
156 	50000,
157 	80000,
158 };
159 
160 struct ad4851_chip_info {
161 	const char *name;
162 	unsigned int product_id;
163 	int num_scales;
164 	unsigned long max_sample_rate_hz;
165 	unsigned int resolution;
166 	unsigned int max_channels;
167 	int (*parse_channels)(struct iio_dev *indio_dev);
168 };
169 
170 enum {
171 	AD4851_SCAN_TYPE_NORMAL,
172 	AD4851_SCAN_TYPE_RESOLUTION_BOOST,
173 };
174 
175 struct ad4851_state {
176 	struct spi_device *spi;
177 	struct pwm_device *cnv;
178 	struct iio_backend *back;
179 	/*
180 	 * Synchronize access to members the of driver state, and ensure
181 	 * atomicity of consecutive regmap operations.
182 	 */
183 	struct mutex lock;
184 	struct regmap *regmap;
185 	const struct ad4851_chip_info *info;
186 	struct gpio_desc *pd_gpio;
187 	bool resolution_boost_enabled;
188 	unsigned long cnv_trigger_rate_hz;
189 	unsigned int osr;
190 	bool vrefbuf_en;
191 	bool vrefio_en;
192 	bool bipolar_ch[AD4851_MAX_CH_NR];
193 	unsigned int scales_unipolar[AD4841_MAX_SCALE_AVAIL][2];
194 	unsigned int scales_bipolar[AD4841_MAX_SCALE_AVAIL][2];
195 };
196 
ad4851_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)197 static int ad4851_reg_access(struct iio_dev *indio_dev,
198 			     unsigned int reg,
199 			     unsigned int writeval,
200 			     unsigned int *readval)
201 {
202 	struct ad4851_state *st = iio_priv(indio_dev);
203 
204 	if (readval)
205 		return regmap_read(st->regmap, reg, readval);
206 
207 	return regmap_write(st->regmap, reg, writeval);
208 }
209 
ad4851_set_sampling_freq(struct ad4851_state * st,unsigned int freq)210 static int ad4851_set_sampling_freq(struct ad4851_state *st, unsigned int freq)
211 {
212 	struct pwm_state cnv_state = {
213 		.duty_cycle = AD4851_T_CNVH_NS + AD4851_T_CNVH_NS_MARGIN,
214 		.enabled = true,
215 	};
216 	int ret;
217 
218 	freq = clamp(freq, 1, st->info->max_sample_rate_hz);
219 
220 	cnv_state.period = DIV_ROUND_UP_ULL(NSEC_PER_SEC, freq);
221 
222 	ret = pwm_apply_might_sleep(st->cnv, &cnv_state);
223 	if (ret)
224 		return ret;
225 
226 	st->cnv_trigger_rate_hz = freq;
227 
228 	return 0;
229 }
230 
231 static const int ad4851_oversampling_ratios[] = {
232 	1, 2, 4, 8, 16,	32, 64, 128,
233 	256, 512, 1024, 2048, 4096, 8192, 16384, 32768,
234 	65536,
235 };
236 
ad4851_osr_to_regval(unsigned int ratio)237 static int ad4851_osr_to_regval(unsigned int ratio)
238 {
239 	int i;
240 
241 	for (i = 1; i < ARRAY_SIZE(ad4851_oversampling_ratios); i++)
242 		if (ratio == ad4851_oversampling_ratios[i])
243 			return i - 1;
244 
245 	return -EINVAL;
246 }
247 
__ad4851_get_scale(struct iio_dev * indio_dev,int scale_tbl,unsigned int * val,unsigned int * val2)248 static int __ad4851_get_scale(struct iio_dev *indio_dev, int scale_tbl,
249 			      unsigned int *val, unsigned int *val2)
250 {
251 	const struct iio_scan_type *scan_type;
252 	unsigned int tmp;
253 
254 	scan_type = iio_get_current_scan_type(indio_dev, &indio_dev->channels[0]);
255 	if (IS_ERR(scan_type))
256 		return PTR_ERR(scan_type);
257 
258 	tmp = ((u64)scale_tbl * MICRO) >> scan_type->realbits;
259 	*val = tmp / MICRO;
260 	*val2 = tmp % MICRO;
261 
262 	return 0;
263 }
264 
ad4851_scale_fill(struct iio_dev * indio_dev)265 static int ad4851_scale_fill(struct iio_dev *indio_dev)
266 {
267 	struct ad4851_state *st = iio_priv(indio_dev);
268 	unsigned int i, val1, val2;
269 	int ret;
270 
271 	for (i = 0; i < ARRAY_SIZE(ad4851_scale_avail_unipolar); i++) {
272 		ret = __ad4851_get_scale(indio_dev,
273 					 ad4851_scale_avail_unipolar[i],
274 					 &val1, &val2);
275 		if (ret)
276 			return ret;
277 
278 		st->scales_unipolar[i][0] = val1;
279 		st->scales_unipolar[i][1] = val2;
280 	}
281 
282 	for (i = 0; i < ARRAY_SIZE(ad4851_scale_avail_bipolar); i++) {
283 		ret = __ad4851_get_scale(indio_dev,
284 					 ad4851_scale_avail_bipolar[i],
285 					 &val1, &val2);
286 		if (ret)
287 			return ret;
288 
289 		st->scales_bipolar[i][0] = val1;
290 		st->scales_bipolar[i][1] = val2;
291 	}
292 
293 	return 0;
294 }
295 
ad4851_set_oversampling_ratio(struct iio_dev * indio_dev,unsigned int osr)296 static int ad4851_set_oversampling_ratio(struct iio_dev *indio_dev,
297 					 unsigned int osr)
298 {
299 	struct ad4851_state *st = iio_priv(indio_dev);
300 	int val, ret;
301 
302 	guard(mutex)(&st->lock);
303 
304 	if (osr == 1) {
305 		ret = regmap_clear_bits(st->regmap, AD4851_REG_OVERSAMPLE,
306 					AD4851_OS_EN_MSK);
307 		if (ret)
308 			return ret;
309 	} else {
310 		val = ad4851_osr_to_regval(osr);
311 		if (val < 0)
312 			return -EINVAL;
313 
314 		ret = regmap_update_bits(st->regmap, AD4851_REG_OVERSAMPLE,
315 					 AD4851_OS_EN_MSK |
316 					 AD4851_OS_RATIO_MSK,
317 					 FIELD_PREP(AD4851_OS_EN_MSK, 1) |
318 					 FIELD_PREP(AD4851_OS_RATIO_MSK, val));
319 		if (ret)
320 			return ret;
321 	}
322 
323 	/* Channel is ignored by the backend being used here */
324 	ret = iio_backend_oversampling_ratio_set(st->back, 0, osr);
325 	if (ret)
326 		return ret;
327 
328 	switch (st->info->resolution) {
329 	case 20:
330 		switch (osr) {
331 		case 0:
332 			return -EINVAL;
333 		case 1:
334 			val = 20;
335 			break;
336 		default:
337 			val = 24;
338 			break;
339 		}
340 		break;
341 	case 16:
342 		val = 16;
343 		break;
344 	default:
345 		return -EINVAL;
346 	}
347 
348 	ret = iio_backend_data_size_set(st->back, val);
349 	if (ret)
350 		return ret;
351 
352 	if (osr == 1 || st->info->resolution == 16) {
353 		ret = regmap_clear_bits(st->regmap, AD4851_REG_PACKET,
354 					AD4851_PACKET_FORMAT_MASK);
355 		if (ret)
356 			return ret;
357 
358 		st->resolution_boost_enabled = false;
359 	} else {
360 		ret = regmap_update_bits(st->regmap, AD4851_REG_PACKET,
361 					 AD4851_PACKET_FORMAT_MASK,
362 					 FIELD_PREP(AD4851_PACKET_FORMAT_MASK, 1));
363 		if (ret)
364 			return ret;
365 
366 		st->resolution_boost_enabled = true;
367 	}
368 
369 	if (st->osr != osr) {
370 		ret = ad4851_scale_fill(indio_dev);
371 		if (ret)
372 			return ret;
373 
374 		st->osr = osr;
375 	}
376 
377 	return 0;
378 }
379 
ad4851_get_oversampling_ratio(struct ad4851_state * st,unsigned int * val)380 static int ad4851_get_oversampling_ratio(struct ad4851_state *st, unsigned int *val)
381 {
382 	unsigned int osr;
383 	int ret;
384 
385 	guard(mutex)(&st->lock);
386 
387 	ret = regmap_read(st->regmap, AD4851_REG_OVERSAMPLE, &osr);
388 	if (ret)
389 		return ret;
390 
391 	if (!FIELD_GET(AD4851_OS_EN_MSK, osr))
392 		*val = 1;
393 	else
394 		*val = ad4851_oversampling_ratios[FIELD_GET(AD4851_OS_RATIO_MSK, osr) + 1];
395 
396 	st->osr = *val;
397 
398 	return IIO_VAL_INT;
399 }
400 
ad4851_pwm_disable(void * data)401 static void ad4851_pwm_disable(void *data)
402 {
403 	pwm_disable(data);
404 }
405 
ad4851_setup(struct ad4851_state * st)406 static int ad4851_setup(struct ad4851_state *st)
407 {
408 	unsigned int product_id;
409 	int ret;
410 
411 	if (st->pd_gpio) {
412 		/* To initiate a global reset, bring the PD pin high twice */
413 		gpiod_set_value(st->pd_gpio, 1);
414 		fsleep(1);
415 		gpiod_set_value(st->pd_gpio, 0);
416 		fsleep(1);
417 		gpiod_set_value(st->pd_gpio, 1);
418 		fsleep(1);
419 		gpiod_set_value(st->pd_gpio, 0);
420 		fsleep(1000);
421 	} else {
422 		ret = regmap_set_bits(st->regmap, AD4851_REG_INTERFACE_CONFIG_A,
423 				      AD4851_SW_RESET);
424 		if (ret)
425 			return ret;
426 	}
427 
428 	if (st->vrefbuf_en) {
429 		ret = regmap_set_bits(st->regmap, AD4851_REG_DEVICE_CTRL,
430 				      AD4851_REFBUF);
431 		if (ret)
432 			return ret;
433 	}
434 
435 	if (st->vrefio_en) {
436 		ret = regmap_set_bits(st->regmap, AD4851_REG_DEVICE_CTRL,
437 				      AD4851_REFSEL);
438 		if (ret)
439 			return ret;
440 	}
441 
442 	ret = regmap_write(st->regmap, AD4851_REG_INTERFACE_CONFIG_B,
443 			   AD4851_SINGLE_INSTRUCTION);
444 	if (ret)
445 		return ret;
446 
447 	if (!(st->spi->mode & SPI_3WIRE)) {
448 		ret = regmap_write(st->regmap, AD4851_REG_INTERFACE_CONFIG_A,
449 				   AD4851_SDO_ENABLE);
450 		if (ret)
451 			return ret;
452 	}
453 
454 	ret = regmap_read(st->regmap, AD4851_REG_PRODUCT_ID_L, &product_id);
455 	if (ret)
456 		return ret;
457 
458 	if (product_id != st->info->product_id)
459 		dev_info(&st->spi->dev, "Unknown product ID: 0x%02X\n",
460 			 product_id);
461 
462 	ret = regmap_set_bits(st->regmap, AD4851_REG_DEVICE_CTRL,
463 			      AD4851_ECHO_CLOCK_MODE);
464 	if (ret)
465 		return ret;
466 
467 	return regmap_write(st->regmap, AD4851_REG_PACKET, 0);
468 }
469 
470 /*
471  * Find the longest consecutive sequence of false values from field
472  * and return starting index.
473  */
ad4851_find_opt(const unsigned long * field,unsigned int start,unsigned int nbits,unsigned int * val)474 static int ad4851_find_opt(const unsigned long *field, unsigned int start,
475 			   unsigned int nbits, unsigned int *val)
476 {
477 	unsigned int bit = start, end, start_cnt, cnt = 0;
478 
479 	for_each_clear_bitrange_from(bit, end, field, start + nbits) {
480 		if (end - bit > cnt) {
481 			cnt = end - bit;
482 			start_cnt = bit - start;
483 		}
484 	}
485 
486 	if (!cnt)
487 		return -ENOENT;
488 
489 	*val = start_cnt;
490 
491 	return cnt;
492 }
493 
ad4851_calibrate(struct iio_dev * indio_dev)494 static int ad4851_calibrate(struct iio_dev *indio_dev)
495 {
496 	struct ad4851_state *st = iio_priv(indio_dev);
497 	unsigned int opt_delay, num_lanes, delay, i, s;
498 	enum iio_backend_interface_type interface_type;
499 	DECLARE_BITMAP(pn_status, AD4851_MAX_LANES * AD4851_MAX_IODELAY);
500 	bool status;
501 	int c, ret;
502 
503 	ret = iio_backend_interface_type_get(st->back, &interface_type);
504 	if (ret)
505 		return ret;
506 
507 	switch (interface_type) {
508 	case IIO_BACKEND_INTERFACE_SERIAL_CMOS:
509 		num_lanes = indio_dev->num_channels;
510 		break;
511 	case IIO_BACKEND_INTERFACE_SERIAL_LVDS:
512 		num_lanes = 1;
513 		break;
514 	default:
515 		return -EINVAL;
516 	}
517 
518 	if (st->info->resolution == 16) {
519 		ret = iio_backend_data_size_set(st->back, 24);
520 		if (ret)
521 			return ret;
522 
523 		ret = regmap_write(st->regmap, AD4851_REG_PACKET,
524 				   AD4851_TEST_PAT | AD4857_PACKET_SIZE_24);
525 		if (ret)
526 			return ret;
527 	} else {
528 		ret = iio_backend_data_size_set(st->back, 32);
529 		if (ret)
530 			return ret;
531 
532 		ret = regmap_write(st->regmap, AD4851_REG_PACKET,
533 				   AD4851_TEST_PAT | AD4858_PACKET_SIZE_32);
534 		if (ret)
535 			return ret;
536 	}
537 
538 	for (i = 0; i < indio_dev->num_channels; i++) {
539 		ret = regmap_write(st->regmap, AD4851_REG_TESTPAT_0(i),
540 				   AD4851_TESTPAT_0_DEFAULT);
541 		if (ret)
542 			return ret;
543 
544 		ret = regmap_write(st->regmap, AD4851_REG_TESTPAT_1(i),
545 				   AD4851_TESTPAT_1_DEFAULT);
546 		if (ret)
547 			return ret;
548 
549 		ret = regmap_write(st->regmap, AD4851_REG_TESTPAT_2(i),
550 				   AD4851_TESTPAT_2_DEFAULT);
551 		if (ret)
552 			return ret;
553 
554 		ret = regmap_write(st->regmap, AD4851_REG_TESTPAT_3(i),
555 				   AD4851_TESTPAT_3_DEFAULT(i));
556 		if (ret)
557 			return ret;
558 
559 		ret = iio_backend_chan_enable(st->back,
560 					      indio_dev->channels[i].channel);
561 		if (ret)
562 			return ret;
563 	}
564 
565 	for (i = 0; i < num_lanes; i++) {
566 		for (delay = 0; delay < AD4851_MAX_IODELAY; delay++) {
567 			ret = iio_backend_iodelay_set(st->back, i, delay);
568 			if (ret)
569 				return ret;
570 
571 			ret = iio_backend_chan_status(st->back, i, &status);
572 			if (ret)
573 				return ret;
574 
575 			__assign_bit(i * AD4851_MAX_IODELAY + delay, pn_status,
576 				     status);
577 		}
578 	}
579 
580 	for (i = 0; i < num_lanes; i++) {
581 		c = ad4851_find_opt(pn_status, i * AD4851_MAX_IODELAY,
582 				    AD4851_MAX_IODELAY, &s);
583 		if (c < 0)
584 			return c;
585 
586 		opt_delay = s + c / 2;
587 		ret = iio_backend_iodelay_set(st->back, i, opt_delay);
588 		if (ret)
589 			return ret;
590 	}
591 
592 	for (i = 0; i < indio_dev->num_channels; i++) {
593 		ret = iio_backend_chan_disable(st->back, i);
594 		if (ret)
595 			return ret;
596 	}
597 
598 	ret = iio_backend_data_size_set(st->back, 20);
599 	if (ret)
600 		return ret;
601 
602 	return regmap_write(st->regmap, AD4851_REG_PACKET, 0);
603 }
604 
ad4851_get_calibscale(struct ad4851_state * st,int ch,int * val,int * val2)605 static int ad4851_get_calibscale(struct ad4851_state *st, int ch, int *val, int *val2)
606 {
607 	unsigned int reg_val;
608 	int gain;
609 	int ret;
610 
611 	guard(mutex)(&st->lock);
612 
613 	ret = regmap_read(st->regmap, AD4851_REG_CHX_GAIN_MSB(ch), &reg_val);
614 	if (ret)
615 		return ret;
616 
617 	gain = reg_val << 8;
618 
619 	ret = regmap_read(st->regmap, AD4851_REG_CHX_GAIN_LSB(ch), &reg_val);
620 	if (ret)
621 		return ret;
622 
623 	gain |= reg_val;
624 
625 	*val = gain;
626 	*val2 = 15;
627 
628 	return IIO_VAL_FRACTIONAL_LOG2;
629 }
630 
ad4851_set_calibscale(struct ad4851_state * st,int ch,int val,int val2)631 static int ad4851_set_calibscale(struct ad4851_state *st, int ch, int val,
632 				 int val2)
633 {
634 	u64 gain;
635 	u8 buf[2];
636 	int ret;
637 
638 	if (val < 0 || val2 < 0)
639 		return -EINVAL;
640 
641 	gain = val * MICRO + val2;
642 	gain = DIV_U64_ROUND_CLOSEST(gain * 32768, MICRO);
643 
644 	put_unaligned_be16(gain, buf);
645 
646 	guard(mutex)(&st->lock);
647 
648 	ret = regmap_write(st->regmap, AD4851_REG_CHX_GAIN_MSB(ch), buf[0]);
649 	if (ret)
650 		return ret;
651 
652 	return regmap_write(st->regmap, AD4851_REG_CHX_GAIN_LSB(ch), buf[1]);
653 }
654 
ad4851_get_calibbias(struct ad4851_state * st,int ch,int * val)655 static int ad4851_get_calibbias(struct ad4851_state *st, int ch, int *val)
656 {
657 	unsigned int lsb, mid, msb;
658 	int ret;
659 
660 	guard(mutex)(&st->lock);
661 	/*
662 	 * After testing, the bulk_write operations doesn't work as expected
663 	 * here since the cs needs to be raised after each byte transaction.
664 	 */
665 	ret = regmap_read(st->regmap, AD4851_REG_CHX_OFFSET_MSB(ch), &msb);
666 	if (ret)
667 		return ret;
668 
669 	ret = regmap_read(st->regmap, AD4851_REG_CHX_OFFSET_MID(ch), &mid);
670 	if (ret)
671 		return ret;
672 
673 	ret = regmap_read(st->regmap, AD4851_REG_CHX_OFFSET_LSB(ch), &lsb);
674 	if (ret)
675 		return ret;
676 
677 	if (st->info->resolution == 16) {
678 		*val = msb << 8;
679 		*val |= mid;
680 		*val = sign_extend32(*val, 15);
681 	} else {
682 		*val = msb << 12;
683 		*val |= mid << 4;
684 		*val |= lsb >> 4;
685 		*val = sign_extend32(*val, 19);
686 	}
687 
688 	return IIO_VAL_INT;
689 }
690 
ad4851_set_calibbias(struct ad4851_state * st,int ch,int val)691 static int ad4851_set_calibbias(struct ad4851_state *st, int ch, int val)
692 {
693 	u8 buf[3];
694 	int ret;
695 
696 	if (val < 0)
697 		return -EINVAL;
698 
699 	if (st->info->resolution == 16)
700 		put_unaligned_be16(val, buf);
701 	else
702 		put_unaligned_be24(val << 4, buf);
703 
704 	guard(mutex)(&st->lock);
705 	/*
706 	 * After testing, the bulk_write operations doesn't work as expected
707 	 * here since the cs needs to be raised after each byte transaction.
708 	 */
709 	ret = regmap_write(st->regmap, AD4851_REG_CHX_OFFSET_LSB(ch), buf[2]);
710 	if (ret)
711 		return ret;
712 
713 	ret = regmap_write(st->regmap, AD4851_REG_CHX_OFFSET_MID(ch), buf[1]);
714 	if (ret)
715 		return ret;
716 
717 	return regmap_write(st->regmap, AD4851_REG_CHX_OFFSET_MSB(ch), buf[0]);
718 }
719 
ad4851_set_scale(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int val,int val2)720 static int ad4851_set_scale(struct iio_dev *indio_dev,
721 			    const struct iio_chan_spec *chan, int val, int val2)
722 {
723 	struct ad4851_state *st = iio_priv(indio_dev);
724 	unsigned int scale_val[2];
725 	unsigned int i;
726 	const struct ad4851_scale *scale_table;
727 	size_t table_size;
728 	int ret;
729 
730 	if (st->bipolar_ch[chan->channel]) {
731 		scale_table = ad4851_scale_table_bipolar;
732 		table_size = ARRAY_SIZE(ad4851_scale_table_bipolar);
733 	} else {
734 		scale_table = ad4851_scale_table_unipolar;
735 		table_size = ARRAY_SIZE(ad4851_scale_table_unipolar);
736 	}
737 
738 	for (i = 0; i < table_size; i++) {
739 		ret = __ad4851_get_scale(indio_dev, scale_table[i].scale_val,
740 					 &scale_val[0], &scale_val[1]);
741 		if (ret)
742 			return ret;
743 
744 		if (scale_val[0] != val || scale_val[1] != val2)
745 			continue;
746 
747 		return regmap_write(st->regmap,
748 				    AD4851_REG_CHX_SOFTSPAN(chan->channel),
749 				    scale_table[i].reg_val);
750 	}
751 
752 	return -EINVAL;
753 }
754 
ad4851_get_scale(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int * val,int * val2)755 static int ad4851_get_scale(struct iio_dev *indio_dev,
756 			    const struct iio_chan_spec *chan, int *val,
757 			    int *val2)
758 {
759 	struct ad4851_state *st = iio_priv(indio_dev);
760 	const struct ad4851_scale *scale_table;
761 	size_t table_size;
762 	u32 softspan_val;
763 	int i, ret;
764 
765 	if (st->bipolar_ch[chan->channel]) {
766 		scale_table = ad4851_scale_table_bipolar;
767 		table_size = ARRAY_SIZE(ad4851_scale_table_bipolar);
768 	} else {
769 		scale_table = ad4851_scale_table_unipolar;
770 		table_size = ARRAY_SIZE(ad4851_scale_table_unipolar);
771 	}
772 
773 	ret = regmap_read(st->regmap, AD4851_REG_CHX_SOFTSPAN(chan->channel),
774 			  &softspan_val);
775 	if (ret)
776 		return ret;
777 
778 	for (i = 0; i < table_size; i++) {
779 		if (softspan_val == scale_table[i].reg_val)
780 			break;
781 	}
782 
783 	if (i == table_size)
784 		return -EIO;
785 
786 	ret = __ad4851_get_scale(indio_dev, scale_table[i].scale_val, val,
787 				 val2);
788 	if (ret)
789 		return ret;
790 
791 	return IIO_VAL_INT_PLUS_MICRO;
792 }
793 
ad4851_read_raw(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int * val,int * val2,long info)794 static int ad4851_read_raw(struct iio_dev *indio_dev,
795 			   const struct iio_chan_spec *chan,
796 			   int *val, int *val2, long info)
797 {
798 	struct ad4851_state *st = iio_priv(indio_dev);
799 
800 	switch (info) {
801 	case IIO_CHAN_INFO_SAMP_FREQ:
802 		*val = st->cnv_trigger_rate_hz;
803 		*val2 = st->osr;
804 		return IIO_VAL_FRACTIONAL;
805 	case IIO_CHAN_INFO_CALIBSCALE:
806 		return ad4851_get_calibscale(st, chan->channel, val, val2);
807 	case IIO_CHAN_INFO_SCALE:
808 		return ad4851_get_scale(indio_dev, chan, val, val2);
809 	case IIO_CHAN_INFO_CALIBBIAS:
810 		return ad4851_get_calibbias(st, chan->channel, val);
811 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
812 		return ad4851_get_oversampling_ratio(st, val);
813 	default:
814 		return -EINVAL;
815 	}
816 }
817 
ad4851_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long info)818 static int ad4851_write_raw(struct iio_dev *indio_dev,
819 			    struct iio_chan_spec const *chan,
820 			    int val, int val2, long info)
821 {
822 	struct ad4851_state *st = iio_priv(indio_dev);
823 
824 	switch (info) {
825 	case IIO_CHAN_INFO_SAMP_FREQ:
826 		if (val < 0 || val2 < 0)
827 			return -EINVAL;
828 		return ad4851_set_sampling_freq(st, val * st->osr + val2 * st->osr / MICRO);
829 	case IIO_CHAN_INFO_SCALE:
830 		return ad4851_set_scale(indio_dev, chan, val, val2);
831 	case IIO_CHAN_INFO_CALIBSCALE:
832 		return ad4851_set_calibscale(st, chan->channel, val, val2);
833 	case IIO_CHAN_INFO_CALIBBIAS:
834 		return ad4851_set_calibbias(st, chan->channel, val);
835 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
836 		return ad4851_set_oversampling_ratio(indio_dev, val);
837 	default:
838 		return -EINVAL;
839 	}
840 }
841 
ad4851_update_scan_mode(struct iio_dev * indio_dev,const unsigned long * scan_mask)842 static int ad4851_update_scan_mode(struct iio_dev *indio_dev,
843 				   const unsigned long *scan_mask)
844 {
845 	struct ad4851_state *st = iio_priv(indio_dev);
846 	unsigned int c;
847 	int ret;
848 
849 	for (c = 0; c < indio_dev->num_channels; c++) {
850 		if (test_bit(c, scan_mask))
851 			ret = iio_backend_chan_enable(st->back, c);
852 		else
853 			ret = iio_backend_chan_disable(st->back, c);
854 		if (ret)
855 			return ret;
856 	}
857 
858 	return 0;
859 }
860 
ad4851_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)861 static int ad4851_read_avail(struct iio_dev *indio_dev,
862 			     struct iio_chan_spec const *chan,
863 			     const int **vals, int *type, int *length,
864 			     long mask)
865 {
866 	struct ad4851_state *st = iio_priv(indio_dev);
867 
868 	switch (mask) {
869 	case IIO_CHAN_INFO_SCALE:
870 		if (st->bipolar_ch[chan->channel]) {
871 			*vals = (const int *)st->scales_bipolar;
872 			*type = IIO_VAL_INT_PLUS_MICRO;
873 			/* Values are stored in a 2D matrix */
874 			*length = ARRAY_SIZE(ad4851_scale_avail_bipolar) * 2;
875 		} else {
876 			*vals = (const int *)st->scales_unipolar;
877 			*type = IIO_VAL_INT_PLUS_MICRO;
878 			/* Values are stored in a 2D matrix */
879 			*length = ARRAY_SIZE(ad4851_scale_avail_unipolar) * 2;
880 		}
881 		return IIO_AVAIL_LIST;
882 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
883 		*vals = ad4851_oversampling_ratios;
884 		*length = ARRAY_SIZE(ad4851_oversampling_ratios);
885 		*type = IIO_VAL_INT;
886 		return IIO_AVAIL_LIST;
887 	default:
888 		return -EINVAL;
889 	}
890 }
891 
892 static const struct iio_scan_type ad4851_scan_type_20_u[] = {
893 	[AD4851_SCAN_TYPE_NORMAL] = {
894 		.sign = 'u',
895 		.realbits = 20,
896 		.storagebits = 32,
897 	},
898 	[AD4851_SCAN_TYPE_RESOLUTION_BOOST] = {
899 		.sign = 'u',
900 		.realbits = 24,
901 		.storagebits = 32,
902 	},
903 };
904 
905 static const struct iio_scan_type ad4851_scan_type_20_b[] = {
906 	[AD4851_SCAN_TYPE_NORMAL] = {
907 		.sign = 's',
908 		.realbits = 20,
909 		.storagebits = 32,
910 	},
911 	[AD4851_SCAN_TYPE_RESOLUTION_BOOST] = {
912 		.sign = 's',
913 		.realbits = 24,
914 		.storagebits = 32,
915 	},
916 };
917 
ad4851_get_current_scan_type(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)918 static int ad4851_get_current_scan_type(const struct iio_dev *indio_dev,
919 					const struct iio_chan_spec *chan)
920 {
921 	struct ad4851_state *st = iio_priv(indio_dev);
922 
923 	return st->resolution_boost_enabled ? AD4851_SCAN_TYPE_RESOLUTION_BOOST
924 					    : AD4851_SCAN_TYPE_NORMAL;
925 }
926 
927 #define AD4851_IIO_CHANNEL							\
928 	.type = IIO_VOLTAGE,							\
929 	.info_mask_separate = BIT(IIO_CHAN_INFO_CALIBSCALE) |			\
930 		BIT(IIO_CHAN_INFO_CALIBBIAS) |					\
931 		BIT(IIO_CHAN_INFO_SCALE),					\
932 	.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE),		\
933 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |		\
934 		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),				\
935 	.info_mask_shared_by_all_available =					\
936 		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),				\
937 	.indexed = 1
938 
939 /*
940  * In case of AD4858_IIO_CHANNEL the scan_type is handled dynamically during the
941  * parse_channels function.
942  */
943 #define AD4858_IIO_CHANNEL							\
944 {										\
945 	AD4851_IIO_CHANNEL							\
946 }
947 
948 #define AD4857_IIO_CHANNEL							\
949 {										\
950 	AD4851_IIO_CHANNEL,							\
951 	.scan_type = {								\
952 		.sign = 'u',							\
953 		.realbits = 16,							\
954 		.storagebits = 16,						\
955 	},									\
956 }
957 
ad4851_parse_channels_common(struct iio_dev * indio_dev,struct iio_chan_spec ** chans,const struct iio_chan_spec ad4851_chan)958 static int ad4851_parse_channels_common(struct iio_dev *indio_dev,
959 					struct iio_chan_spec **chans,
960 					const struct iio_chan_spec ad4851_chan)
961 {
962 	struct ad4851_state *st = iio_priv(indio_dev);
963 	struct device *dev = &st->spi->dev;
964 	struct iio_chan_spec *channels, *chan_start;
965 	unsigned int num_channels, reg;
966 	unsigned int index = 0;
967 	int ret;
968 
969 	num_channels = device_get_child_node_count(dev);
970 	if (num_channels > AD4851_MAX_CH_NR)
971 		return dev_err_probe(dev, -EINVAL, "Too many channels: %u\n",
972 				     num_channels);
973 
974 	channels = devm_kcalloc(dev, num_channels, sizeof(*channels), GFP_KERNEL);
975 	if (!channels)
976 		return -ENOMEM;
977 
978 	chan_start = channels;
979 
980 	device_for_each_child_node_scoped(dev, child) {
981 		ret = fwnode_property_read_u32(child, "reg", &reg);
982 		if (ret)
983 			return dev_err_probe(dev, ret,
984 					     "Missing channel number\n");
985 		if (reg >= AD4851_MAX_CH_NR)
986 			return dev_err_probe(dev, -EINVAL,
987 					     "Invalid channel number\n");
988 		*channels = ad4851_chan;
989 		channels->scan_index = index++;
990 		channels->channel = reg;
991 
992 		if (fwnode_property_present(child, "diff-channels")) {
993 			channels->channel2 = reg + st->info->max_channels;
994 			channels->differential = 1;
995 		}
996 
997 		st->bipolar_ch[reg] = fwnode_property_read_bool(child, "bipolar");
998 
999 		if (st->bipolar_ch[reg]) {
1000 			channels->scan_type.sign = 's';
1001 		} else {
1002 			ret = regmap_write(st->regmap, AD4851_REG_CHX_SOFTSPAN(reg),
1003 					   AD4851_SOFTSPAN_0V_40V);
1004 			if (ret)
1005 				return ret;
1006 		}
1007 
1008 		channels++;
1009 	}
1010 
1011 	*chans = chan_start;
1012 
1013 	return num_channels;
1014 }
1015 
ad4857_parse_channels(struct iio_dev * indio_dev)1016 static int ad4857_parse_channels(struct iio_dev *indio_dev)
1017 {
1018 	struct iio_chan_spec *ad4851_channels;
1019 	const struct iio_chan_spec ad4851_chan = AD4857_IIO_CHANNEL;
1020 	int ret;
1021 
1022 	ret = ad4851_parse_channels_common(indio_dev, &ad4851_channels,
1023 					   ad4851_chan);
1024 	if (ret < 0)
1025 		return ret;
1026 
1027 	indio_dev->channels = ad4851_channels;
1028 	indio_dev->num_channels = ret;
1029 
1030 	return 0;
1031 }
1032 
ad4858_parse_channels(struct iio_dev * indio_dev)1033 static int ad4858_parse_channels(struct iio_dev *indio_dev)
1034 {
1035 	struct ad4851_state *st = iio_priv(indio_dev);
1036 	struct device *dev = &st->spi->dev;
1037 	struct iio_chan_spec *ad4851_channels;
1038 	const struct iio_chan_spec ad4851_chan = AD4858_IIO_CHANNEL;
1039 	int ret, i = 0;
1040 
1041 	ret = ad4851_parse_channels_common(indio_dev, &ad4851_channels,
1042 					   ad4851_chan);
1043 	if (ret < 0)
1044 		return ret;
1045 
1046 	device_for_each_child_node_scoped(dev, child) {
1047 		ad4851_channels[i].has_ext_scan_type = 1;
1048 		if (fwnode_property_read_bool(child, "bipolar")) {
1049 			ad4851_channels[i].ext_scan_type = ad4851_scan_type_20_b;
1050 			ad4851_channels[i].num_ext_scan_type = ARRAY_SIZE(ad4851_scan_type_20_b);
1051 		} else {
1052 			ad4851_channels[i].ext_scan_type = ad4851_scan_type_20_u;
1053 			ad4851_channels[i].num_ext_scan_type = ARRAY_SIZE(ad4851_scan_type_20_u);
1054 		}
1055 		i++;
1056 	}
1057 
1058 	indio_dev->channels = ad4851_channels;
1059 	indio_dev->num_channels = ret;
1060 
1061 	return 0;
1062 }
1063 
1064 /*
1065  * parse_channels() function handles the rest of the channel related attributes
1066  * that are usually are stored in the chip info structure.
1067  */
1068 static const struct ad4851_chip_info ad4851_info = {
1069 	.name = "ad4851",
1070 	.product_id = 0x67,
1071 	.max_sample_rate_hz = 250 * KILO,
1072 	.resolution = 16,
1073 	.max_channels = AD4851_MAX_CH_NR,
1074 	.parse_channels = ad4857_parse_channels,
1075 };
1076 
1077 static const struct ad4851_chip_info ad4852_info = {
1078 	.name = "ad4852",
1079 	.product_id = 0x66,
1080 	.max_sample_rate_hz = 250 * KILO,
1081 	.resolution = 20,
1082 	.max_channels = AD4851_MAX_CH_NR,
1083 	.parse_channels = ad4858_parse_channels,
1084 };
1085 
1086 static const struct ad4851_chip_info ad4853_info = {
1087 	.name = "ad4853",
1088 	.product_id = 0x65,
1089 	.max_sample_rate_hz = 1 * MEGA,
1090 	.resolution = 16,
1091 	.max_channels = AD4851_MAX_CH_NR,
1092 	.parse_channels = ad4857_parse_channels,
1093 };
1094 
1095 static const struct ad4851_chip_info ad4854_info = {
1096 	.name = "ad4854",
1097 	.product_id = 0x64,
1098 	.max_sample_rate_hz = 1 * MEGA,
1099 	.resolution = 20,
1100 	.max_channels = AD4851_MAX_CH_NR,
1101 	.parse_channels = ad4858_parse_channels,
1102 };
1103 
1104 static const struct ad4851_chip_info ad4855_info = {
1105 	.name = "ad4855",
1106 	.product_id = 0x63,
1107 	.max_sample_rate_hz = 250 * KILO,
1108 	.resolution = 16,
1109 	.max_channels = AD4851_MAX_CH_NR,
1110 	.parse_channels = ad4857_parse_channels,
1111 };
1112 
1113 static const struct ad4851_chip_info ad4856_info = {
1114 	.name = "ad4856",
1115 	.product_id = 0x62,
1116 	.max_sample_rate_hz = 250 * KILO,
1117 	.resolution = 20,
1118 	.max_channels = AD4851_MAX_CH_NR,
1119 	.parse_channels = ad4858_parse_channels,
1120 };
1121 
1122 static const struct ad4851_chip_info ad4857_info = {
1123 	.name = "ad4857",
1124 	.product_id = 0x61,
1125 	.max_sample_rate_hz = 1 * MEGA,
1126 	.resolution = 16,
1127 	.max_channels = AD4851_MAX_CH_NR,
1128 	.parse_channels = ad4857_parse_channels,
1129 };
1130 
1131 static const struct ad4851_chip_info ad4858_info = {
1132 	.name = "ad4858",
1133 	.product_id = 0x60,
1134 	.max_sample_rate_hz = 1 * MEGA,
1135 	.resolution = 20,
1136 	.max_channels = AD4851_MAX_CH_NR,
1137 	.parse_channels = ad4858_parse_channels,
1138 };
1139 
1140 static const struct ad4851_chip_info ad4858i_info = {
1141 	.name = "ad4858i",
1142 	.product_id = 0x6F,
1143 	.max_sample_rate_hz = 1 * MEGA,
1144 	.resolution = 20,
1145 	.max_channels = AD4851_MAX_CH_NR,
1146 	.parse_channels = ad4858_parse_channels,
1147 };
1148 
1149 static const struct iio_info ad4851_iio_info = {
1150 	.debugfs_reg_access = ad4851_reg_access,
1151 	.read_raw = ad4851_read_raw,
1152 	.write_raw = ad4851_write_raw,
1153 	.update_scan_mode = ad4851_update_scan_mode,
1154 	.get_current_scan_type = ad4851_get_current_scan_type,
1155 	.read_avail = ad4851_read_avail,
1156 };
1157 
1158 static const struct regmap_config regmap_config = {
1159 	.reg_bits = 16,
1160 	.val_bits = 8,
1161 	.read_flag_mask = BIT(7),
1162 };
1163 
1164 static const char * const ad4851_power_supplies[] = {
1165 	"vcc",	"vdd", "vee", "vio",
1166 };
1167 
ad4851_probe(struct spi_device * spi)1168 static int ad4851_probe(struct spi_device *spi)
1169 {
1170 	struct iio_dev *indio_dev;
1171 	struct device *dev = &spi->dev;
1172 	struct ad4851_state *st;
1173 	int ret;
1174 
1175 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
1176 	if (!indio_dev)
1177 		return -ENOMEM;
1178 
1179 	st = iio_priv(indio_dev);
1180 	st->spi = spi;
1181 
1182 	ret = devm_mutex_init(dev, &st->lock);
1183 	if (ret)
1184 		return ret;
1185 
1186 	ret = devm_regulator_bulk_get_enable(dev,
1187 					     ARRAY_SIZE(ad4851_power_supplies),
1188 					     ad4851_power_supplies);
1189 	if (ret)
1190 		return dev_err_probe(dev, ret,
1191 				     "failed to get and enable supplies\n");
1192 
1193 	ret = devm_regulator_get_enable_optional(dev, "vddh");
1194 	if (ret < 0 && ret != -ENODEV)
1195 		return dev_err_probe(dev, ret, "failed to enable vddh voltage\n");
1196 
1197 	ret = devm_regulator_get_enable_optional(dev, "vddl");
1198 	if (ret < 0 && ret != -ENODEV)
1199 		return dev_err_probe(dev, ret, "failed to enable vddl voltage\n");
1200 
1201 	ret = devm_regulator_get_enable_optional(dev, "vrefbuf");
1202 	if (ret < 0 && ret != -ENODEV)
1203 		return dev_err_probe(dev, ret, "failed to enable vrefbuf voltage\n");
1204 
1205 	st->vrefbuf_en = ret != -ENODEV;
1206 
1207 	ret = devm_regulator_get_enable_optional(dev, "vrefio");
1208 	if (ret < 0 && ret != -ENODEV)
1209 		return dev_err_probe(dev, ret, "failed to enable vrefio voltage\n");
1210 
1211 	st->vrefio_en = ret != -ENODEV;
1212 
1213 	st->pd_gpio = devm_gpiod_get_optional(dev, "pd", GPIOD_OUT_LOW);
1214 	if (IS_ERR(st->pd_gpio))
1215 		return dev_err_probe(dev, PTR_ERR(st->pd_gpio),
1216 				     "Error on requesting pd GPIO\n");
1217 
1218 	st->cnv = devm_pwm_get(dev, NULL);
1219 	if (IS_ERR(st->cnv))
1220 		return dev_err_probe(dev, PTR_ERR(st->cnv),
1221 				     "Error on requesting pwm\n");
1222 
1223 	st->info = spi_get_device_match_data(spi);
1224 	if (!st->info)
1225 		return -ENODEV;
1226 
1227 	st->regmap = devm_regmap_init_spi(spi, &regmap_config);
1228 	if (IS_ERR(st->regmap))
1229 		return PTR_ERR(st->regmap);
1230 
1231 	ret = ad4851_set_sampling_freq(st, HZ_PER_MHZ);
1232 	if (ret)
1233 		return ret;
1234 
1235 	ret = devm_add_action_or_reset(&st->spi->dev, ad4851_pwm_disable,
1236 				       st->cnv);
1237 	if (ret)
1238 		return ret;
1239 
1240 	ret = ad4851_setup(st);
1241 	if (ret)
1242 		return ret;
1243 
1244 	indio_dev->name = st->info->name;
1245 	indio_dev->info = &ad4851_iio_info;
1246 	indio_dev->modes = INDIO_DIRECT_MODE;
1247 
1248 	ret = st->info->parse_channels(indio_dev);
1249 	if (ret)
1250 		return ret;
1251 
1252 	ret = ad4851_scale_fill(indio_dev);
1253 	if (ret)
1254 		return ret;
1255 
1256 	st->back = devm_iio_backend_get(dev, NULL);
1257 	if (IS_ERR(st->back))
1258 		return PTR_ERR(st->back);
1259 
1260 	ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev);
1261 	if (ret)
1262 		return ret;
1263 
1264 	ret = devm_iio_backend_enable(dev, st->back);
1265 	if (ret)
1266 		return ret;
1267 
1268 	ret = ad4851_calibrate(indio_dev);
1269 	if (ret)
1270 		return ret;
1271 
1272 	return devm_iio_device_register(dev, indio_dev);
1273 }
1274 
1275 static const struct of_device_id ad4851_of_match[] = {
1276 	{ .compatible = "adi,ad4851", .data = &ad4851_info, },
1277 	{ .compatible = "adi,ad4852", .data = &ad4852_info, },
1278 	{ .compatible = "adi,ad4853", .data = &ad4853_info, },
1279 	{ .compatible = "adi,ad4854", .data = &ad4854_info, },
1280 	{ .compatible = "adi,ad4855", .data = &ad4855_info, },
1281 	{ .compatible = "adi,ad4856", .data = &ad4856_info, },
1282 	{ .compatible = "adi,ad4857", .data = &ad4857_info, },
1283 	{ .compatible = "adi,ad4858", .data = &ad4858_info, },
1284 	{ .compatible = "adi,ad4858i", .data = &ad4858i_info, },
1285 	{ }
1286 };
1287 
1288 static const struct spi_device_id ad4851_spi_id[] = {
1289 	{ "ad4851", (kernel_ulong_t)&ad4851_info },
1290 	{ "ad4852", (kernel_ulong_t)&ad4852_info },
1291 	{ "ad4853", (kernel_ulong_t)&ad4853_info },
1292 	{ "ad4854", (kernel_ulong_t)&ad4854_info },
1293 	{ "ad4855", (kernel_ulong_t)&ad4855_info },
1294 	{ "ad4856", (kernel_ulong_t)&ad4856_info },
1295 	{ "ad4857", (kernel_ulong_t)&ad4857_info },
1296 	{ "ad4858", (kernel_ulong_t)&ad4858_info },
1297 	{ "ad4858i", (kernel_ulong_t)&ad4858i_info },
1298 	{ }
1299 };
1300 MODULE_DEVICE_TABLE(spi, ad4851_spi_id);
1301 
1302 static struct spi_driver ad4851_driver = {
1303 	.probe = ad4851_probe,
1304 	.driver = {
1305 		.name = "ad4851",
1306 		.of_match_table = ad4851_of_match,
1307 	},
1308 	.id_table = ad4851_spi_id,
1309 };
1310 module_spi_driver(ad4851_driver);
1311 
1312 MODULE_AUTHOR("Sergiu Cuciurean <sergiu.cuciurean@analog.com>");
1313 MODULE_AUTHOR("Dragos Bogdan <dragos.bogdan@analog.com>");
1314 MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
1315 MODULE_DESCRIPTION("Analog Devices AD4851 DAS driver");
1316 MODULE_LICENSE("GPL");
1317 MODULE_IMPORT_NS("IIO_BACKEND");
1318