1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * AD7770, AD7771, AD7779 ADC
4  *
5  * Copyright 2023-2024 Analog Devices Inc.
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/bitmap.h>
10 #include <linux/clk.h>
11 #include <linux/crc8.h>
12 #include <linux/delay.h>
13 #include <linux/err.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/math.h>
18 #include <linux/module.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/regulator/consumer.h>
21 #include <linux/spi/spi.h>
22 #include <linux/string.h>
23 #include <linux/types.h>
24 #include <linux/unaligned.h>
25 #include <linux/units.h>
26 
27 #include <linux/iio/iio.h>
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/sysfs.h>
30 #include <linux/iio/trigger.h>
31 #include <linux/iio/triggered_buffer.h>
32 #include <linux/iio/trigger_consumer.h>
33 
34 #define AD7779_SPI_READ_CMD			BIT(7)
35 
36 #define AD7779_DISABLE_SD			BIT(7)
37 
38 #define AD7779_REG_CH_DISABLE			0x08
39 #define AD7779_REG_CH_SYNC_OFFSET(ch)		(0x09 + (ch))
40 #define AD7779_REG_CH_CONFIG(ch)		(0x00 + (ch))
41 #define AD7779_REG_GENERAL_USER_CONFIG_1	0x11
42 #define AD7779_REG_GENERAL_USER_CONFIG_2	0x12
43 #define AD7779_REG_GENERAL_USER_CONFIG_3	0x13
44 #define AD7779_REG_DOUT_FORMAT			0x14
45 #define AD7779_REG_ADC_MUX_CONFIG		0x15
46 #define AD7779_REG_GPIO_CONFIG			0x17
47 #define AD7779_REG_BUFFER_CONFIG_1		0x19
48 #define AD7779_REG_GLOBAL_MUX_CONFIG		0x16
49 #define AD7779_REG_BUFFER_CONFIG_2		0x1A
50 #define AD7779_REG_GPIO_DATA			0x18
51 #define AD7779_REG_CH_OFFSET_UPPER_BYTE(ch)	(0x1C + (ch) * 6)
52 #define AD7779_REG_CH_OFFSET_LOWER_BYTE(ch)	(0x1E + (ch) * 6)
53 #define AD7779_REG_CH_GAIN_UPPER_BYTE(ch)	(0x1F + (ch) * 6)
54 #define AD7779_REG_CH_OFFSET_MID_BYTE(ch)	(0x1D + (ch) * 6)
55 #define AD7779_REG_CH_GAIN_MID_BYTE(ch)		(0x20 + (ch) * 6)
56 #define AD7779_REG_CH_ERR_REG(ch)		(0x4C + (ch))
57 #define AD7779_REG_CH0_1_SAT_ERR		0x54
58 #define AD7779_REG_CH_GAIN_LOWER_BYTE(ch)	(0x21 + (ch) * 6)
59 #define AD7779_REG_CH2_3_SAT_ERR		0x55
60 #define AD7779_REG_CH4_5_SAT_ERR		0x56
61 #define AD7779_REG_CH6_7_SAT_ERR		0x57
62 #define AD7779_REG_CHX_ERR_REG_EN		0x58
63 #define AD7779_REG_GEN_ERR_REG_1		0x59
64 #define AD7779_REG_GEN_ERR_REG_1_EN		0x5A
65 #define AD7779_REG_GEN_ERR_REG_2		0x5B
66 #define AD7779_REG_GEN_ERR_REG_2_EN		0x5C
67 #define AD7779_REG_STATUS_REG_1			0x5D
68 #define AD7779_REG_STATUS_REG_2			0x5E
69 #define AD7779_REG_STATUS_REG_3			0x5F
70 #define AD7779_REG_SRC_N_MSB			0x60
71 #define AD7779_REG_SRC_N_LSB			0x61
72 #define AD7779_REG_SRC_IF_MSB			0x62
73 #define AD7779_REG_SRC_IF_LSB			0x63
74 #define AD7779_REG_SRC_UPDATE			0x64
75 
76 #define AD7779_FILTER_MSK			BIT(6)
77 #define AD7779_MOD_POWERMODE_MSK		BIT(6)
78 #define AD7779_MOD_PDB_REFOUT_MSK		BIT(4)
79 #define AD7779_MOD_SPI_EN_MSK			BIT(4)
80 #define AD7779_USRMOD_INIT_MSK			GENMASK(6, 4)
81 
82 /* AD7779_REG_DOUT_FORMAT */
83 #define AD7779_DOUT_FORMAT_MSK			GENMASK(7, 6)
84 #define AD7779_DOUT_HEADER_FORMAT		BIT(5)
85 #define AD7779_DCLK_CLK_DIV_MSK			GENMASK(3, 1)
86 
87 #define AD7779_REFMUX_CTRL_MSK			GENMASK(7, 6)
88 #define AD7779_SPI_CRC_EN_MSK			BIT(0)
89 
90 #define AD7779_MAXCLK_LOWPOWER			(4096 * HZ_PER_KHZ)
91 #define AD7779_NUM_CHANNELS			8
92 #define AD7779_RESET_BUF_SIZE			8
93 #define AD7779_CHAN_DATA_SIZE			4
94 
95 #define AD7779_LOWPOWER_DIV			512
96 #define AD7779_HIGHPOWER_DIV			2048
97 
98 #define AD7779_SINC3_MAXFREQ			(16 * HZ_PER_KHZ)
99 #define AD7779_SINC5_MAXFREQ			(128 * HZ_PER_KHZ)
100 
101 #define AD7779_DEFAULT_SAMPLING_FREQ		(8 * HZ_PER_KHZ)
102 #define AD7779_DEFAULT_SAMPLING_2LINE		(4 * HZ_PER_KHZ)
103 #define AD7779_DEFAULT_SAMPLING_1LINE		(2 * HZ_PER_KHZ)
104 
105 #define AD7779_SPIMODE_MAX_SAMP_FREQ		(16 * HZ_PER_KHZ)
106 
107 #define GAIN_REL				0x555555
108 #define AD7779_FREQ_MSB_MSK			GENMASK(15, 8)
109 #define AD7779_FREQ_LSB_MSK			GENMASK(7, 0)
110 #define AD7779_UPPER				GENMASK(23, 16)
111 #define AD7779_MID				GENMASK(15, 8)
112 #define AD7779_LOWER				GENMASK(7, 0)
113 
114 #define AD7779_REG_MSK		GENMASK(6, 0)
115 
116 #define AD7779_CRC8_POLY			0x07
117 DECLARE_CRC8_TABLE(ad7779_crc8_table);
118 
119 enum ad7779_filter {
120 	AD7779_SINC3,
121 	AD7779_SINC5,
122 };
123 
124 enum ad7779_variant {
125 	ad7770,
126 	ad7771,
127 	ad7779,
128 };
129 
130 enum ad7779_power_mode {
131 	AD7779_LOW_POWER,
132 	AD7779_HIGH_POWER,
133 };
134 
135 struct ad7779_chip_info {
136 	const char *name;
137 	struct iio_chan_spec const *channels;
138 };
139 
140 struct ad7779_state {
141 	struct spi_device *spi;
142 	const struct ad7779_chip_info *chip_info;
143 	struct clk *mclk;
144 	struct iio_trigger *trig;
145 	struct completion completion;
146 	unsigned int sampling_freq;
147 	enum ad7779_filter filter_enabled;
148 	/*
149 	 * DMA (thus cache coherency maintenance) requires the
150 	 * transfer buffers to live in their own cache lines.
151 	 */
152 	struct {
153 		u32 chans[8];
154 		aligned_s64 timestamp;
155 	} data __aligned(IIO_DMA_MINALIGN);
156 	u32			spidata_tx[8];
157 	u8			reg_rx_buf[3];
158 	u8			reg_tx_buf[3];
159 	u8			reset_buf[8];
160 };
161 
162 static const char * const ad7779_filter_type[] = {
163 	[AD7779_SINC3] = "sinc3",
164 	[AD7779_SINC5] = "sinc5",
165 };
166 
167 static const char * const ad7779_power_supplies[] = {
168 	"avdd1", "avdd2", "avdd4",
169 };
170 
171 static int ad7779_spi_read(struct ad7779_state *st, u8 reg, u8 *rbuf)
172 {
173 	int ret;
174 	u8 crc_buf[2];
175 	u8 exp_crc;
176 	struct spi_transfer t = {
177 		.tx_buf = st->reg_tx_buf,
178 		.rx_buf = st->reg_rx_buf,
179 	};
180 
181 	st->reg_tx_buf[0] = AD7779_SPI_READ_CMD | FIELD_GET(AD7779_REG_MSK, reg);
182 	st->reg_tx_buf[1] = 0;
183 
184 	if (reg == AD7779_REG_GEN_ERR_REG_1_EN) {
185 		t.len = 2;
186 	} else {
187 		t.len = 3;
188 		st->reg_tx_buf[2] = crc8(ad7779_crc8_table, st->reg_tx_buf,
189 					 t.len - 1, 0);
190 	}
191 
192 	ret = spi_sync_transfer(st->spi, &t, 1);
193 	if (ret)
194 		return ret;
195 
196 	crc_buf[0] = AD7779_SPI_READ_CMD | FIELD_GET(AD7779_REG_MSK, reg);
197 	crc_buf[1] = st->reg_rx_buf[1];
198 	exp_crc = crc8(ad7779_crc8_table, crc_buf, ARRAY_SIZE(crc_buf), 0);
199 	if (reg != AD7779_REG_GEN_ERR_REG_1_EN && exp_crc != st->reg_rx_buf[2]) {
200 		dev_err(&st->spi->dev, "Bad CRC %x, expected %x",
201 			st->reg_rx_buf[2], exp_crc);
202 		return -EINVAL;
203 	}
204 	*rbuf = st->reg_rx_buf[1];
205 
206 	return 0;
207 }
208 
209 static int ad7779_spi_write(struct ad7779_state *st, u8 reg, u8 val)
210 {
211 	u8 length = 3;
212 
213 	st->reg_tx_buf[0] = FIELD_GET(AD7779_REG_MSK, reg);
214 	st->reg_tx_buf[1] = val;
215 	if (reg == AD7779_REG_GEN_ERR_REG_1_EN)
216 		length = 2;
217 	else
218 		st->reg_tx_buf[2] = crc8(ad7779_crc8_table, st->reg_tx_buf,
219 					 length - 1, 0);
220 
221 	return spi_write(st->spi, st->reg_tx_buf, length);
222 }
223 
224 static int ad7779_spi_write_mask(struct ad7779_state *st, u8 reg, u8 mask,
225 				 u8 val)
226 {
227 	int ret;
228 	u8 regval, data;
229 
230 	ret = ad7779_spi_read(st, reg, &data);
231 	if (ret)
232 		return ret;
233 
234 	regval = (data & ~mask) | (val & mask);
235 
236 	if (regval == data)
237 		return 0;
238 
239 	return ad7779_spi_write(st, reg, regval);
240 }
241 
242 static int ad7779_reg_access(struct iio_dev *indio_dev,
243 			     unsigned int reg,
244 			     unsigned int writeval,
245 			     unsigned int *readval)
246 {
247 	struct ad7779_state *st = iio_priv(indio_dev);
248 	u8 rval;
249 	int ret;
250 
251 	if (readval) {
252 		ret = ad7779_spi_read(st, reg, &rval);
253 		*readval = rval;
254 		return ret;
255 	}
256 
257 	return ad7779_spi_write(st, reg, writeval);
258 }
259 
260 static int ad7779_set_sampling_frequency(struct ad7779_state *st,
261 					 unsigned int sampling_freq)
262 {
263 	int ret;
264 	unsigned int dec;
265 	unsigned int frac;
266 	unsigned int div;
267 	unsigned int decimal;
268 	unsigned int freq_khz;
269 
270 	if (st->filter_enabled == AD7779_SINC3 &&
271 	    sampling_freq > AD7779_SINC3_MAXFREQ)
272 		return -EINVAL;
273 
274 	if (st->filter_enabled == AD7779_SINC5 &&
275 	    sampling_freq > AD7779_SINC5_MAXFREQ)
276 		return -EINVAL;
277 
278 	if (sampling_freq > AD7779_SPIMODE_MAX_SAMP_FREQ)
279 		return -EINVAL;
280 
281 	div = AD7779_HIGHPOWER_DIV;
282 
283 	freq_khz = sampling_freq / HZ_PER_KHZ;
284 	dec = div / freq_khz;
285 	frac = div % freq_khz;
286 
287 	ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
288 			       FIELD_GET(AD7779_FREQ_MSB_MSK, dec));
289 	if (ret)
290 		return ret;
291 	ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
292 			       FIELD_GET(AD7779_FREQ_LSB_MSK, dec));
293 	if (ret)
294 		return ret;
295 
296 	if (frac) {
297 		/*
298 		 * In order to obtain the first three decimals of the decimation
299 		 * the initial number is multiplied with 10^3 prior to the
300 		 * division, then the original division result is subtracted and
301 		 * the number is divided by 10^3.
302 		 */
303 		decimal = ((mult_frac(div, KILO, freq_khz) - dec * KILO) << 16)
304 			  / KILO;
305 		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
306 				       FIELD_GET(AD7779_FREQ_MSB_MSK, decimal));
307 		if (ret)
308 			return ret;
309 		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
310 				       FIELD_GET(AD7779_FREQ_LSB_MSK, decimal));
311 		if (ret)
312 			return ret;
313 	} else {
314 		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
315 				       FIELD_GET(AD7779_FREQ_MSB_MSK, 0x0));
316 		if (ret)
317 			return ret;
318 		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
319 				       FIELD_GET(AD7779_FREQ_LSB_MSK, 0x0));
320 		if (ret)
321 			return ret;
322 	}
323 	ret = ad7779_spi_write(st, AD7779_REG_SRC_UPDATE, BIT(0));
324 	if (ret)
325 		return ret;
326 
327 	/* SRC update settling time */
328 	fsleep(15);
329 
330 	ret = ad7779_spi_write(st, AD7779_REG_SRC_UPDATE, 0x0);
331 	if (ret)
332 		return ret;
333 
334 	/* SRC update settling time */
335 	fsleep(15);
336 
337 	st->sampling_freq = sampling_freq;
338 
339 	return 0;
340 }
341 
342 static int ad7779_get_filter(struct iio_dev *indio_dev,
343 			     struct iio_chan_spec const *chan)
344 {
345 	struct ad7779_state *st = iio_priv(indio_dev);
346 	u8 temp;
347 	int ret;
348 
349 	ret = ad7779_spi_read(st, AD7779_REG_GENERAL_USER_CONFIG_2, &temp);
350 	if (ret)
351 		return ret;
352 
353 	return FIELD_GET(AD7779_FILTER_MSK, temp);
354 }
355 
356 static int ad7779_set_filter(struct iio_dev *indio_dev,
357 			     struct iio_chan_spec const *chan,
358 			     unsigned int mode)
359 {
360 	struct ad7779_state *st = iio_priv(indio_dev);
361 	int ret;
362 
363 	ret = ad7779_spi_write_mask(st,
364 				    AD7779_REG_GENERAL_USER_CONFIG_2,
365 				    AD7779_FILTER_MSK,
366 				    FIELD_PREP(AD7779_FILTER_MSK, mode));
367 	if (ret)
368 		return ret;
369 
370 	ret = ad7779_set_sampling_frequency(st, st->sampling_freq);
371 	if (ret)
372 		return ret;
373 
374 	st->filter_enabled = mode;
375 
376 	return 0;
377 }
378 
379 static int ad7779_get_calibscale(struct ad7779_state *st, int channel)
380 {
381 	int ret;
382 	u8 calibscale[3];
383 
384 	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_LOWER_BYTE(channel),
385 			      &calibscale[0]);
386 	if (ret)
387 		return ret;
388 
389 	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_MID_BYTE(channel),
390 			      &calibscale[1]);
391 	if (ret)
392 		return ret;
393 
394 	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_UPPER_BYTE(channel),
395 			      &calibscale[2]);
396 	if (ret)
397 		return ret;
398 
399 	return get_unaligned_be24(calibscale);
400 }
401 
402 static int ad7779_set_calibscale(struct ad7779_state *st, int channel, int val)
403 {
404 	int ret;
405 	unsigned int gain;
406 	u8 gain_bytes[3];
407 
408 	/*
409 	 * The gain value is relative to 0x555555, which represents a gain of 1
410 	 */
411 	gain = DIV_ROUND_CLOSEST_ULL((u64)val * 5592405LL, MEGA);
412 	put_unaligned_be24(gain, gain_bytes);
413 	ret = ad7779_spi_write(st, AD7779_REG_CH_GAIN_UPPER_BYTE(channel),
414 			       gain_bytes[0]);
415 	if (ret)
416 		return ret;
417 
418 	ret = ad7779_spi_write(st, AD7779_REG_CH_GAIN_MID_BYTE(channel),
419 			       gain_bytes[1]);
420 	if (ret)
421 		return ret;
422 
423 	return ad7779_spi_write(st, AD7779_REG_CH_GAIN_LOWER_BYTE(channel),
424 				gain_bytes[2]);
425 }
426 
427 static int ad7779_get_calibbias(struct ad7779_state *st, int channel)
428 {
429 	int ret;
430 	u8 calibbias[3];
431 
432 	ret = ad7779_spi_read(st, AD7779_REG_CH_OFFSET_LOWER_BYTE(channel),
433 			      &calibbias[0]);
434 	if (ret)
435 		return ret;
436 
437 	ret = ad7779_spi_read(st, AD7779_REG_CH_OFFSET_MID_BYTE(channel),
438 			      &calibbias[1]);
439 	if (ret)
440 		return ret;
441 
442 	ret = ad7779_spi_read(st, AD7779_REG_CH_OFFSET_UPPER_BYTE(channel),
443 			      &calibbias[2]);
444 	if (ret)
445 		return ret;
446 
447 	return get_unaligned_be24(calibbias);
448 }
449 
450 static int ad7779_set_calibbias(struct ad7779_state *st, int channel, int val)
451 {
452 	int ret;
453 	u8 calibbias[3];
454 
455 	put_unaligned_be24(val, calibbias);
456 	ret = ad7779_spi_write(st, AD7779_REG_CH_OFFSET_UPPER_BYTE(channel),
457 			       calibbias[0]);
458 	if (ret)
459 		return ret;
460 
461 	ret = ad7779_spi_write(st, AD7779_REG_CH_OFFSET_MID_BYTE(channel),
462 			       calibbias[1]);
463 	if (ret)
464 		return ret;
465 
466 	return ad7779_spi_write(st, AD7779_REG_CH_OFFSET_LOWER_BYTE(channel),
467 				calibbias[2]);
468 }
469 
470 static int __ad7779_read_raw(struct iio_dev *indio_dev,
471 			     struct iio_chan_spec const *chan, int *val,
472 			     int *val2, long mask)
473 {
474 	struct ad7779_state *st = iio_priv(indio_dev);
475 	int ret;
476 
477 	switch (mask) {
478 	case IIO_CHAN_INFO_CALIBSCALE:
479 		ret = ad7779_get_calibscale(st, chan->channel);
480 		if (ret < 0)
481 			return ret;
482 		*val = ret;
483 		*val2 = GAIN_REL;
484 		return IIO_VAL_FRACTIONAL;
485 	case IIO_CHAN_INFO_CALIBBIAS:
486 		ret = ad7779_get_calibbias(st, chan->channel);
487 		if (ret < 0)
488 			return ret;
489 		*val = ret;
490 		return IIO_VAL_INT;
491 	case IIO_CHAN_INFO_SAMP_FREQ:
492 		*val = st->sampling_freq;
493 		if (*val < 0)
494 			return -EINVAL;
495 		return IIO_VAL_INT;
496 	default:
497 		return -EINVAL;
498 	}
499 }
500 
501 static int ad7779_read_raw(struct iio_dev *indio_dev,
502 			   struct iio_chan_spec const *chan, int *val,
503 			   int *val2, long mask)
504 {
505 	int ret;
506 
507 	if (!iio_device_claim_direct(indio_dev))
508 		return -EBUSY;
509 
510 	ret = __ad7779_read_raw(indio_dev, chan, val, val2, mask);
511 	iio_device_release_direct(indio_dev);
512 	return ret;
513 }
514 
515 static int __ad7779_write_raw(struct iio_dev *indio_dev,
516 			      struct iio_chan_spec const *chan,
517 			      int val, int val2,
518 			      long mask)
519 {
520 	struct ad7779_state *st = iio_priv(indio_dev);
521 
522 	switch (mask) {
523 	case IIO_CHAN_INFO_CALIBSCALE:
524 		return ad7779_set_calibscale(st, chan->channel, val2);
525 	case IIO_CHAN_INFO_CALIBBIAS:
526 		return ad7779_set_calibbias(st, chan->channel, val);
527 	case IIO_CHAN_INFO_SAMP_FREQ:
528 		return ad7779_set_sampling_frequency(st, val);
529 	default:
530 		return -EINVAL;
531 	}
532 }
533 
534 static int ad7779_write_raw(struct iio_dev *indio_dev,
535 			    struct iio_chan_spec const *chan, int val, int val2,
536 			    long mask)
537 {
538 	int ret;
539 
540 	if (!iio_device_claim_direct(indio_dev))
541 		return -EBUSY;
542 
543 	ret = __ad7779_write_raw(indio_dev, chan, val, val2, mask);
544 	iio_device_release_direct(indio_dev);
545 	return ret;
546 }
547 
548 static int ad7779_buffer_preenable(struct iio_dev *indio_dev)
549 {
550 	int ret;
551 	struct ad7779_state *st = iio_priv(indio_dev);
552 
553 	ret = ad7779_spi_write_mask(st,
554 				    AD7779_REG_GENERAL_USER_CONFIG_3,
555 				    AD7779_MOD_SPI_EN_MSK,
556 				    FIELD_PREP(AD7779_MOD_SPI_EN_MSK, 1));
557 	if (ret)
558 		return ret;
559 
560 	/*
561 	 * DRDY output cannot be disabled at device level therefore we mask
562 	 * the irq at host end.
563 	 */
564 	enable_irq(st->spi->irq);
565 
566 	return 0;
567 }
568 
569 static int ad7779_buffer_postdisable(struct iio_dev *indio_dev)
570 {
571 	struct ad7779_state *st = iio_priv(indio_dev);
572 
573 	disable_irq(st->spi->irq);
574 
575 	return ad7779_spi_write(st, AD7779_REG_GENERAL_USER_CONFIG_3,
576 			       AD7779_DISABLE_SD);
577 }
578 
579 static irqreturn_t ad7779_trigger_handler(int irq, void *p)
580 {
581 	struct iio_poll_func *pf = p;
582 	struct iio_dev *indio_dev = pf->indio_dev;
583 	struct ad7779_state *st = iio_priv(indio_dev);
584 	int ret;
585 	struct spi_transfer t = {
586 		.rx_buf = st->data.chans,
587 		.tx_buf = st->spidata_tx,
588 		.len = AD7779_NUM_CHANNELS * AD7779_CHAN_DATA_SIZE,
589 	};
590 
591 	st->spidata_tx[0] = AD7779_SPI_READ_CMD;
592 	ret = spi_sync_transfer(st->spi, &t, 1);
593 	if (ret) {
594 		dev_err(&st->spi->dev, "SPI transfer error in IRQ handler");
595 		goto exit_handler;
596 	}
597 
598 	iio_push_to_buffers_with_ts(indio_dev, &st->data, sizeof(st->data),
599 				    pf->timestamp);
600 
601 exit_handler:
602 	iio_trigger_notify_done(indio_dev->trig);
603 	return IRQ_HANDLED;
604 }
605 
606 static int ad7779_reset(struct iio_dev *indio_dev, struct gpio_desc *reset_gpio)
607 {
608 	struct ad7779_state *st = iio_priv(indio_dev);
609 	int ret;
610 	struct spi_transfer t = {
611 		.tx_buf = st->reset_buf,
612 		.len = 8,
613 	};
614 
615 	if (reset_gpio) {
616 		gpiod_set_value(reset_gpio, 1);
617 		/* Delay for reset to occur is 225 microseconds */
618 		fsleep(230);
619 		ret = 0;
620 	} else {
621 		memset(st->reset_buf, 0xff, sizeof(st->reset_buf));
622 		ret = spi_sync_transfer(st->spi, &t, 1);
623 		if (ret)
624 			return ret;
625 	}
626 
627 	/* Delay for reset to occur is 225 microseconds */
628 	fsleep(230);
629 
630 	return ret;
631 }
632 
633 static const struct iio_info ad7779_info = {
634 	.read_raw = ad7779_read_raw,
635 	.write_raw = ad7779_write_raw,
636 	.debugfs_reg_access = &ad7779_reg_access,
637 };
638 
639 static const struct iio_enum ad7779_filter_enum = {
640 	.items = ad7779_filter_type,
641 	.num_items = ARRAY_SIZE(ad7779_filter_type),
642 	.get = ad7779_get_filter,
643 	.set = ad7779_set_filter,
644 };
645 
646 static const struct iio_chan_spec_ext_info ad7779_ext_filter[] = {
647 	IIO_ENUM("filter_type", IIO_SHARED_BY_ALL, &ad7779_filter_enum),
648 	IIO_ENUM_AVAILABLE("filter_type", IIO_SHARED_BY_ALL,
649 				  &ad7779_filter_enum),
650 	{ }
651 };
652 
653 #define AD777x_CHAN_S(index, _ext_info)					\
654 	{								\
655 		.type = IIO_VOLTAGE,					\
656 		.info_mask_separate = BIT(IIO_CHAN_INFO_CALIBSCALE)  |	\
657 				      BIT(IIO_CHAN_INFO_CALIBBIAS),	\
658 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
659 		.address = (index),					\
660 		.indexed = 1,						\
661 		.channel = (index),					\
662 		.scan_index = (index),					\
663 		.ext_info = (_ext_info),				\
664 		.scan_type = {						\
665 			.sign = 's',					\
666 			.realbits = 24,					\
667 			.storagebits = 32,				\
668 			.endianness = IIO_BE,				\
669 		},							\
670 	}
671 
672 #define AD777x_CHAN_NO_FILTER_S(index)					\
673 	AD777x_CHAN_S(index, NULL)
674 
675 #define AD777x_CHAN_FILTER_S(index)					\
676 	AD777x_CHAN_S(index, ad7779_ext_filter)
677 static const struct iio_chan_spec ad7779_channels[] = {
678 	AD777x_CHAN_NO_FILTER_S(0),
679 	AD777x_CHAN_NO_FILTER_S(1),
680 	AD777x_CHAN_NO_FILTER_S(2),
681 	AD777x_CHAN_NO_FILTER_S(3),
682 	AD777x_CHAN_NO_FILTER_S(4),
683 	AD777x_CHAN_NO_FILTER_S(5),
684 	AD777x_CHAN_NO_FILTER_S(6),
685 	AD777x_CHAN_NO_FILTER_S(7),
686 	IIO_CHAN_SOFT_TIMESTAMP(8),
687 };
688 
689 static const struct iio_chan_spec ad7779_channels_filter[] = {
690 	AD777x_CHAN_FILTER_S(0),
691 	AD777x_CHAN_FILTER_S(1),
692 	AD777x_CHAN_FILTER_S(2),
693 	AD777x_CHAN_FILTER_S(3),
694 	AD777x_CHAN_FILTER_S(4),
695 	AD777x_CHAN_FILTER_S(5),
696 	AD777x_CHAN_FILTER_S(6),
697 	AD777x_CHAN_FILTER_S(7),
698 	IIO_CHAN_SOFT_TIMESTAMP(8),
699 };
700 
701 static const struct iio_buffer_setup_ops ad7779_buffer_setup_ops = {
702 	.preenable = ad7779_buffer_preenable,
703 	.postdisable = ad7779_buffer_postdisable,
704 };
705 
706 static const struct iio_trigger_ops ad7779_trigger_ops = {
707 	.validate_device = iio_trigger_validate_own_device,
708 };
709 
710 static int ad7779_conf(struct ad7779_state *st, struct gpio_desc *start_gpio)
711 {
712 	int ret;
713 
714 	ret = ad7779_spi_write_mask(st, AD7779_REG_GEN_ERR_REG_1_EN,
715 				    AD7779_SPI_CRC_EN_MSK,
716 				    FIELD_PREP(AD7779_SPI_CRC_EN_MSK, 1));
717 	if (ret)
718 		return ret;
719 
720 	ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
721 				    AD7779_USRMOD_INIT_MSK,
722 				    FIELD_PREP(AD7779_USRMOD_INIT_MSK, 5));
723 	if (ret)
724 		return ret;
725 
726 	ret = ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
727 				    AD7779_DCLK_CLK_DIV_MSK,
728 				    FIELD_PREP(AD7779_DCLK_CLK_DIV_MSK, 1));
729 	if (ret)
730 		return ret;
731 
732 	ret = ad7779_spi_write_mask(st, AD7779_REG_ADC_MUX_CONFIG,
733 				    AD7779_REFMUX_CTRL_MSK,
734 				    FIELD_PREP(AD7779_REFMUX_CTRL_MSK, 1));
735 	if (ret)
736 		return ret;
737 
738 	ret = ad7779_set_sampling_frequency(st, AD7779_DEFAULT_SAMPLING_FREQ);
739 	if (ret)
740 		return ret;
741 
742 	gpiod_set_value(start_gpio, 0);
743 	/* Start setup time */
744 	fsleep(15);
745 	gpiod_set_value(start_gpio, 1);
746 	/* Start setup time */
747 	fsleep(15);
748 	gpiod_set_value(start_gpio, 0);
749 	/* Start setup time */
750 	fsleep(15);
751 
752 	return 0;
753 }
754 
755 static int ad7779_probe(struct spi_device *spi)
756 {
757 	struct iio_dev *indio_dev;
758 	struct ad7779_state *st;
759 	struct gpio_desc *reset_gpio, *start_gpio;
760 	struct device *dev = &spi->dev;
761 	int ret = -EINVAL;
762 
763 	if (!spi->irq)
764 		return dev_err_probe(dev, ret, "DRDY irq not present\n");
765 
766 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
767 	if (!indio_dev)
768 		return -ENOMEM;
769 
770 	st = iio_priv(indio_dev);
771 
772 	ret = devm_regulator_bulk_get_enable(dev,
773 					     ARRAY_SIZE(ad7779_power_supplies),
774 					     ad7779_power_supplies);
775 	if (ret)
776 		return dev_err_probe(dev, ret,
777 				     "failed to get and enable supplies\n");
778 
779 	st->mclk = devm_clk_get_enabled(dev, "mclk");
780 	if (IS_ERR(st->mclk))
781 		return PTR_ERR(st->mclk);
782 
783 	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
784 	if (IS_ERR(reset_gpio))
785 		return PTR_ERR(reset_gpio);
786 
787 	start_gpio = devm_gpiod_get(dev, "start", GPIOD_OUT_HIGH);
788 	if (IS_ERR(start_gpio))
789 		return PTR_ERR(start_gpio);
790 
791 	crc8_populate_msb(ad7779_crc8_table, AD7779_CRC8_POLY);
792 	st->spi = spi;
793 
794 	st->chip_info = spi_get_device_match_data(spi);
795 	if (!st->chip_info)
796 		return -ENODEV;
797 
798 	ret = ad7779_reset(indio_dev, reset_gpio);
799 	if (ret)
800 		return ret;
801 
802 	ret = ad7779_conf(st, start_gpio);
803 	if (ret)
804 		return ret;
805 
806 	indio_dev->name = st->chip_info->name;
807 	indio_dev->info = &ad7779_info;
808 	indio_dev->modes = INDIO_DIRECT_MODE;
809 	indio_dev->channels = st->chip_info->channels;
810 	indio_dev->num_channels = ARRAY_SIZE(ad7779_channels);
811 
812 	st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
813 					  iio_device_id(indio_dev));
814 	if (!st->trig)
815 		return -ENOMEM;
816 
817 	st->trig->ops = &ad7779_trigger_ops;
818 
819 	iio_trigger_set_drvdata(st->trig, st);
820 
821 	ret = devm_request_irq(dev, spi->irq, iio_trigger_generic_data_rdy_poll,
822 			       IRQF_ONESHOT | IRQF_NO_AUTOEN, indio_dev->name,
823 			       st->trig);
824 	if (ret)
825 		return dev_err_probe(dev, ret, "request IRQ %d failed\n",
826 				     st->spi->irq);
827 
828 	ret = devm_iio_trigger_register(dev, st->trig);
829 	if (ret)
830 		return ret;
831 
832 	indio_dev->trig = iio_trigger_get(st->trig);
833 
834 	init_completion(&st->completion);
835 
836 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
837 					      &iio_pollfunc_store_time,
838 					      &ad7779_trigger_handler,
839 					      &ad7779_buffer_setup_ops);
840 	if (ret)
841 		return ret;
842 
843 	ret = ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
844 				    AD7779_DCLK_CLK_DIV_MSK,
845 				    FIELD_PREP(AD7779_DCLK_CLK_DIV_MSK, 7));
846 	if (ret)
847 		return ret;
848 
849 	return devm_iio_device_register(dev, indio_dev);
850 }
851 
852 static int ad7779_suspend(struct device *dev)
853 {
854 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
855 	struct ad7779_state *st = iio_priv(indio_dev);
856 
857 	return ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
858 				     AD7779_MOD_POWERMODE_MSK,
859 				     FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
860 					       AD7779_LOW_POWER));
861 }
862 
863 static int ad7779_resume(struct device *dev)
864 {
865 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
866 	struct ad7779_state *st = iio_priv(indio_dev);
867 
868 	return ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
869 				     AD7779_MOD_POWERMODE_MSK,
870 				     FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
871 					       AD7779_HIGH_POWER));
872 }
873 
874 static DEFINE_SIMPLE_DEV_PM_OPS(ad7779_pm_ops, ad7779_suspend, ad7779_resume);
875 
876 static const struct ad7779_chip_info ad7770_chip_info = {
877 	.name = "ad7770",
878 	.channels = ad7779_channels,
879 };
880 
881 static const struct ad7779_chip_info ad7771_chip_info = {
882 	.name = "ad7771",
883 	.channels = ad7779_channels_filter,
884 };
885 
886 static const struct ad7779_chip_info ad7779_chip_info = {
887 	.name = "ad7779",
888 	.channels = ad7779_channels,
889 };
890 
891 static const struct spi_device_id ad7779_id[] = {
892 	{
893 		.name = "ad7770",
894 		.driver_data = (kernel_ulong_t)&ad7770_chip_info,
895 	},
896 	{
897 		.name = "ad7771",
898 		.driver_data = (kernel_ulong_t)&ad7771_chip_info,
899 	},
900 	{
901 		.name = "ad7779",
902 		.driver_data = (kernel_ulong_t)&ad7779_chip_info,
903 	},
904 	{ }
905 };
906 MODULE_DEVICE_TABLE(spi, ad7779_id);
907 
908 static const struct of_device_id ad7779_of_table[] = {
909 	{
910 		.compatible = "adi,ad7770",
911 		.data = &ad7770_chip_info,
912 	},
913 	{
914 		.compatible = "adi,ad7771",
915 		.data = &ad7771_chip_info,
916 	},
917 	{
918 		.compatible = "adi,ad7779",
919 		.data = &ad7779_chip_info,
920 	},
921 	{ }
922 };
923 MODULE_DEVICE_TABLE(of, ad7779_of_table);
924 
925 static struct spi_driver ad7779_driver = {
926 	.driver = {
927 		.name = "ad7779",
928 		.pm = pm_sleep_ptr(&ad7779_pm_ops),
929 		.of_match_table = ad7779_of_table,
930 	},
931 	.probe = ad7779_probe,
932 	.id_table = ad7779_id,
933 };
934 module_spi_driver(ad7779_driver);
935 
936 MODULE_AUTHOR("Ramona Alexandra Nechita <ramona.nechita@analog.com>");
937 MODULE_DESCRIPTION("Analog Devices AD7779 ADC");
938 MODULE_LICENSE("GPL");
939