xref: /linux/drivers/iio/adc/ad7779.c (revision 331ca76fe5cee0df5a025d97d68fee53140053c7)
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/backend.h>
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/sysfs.h>
31 #include <linux/iio/trigger.h>
32 #include <linux/iio/triggered_buffer.h>
33 #include <linux/iio/trigger_consumer.h>
34 
35 #define AD7779_SPI_READ_CMD			BIT(7)
36 
37 #define AD7779_DISABLE_SD			BIT(7)
38 
39 #define AD7779_REG_CH_DISABLE			0x08
40 #define AD7779_REG_CH_SYNC_OFFSET(ch)		(0x09 + (ch))
41 #define AD7779_REG_CH_CONFIG(ch)		(0x00 + (ch))
42 #define AD7779_REG_GENERAL_USER_CONFIG_1	0x11
43 #define AD7779_REG_GENERAL_USER_CONFIG_2	0x12
44 #define AD7779_REG_GENERAL_USER_CONFIG_3	0x13
45 #define AD7779_REG_DOUT_FORMAT			0x14
46 #define AD7779_REG_ADC_MUX_CONFIG		0x15
47 #define AD7779_REG_GPIO_CONFIG			0x17
48 #define AD7779_REG_BUFFER_CONFIG_1		0x19
49 #define AD7779_REG_GLOBAL_MUX_CONFIG		0x16
50 #define AD7779_REG_BUFFER_CONFIG_2		0x1A
51 #define AD7779_REG_GPIO_DATA			0x18
52 #define AD7779_REG_CH_OFFSET_UPPER_BYTE(ch)	(0x1C + (ch) * 6)
53 #define AD7779_REG_CH_OFFSET_LOWER_BYTE(ch)	(0x1E + (ch) * 6)
54 #define AD7779_REG_CH_GAIN_UPPER_BYTE(ch)	(0x1F + (ch) * 6)
55 #define AD7779_REG_CH_OFFSET_MID_BYTE(ch)	(0x1D + (ch) * 6)
56 #define AD7779_REG_CH_GAIN_MID_BYTE(ch)		(0x20 + (ch) * 6)
57 #define AD7779_REG_CH_ERR_REG(ch)		(0x4C + (ch))
58 #define AD7779_REG_CH0_1_SAT_ERR		0x54
59 #define AD7779_REG_CH_GAIN_LOWER_BYTE(ch)	(0x21 + (ch) * 6)
60 #define AD7779_REG_CH2_3_SAT_ERR		0x55
61 #define AD7779_REG_CH4_5_SAT_ERR		0x56
62 #define AD7779_REG_CH6_7_SAT_ERR		0x57
63 #define AD7779_REG_CHX_ERR_REG_EN		0x58
64 #define AD7779_REG_GEN_ERR_REG_1		0x59
65 #define AD7779_REG_GEN_ERR_REG_1_EN		0x5A
66 #define AD7779_REG_GEN_ERR_REG_2		0x5B
67 #define AD7779_REG_GEN_ERR_REG_2_EN		0x5C
68 #define AD7779_REG_STATUS_REG_1			0x5D
69 #define AD7779_REG_STATUS_REG_2			0x5E
70 #define AD7779_REG_STATUS_REG_3			0x5F
71 #define AD7779_REG_SRC_N_MSB			0x60
72 #define AD7779_REG_SRC_N_LSB			0x61
73 #define AD7779_REG_SRC_IF_MSB			0x62
74 #define AD7779_REG_SRC_IF_LSB			0x63
75 #define AD7779_REG_SRC_UPDATE			0x64
76 
77 #define AD7779_FILTER_MSK			BIT(6)
78 #define AD7779_MOD_POWERMODE_MSK		BIT(6)
79 #define AD7779_MOD_PDB_REFOUT_MSK		BIT(4)
80 #define AD7779_MOD_SPI_EN_MSK			BIT(4)
81 #define AD7779_USRMOD_INIT_MSK			GENMASK(6, 4)
82 
83 /* AD7779_REG_DOUT_FORMAT */
84 #define AD7779_DOUT_FORMAT_MSK			GENMASK(7, 6)
85 #define AD7779_DOUT_HEADER_FORMAT		BIT(5)
86 #define AD7779_DCLK_CLK_DIV_MSK			GENMASK(3, 1)
87 
88 #define AD7779_REFMUX_CTRL_MSK			GENMASK(7, 6)
89 #define AD7779_SPI_CRC_EN_MSK			BIT(0)
90 
91 #define AD7779_MAXCLK_LOWPOWER			(4096 * HZ_PER_KHZ)
92 #define AD7779_NUM_CHANNELS			8
93 #define AD7779_RESET_BUF_SIZE			8
94 #define AD7779_CHAN_DATA_SIZE			4
95 
96 #define AD7779_LOWPOWER_DIV			512
97 #define AD7779_HIGHPOWER_DIV			2048
98 
99 #define AD7779_SINC3_MAXFREQ			(16 * HZ_PER_KHZ)
100 #define AD7779_SINC5_MAXFREQ			(128 * HZ_PER_KHZ)
101 
102 #define AD7779_DEFAULT_SAMPLING_FREQ		(8 * HZ_PER_KHZ)
103 #define AD7779_DEFAULT_SAMPLING_2LINE		(4 * HZ_PER_KHZ)
104 #define AD7779_DEFAULT_SAMPLING_1LINE		(2 * HZ_PER_KHZ)
105 
106 #define AD7779_SPIMODE_MAX_SAMP_FREQ		(16 * HZ_PER_KHZ)
107 
108 #define GAIN_REL				0x555555
109 #define AD7779_FREQ_MSB_MSK			GENMASK(15, 8)
110 #define AD7779_FREQ_LSB_MSK			GENMASK(7, 0)
111 #define AD7779_UPPER				GENMASK(23, 16)
112 #define AD7779_MID				GENMASK(15, 8)
113 #define AD7779_LOWER				GENMASK(7, 0)
114 
115 #define AD7779_REG_MSK		GENMASK(6, 0)
116 
117 #define AD7779_CRC8_POLY			0x07
118 DECLARE_CRC8_TABLE(ad7779_crc8_table);
119 
120 enum ad7779_filter {
121 	AD7779_SINC3,
122 	AD7779_SINC5,
123 };
124 
125 enum ad7779_variant {
126 	ad7770,
127 	ad7771,
128 	ad7779,
129 };
130 
131 enum ad7779_power_mode {
132 	AD7779_LOW_POWER,
133 	AD7779_HIGH_POWER,
134 };
135 
136 struct ad7779_chip_info {
137 	const char *name;
138 	struct iio_chan_spec const *channels;
139 };
140 
141 struct ad7779_state {
142 	struct spi_device *spi;
143 	const struct ad7779_chip_info *chip_info;
144 	struct clk *mclk;
145 	struct iio_trigger *trig;
146 	unsigned int sampling_freq;
147 	enum ad7779_filter filter_enabled;
148 	struct iio_backend *back;
149 	/*
150 	 * DMA (thus cache coherency maintenance) requires the
151 	 * transfer buffers to live in their own cache lines.
152 	 */
153 	struct {
154 		u32 chans[8];
155 		aligned_s64 timestamp;
156 	} data __aligned(IIO_DMA_MINALIGN);
157 	u32			spidata_tx[8];
158 	u8			reg_rx_buf[3];
159 	u8			reg_tx_buf[3];
160 	u8			reset_buf[8];
161 };
162 
163 static const char * const ad7779_filter_type[] = {
164 	[AD7779_SINC3] = "sinc3",
165 	[AD7779_SINC5] = "sinc5",
166 };
167 
168 static const char * const ad7779_power_supplies[] = {
169 	"avdd1", "avdd2", "avdd4",
170 };
171 
172 static int ad7779_spi_read(struct ad7779_state *st, u8 reg, u8 *rbuf)
173 {
174 	int ret;
175 	u8 crc_buf[2];
176 	u8 exp_crc;
177 	struct spi_transfer t = {
178 		.tx_buf = st->reg_tx_buf,
179 		.rx_buf = st->reg_rx_buf,
180 	};
181 
182 	st->reg_tx_buf[0] = AD7779_SPI_READ_CMD | FIELD_GET(AD7779_REG_MSK, reg);
183 	st->reg_tx_buf[1] = 0;
184 
185 	if (reg == AD7779_REG_GEN_ERR_REG_1_EN) {
186 		t.len = 2;
187 	} else {
188 		t.len = 3;
189 		st->reg_tx_buf[2] = crc8(ad7779_crc8_table, st->reg_tx_buf,
190 					 t.len - 1, 0);
191 	}
192 
193 	ret = spi_sync_transfer(st->spi, &t, 1);
194 	if (ret)
195 		return ret;
196 
197 	crc_buf[0] = AD7779_SPI_READ_CMD | FIELD_GET(AD7779_REG_MSK, reg);
198 	crc_buf[1] = st->reg_rx_buf[1];
199 	exp_crc = crc8(ad7779_crc8_table, crc_buf, ARRAY_SIZE(crc_buf), 0);
200 	if (reg != AD7779_REG_GEN_ERR_REG_1_EN && exp_crc != st->reg_rx_buf[2]) {
201 		dev_err(&st->spi->dev, "Bad CRC %x, expected %x",
202 			st->reg_rx_buf[2], exp_crc);
203 		return -EINVAL;
204 	}
205 	*rbuf = st->reg_rx_buf[1];
206 
207 	return 0;
208 }
209 
210 static int ad7779_spi_write(struct ad7779_state *st, u8 reg, u8 val)
211 {
212 	u8 length = 3;
213 
214 	st->reg_tx_buf[0] = FIELD_GET(AD7779_REG_MSK, reg);
215 	st->reg_tx_buf[1] = val;
216 	if (reg == AD7779_REG_GEN_ERR_REG_1_EN)
217 		length = 2;
218 	else
219 		st->reg_tx_buf[2] = crc8(ad7779_crc8_table, st->reg_tx_buf,
220 					 length - 1, 0);
221 
222 	return spi_write(st->spi, st->reg_tx_buf, length);
223 }
224 
225 static int ad7779_spi_write_mask(struct ad7779_state *st, u8 reg, u8 mask,
226 				 u8 val)
227 {
228 	int ret;
229 	u8 regval, data;
230 
231 	ret = ad7779_spi_read(st, reg, &data);
232 	if (ret)
233 		return ret;
234 
235 	regval = (data & ~mask) | (val & mask);
236 
237 	if (regval == data)
238 		return 0;
239 
240 	return ad7779_spi_write(st, reg, regval);
241 }
242 
243 static int ad7779_reg_access(struct iio_dev *indio_dev,
244 			     unsigned int reg,
245 			     unsigned int writeval,
246 			     unsigned int *readval)
247 {
248 	struct ad7779_state *st = iio_priv(indio_dev);
249 	u8 rval;
250 	int ret;
251 
252 	if (readval) {
253 		ret = ad7779_spi_read(st, reg, &rval);
254 		*readval = rval;
255 		return ret;
256 	}
257 
258 	return ad7779_spi_write(st, reg, writeval);
259 }
260 
261 static int ad7779_set_sampling_frequency(struct ad7779_state *st,
262 					 unsigned int sampling_freq)
263 {
264 	int ret;
265 	unsigned int dec;
266 	unsigned int frac;
267 	unsigned int div;
268 	unsigned int decimal;
269 	unsigned int freq_khz;
270 
271 	if (st->filter_enabled == AD7779_SINC3 &&
272 	    sampling_freq > AD7779_SINC3_MAXFREQ)
273 		return -EINVAL;
274 
275 	if (st->filter_enabled == AD7779_SINC5 &&
276 	    sampling_freq > AD7779_SINC5_MAXFREQ)
277 		return -EINVAL;
278 
279 	if (sampling_freq > AD7779_SPIMODE_MAX_SAMP_FREQ)
280 		return -EINVAL;
281 
282 	div = AD7779_HIGHPOWER_DIV;
283 
284 	freq_khz = sampling_freq / HZ_PER_KHZ;
285 	dec = div / freq_khz;
286 	frac = div % freq_khz;
287 
288 	ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
289 			       FIELD_GET(AD7779_FREQ_MSB_MSK, dec));
290 	if (ret)
291 		return ret;
292 	ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
293 			       FIELD_GET(AD7779_FREQ_LSB_MSK, dec));
294 	if (ret)
295 		return ret;
296 
297 	if (frac) {
298 		/*
299 		 * In order to obtain the first three decimals of the decimation
300 		 * the initial number is multiplied with 10^3 prior to the
301 		 * division, then the original division result is subtracted and
302 		 * the number is divided by 10^3.
303 		 */
304 		decimal = ((mult_frac(div, KILO, freq_khz) - dec * KILO) << 16)
305 			  / KILO;
306 		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
307 				       FIELD_GET(AD7779_FREQ_MSB_MSK, decimal));
308 		if (ret)
309 			return ret;
310 		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
311 				       FIELD_GET(AD7779_FREQ_LSB_MSK, decimal));
312 		if (ret)
313 			return ret;
314 	} else {
315 		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_MSB,
316 				       FIELD_GET(AD7779_FREQ_MSB_MSK, 0x0));
317 		if (ret)
318 			return ret;
319 		ret = ad7779_spi_write(st, AD7779_REG_SRC_N_LSB,
320 				       FIELD_GET(AD7779_FREQ_LSB_MSK, 0x0));
321 		if (ret)
322 			return ret;
323 	}
324 	ret = ad7779_spi_write(st, AD7779_REG_SRC_UPDATE, BIT(0));
325 	if (ret)
326 		return ret;
327 
328 	/* SRC update settling time */
329 	fsleep(15);
330 
331 	ret = ad7779_spi_write(st, AD7779_REG_SRC_UPDATE, 0x0);
332 	if (ret)
333 		return ret;
334 
335 	/* SRC update settling time */
336 	fsleep(15);
337 
338 	st->sampling_freq = sampling_freq;
339 
340 	return 0;
341 }
342 
343 static int ad7779_get_filter(struct iio_dev *indio_dev,
344 			     struct iio_chan_spec const *chan)
345 {
346 	struct ad7779_state *st = iio_priv(indio_dev);
347 	u8 temp;
348 	int ret;
349 
350 	ret = ad7779_spi_read(st, AD7779_REG_GENERAL_USER_CONFIG_2, &temp);
351 	if (ret)
352 		return ret;
353 
354 	return FIELD_GET(AD7779_FILTER_MSK, temp);
355 }
356 
357 static int ad7779_set_filter(struct iio_dev *indio_dev,
358 			     struct iio_chan_spec const *chan,
359 			     unsigned int mode)
360 {
361 	struct ad7779_state *st = iio_priv(indio_dev);
362 	int ret;
363 
364 	ret = ad7779_spi_write_mask(st,
365 				    AD7779_REG_GENERAL_USER_CONFIG_2,
366 				    AD7779_FILTER_MSK,
367 				    FIELD_PREP(AD7779_FILTER_MSK, mode));
368 	if (ret)
369 		return ret;
370 
371 	ret = ad7779_set_sampling_frequency(st, st->sampling_freq);
372 	if (ret)
373 		return ret;
374 
375 	st->filter_enabled = mode;
376 
377 	return 0;
378 }
379 
380 static int ad7779_get_calibscale(struct ad7779_state *st, int channel)
381 {
382 	int ret;
383 	u8 calibscale[3];
384 
385 	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_LOWER_BYTE(channel),
386 			      &calibscale[0]);
387 	if (ret)
388 		return ret;
389 
390 	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_MID_BYTE(channel),
391 			      &calibscale[1]);
392 	if (ret)
393 		return ret;
394 
395 	ret = ad7779_spi_read(st, AD7779_REG_CH_GAIN_UPPER_BYTE(channel),
396 			      &calibscale[2]);
397 	if (ret)
398 		return ret;
399 
400 	return get_unaligned_be24(calibscale);
401 }
402 
403 static int ad7779_set_calibscale(struct ad7779_state *st, int channel, int val)
404 {
405 	int ret;
406 	unsigned int gain;
407 	u8 gain_bytes[3];
408 
409 	/*
410 	 * The gain value is relative to 0x555555, which represents a gain of 1
411 	 */
412 	gain = DIV_ROUND_CLOSEST_ULL((u64)val * 5592405LL, MEGA);
413 	put_unaligned_be24(gain, gain_bytes);
414 	ret = ad7779_spi_write(st, AD7779_REG_CH_GAIN_UPPER_BYTE(channel),
415 			       gain_bytes[0]);
416 	if (ret)
417 		return ret;
418 
419 	ret = ad7779_spi_write(st, AD7779_REG_CH_GAIN_MID_BYTE(channel),
420 			       gain_bytes[1]);
421 	if (ret)
422 		return ret;
423 
424 	return ad7779_spi_write(st, AD7779_REG_CH_GAIN_LOWER_BYTE(channel),
425 				gain_bytes[2]);
426 }
427 
428 static int ad7779_get_calibbias(struct ad7779_state *st, int channel)
429 {
430 	int ret;
431 	u8 calibbias[3];
432 
433 	ret = ad7779_spi_read(st, AD7779_REG_CH_OFFSET_LOWER_BYTE(channel),
434 			      &calibbias[0]);
435 	if (ret)
436 		return ret;
437 
438 	ret = ad7779_spi_read(st, AD7779_REG_CH_OFFSET_MID_BYTE(channel),
439 			      &calibbias[1]);
440 	if (ret)
441 		return ret;
442 
443 	ret = ad7779_spi_read(st, AD7779_REG_CH_OFFSET_UPPER_BYTE(channel),
444 			      &calibbias[2]);
445 	if (ret)
446 		return ret;
447 
448 	return get_unaligned_be24(calibbias);
449 }
450 
451 static int ad7779_set_calibbias(struct ad7779_state *st, int channel, int val)
452 {
453 	int ret;
454 	u8 calibbias[3];
455 
456 	put_unaligned_be24(val, calibbias);
457 	ret = ad7779_spi_write(st, AD7779_REG_CH_OFFSET_UPPER_BYTE(channel),
458 			       calibbias[0]);
459 	if (ret)
460 		return ret;
461 
462 	ret = ad7779_spi_write(st, AD7779_REG_CH_OFFSET_MID_BYTE(channel),
463 			       calibbias[1]);
464 	if (ret)
465 		return ret;
466 
467 	return ad7779_spi_write(st, AD7779_REG_CH_OFFSET_LOWER_BYTE(channel),
468 				calibbias[2]);
469 }
470 
471 static int __ad7779_read_raw(struct iio_dev *indio_dev,
472 			     struct iio_chan_spec const *chan, int *val,
473 			     int *val2, long mask)
474 {
475 	struct ad7779_state *st = iio_priv(indio_dev);
476 	int ret;
477 
478 	switch (mask) {
479 	case IIO_CHAN_INFO_CALIBSCALE:
480 		ret = ad7779_get_calibscale(st, chan->channel);
481 		if (ret < 0)
482 			return ret;
483 		*val = ret;
484 		*val2 = GAIN_REL;
485 		return IIO_VAL_FRACTIONAL;
486 	case IIO_CHAN_INFO_CALIBBIAS:
487 		ret = ad7779_get_calibbias(st, chan->channel);
488 		if (ret < 0)
489 			return ret;
490 		*val = ret;
491 		return IIO_VAL_INT;
492 	case IIO_CHAN_INFO_SAMP_FREQ:
493 		*val = st->sampling_freq;
494 		if (*val < 0)
495 			return -EINVAL;
496 		return IIO_VAL_INT;
497 	default:
498 		return -EINVAL;
499 	}
500 }
501 
502 static int ad7779_read_raw(struct iio_dev *indio_dev,
503 			   struct iio_chan_spec const *chan, int *val,
504 			   int *val2, long mask)
505 {
506 	int ret;
507 
508 	if (!iio_device_claim_direct(indio_dev))
509 		return -EBUSY;
510 
511 	ret = __ad7779_read_raw(indio_dev, chan, val, val2, mask);
512 	iio_device_release_direct(indio_dev);
513 	return ret;
514 }
515 
516 static int __ad7779_write_raw(struct iio_dev *indio_dev,
517 			      struct iio_chan_spec const *chan,
518 			      int val, int val2,
519 			      long mask)
520 {
521 	struct ad7779_state *st = iio_priv(indio_dev);
522 
523 	switch (mask) {
524 	case IIO_CHAN_INFO_CALIBSCALE:
525 		return ad7779_set_calibscale(st, chan->channel, val2);
526 	case IIO_CHAN_INFO_CALIBBIAS:
527 		return ad7779_set_calibbias(st, chan->channel, val);
528 	case IIO_CHAN_INFO_SAMP_FREQ:
529 		return ad7779_set_sampling_frequency(st, val);
530 	default:
531 		return -EINVAL;
532 	}
533 }
534 
535 static int ad7779_write_raw(struct iio_dev *indio_dev,
536 			    struct iio_chan_spec const *chan, int val, int val2,
537 			    long mask)
538 {
539 	int ret;
540 
541 	if (!iio_device_claim_direct(indio_dev))
542 		return -EBUSY;
543 
544 	ret = __ad7779_write_raw(indio_dev, chan, val, val2, mask);
545 	iio_device_release_direct(indio_dev);
546 	return ret;
547 }
548 
549 static int ad7779_buffer_preenable(struct iio_dev *indio_dev)
550 {
551 	int ret;
552 	struct ad7779_state *st = iio_priv(indio_dev);
553 
554 	ret = ad7779_spi_write_mask(st,
555 				    AD7779_REG_GENERAL_USER_CONFIG_3,
556 				    AD7779_MOD_SPI_EN_MSK,
557 				    FIELD_PREP(AD7779_MOD_SPI_EN_MSK, 1));
558 	if (ret)
559 		return ret;
560 
561 	/*
562 	 * DRDY output cannot be disabled at device level therefore we mask
563 	 * the irq at host end.
564 	 */
565 	enable_irq(st->spi->irq);
566 
567 	return 0;
568 }
569 
570 static int ad7779_buffer_postdisable(struct iio_dev *indio_dev)
571 {
572 	struct ad7779_state *st = iio_priv(indio_dev);
573 
574 	disable_irq(st->spi->irq);
575 
576 	return ad7779_spi_write(st, AD7779_REG_GENERAL_USER_CONFIG_3,
577 			       AD7779_DISABLE_SD);
578 }
579 
580 static irqreturn_t ad7779_trigger_handler(int irq, void *p)
581 {
582 	struct iio_poll_func *pf = p;
583 	struct iio_dev *indio_dev = pf->indio_dev;
584 	struct ad7779_state *st = iio_priv(indio_dev);
585 	int ret;
586 	struct spi_transfer t = {
587 		.rx_buf = st->data.chans,
588 		.tx_buf = st->spidata_tx,
589 		.len = AD7779_NUM_CHANNELS * AD7779_CHAN_DATA_SIZE,
590 	};
591 
592 	st->spidata_tx[0] = AD7779_SPI_READ_CMD;
593 	ret = spi_sync_transfer(st->spi, &t, 1);
594 	if (ret) {
595 		dev_err(&st->spi->dev, "SPI transfer error in IRQ handler");
596 		goto exit_handler;
597 	}
598 
599 	iio_push_to_buffers_with_ts(indio_dev, &st->data, sizeof(st->data),
600 				    pf->timestamp);
601 
602 exit_handler:
603 	iio_trigger_notify_done(indio_dev->trig);
604 	return IRQ_HANDLED;
605 }
606 
607 static int ad7779_reset(struct iio_dev *indio_dev, struct gpio_desc *reset_gpio)
608 {
609 	struct ad7779_state *st = iio_priv(indio_dev);
610 	int ret;
611 	struct spi_transfer t = {
612 		.tx_buf = st->reset_buf,
613 		.len = 8,
614 	};
615 
616 	if (reset_gpio) {
617 		gpiod_set_value(reset_gpio, 1);
618 		/* Delay for reset to occur is 225 microseconds */
619 		fsleep(230);
620 		ret = 0;
621 	} else {
622 		memset(st->reset_buf, 0xff, sizeof(st->reset_buf));
623 		ret = spi_sync_transfer(st->spi, &t, 1);
624 		if (ret)
625 			return ret;
626 	}
627 
628 	/* Delay for reset to occur is 225 microseconds */
629 	fsleep(230);
630 
631 	return ret;
632 }
633 
634 static int ad7779_update_scan_mode(struct iio_dev *indio_dev,
635 				   const unsigned long *scan_mask)
636 {
637 	struct ad7779_state *st = iio_priv(indio_dev);
638 	unsigned int c;
639 	int ret;
640 
641 	for (c = 0; c < AD7779_NUM_CHANNELS; c++) {
642 		if (test_bit(c, scan_mask))
643 			ret = iio_backend_chan_enable(st->back, c);
644 		else
645 			ret = iio_backend_chan_disable(st->back, c);
646 		if (ret)
647 			return ret;
648 	}
649 
650 	return 0;
651 }
652 
653 static const struct iio_info ad7779_info = {
654 	.read_raw = ad7779_read_raw,
655 	.write_raw = ad7779_write_raw,
656 	.debugfs_reg_access = &ad7779_reg_access,
657 };
658 
659 static const struct iio_info ad7779_info_data = {
660 	.read_raw = ad7779_read_raw,
661 	.write_raw = ad7779_write_raw,
662 	.debugfs_reg_access = &ad7779_reg_access,
663 	.update_scan_mode = &ad7779_update_scan_mode,
664 };
665 
666 static const struct iio_enum ad7779_filter_enum = {
667 	.items = ad7779_filter_type,
668 	.num_items = ARRAY_SIZE(ad7779_filter_type),
669 	.get = ad7779_get_filter,
670 	.set = ad7779_set_filter,
671 };
672 
673 static const struct iio_chan_spec_ext_info ad7779_ext_filter[] = {
674 	IIO_ENUM("filter_type", IIO_SHARED_BY_ALL, &ad7779_filter_enum),
675 	IIO_ENUM_AVAILABLE("filter_type", IIO_SHARED_BY_ALL,
676 				  &ad7779_filter_enum),
677 	{ }
678 };
679 
680 #define AD777x_CHAN_S(index, _ext_info)					\
681 	{								\
682 		.type = IIO_VOLTAGE,					\
683 		.info_mask_separate = BIT(IIO_CHAN_INFO_CALIBSCALE)  |	\
684 				      BIT(IIO_CHAN_INFO_CALIBBIAS),	\
685 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
686 		.address = (index),					\
687 		.indexed = 1,						\
688 		.channel = (index),					\
689 		.scan_index = (index),					\
690 		.ext_info = (_ext_info),				\
691 		.scan_type = {						\
692 			.sign = 's',					\
693 			.realbits = 24,					\
694 			.storagebits = 32,				\
695 			.endianness = IIO_BE,				\
696 		},							\
697 	}
698 
699 #define AD777x_CHAN_NO_FILTER_S(index)					\
700 	AD777x_CHAN_S(index, NULL)
701 
702 #define AD777x_CHAN_FILTER_S(index)					\
703 	AD777x_CHAN_S(index, ad7779_ext_filter)
704 static const struct iio_chan_spec ad7779_channels[] = {
705 	AD777x_CHAN_NO_FILTER_S(0),
706 	AD777x_CHAN_NO_FILTER_S(1),
707 	AD777x_CHAN_NO_FILTER_S(2),
708 	AD777x_CHAN_NO_FILTER_S(3),
709 	AD777x_CHAN_NO_FILTER_S(4),
710 	AD777x_CHAN_NO_FILTER_S(5),
711 	AD777x_CHAN_NO_FILTER_S(6),
712 	AD777x_CHAN_NO_FILTER_S(7),
713 	IIO_CHAN_SOFT_TIMESTAMP(8),
714 };
715 
716 static const struct iio_chan_spec ad7779_channels_filter[] = {
717 	AD777x_CHAN_FILTER_S(0),
718 	AD777x_CHAN_FILTER_S(1),
719 	AD777x_CHAN_FILTER_S(2),
720 	AD777x_CHAN_FILTER_S(3),
721 	AD777x_CHAN_FILTER_S(4),
722 	AD777x_CHAN_FILTER_S(5),
723 	AD777x_CHAN_FILTER_S(6),
724 	AD777x_CHAN_FILTER_S(7),
725 	IIO_CHAN_SOFT_TIMESTAMP(8),
726 };
727 
728 static const struct iio_buffer_setup_ops ad7779_buffer_setup_ops = {
729 	.preenable = ad7779_buffer_preenable,
730 	.postdisable = ad7779_buffer_postdisable,
731 };
732 
733 static const struct iio_trigger_ops ad7779_trigger_ops = {
734 	.validate_device = iio_trigger_validate_own_device,
735 };
736 
737 static int ad7779_conf(struct ad7779_state *st, struct gpio_desc *start_gpio)
738 {
739 	int ret;
740 
741 	ret = ad7779_spi_write_mask(st, AD7779_REG_GEN_ERR_REG_1_EN,
742 				    AD7779_SPI_CRC_EN_MSK,
743 				    FIELD_PREP(AD7779_SPI_CRC_EN_MSK, 1));
744 	if (ret)
745 		return ret;
746 
747 	ret = ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
748 				    AD7779_USRMOD_INIT_MSK,
749 				    FIELD_PREP(AD7779_USRMOD_INIT_MSK, 5));
750 	if (ret)
751 		return ret;
752 
753 	ret = ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
754 				    AD7779_DCLK_CLK_DIV_MSK,
755 				    FIELD_PREP(AD7779_DCLK_CLK_DIV_MSK, 1));
756 	if (ret)
757 		return ret;
758 
759 	ret = ad7779_spi_write_mask(st, AD7779_REG_ADC_MUX_CONFIG,
760 				    AD7779_REFMUX_CTRL_MSK,
761 				    FIELD_PREP(AD7779_REFMUX_CTRL_MSK, 1));
762 	if (ret)
763 		return ret;
764 
765 	ret = ad7779_set_sampling_frequency(st, AD7779_DEFAULT_SAMPLING_FREQ);
766 	if (ret)
767 		return ret;
768 
769 	gpiod_set_value(start_gpio, 0);
770 	/* Start setup time */
771 	fsleep(15);
772 	gpiod_set_value(start_gpio, 1);
773 	/* Start setup time */
774 	fsleep(15);
775 	gpiod_set_value(start_gpio, 0);
776 	/* Start setup time */
777 	fsleep(15);
778 
779 	return 0;
780 }
781 
782 static int ad7779_set_data_lines(struct iio_dev *indio_dev, u32 num_lanes)
783 {
784 	struct ad7779_state *st = iio_priv(indio_dev);
785 	int ret;
786 
787 	if (num_lanes != 1 && num_lanes != 2 && num_lanes != 4)
788 		return -EINVAL;
789 
790 	ret = ad7779_set_sampling_frequency(st, num_lanes * AD7779_DEFAULT_SAMPLING_1LINE);
791 	if (ret)
792 		return ret;
793 
794 	ret = iio_backend_num_lanes_set(st->back, num_lanes);
795 	if (ret)
796 		return ret;
797 
798 	return ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
799 				     AD7779_DOUT_FORMAT_MSK,
800 				     FIELD_PREP(AD7779_DOUT_FORMAT_MSK, 2 - ilog2(num_lanes)));
801 }
802 
803 static int ad7779_setup_channels(struct iio_dev *indio_dev, const struct ad7779_state *st)
804 {
805 	struct iio_chan_spec *channels;
806 	struct device *dev = &st->spi->dev;
807 
808 	channels = devm_kmemdup_array(dev, st->chip_info->channels,
809 				      ARRAY_SIZE(ad7779_channels),
810 				      sizeof(*channels), GFP_KERNEL);
811 	if (!channels)
812 		return -ENOMEM;
813 
814 	for (unsigned int i = 0; i < ARRAY_SIZE(ad7779_channels); i++)
815 		channels[i].scan_type.endianness = IIO_CPU;
816 
817 	indio_dev->channels = channels;
818 	indio_dev->num_channels = ARRAY_SIZE(ad7779_channels);
819 
820 	return 0;
821 }
822 
823 static int ad7779_setup_without_backend(struct ad7779_state *st, struct iio_dev *indio_dev)
824 {
825 	int ret;
826 	struct device *dev = &st->spi->dev;
827 
828 	indio_dev->info = &ad7779_info;
829 	indio_dev->channels = st->chip_info->channels;
830 	indio_dev->num_channels = ARRAY_SIZE(ad7779_channels);
831 
832 	st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
833 					  iio_device_id(indio_dev));
834 	if (!st->trig)
835 		return -ENOMEM;
836 
837 	st->trig->ops = &ad7779_trigger_ops;
838 
839 	iio_trigger_set_drvdata(st->trig, st);
840 
841 	ret = devm_request_irq(dev, st->spi->irq, iio_trigger_generic_data_rdy_poll,
842 			       IRQF_NO_THREAD | IRQF_NO_AUTOEN, indio_dev->name,
843 			       st->trig);
844 	if (ret)
845 		return ret;
846 
847 	ret = devm_iio_trigger_register(dev, st->trig);
848 	if (ret)
849 		return ret;
850 
851 	indio_dev->trig = iio_trigger_get(st->trig);
852 
853 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
854 					      &iio_pollfunc_store_time,
855 					      &ad7779_trigger_handler,
856 					      &ad7779_buffer_setup_ops);
857 	if (ret)
858 		return ret;
859 
860 	return ad7779_spi_write_mask(st, AD7779_REG_DOUT_FORMAT,
861 				     AD7779_DCLK_CLK_DIV_MSK,
862 				     FIELD_PREP(AD7779_DCLK_CLK_DIV_MSK, 7));
863 }
864 
865 static int ad7779_setup_backend(struct ad7779_state *st, struct iio_dev *indio_dev)
866 {
867 	struct device *dev = &st->spi->dev;
868 	int ret;
869 	u32 num_lanes;
870 
871 	indio_dev->info = &ad7779_info_data;
872 
873 	ret = ad7779_setup_channels(indio_dev, st);
874 	if (ret)
875 		return ret;
876 
877 	st->back = devm_iio_backend_get(dev, NULL);
878 	if (IS_ERR(st->back))
879 		return dev_err_probe(dev, PTR_ERR(st->back),
880 				     "failed to get iio backend");
881 
882 	ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev);
883 	if (ret)
884 		return ret;
885 
886 	ret = devm_iio_backend_enable(dev, st->back);
887 	if (ret)
888 		return ret;
889 
890 	num_lanes = 4;
891 	ret = device_property_read_u32(dev, "adi,num-lanes", &num_lanes);
892 	if (ret && ret != -EINVAL)
893 		return ret;
894 
895 	return ad7779_set_data_lines(indio_dev, num_lanes);
896 }
897 
898 static int ad7779_probe(struct spi_device *spi)
899 {
900 	struct iio_dev *indio_dev;
901 	struct ad7779_state *st;
902 	struct gpio_desc *reset_gpio, *start_gpio;
903 	struct device *dev = &spi->dev;
904 	int ret = -EINVAL;
905 
906 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
907 	if (!indio_dev)
908 		return -ENOMEM;
909 
910 	st = iio_priv(indio_dev);
911 
912 	ret = devm_regulator_bulk_get_enable(dev,
913 					     ARRAY_SIZE(ad7779_power_supplies),
914 					     ad7779_power_supplies);
915 	if (ret)
916 		return dev_err_probe(dev, ret,
917 				     "failed to get and enable supplies\n");
918 
919 	st->mclk = devm_clk_get_enabled(dev, "mclk");
920 	if (IS_ERR(st->mclk))
921 		return PTR_ERR(st->mclk);
922 
923 	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
924 	if (IS_ERR(reset_gpio))
925 		return PTR_ERR(reset_gpio);
926 
927 	start_gpio = devm_gpiod_get(dev, "start", GPIOD_OUT_HIGH);
928 	if (IS_ERR(start_gpio))
929 		return PTR_ERR(start_gpio);
930 
931 	crc8_populate_msb(ad7779_crc8_table, AD7779_CRC8_POLY);
932 	st->spi = spi;
933 
934 	st->chip_info = spi_get_device_match_data(spi);
935 	if (!st->chip_info)
936 		return -ENODEV;
937 
938 	ret = ad7779_reset(indio_dev, reset_gpio);
939 	if (ret)
940 		return ret;
941 
942 	ret = ad7779_conf(st, start_gpio);
943 	if (ret)
944 		return ret;
945 
946 	indio_dev->name = st->chip_info->name;
947 	indio_dev->modes = INDIO_DIRECT_MODE;
948 
949 	if (device_property_present(dev, "io-backends"))
950 		ret = ad7779_setup_backend(st, indio_dev);
951 	else
952 		ret = ad7779_setup_without_backend(st, indio_dev);
953 	if (ret)
954 		return ret;
955 
956 	return devm_iio_device_register(dev, indio_dev);
957 }
958 
959 static int ad7779_suspend(struct device *dev)
960 {
961 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
962 	struct ad7779_state *st = iio_priv(indio_dev);
963 
964 	return ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
965 				     AD7779_MOD_POWERMODE_MSK,
966 				     FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
967 					       AD7779_LOW_POWER));
968 }
969 
970 static int ad7779_resume(struct device *dev)
971 {
972 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
973 	struct ad7779_state *st = iio_priv(indio_dev);
974 
975 	return ad7779_spi_write_mask(st, AD7779_REG_GENERAL_USER_CONFIG_1,
976 				     AD7779_MOD_POWERMODE_MSK,
977 				     FIELD_PREP(AD7779_MOD_POWERMODE_MSK,
978 					       AD7779_HIGH_POWER));
979 }
980 
981 static DEFINE_SIMPLE_DEV_PM_OPS(ad7779_pm_ops, ad7779_suspend, ad7779_resume);
982 
983 static const struct ad7779_chip_info ad7770_chip_info = {
984 	.name = "ad7770",
985 	.channels = ad7779_channels,
986 };
987 
988 static const struct ad7779_chip_info ad7771_chip_info = {
989 	.name = "ad7771",
990 	.channels = ad7779_channels_filter,
991 };
992 
993 static const struct ad7779_chip_info ad7779_chip_info = {
994 	.name = "ad7779",
995 	.channels = ad7779_channels,
996 };
997 
998 static const struct spi_device_id ad7779_id[] = {
999 	{
1000 		.name = "ad7770",
1001 		.driver_data = (kernel_ulong_t)&ad7770_chip_info,
1002 	},
1003 	{
1004 		.name = "ad7771",
1005 		.driver_data = (kernel_ulong_t)&ad7771_chip_info,
1006 	},
1007 	{
1008 		.name = "ad7779",
1009 		.driver_data = (kernel_ulong_t)&ad7779_chip_info,
1010 	},
1011 	{ }
1012 };
1013 MODULE_DEVICE_TABLE(spi, ad7779_id);
1014 
1015 static const struct of_device_id ad7779_of_table[] = {
1016 	{
1017 		.compatible = "adi,ad7770",
1018 		.data = &ad7770_chip_info,
1019 	},
1020 	{
1021 		.compatible = "adi,ad7771",
1022 		.data = &ad7771_chip_info,
1023 	},
1024 	{
1025 		.compatible = "adi,ad7779",
1026 		.data = &ad7779_chip_info,
1027 	},
1028 	{ }
1029 };
1030 MODULE_DEVICE_TABLE(of, ad7779_of_table);
1031 
1032 static struct spi_driver ad7779_driver = {
1033 	.driver = {
1034 		.name = "ad7779",
1035 		.pm = pm_sleep_ptr(&ad7779_pm_ops),
1036 		.of_match_table = ad7779_of_table,
1037 	},
1038 	.probe = ad7779_probe,
1039 	.id_table = ad7779_id,
1040 };
1041 module_spi_driver(ad7779_driver);
1042 
1043 MODULE_AUTHOR("Ramona Alexandra Nechita <ramona.nechita@analog.com>");
1044 MODULE_DESCRIPTION("Analog Devices AD7779 ADC");
1045 MODULE_LICENSE("GPL");
1046 MODULE_IMPORT_NS("IIO_BACKEND");
1047