1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Analog Devices AD7768-1 SPI ADC driver
4  *
5  * Copyright 2017 Analog Devices Inc.
6  */
7 #include <linux/bitfield.h>
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/sysfs.h>
17 #include <linux/spi/spi.h>
18 
19 #include <linux/iio/buffer.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/trigger.h>
23 #include <linux/iio/triggered_buffer.h>
24 #include <linux/iio/trigger_consumer.h>
25 
26 /* AD7768 registers definition */
27 #define AD7768_REG_CHIP_TYPE		0x3
28 #define AD7768_REG_PROD_ID_L		0x4
29 #define AD7768_REG_PROD_ID_H		0x5
30 #define AD7768_REG_CHIP_GRADE		0x6
31 #define AD7768_REG_SCRATCH_PAD		0x0A
32 #define AD7768_REG_VENDOR_L		0x0C
33 #define AD7768_REG_VENDOR_H		0x0D
34 #define AD7768_REG_INTERFACE_FORMAT	0x14
35 #define AD7768_REG_POWER_CLOCK		0x15
36 #define AD7768_REG_ANALOG		0x16
37 #define AD7768_REG_ANALOG2		0x17
38 #define AD7768_REG_CONVERSION		0x18
39 #define AD7768_REG_DIGITAL_FILTER	0x19
40 #define AD7768_REG_SINC3_DEC_RATE_MSB	0x1A
41 #define AD7768_REG_SINC3_DEC_RATE_LSB	0x1B
42 #define AD7768_REG_DUTY_CYCLE_RATIO	0x1C
43 #define AD7768_REG_SYNC_RESET		0x1D
44 #define AD7768_REG_GPIO_CONTROL		0x1E
45 #define AD7768_REG_GPIO_WRITE		0x1F
46 #define AD7768_REG_GPIO_READ		0x20
47 #define AD7768_REG_OFFSET_HI		0x21
48 #define AD7768_REG_OFFSET_MID		0x22
49 #define AD7768_REG_OFFSET_LO		0x23
50 #define AD7768_REG_GAIN_HI		0x24
51 #define AD7768_REG_GAIN_MID		0x25
52 #define AD7768_REG_GAIN_LO		0x26
53 #define AD7768_REG_SPI_DIAG_ENABLE	0x28
54 #define AD7768_REG_ADC_DIAG_ENABLE	0x29
55 #define AD7768_REG_DIG_DIAG_ENABLE	0x2A
56 #define AD7768_REG_ADC_DATA		0x2C
57 #define AD7768_REG_MASTER_STATUS	0x2D
58 #define AD7768_REG_SPI_DIAG_STATUS	0x2E
59 #define AD7768_REG_ADC_DIAG_STATUS	0x2F
60 #define AD7768_REG_DIG_DIAG_STATUS	0x30
61 #define AD7768_REG_MCLK_COUNTER		0x31
62 
63 /* AD7768_REG_POWER_CLOCK */
64 #define AD7768_PWR_MCLK_DIV_MSK		GENMASK(5, 4)
65 #define AD7768_PWR_MCLK_DIV(x)		FIELD_PREP(AD7768_PWR_MCLK_DIV_MSK, x)
66 #define AD7768_PWR_PWRMODE_MSK		GENMASK(1, 0)
67 #define AD7768_PWR_PWRMODE(x)		FIELD_PREP(AD7768_PWR_PWRMODE_MSK, x)
68 
69 /* AD7768_REG_DIGITAL_FILTER */
70 #define AD7768_DIG_FIL_FIL_MSK		GENMASK(6, 4)
71 #define AD7768_DIG_FIL_FIL(x)		FIELD_PREP(AD7768_DIG_FIL_FIL_MSK, x)
72 #define AD7768_DIG_FIL_DEC_MSK		GENMASK(2, 0)
73 #define AD7768_DIG_FIL_DEC_RATE(x)	FIELD_PREP(AD7768_DIG_FIL_DEC_MSK, x)
74 
75 /* AD7768_REG_CONVERSION */
76 #define AD7768_CONV_MODE_MSK		GENMASK(2, 0)
77 #define AD7768_CONV_MODE(x)		FIELD_PREP(AD7768_CONV_MODE_MSK, x)
78 
79 #define AD7768_RD_FLAG_MSK(x)		(BIT(6) | ((x) & 0x3F))
80 #define AD7768_WR_FLAG_MSK(x)		((x) & 0x3F)
81 
82 enum ad7768_conv_mode {
83 	AD7768_CONTINUOUS,
84 	AD7768_ONE_SHOT,
85 	AD7768_SINGLE,
86 	AD7768_PERIODIC,
87 	AD7768_STANDBY
88 };
89 
90 enum ad7768_pwrmode {
91 	AD7768_ECO_MODE = 0,
92 	AD7768_MED_MODE = 2,
93 	AD7768_FAST_MODE = 3
94 };
95 
96 enum ad7768_mclk_div {
97 	AD7768_MCLK_DIV_16,
98 	AD7768_MCLK_DIV_8,
99 	AD7768_MCLK_DIV_4,
100 	AD7768_MCLK_DIV_2
101 };
102 
103 enum ad7768_dec_rate {
104 	AD7768_DEC_RATE_32 = 0,
105 	AD7768_DEC_RATE_64 = 1,
106 	AD7768_DEC_RATE_128 = 2,
107 	AD7768_DEC_RATE_256 = 3,
108 	AD7768_DEC_RATE_512 = 4,
109 	AD7768_DEC_RATE_1024 = 5,
110 	AD7768_DEC_RATE_8 = 9,
111 	AD7768_DEC_RATE_16 = 10
112 };
113 
114 struct ad7768_clk_configuration {
115 	enum ad7768_mclk_div mclk_div;
116 	enum ad7768_dec_rate dec_rate;
117 	unsigned int clk_div;
118 	enum ad7768_pwrmode pwrmode;
119 };
120 
121 static const struct ad7768_clk_configuration ad7768_clk_config[] = {
122 	{ AD7768_MCLK_DIV_2, AD7768_DEC_RATE_8, 16,  AD7768_FAST_MODE },
123 	{ AD7768_MCLK_DIV_2, AD7768_DEC_RATE_16, 32,  AD7768_FAST_MODE },
124 	{ AD7768_MCLK_DIV_2, AD7768_DEC_RATE_32, 64, AD7768_FAST_MODE },
125 	{ AD7768_MCLK_DIV_2, AD7768_DEC_RATE_64, 128, AD7768_FAST_MODE },
126 	{ AD7768_MCLK_DIV_2, AD7768_DEC_RATE_128, 256, AD7768_FAST_MODE },
127 	{ AD7768_MCLK_DIV_4, AD7768_DEC_RATE_128, 512, AD7768_MED_MODE },
128 	{ AD7768_MCLK_DIV_4, AD7768_DEC_RATE_256, 1024, AD7768_MED_MODE },
129 	{ AD7768_MCLK_DIV_4, AD7768_DEC_RATE_512, 2048, AD7768_MED_MODE },
130 	{ AD7768_MCLK_DIV_4, AD7768_DEC_RATE_1024, 4096, AD7768_MED_MODE },
131 	{ AD7768_MCLK_DIV_8, AD7768_DEC_RATE_1024, 8192, AD7768_MED_MODE },
132 	{ AD7768_MCLK_DIV_16, AD7768_DEC_RATE_1024, 16384, AD7768_ECO_MODE },
133 };
134 
135 static const struct iio_chan_spec ad7768_channels[] = {
136 	{
137 		.type = IIO_VOLTAGE,
138 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
139 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
140 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
141 		.indexed = 1,
142 		.channel = 0,
143 		.scan_index = 0,
144 		.scan_type = {
145 			.sign = 'u',
146 			.realbits = 24,
147 			.storagebits = 32,
148 			.shift = 8,
149 			.endianness = IIO_BE,
150 		},
151 	},
152 };
153 
154 struct ad7768_state {
155 	struct spi_device *spi;
156 	struct regulator *vref;
157 	struct mutex lock;
158 	struct clk *mclk;
159 	unsigned int mclk_freq;
160 	unsigned int samp_freq;
161 	struct completion completion;
162 	struct iio_trigger *trig;
163 	struct gpio_desc *gpio_sync_in;
164 	/*
165 	 * DMA (thus cache coherency maintenance) requires the
166 	 * transfer buffers to live in their own cache lines.
167 	 */
168 	union {
169 		__be32 d32;
170 		u8 d8[2];
171 	} data ____cacheline_aligned;
172 };
173 
ad7768_spi_reg_read(struct ad7768_state * st,unsigned int addr,unsigned int len)174 static int ad7768_spi_reg_read(struct ad7768_state *st, unsigned int addr,
175 			       unsigned int len)
176 {
177 	unsigned int shift;
178 	int ret;
179 
180 	shift = 32 - (8 * len);
181 	st->data.d8[0] = AD7768_RD_FLAG_MSK(addr);
182 
183 	ret = spi_write_then_read(st->spi, st->data.d8, 1,
184 				  &st->data.d32, len);
185 	if (ret < 0)
186 		return ret;
187 
188 	return (be32_to_cpu(st->data.d32) >> shift);
189 }
190 
ad7768_spi_reg_write(struct ad7768_state * st,unsigned int addr,unsigned int val)191 static int ad7768_spi_reg_write(struct ad7768_state *st,
192 				unsigned int addr,
193 				unsigned int val)
194 {
195 	st->data.d8[0] = AD7768_WR_FLAG_MSK(addr);
196 	st->data.d8[1] = val & 0xFF;
197 
198 	return spi_write(st->spi, st->data.d8, 2);
199 }
200 
ad7768_set_mode(struct ad7768_state * st,enum ad7768_conv_mode mode)201 static int ad7768_set_mode(struct ad7768_state *st,
202 			   enum ad7768_conv_mode mode)
203 {
204 	int regval;
205 
206 	regval = ad7768_spi_reg_read(st, AD7768_REG_CONVERSION, 1);
207 	if (regval < 0)
208 		return regval;
209 
210 	regval &= ~AD7768_CONV_MODE_MSK;
211 	regval |= AD7768_CONV_MODE(mode);
212 
213 	return ad7768_spi_reg_write(st, AD7768_REG_CONVERSION, regval);
214 }
215 
ad7768_scan_direct(struct iio_dev * indio_dev)216 static int ad7768_scan_direct(struct iio_dev *indio_dev)
217 {
218 	struct ad7768_state *st = iio_priv(indio_dev);
219 	int readval, ret;
220 
221 	reinit_completion(&st->completion);
222 
223 	ret = ad7768_set_mode(st, AD7768_ONE_SHOT);
224 	if (ret < 0)
225 		return ret;
226 
227 	ret = wait_for_completion_timeout(&st->completion,
228 					  msecs_to_jiffies(1000));
229 	if (!ret)
230 		return -ETIMEDOUT;
231 
232 	readval = ad7768_spi_reg_read(st, AD7768_REG_ADC_DATA, 3);
233 	if (readval < 0)
234 		return readval;
235 	/*
236 	 * Any SPI configuration of the AD7768-1 can only be
237 	 * performed in continuous conversion mode.
238 	 */
239 	ret = ad7768_set_mode(st, AD7768_CONTINUOUS);
240 	if (ret < 0)
241 		return ret;
242 
243 	return readval;
244 }
245 
ad7768_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)246 static int ad7768_reg_access(struct iio_dev *indio_dev,
247 			     unsigned int reg,
248 			     unsigned int writeval,
249 			     unsigned int *readval)
250 {
251 	struct ad7768_state *st = iio_priv(indio_dev);
252 	int ret;
253 
254 	mutex_lock(&st->lock);
255 	if (readval) {
256 		ret = ad7768_spi_reg_read(st, reg, 1);
257 		if (ret < 0)
258 			goto err_unlock;
259 		*readval = ret;
260 		ret = 0;
261 	} else {
262 		ret = ad7768_spi_reg_write(st, reg, writeval);
263 	}
264 err_unlock:
265 	mutex_unlock(&st->lock);
266 
267 	return ret;
268 }
269 
ad7768_set_dig_fil(struct ad7768_state * st,enum ad7768_dec_rate dec_rate)270 static int ad7768_set_dig_fil(struct ad7768_state *st,
271 			      enum ad7768_dec_rate dec_rate)
272 {
273 	unsigned int mode;
274 	int ret;
275 
276 	if (dec_rate == AD7768_DEC_RATE_8 || dec_rate == AD7768_DEC_RATE_16)
277 		mode = AD7768_DIG_FIL_FIL(dec_rate);
278 	else
279 		mode = AD7768_DIG_FIL_DEC_RATE(dec_rate);
280 
281 	ret = ad7768_spi_reg_write(st, AD7768_REG_DIGITAL_FILTER, mode);
282 	if (ret < 0)
283 		return ret;
284 
285 	/* A sync-in pulse is required every time the filter dec rate changes */
286 	gpiod_set_value(st->gpio_sync_in, 1);
287 	gpiod_set_value(st->gpio_sync_in, 0);
288 
289 	return 0;
290 }
291 
ad7768_set_freq(struct ad7768_state * st,unsigned int freq)292 static int ad7768_set_freq(struct ad7768_state *st,
293 			   unsigned int freq)
294 {
295 	unsigned int diff_new, diff_old, pwr_mode, i, idx;
296 	int res, ret;
297 
298 	diff_old = U32_MAX;
299 	idx = 0;
300 
301 	res = DIV_ROUND_CLOSEST(st->mclk_freq, freq);
302 
303 	/* Find the closest match for the desired sampling frequency */
304 	for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
305 		diff_new = abs(res - ad7768_clk_config[i].clk_div);
306 		if (diff_new < diff_old) {
307 			diff_old = diff_new;
308 			idx = i;
309 		}
310 	}
311 
312 	/*
313 	 * Set both the mclk_div and pwrmode with a single write to the
314 	 * POWER_CLOCK register
315 	 */
316 	pwr_mode = AD7768_PWR_MCLK_DIV(ad7768_clk_config[idx].mclk_div) |
317 		   AD7768_PWR_PWRMODE(ad7768_clk_config[idx].pwrmode);
318 	ret = ad7768_spi_reg_write(st, AD7768_REG_POWER_CLOCK, pwr_mode);
319 	if (ret < 0)
320 		return ret;
321 
322 	ret =  ad7768_set_dig_fil(st, ad7768_clk_config[idx].dec_rate);
323 	if (ret < 0)
324 		return ret;
325 
326 	st->samp_freq = DIV_ROUND_CLOSEST(st->mclk_freq,
327 					  ad7768_clk_config[idx].clk_div);
328 
329 	return 0;
330 }
331 
ad7768_sampling_freq_avail(struct device * dev,struct device_attribute * attr,char * buf)332 static ssize_t ad7768_sampling_freq_avail(struct device *dev,
333 					  struct device_attribute *attr,
334 					  char *buf)
335 {
336 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
337 	struct ad7768_state *st = iio_priv(indio_dev);
338 	unsigned int freq;
339 	int i, len = 0;
340 
341 	for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
342 		freq = DIV_ROUND_CLOSEST(st->mclk_freq,
343 					 ad7768_clk_config[i].clk_div);
344 		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", freq);
345 	}
346 
347 	buf[len - 1] = '\n';
348 
349 	return len;
350 }
351 
352 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(ad7768_sampling_freq_avail);
353 
ad7768_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long info)354 static int ad7768_read_raw(struct iio_dev *indio_dev,
355 			   struct iio_chan_spec const *chan,
356 			   int *val, int *val2, long info)
357 {
358 	struct ad7768_state *st = iio_priv(indio_dev);
359 	int scale_uv, ret;
360 
361 	switch (info) {
362 	case IIO_CHAN_INFO_RAW:
363 		ret = iio_device_claim_direct_mode(indio_dev);
364 		if (ret)
365 			return ret;
366 
367 		ret = ad7768_scan_direct(indio_dev);
368 		if (ret >= 0)
369 			*val = ret;
370 
371 		iio_device_release_direct_mode(indio_dev);
372 		if (ret < 0)
373 			return ret;
374 
375 		return IIO_VAL_INT;
376 
377 	case IIO_CHAN_INFO_SCALE:
378 		scale_uv = regulator_get_voltage(st->vref);
379 		if (scale_uv < 0)
380 			return scale_uv;
381 
382 		*val = (scale_uv * 2) / 1000;
383 		*val2 = chan->scan_type.realbits;
384 
385 		return IIO_VAL_FRACTIONAL_LOG2;
386 
387 	case IIO_CHAN_INFO_SAMP_FREQ:
388 		*val = st->samp_freq;
389 
390 		return IIO_VAL_INT;
391 	}
392 
393 	return -EINVAL;
394 }
395 
ad7768_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long info)396 static int ad7768_write_raw(struct iio_dev *indio_dev,
397 			    struct iio_chan_spec const *chan,
398 			    int val, int val2, long info)
399 {
400 	struct ad7768_state *st = iio_priv(indio_dev);
401 
402 	switch (info) {
403 	case IIO_CHAN_INFO_SAMP_FREQ:
404 		return ad7768_set_freq(st, val);
405 	default:
406 		return -EINVAL;
407 	}
408 }
409 
410 static struct attribute *ad7768_attributes[] = {
411 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
412 	NULL
413 };
414 
415 static const struct attribute_group ad7768_group = {
416 	.attrs = ad7768_attributes,
417 };
418 
419 static const struct iio_info ad7768_info = {
420 	.attrs = &ad7768_group,
421 	.read_raw = &ad7768_read_raw,
422 	.write_raw = &ad7768_write_raw,
423 	.debugfs_reg_access = &ad7768_reg_access,
424 };
425 
ad7768_setup(struct ad7768_state * st)426 static int ad7768_setup(struct ad7768_state *st)
427 {
428 	int ret;
429 
430 	/*
431 	 * Two writes to the SPI_RESET[1:0] bits are required to initiate
432 	 * a software reset. The bits must first be set to 11, and then
433 	 * to 10. When the sequence is detected, the reset occurs.
434 	 * See the datasheet, page 70.
435 	 */
436 	ret = ad7768_spi_reg_write(st, AD7768_REG_SYNC_RESET, 0x3);
437 	if (ret)
438 		return ret;
439 
440 	ret = ad7768_spi_reg_write(st, AD7768_REG_SYNC_RESET, 0x2);
441 	if (ret)
442 		return ret;
443 
444 	st->gpio_sync_in = devm_gpiod_get(&st->spi->dev, "adi,sync-in",
445 					  GPIOD_OUT_LOW);
446 	if (IS_ERR(st->gpio_sync_in))
447 		return PTR_ERR(st->gpio_sync_in);
448 
449 	/* Set the default sampling frequency to 32000 kSPS */
450 	return ad7768_set_freq(st, 32000);
451 }
452 
ad7768_trigger_handler(int irq,void * p)453 static irqreturn_t ad7768_trigger_handler(int irq, void *p)
454 {
455 	struct iio_poll_func *pf = p;
456 	struct iio_dev *indio_dev = pf->indio_dev;
457 	struct ad7768_state *st = iio_priv(indio_dev);
458 	int ret;
459 
460 	mutex_lock(&st->lock);
461 
462 	ret = spi_read(st->spi, &st->data.d32, 3);
463 	if (ret < 0)
464 		goto err_unlock;
465 
466 	iio_push_to_buffers_with_timestamp(indio_dev, &st->data.d32,
467 					   iio_get_time_ns(indio_dev));
468 
469 	iio_trigger_notify_done(indio_dev->trig);
470 err_unlock:
471 	mutex_unlock(&st->lock);
472 
473 	return IRQ_HANDLED;
474 }
475 
ad7768_interrupt(int irq,void * dev_id)476 static irqreturn_t ad7768_interrupt(int irq, void *dev_id)
477 {
478 	struct iio_dev *indio_dev = dev_id;
479 	struct ad7768_state *st = iio_priv(indio_dev);
480 
481 	if (iio_buffer_enabled(indio_dev))
482 		iio_trigger_poll(st->trig);
483 	else
484 		complete(&st->completion);
485 
486 	return IRQ_HANDLED;
487 };
488 
ad7768_buffer_postenable(struct iio_dev * indio_dev)489 static int ad7768_buffer_postenable(struct iio_dev *indio_dev)
490 {
491 	struct ad7768_state *st = iio_priv(indio_dev);
492 
493 	iio_triggered_buffer_postenable(indio_dev);
494 	/*
495 	 * Write a 1 to the LSB of the INTERFACE_FORMAT register to enter
496 	 * continuous read mode. Subsequent data reads do not require an
497 	 * initial 8-bit write to query the ADC_DATA register.
498 	 */
499 	return ad7768_spi_reg_write(st, AD7768_REG_INTERFACE_FORMAT, 0x01);
500 }
501 
ad7768_buffer_predisable(struct iio_dev * indio_dev)502 static int ad7768_buffer_predisable(struct iio_dev *indio_dev)
503 {
504 	struct ad7768_state *st = iio_priv(indio_dev);
505 	int ret;
506 
507 	/*
508 	 * To exit continuous read mode, perform a single read of the ADC_DATA
509 	 * reg (0x2C), which allows further configuration of the device.
510 	 */
511 	ret = ad7768_spi_reg_read(st, AD7768_REG_ADC_DATA, 3);
512 	if (ret < 0)
513 		return ret;
514 
515 	return iio_triggered_buffer_predisable(indio_dev);
516 }
517 
518 static const struct iio_buffer_setup_ops ad7768_buffer_ops = {
519 	.postenable = &ad7768_buffer_postenable,
520 	.predisable = &ad7768_buffer_predisable,
521 };
522 
523 static const struct iio_trigger_ops ad7768_trigger_ops = {
524 	.validate_device = iio_trigger_validate_own_device,
525 };
526 
ad7768_regulator_disable(void * data)527 static void ad7768_regulator_disable(void *data)
528 {
529 	struct ad7768_state *st = data;
530 
531 	regulator_disable(st->vref);
532 }
533 
ad7768_clk_disable(void * data)534 static void ad7768_clk_disable(void *data)
535 {
536 	struct ad7768_state *st = data;
537 
538 	clk_disable_unprepare(st->mclk);
539 }
540 
ad7768_probe(struct spi_device * spi)541 static int ad7768_probe(struct spi_device *spi)
542 {
543 	struct ad7768_state *st;
544 	struct iio_dev *indio_dev;
545 	int ret;
546 
547 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
548 	if (!indio_dev)
549 		return -ENOMEM;
550 
551 	st = iio_priv(indio_dev);
552 	st->spi = spi;
553 
554 	st->vref = devm_regulator_get(&spi->dev, "vref");
555 	if (IS_ERR(st->vref))
556 		return PTR_ERR(st->vref);
557 
558 	ret = regulator_enable(st->vref);
559 	if (ret) {
560 		dev_err(&spi->dev, "Failed to enable specified vref supply\n");
561 		return ret;
562 	}
563 
564 	ret = devm_add_action_or_reset(&spi->dev, ad7768_regulator_disable, st);
565 	if (ret)
566 		return ret;
567 
568 	st->mclk = devm_clk_get(&spi->dev, "mclk");
569 	if (IS_ERR(st->mclk))
570 		return PTR_ERR(st->mclk);
571 
572 	ret = clk_prepare_enable(st->mclk);
573 	if (ret < 0)
574 		return ret;
575 
576 	ret = devm_add_action_or_reset(&spi->dev, ad7768_clk_disable, st);
577 	if (ret)
578 		return ret;
579 
580 	st->mclk_freq = clk_get_rate(st->mclk);
581 
582 	spi_set_drvdata(spi, indio_dev);
583 	mutex_init(&st->lock);
584 
585 	indio_dev->channels = ad7768_channels;
586 	indio_dev->num_channels = ARRAY_SIZE(ad7768_channels);
587 	indio_dev->dev.parent = &spi->dev;
588 	indio_dev->name = spi_get_device_id(spi)->name;
589 	indio_dev->info = &ad7768_info;
590 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_TRIGGERED;
591 
592 	ret = ad7768_setup(st);
593 	if (ret < 0) {
594 		dev_err(&spi->dev, "AD7768 setup failed\n");
595 		return ret;
596 	}
597 
598 	st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
599 					  indio_dev->name, indio_dev->id);
600 	if (!st->trig)
601 		return -ENOMEM;
602 
603 	st->trig->ops = &ad7768_trigger_ops;
604 	st->trig->dev.parent = &spi->dev;
605 	iio_trigger_set_drvdata(st->trig, indio_dev);
606 	ret = devm_iio_trigger_register(&spi->dev, st->trig);
607 	if (ret)
608 		return ret;
609 
610 	indio_dev->trig = iio_trigger_get(st->trig);
611 
612 	init_completion(&st->completion);
613 
614 	ret = devm_request_irq(&spi->dev, spi->irq,
615 			       &ad7768_interrupt,
616 			       IRQF_TRIGGER_RISING | IRQF_ONESHOT,
617 			       indio_dev->name, indio_dev);
618 	if (ret)
619 		return ret;
620 
621 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
622 					      &iio_pollfunc_store_time,
623 					      &ad7768_trigger_handler,
624 					      &ad7768_buffer_ops);
625 	if (ret)
626 		return ret;
627 
628 	return devm_iio_device_register(&spi->dev, indio_dev);
629 }
630 
631 static const struct spi_device_id ad7768_id_table[] = {
632 	{ "ad7768-1", 0 },
633 	{}
634 };
635 MODULE_DEVICE_TABLE(spi, ad7768_id_table);
636 
637 static const struct of_device_id ad7768_of_match[] = {
638 	{ .compatible = "adi,ad7768-1" },
639 	{ },
640 };
641 MODULE_DEVICE_TABLE(of, ad7768_of_match);
642 
643 static struct spi_driver ad7768_driver = {
644 	.driver = {
645 		.name = "ad7768-1",
646 		.of_match_table = ad7768_of_match,
647 	},
648 	.probe = ad7768_probe,
649 	.id_table = ad7768_id_table,
650 };
651 module_spi_driver(ad7768_driver);
652 
653 MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
654 MODULE_DESCRIPTION("Analog Devices AD7768-1 ADC driver");
655 MODULE_LICENSE("GPL v2");
656