xref: /openbmc/linux/drivers/iio/gyro/adxrs290.c (revision 84b102f5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ADXRS290 SPI Gyroscope Driver
4  *
5  * Copyright (C) 2020 Nishant Malpani <nish.malpani25@gmail.com>
6  * Copyright (C) 2020 Analog Devices, Inc.
7  */
8 
9 #include <linux/bitfield.h>
10 #include <linux/delay.h>
11 #include <linux/device.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/spi/spi.h>
15 
16 #include <linux/iio/buffer.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19 #include <linux/iio/trigger.h>
20 #include <linux/iio/triggered_buffer.h>
21 #include <linux/iio/trigger_consumer.h>
22 
23 #define ADXRS290_ADI_ID		0xAD
24 #define ADXRS290_MEMS_ID	0x1D
25 #define ADXRS290_DEV_ID		0x92
26 
27 #define ADXRS290_REG_ADI_ID	0x00
28 #define ADXRS290_REG_MEMS_ID	0x01
29 #define ADXRS290_REG_DEV_ID	0x02
30 #define ADXRS290_REG_REV_ID	0x03
31 #define ADXRS290_REG_SN0	0x04 /* Serial Number Registers, 4 bytes */
32 #define ADXRS290_REG_DATAX0	0x08 /* Roll Rate o/p Data Regs, 2 bytes */
33 #define ADXRS290_REG_DATAY0	0x0A /* Pitch Rate o/p Data Regs, 2 bytes */
34 #define ADXRS290_REG_TEMP0	0x0C
35 #define ADXRS290_REG_POWER_CTL	0x10
36 #define ADXRS290_REG_FILTER	0x11
37 #define ADXRS290_REG_DATA_RDY	0x12
38 
39 #define ADXRS290_READ		BIT(7)
40 #define ADXRS290_TSM		BIT(0)
41 #define ADXRS290_MEASUREMENT	BIT(1)
42 #define ADXRS290_DATA_RDY_OUT	BIT(0)
43 #define ADXRS290_SYNC_MASK	GENMASK(1, 0)
44 #define ADXRS290_SYNC(x)	FIELD_PREP(ADXRS290_SYNC_MASK, x)
45 #define ADXRS290_LPF_MASK	GENMASK(2, 0)
46 #define ADXRS290_LPF(x)		FIELD_PREP(ADXRS290_LPF_MASK, x)
47 #define ADXRS290_HPF_MASK	GENMASK(7, 4)
48 #define ADXRS290_HPF(x)		FIELD_PREP(ADXRS290_HPF_MASK, x)
49 
50 #define ADXRS290_READ_REG(reg)	(ADXRS290_READ | (reg))
51 
52 #define ADXRS290_MAX_TRANSITION_TIME_MS 100
53 
54 enum adxrs290_mode {
55 	ADXRS290_MODE_STANDBY,
56 	ADXRS290_MODE_MEASUREMENT,
57 };
58 
59 enum adxrs290_scan_index {
60 	ADXRS290_IDX_X,
61 	ADXRS290_IDX_Y,
62 	ADXRS290_IDX_TEMP,
63 	ADXRS290_IDX_TS,
64 };
65 
66 struct adxrs290_state {
67 	struct spi_device	*spi;
68 	/* Serialize reads and their subsequent processing */
69 	struct mutex		lock;
70 	enum adxrs290_mode	mode;
71 	unsigned int		lpf_3db_freq_idx;
72 	unsigned int		hpf_3db_freq_idx;
73 	struct iio_trigger      *dready_trig;
74 	/* Ensure correct alignment of timestamp when present */
75 	struct {
76 		s16 channels[3];
77 		s64 ts __aligned(8);
78 	} buffer;
79 };
80 
81 /*
82  * Available cut-off frequencies of the low pass filter in Hz.
83  * The integer part and fractional part are represented separately.
84  */
85 static const int adxrs290_lpf_3db_freq_hz_table[][2] = {
86 	[0] = {480, 0},
87 	[1] = {320, 0},
88 	[2] = {160, 0},
89 	[3] = {80, 0},
90 	[4] = {56, 600000},
91 	[5] = {40, 0},
92 	[6] = {28, 300000},
93 	[7] = {20, 0},
94 };
95 
96 /*
97  * Available cut-off frequencies of the high pass filter in Hz.
98  * The integer part and fractional part are represented separately.
99  */
100 static const int adxrs290_hpf_3db_freq_hz_table[][2] = {
101 	[0] = {0, 0},
102 	[1] = {0, 11000},
103 	[2] = {0, 22000},
104 	[3] = {0, 44000},
105 	[4] = {0, 87000},
106 	[5] = {0, 175000},
107 	[6] = {0, 350000},
108 	[7] = {0, 700000},
109 	[8] = {1, 400000},
110 	[9] = {2, 800000},
111 	[10] = {11, 300000},
112 };
113 
114 static int adxrs290_get_rate_data(struct iio_dev *indio_dev, const u8 cmd, int *val)
115 {
116 	struct adxrs290_state *st = iio_priv(indio_dev);
117 	int ret = 0;
118 	int temp;
119 
120 	mutex_lock(&st->lock);
121 	temp = spi_w8r16(st->spi, cmd);
122 	if (temp < 0) {
123 		ret = temp;
124 		goto err_unlock;
125 	}
126 
127 	*val = temp;
128 
129 err_unlock:
130 	mutex_unlock(&st->lock);
131 	return ret;
132 }
133 
134 static int adxrs290_get_temp_data(struct iio_dev *indio_dev, int *val)
135 {
136 	const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_TEMP0);
137 	struct adxrs290_state *st = iio_priv(indio_dev);
138 	int ret = 0;
139 	int temp;
140 
141 	mutex_lock(&st->lock);
142 	temp = spi_w8r16(st->spi, cmd);
143 	if (temp < 0) {
144 		ret = temp;
145 		goto err_unlock;
146 	}
147 
148 	/* extract lower 12 bits temperature reading */
149 	*val = temp & 0x0FFF;
150 
151 err_unlock:
152 	mutex_unlock(&st->lock);
153 	return ret;
154 }
155 
156 static int adxrs290_get_3db_freq(struct iio_dev *indio_dev, u8 *val, u8 *val2)
157 {
158 	const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_FILTER);
159 	struct adxrs290_state *st = iio_priv(indio_dev);
160 	int ret = 0;
161 	short temp;
162 
163 	mutex_lock(&st->lock);
164 	temp = spi_w8r8(st->spi, cmd);
165 	if (temp < 0) {
166 		ret = temp;
167 		goto err_unlock;
168 	}
169 
170 	*val = FIELD_GET(ADXRS290_LPF_MASK, temp);
171 	*val2 = FIELD_GET(ADXRS290_HPF_MASK, temp);
172 
173 err_unlock:
174 	mutex_unlock(&st->lock);
175 	return ret;
176 }
177 
178 static int adxrs290_spi_write_reg(struct spi_device *spi, const u8 reg,
179 				  const u8 val)
180 {
181 	u8 buf[2];
182 
183 	buf[0] = reg;
184 	buf[1] = val;
185 
186 	return spi_write_then_read(spi, buf, ARRAY_SIZE(buf), NULL, 0);
187 }
188 
189 static int adxrs290_find_match(const int (*freq_tbl)[2], const int n,
190 			       const int val, const int val2)
191 {
192 	int i;
193 
194 	for (i = 0; i < n; i++) {
195 		if (freq_tbl[i][0] == val && freq_tbl[i][1] == val2)
196 			return i;
197 	}
198 
199 	return -EINVAL;
200 }
201 
202 static int adxrs290_set_filter_freq(struct iio_dev *indio_dev,
203 				    const unsigned int lpf_idx,
204 				    const unsigned int hpf_idx)
205 {
206 	struct adxrs290_state *st = iio_priv(indio_dev);
207 	u8 val;
208 
209 	val = ADXRS290_HPF(hpf_idx) | ADXRS290_LPF(lpf_idx);
210 
211 	return adxrs290_spi_write_reg(st->spi, ADXRS290_REG_FILTER, val);
212 }
213 
214 static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
215 {
216 	struct adxrs290_state *st = iio_priv(indio_dev);
217 	int val, ret;
218 
219 	if (st->mode == mode)
220 		return 0;
221 
222 	mutex_lock(&st->lock);
223 
224 	ret = spi_w8r8(st->spi, ADXRS290_READ_REG(ADXRS290_REG_POWER_CTL));
225 	if (ret < 0)
226 		goto out_unlock;
227 
228 	val = ret;
229 
230 	switch (mode) {
231 	case ADXRS290_MODE_STANDBY:
232 		val &= ~ADXRS290_MEASUREMENT;
233 		break;
234 	case ADXRS290_MODE_MEASUREMENT:
235 		val |= ADXRS290_MEASUREMENT;
236 		break;
237 	default:
238 		ret = -EINVAL;
239 		goto out_unlock;
240 	}
241 
242 	ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_POWER_CTL, val);
243 	if (ret < 0) {
244 		dev_err(&st->spi->dev, "unable to set mode: %d\n", ret);
245 		goto out_unlock;
246 	}
247 
248 	/* update cached mode */
249 	st->mode = mode;
250 
251 out_unlock:
252 	mutex_unlock(&st->lock);
253 	return ret;
254 }
255 
256 static void adxrs290_chip_off_action(void *data)
257 {
258 	struct iio_dev *indio_dev = data;
259 
260 	adxrs290_set_mode(indio_dev, ADXRS290_MODE_STANDBY);
261 }
262 
263 static int adxrs290_initial_setup(struct iio_dev *indio_dev)
264 {
265 	struct adxrs290_state *st = iio_priv(indio_dev);
266 	struct spi_device *spi = st->spi;
267 	int ret;
268 
269 	ret = adxrs290_spi_write_reg(spi, ADXRS290_REG_POWER_CTL,
270 				     ADXRS290_MEASUREMENT | ADXRS290_TSM);
271 	if (ret < 0)
272 		return ret;
273 
274 	st->mode = ADXRS290_MODE_MEASUREMENT;
275 
276 	return devm_add_action_or_reset(&spi->dev, adxrs290_chip_off_action,
277 					indio_dev);
278 }
279 
280 static int adxrs290_read_raw(struct iio_dev *indio_dev,
281 			     struct iio_chan_spec const *chan,
282 			     int *val,
283 			     int *val2,
284 			     long mask)
285 {
286 	struct adxrs290_state *st = iio_priv(indio_dev);
287 	unsigned int t;
288 	int ret;
289 
290 	switch (mask) {
291 	case IIO_CHAN_INFO_RAW:
292 		ret = iio_device_claim_direct_mode(indio_dev);
293 		if (ret)
294 			return ret;
295 
296 		switch (chan->type) {
297 		case IIO_ANGL_VEL:
298 			ret = adxrs290_get_rate_data(indio_dev,
299 						     ADXRS290_READ_REG(chan->address),
300 						     val);
301 			if (ret < 0)
302 				break;
303 
304 			ret = IIO_VAL_INT;
305 			break;
306 		case IIO_TEMP:
307 			ret = adxrs290_get_temp_data(indio_dev, val);
308 			if (ret < 0)
309 				break;
310 
311 			ret = IIO_VAL_INT;
312 			break;
313 		default:
314 			ret = -EINVAL;
315 			break;
316 		}
317 
318 		iio_device_release_direct_mode(indio_dev);
319 		return ret;
320 	case IIO_CHAN_INFO_SCALE:
321 		switch (chan->type) {
322 		case IIO_ANGL_VEL:
323 			/* 1 LSB = 0.005 degrees/sec */
324 			*val = 0;
325 			*val2 = 87266;
326 			return IIO_VAL_INT_PLUS_NANO;
327 		case IIO_TEMP:
328 			/* 1 LSB = 0.1 degrees Celsius */
329 			*val = 100;
330 			return IIO_VAL_INT;
331 		default:
332 			return -EINVAL;
333 		}
334 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
335 		switch (chan->type) {
336 		case IIO_ANGL_VEL:
337 			t = st->lpf_3db_freq_idx;
338 			*val = adxrs290_lpf_3db_freq_hz_table[t][0];
339 			*val2 = adxrs290_lpf_3db_freq_hz_table[t][1];
340 			return IIO_VAL_INT_PLUS_MICRO;
341 		default:
342 			return -EINVAL;
343 		}
344 	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
345 		switch (chan->type) {
346 		case IIO_ANGL_VEL:
347 			t = st->hpf_3db_freq_idx;
348 			*val = adxrs290_hpf_3db_freq_hz_table[t][0];
349 			*val2 = adxrs290_hpf_3db_freq_hz_table[t][1];
350 			return IIO_VAL_INT_PLUS_MICRO;
351 		default:
352 			return -EINVAL;
353 		}
354 	}
355 
356 	return -EINVAL;
357 }
358 
359 static int adxrs290_write_raw(struct iio_dev *indio_dev,
360 			      struct iio_chan_spec const *chan,
361 			      int val,
362 			      int val2,
363 			      long mask)
364 {
365 	struct adxrs290_state *st = iio_priv(indio_dev);
366 	int ret, lpf_idx, hpf_idx;
367 
368 	ret = iio_device_claim_direct_mode(indio_dev);
369 	if (ret)
370 		return ret;
371 
372 	switch (mask) {
373 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
374 		lpf_idx = adxrs290_find_match(adxrs290_lpf_3db_freq_hz_table,
375 					      ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table),
376 					      val, val2);
377 		if (lpf_idx < 0) {
378 			ret = -EINVAL;
379 			break;
380 		}
381 
382 		/* caching the updated state of the low-pass filter */
383 		st->lpf_3db_freq_idx = lpf_idx;
384 		/* retrieving the current state of the high-pass filter */
385 		hpf_idx = st->hpf_3db_freq_idx;
386 		ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
387 		break;
388 
389 	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
390 		hpf_idx = adxrs290_find_match(adxrs290_hpf_3db_freq_hz_table,
391 					      ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table),
392 					      val, val2);
393 		if (hpf_idx < 0) {
394 			ret = -EINVAL;
395 			break;
396 		}
397 
398 		/* caching the updated state of the high-pass filter */
399 		st->hpf_3db_freq_idx = hpf_idx;
400 		/* retrieving the current state of the low-pass filter */
401 		lpf_idx = st->lpf_3db_freq_idx;
402 		ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
403 		break;
404 
405 	default:
406 		ret = -EINVAL;
407 		break;
408 	}
409 
410 	iio_device_release_direct_mode(indio_dev);
411 	return ret;
412 }
413 
414 static int adxrs290_read_avail(struct iio_dev *indio_dev,
415 			       struct iio_chan_spec const *chan,
416 			       const int **vals, int *type, int *length,
417 			       long mask)
418 {
419 	switch (mask) {
420 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
421 		*vals = (const int *)adxrs290_lpf_3db_freq_hz_table;
422 		*type = IIO_VAL_INT_PLUS_MICRO;
423 		/* Values are stored in a 2D matrix */
424 		*length = ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table) * 2;
425 
426 		return IIO_AVAIL_LIST;
427 	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
428 		*vals = (const int *)adxrs290_hpf_3db_freq_hz_table;
429 		*type = IIO_VAL_INT_PLUS_MICRO;
430 		/* Values are stored in a 2D matrix */
431 		*length = ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table) * 2;
432 
433 		return IIO_AVAIL_LIST;
434 	default:
435 		return -EINVAL;
436 	}
437 }
438 
439 static int adxrs290_reg_access_rw(struct spi_device *spi, unsigned int reg,
440 				  unsigned int *readval)
441 {
442 	int ret;
443 
444 	ret = spi_w8r8(spi, ADXRS290_READ_REG(reg));
445 	if (ret < 0)
446 		return ret;
447 
448 	*readval = ret;
449 
450 	return 0;
451 }
452 
453 static int adxrs290_reg_access(struct iio_dev *indio_dev, unsigned int reg,
454 			       unsigned int writeval, unsigned int *readval)
455 {
456 	struct adxrs290_state *st = iio_priv(indio_dev);
457 
458 	if (readval)
459 		return adxrs290_reg_access_rw(st->spi, reg, readval);
460 	else
461 		return adxrs290_spi_write_reg(st->spi, reg, writeval);
462 }
463 
464 static int adxrs290_data_rdy_trigger_set_state(struct iio_trigger *trig,
465 					       bool state)
466 {
467 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
468 	struct adxrs290_state *st = iio_priv(indio_dev);
469 	int ret;
470 	u8 val;
471 
472 	val = state ? ADXRS290_SYNC(ADXRS290_DATA_RDY_OUT) : 0;
473 
474 	ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_DATA_RDY, val);
475 	if (ret < 0)
476 		dev_err(&st->spi->dev, "failed to start data rdy interrupt\n");
477 
478 	return ret;
479 }
480 
481 static void adxrs290_reset_trig(struct iio_trigger *trig)
482 {
483 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
484 	int val;
485 
486 	/*
487 	 * Data ready interrupt is reset after a read of the data registers.
488 	 * Here, we only read the 16b DATAY registers as that marks the end of
489 	 * a read of the data registers and initiates a reset for the interrupt
490 	 * line.
491 	 */
492 	adxrs290_get_rate_data(indio_dev,
493 			       ADXRS290_READ_REG(ADXRS290_REG_DATAY0), &val);
494 }
495 
496 static const struct iio_trigger_ops adxrs290_trigger_ops = {
497 	.set_trigger_state = &adxrs290_data_rdy_trigger_set_state,
498 	.validate_device = &iio_trigger_validate_own_device,
499 	.reenable = &adxrs290_reset_trig,
500 };
501 
502 static irqreturn_t adxrs290_trigger_handler(int irq, void *p)
503 {
504 	struct iio_poll_func *pf = p;
505 	struct iio_dev *indio_dev = pf->indio_dev;
506 	struct adxrs290_state *st = iio_priv(indio_dev);
507 	u8 tx = ADXRS290_READ_REG(ADXRS290_REG_DATAX0);
508 	int ret;
509 
510 	mutex_lock(&st->lock);
511 
512 	/* exercise a bulk data capture starting from reg DATAX0... */
513 	ret = spi_write_then_read(st->spi, &tx, sizeof(tx), st->buffer.channels,
514 				  sizeof(st->buffer.channels));
515 	if (ret < 0)
516 		goto out_unlock_notify;
517 
518 	iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
519 					   pf->timestamp);
520 
521 out_unlock_notify:
522 	mutex_unlock(&st->lock);
523 	iio_trigger_notify_done(indio_dev->trig);
524 
525 	return IRQ_HANDLED;
526 }
527 
528 #define ADXRS290_ANGL_VEL_CHANNEL(reg, axis) {				\
529 	.type = IIO_ANGL_VEL,						\
530 	.address = reg,							\
531 	.modified = 1,							\
532 	.channel2 = IIO_MOD_##axis,					\
533 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
534 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
535 	BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |		\
536 	BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),		\
537 	.info_mask_shared_by_type_available =				\
538 	BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |		\
539 	BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),		\
540 	.scan_index = ADXRS290_IDX_##axis,				\
541 	.scan_type = {                                                  \
542 		.sign = 's',                                            \
543 		.realbits = 16,                                         \
544 		.storagebits = 16,                                      \
545 		.endianness = IIO_LE,					\
546 	},                                                              \
547 }
548 
549 static const struct iio_chan_spec adxrs290_channels[] = {
550 	ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAX0, X),
551 	ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAY0, Y),
552 	{
553 		.type = IIO_TEMP,
554 		.address = ADXRS290_REG_TEMP0,
555 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
556 		BIT(IIO_CHAN_INFO_SCALE),
557 		.scan_index = ADXRS290_IDX_TEMP,
558 		.scan_type = {
559 			.sign = 's',
560 			.realbits = 12,
561 			.storagebits = 16,
562 			.endianness = IIO_LE,
563 		},
564 	},
565 	IIO_CHAN_SOFT_TIMESTAMP(ADXRS290_IDX_TS),
566 };
567 
568 static const unsigned long adxrs290_avail_scan_masks[] = {
569 	BIT(ADXRS290_IDX_X) | BIT(ADXRS290_IDX_Y) | BIT(ADXRS290_IDX_TEMP),
570 	0
571 };
572 
573 static const struct iio_info adxrs290_info = {
574 	.read_raw = &adxrs290_read_raw,
575 	.write_raw = &adxrs290_write_raw,
576 	.read_avail = &adxrs290_read_avail,
577 	.debugfs_reg_access = &adxrs290_reg_access,
578 };
579 
580 static int adxrs290_probe_trigger(struct iio_dev *indio_dev)
581 {
582 	struct adxrs290_state *st = iio_priv(indio_dev);
583 	int ret;
584 
585 	if (!st->spi->irq) {
586 		dev_info(&st->spi->dev, "no irq, using polling\n");
587 		return 0;
588 	}
589 
590 	st->dready_trig = devm_iio_trigger_alloc(&st->spi->dev, "%s-dev%d",
591 						 indio_dev->name,
592 						 indio_dev->id);
593 	if (!st->dready_trig)
594 		return -ENOMEM;
595 
596 	st->dready_trig->dev.parent = &st->spi->dev;
597 	st->dready_trig->ops = &adxrs290_trigger_ops;
598 	iio_trigger_set_drvdata(st->dready_trig, indio_dev);
599 
600 	ret = devm_request_irq(&st->spi->dev, st->spi->irq,
601 			       &iio_trigger_generic_data_rdy_poll,
602 			       IRQF_ONESHOT, "adxrs290_irq", st->dready_trig);
603 	if (ret < 0)
604 		return dev_err_probe(&st->spi->dev, ret,
605 				     "request irq %d failed\n", st->spi->irq);
606 
607 	ret = devm_iio_trigger_register(&st->spi->dev, st->dready_trig);
608 	if (ret) {
609 		dev_err(&st->spi->dev, "iio trigger register failed\n");
610 		return ret;
611 	}
612 
613 	indio_dev->trig = iio_trigger_get(st->dready_trig);
614 
615 	return 0;
616 }
617 
618 static int adxrs290_probe(struct spi_device *spi)
619 {
620 	struct iio_dev *indio_dev;
621 	struct adxrs290_state *st;
622 	u8 val, val2;
623 	int ret;
624 
625 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
626 	if (!indio_dev)
627 		return -ENOMEM;
628 
629 	st = iio_priv(indio_dev);
630 	st->spi = spi;
631 
632 	indio_dev->name = "adxrs290";
633 	indio_dev->modes = INDIO_DIRECT_MODE;
634 	indio_dev->channels = adxrs290_channels;
635 	indio_dev->num_channels = ARRAY_SIZE(adxrs290_channels);
636 	indio_dev->info = &adxrs290_info;
637 	indio_dev->available_scan_masks = adxrs290_avail_scan_masks;
638 
639 	mutex_init(&st->lock);
640 
641 	val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_ADI_ID));
642 	if (val != ADXRS290_ADI_ID) {
643 		dev_err(&spi->dev, "Wrong ADI ID 0x%02x\n", val);
644 		return -ENODEV;
645 	}
646 
647 	val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_MEMS_ID));
648 	if (val != ADXRS290_MEMS_ID) {
649 		dev_err(&spi->dev, "Wrong MEMS ID 0x%02x\n", val);
650 		return -ENODEV;
651 	}
652 
653 	val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_DEV_ID));
654 	if (val != ADXRS290_DEV_ID) {
655 		dev_err(&spi->dev, "Wrong DEV ID 0x%02x\n", val);
656 		return -ENODEV;
657 	}
658 
659 	/* default mode the gyroscope starts in */
660 	st->mode = ADXRS290_MODE_STANDBY;
661 
662 	/* switch to measurement mode and switch on the temperature sensor */
663 	ret = adxrs290_initial_setup(indio_dev);
664 	if (ret < 0)
665 		return ret;
666 
667 	/* max transition time to measurement mode */
668 	msleep(ADXRS290_MAX_TRANSITION_TIME_MS);
669 
670 	ret = adxrs290_get_3db_freq(indio_dev, &val, &val2);
671 	if (ret < 0)
672 		return ret;
673 
674 	st->lpf_3db_freq_idx = val;
675 	st->hpf_3db_freq_idx = val2;
676 
677 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
678 					      &iio_pollfunc_store_time,
679 					      &adxrs290_trigger_handler, NULL);
680 	if (ret < 0)
681 		return dev_err_probe(&spi->dev, ret,
682 				     "iio triggered buffer setup failed\n");
683 
684 	ret = adxrs290_probe_trigger(indio_dev);
685 	if (ret < 0)
686 		return ret;
687 
688 	return devm_iio_device_register(&spi->dev, indio_dev);
689 }
690 
691 static const struct of_device_id adxrs290_of_match[] = {
692 	{ .compatible = "adi,adxrs290" },
693 	{ }
694 };
695 MODULE_DEVICE_TABLE(of, adxrs290_of_match);
696 
697 static struct spi_driver adxrs290_driver = {
698 	.driver = {
699 		.name = "adxrs290",
700 		.of_match_table = adxrs290_of_match,
701 	},
702 	.probe = adxrs290_probe,
703 };
704 module_spi_driver(adxrs290_driver);
705 
706 MODULE_AUTHOR("Nishant Malpani <nish.malpani25@gmail.com>");
707 MODULE_DESCRIPTION("Analog Devices ADXRS290 Gyroscope SPI driver");
708 MODULE_LICENSE("GPL");
709