xref: /linux/drivers/iio/gyro/adxrs290.c (revision 40d269c000bda9fcd276a0412a9cebd3f6e344c5)
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/bitops.h>
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/spi/spi.h>
16 
17 #include <linux/iio/buffer.h>
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 #include <linux/iio/trigger.h>
21 #include <linux/iio/triggered_buffer.h>
22 #include <linux/iio/trigger_consumer.h>
23 
24 #define ADXRS290_ADI_ID		0xAD
25 #define ADXRS290_MEMS_ID	0x1D
26 #define ADXRS290_DEV_ID		0x92
27 
28 #define ADXRS290_REG_ADI_ID	0x00
29 #define ADXRS290_REG_MEMS_ID	0x01
30 #define ADXRS290_REG_DEV_ID	0x02
31 #define ADXRS290_REG_REV_ID	0x03
32 #define ADXRS290_REG_SN0	0x04 /* Serial Number Registers, 4 bytes */
33 #define ADXRS290_REG_DATAX0	0x08 /* Roll Rate o/p Data Regs, 2 bytes */
34 #define ADXRS290_REG_DATAY0	0x0A /* Pitch Rate o/p Data Regs, 2 bytes */
35 #define ADXRS290_REG_TEMP0	0x0C
36 #define ADXRS290_REG_POWER_CTL	0x10
37 #define ADXRS290_REG_FILTER	0x11
38 #define ADXRS290_REG_DATA_RDY	0x12
39 
40 #define ADXRS290_READ		BIT(7)
41 #define ADXRS290_TSM		BIT(0)
42 #define ADXRS290_MEASUREMENT	BIT(1)
43 #define ADXRS290_DATA_RDY_OUT	BIT(0)
44 #define ADXRS290_SYNC_MASK	GENMASK(1, 0)
45 #define ADXRS290_SYNC(x)	FIELD_PREP(ADXRS290_SYNC_MASK, x)
46 #define ADXRS290_LPF_MASK	GENMASK(2, 0)
47 #define ADXRS290_LPF(x)		FIELD_PREP(ADXRS290_LPF_MASK, x)
48 #define ADXRS290_HPF_MASK	GENMASK(7, 4)
49 #define ADXRS290_HPF(x)		FIELD_PREP(ADXRS290_HPF_MASK, x)
50 
51 #define ADXRS290_READ_REG(reg)	(ADXRS290_READ | (reg))
52 
53 #define ADXRS290_MAX_TRANSITION_TIME_MS 100
54 
55 enum adxrs290_mode {
56 	ADXRS290_MODE_STANDBY,
57 	ADXRS290_MODE_MEASUREMENT,
58 };
59 
60 enum adxrs290_scan_index {
61 	ADXRS290_IDX_X,
62 	ADXRS290_IDX_Y,
63 	ADXRS290_IDX_TEMP,
64 	ADXRS290_IDX_TS,
65 };
66 
67 struct adxrs290_state {
68 	struct spi_device	*spi;
69 	/* Serialize reads and their subsequent processing */
70 	struct mutex		lock;
71 	enum adxrs290_mode	mode;
72 	unsigned int		lpf_3db_freq_idx;
73 	unsigned int		hpf_3db_freq_idx;
74 	struct iio_trigger      *dready_trig;
75 	/* Ensure correct alignment of timestamp when present */
76 	struct {
77 		s16 channels[3];
78 		s64 ts __aligned(8);
79 	} buffer;
80 };
81 
82 /*
83  * Available cut-off frequencies of the low pass filter in Hz.
84  * The integer part and fractional part are represented separately.
85  */
86 static const int adxrs290_lpf_3db_freq_hz_table[][2] = {
87 	[0] = {480, 0},
88 	[1] = {320, 0},
89 	[2] = {160, 0},
90 	[3] = {80, 0},
91 	[4] = {56, 600000},
92 	[5] = {40, 0},
93 	[6] = {28, 300000},
94 	[7] = {20, 0},
95 };
96 
97 /*
98  * Available cut-off frequencies of the high pass filter in Hz.
99  * The integer part and fractional part are represented separately.
100  */
101 static const int adxrs290_hpf_3db_freq_hz_table[][2] = {
102 	[0] = {0, 0},
103 	[1] = {0, 11000},
104 	[2] = {0, 22000},
105 	[3] = {0, 44000},
106 	[4] = {0, 87000},
107 	[5] = {0, 175000},
108 	[6] = {0, 350000},
109 	[7] = {0, 700000},
110 	[8] = {1, 400000},
111 	[9] = {2, 800000},
112 	[10] = {11, 300000},
113 };
114 
115 static int adxrs290_get_rate_data(struct iio_dev *indio_dev, const u8 cmd, int *val)
116 {
117 	struct adxrs290_state *st = iio_priv(indio_dev);
118 	int ret = 0;
119 	int temp;
120 
121 	mutex_lock(&st->lock);
122 	temp = spi_w8r16(st->spi, cmd);
123 	if (temp < 0) {
124 		ret = temp;
125 		goto err_unlock;
126 	}
127 
128 	*val = sign_extend32(temp, 15);
129 
130 err_unlock:
131 	mutex_unlock(&st->lock);
132 	return ret;
133 }
134 
135 static int adxrs290_get_temp_data(struct iio_dev *indio_dev, int *val)
136 {
137 	const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_TEMP0);
138 	struct adxrs290_state *st = iio_priv(indio_dev);
139 	int ret = 0;
140 	int temp;
141 
142 	mutex_lock(&st->lock);
143 	temp = spi_w8r16(st->spi, cmd);
144 	if (temp < 0) {
145 		ret = temp;
146 		goto err_unlock;
147 	}
148 
149 	/* extract lower 12 bits temperature reading */
150 	*val = sign_extend32(temp, 11);
151 
152 err_unlock:
153 	mutex_unlock(&st->lock);
154 	return ret;
155 }
156 
157 static int adxrs290_get_3db_freq(struct iio_dev *indio_dev, u8 *val, u8 *val2)
158 {
159 	const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_FILTER);
160 	struct adxrs290_state *st = iio_priv(indio_dev);
161 	int ret = 0;
162 	short temp;
163 
164 	mutex_lock(&st->lock);
165 	temp = spi_w8r8(st->spi, cmd);
166 	if (temp < 0) {
167 		ret = temp;
168 		goto err_unlock;
169 	}
170 
171 	*val = FIELD_GET(ADXRS290_LPF_MASK, temp);
172 	*val2 = FIELD_GET(ADXRS290_HPF_MASK, temp);
173 
174 err_unlock:
175 	mutex_unlock(&st->lock);
176 	return ret;
177 }
178 
179 static int adxrs290_spi_write_reg(struct spi_device *spi, const u8 reg,
180 				  const u8 val)
181 {
182 	u8 buf[2];
183 
184 	buf[0] = reg;
185 	buf[1] = val;
186 
187 	return spi_write_then_read(spi, buf, ARRAY_SIZE(buf), NULL, 0);
188 }
189 
190 static int adxrs290_find_match(const int (*freq_tbl)[2], const int n,
191 			       const int val, const int val2)
192 {
193 	int i;
194 
195 	for (i = 0; i < n; i++) {
196 		if (freq_tbl[i][0] == val && freq_tbl[i][1] == val2)
197 			return i;
198 	}
199 
200 	return -EINVAL;
201 }
202 
203 static int adxrs290_set_filter_freq(struct iio_dev *indio_dev,
204 				    const unsigned int lpf_idx,
205 				    const unsigned int hpf_idx)
206 {
207 	struct adxrs290_state *st = iio_priv(indio_dev);
208 	u8 val;
209 
210 	val = ADXRS290_HPF(hpf_idx) | ADXRS290_LPF(lpf_idx);
211 
212 	return adxrs290_spi_write_reg(st->spi, ADXRS290_REG_FILTER, val);
213 }
214 
215 static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
216 {
217 	struct adxrs290_state *st = iio_priv(indio_dev);
218 	int val, ret;
219 
220 	if (st->mode == mode)
221 		return 0;
222 
223 	mutex_lock(&st->lock);
224 
225 	ret = spi_w8r8(st->spi, ADXRS290_READ_REG(ADXRS290_REG_POWER_CTL));
226 	if (ret < 0)
227 		goto out_unlock;
228 
229 	val = ret;
230 
231 	switch (mode) {
232 	case ADXRS290_MODE_STANDBY:
233 		val &= ~ADXRS290_MEASUREMENT;
234 		break;
235 	case ADXRS290_MODE_MEASUREMENT:
236 		val |= ADXRS290_MEASUREMENT;
237 		break;
238 	default:
239 		ret = -EINVAL;
240 		goto out_unlock;
241 	}
242 
243 	ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_POWER_CTL, val);
244 	if (ret < 0) {
245 		dev_err(&st->spi->dev, "unable to set mode: %d\n", ret);
246 		goto out_unlock;
247 	}
248 
249 	/* update cached mode */
250 	st->mode = mode;
251 
252 out_unlock:
253 	mutex_unlock(&st->lock);
254 	return ret;
255 }
256 
257 static void adxrs290_chip_off_action(void *data)
258 {
259 	struct iio_dev *indio_dev = data;
260 
261 	adxrs290_set_mode(indio_dev, ADXRS290_MODE_STANDBY);
262 }
263 
264 static int adxrs290_initial_setup(struct iio_dev *indio_dev)
265 {
266 	struct adxrs290_state *st = iio_priv(indio_dev);
267 	struct spi_device *spi = st->spi;
268 	int ret;
269 
270 	ret = adxrs290_spi_write_reg(spi, ADXRS290_REG_POWER_CTL,
271 				     ADXRS290_MEASUREMENT | ADXRS290_TSM);
272 	if (ret < 0)
273 		return ret;
274 
275 	st->mode = ADXRS290_MODE_MEASUREMENT;
276 
277 	return devm_add_action_or_reset(&spi->dev, adxrs290_chip_off_action,
278 					indio_dev);
279 }
280 
281 static int adxrs290_read_raw(struct iio_dev *indio_dev,
282 			     struct iio_chan_spec const *chan,
283 			     int *val,
284 			     int *val2,
285 			     long mask)
286 {
287 	struct adxrs290_state *st = iio_priv(indio_dev);
288 	unsigned int t;
289 	int ret;
290 
291 	switch (mask) {
292 	case IIO_CHAN_INFO_RAW:
293 		ret = iio_device_claim_direct_mode(indio_dev);
294 		if (ret)
295 			return ret;
296 
297 		switch (chan->type) {
298 		case IIO_ANGL_VEL:
299 			ret = adxrs290_get_rate_data(indio_dev,
300 						     ADXRS290_READ_REG(chan->address),
301 						     val);
302 			if (ret < 0)
303 				break;
304 
305 			ret = IIO_VAL_INT;
306 			break;
307 		case IIO_TEMP:
308 			ret = adxrs290_get_temp_data(indio_dev, val);
309 			if (ret < 0)
310 				break;
311 
312 			ret = IIO_VAL_INT;
313 			break;
314 		default:
315 			ret = -EINVAL;
316 			break;
317 		}
318 
319 		iio_device_release_direct_mode(indio_dev);
320 		return ret;
321 	case IIO_CHAN_INFO_SCALE:
322 		switch (chan->type) {
323 		case IIO_ANGL_VEL:
324 			/* 1 LSB = 0.005 degrees/sec */
325 			*val = 0;
326 			*val2 = 87266;
327 			return IIO_VAL_INT_PLUS_NANO;
328 		case IIO_TEMP:
329 			/* 1 LSB = 0.1 degrees Celsius */
330 			*val = 100;
331 			return IIO_VAL_INT;
332 		default:
333 			return -EINVAL;
334 		}
335 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
336 		switch (chan->type) {
337 		case IIO_ANGL_VEL:
338 			t = st->lpf_3db_freq_idx;
339 			*val = adxrs290_lpf_3db_freq_hz_table[t][0];
340 			*val2 = adxrs290_lpf_3db_freq_hz_table[t][1];
341 			return IIO_VAL_INT_PLUS_MICRO;
342 		default:
343 			return -EINVAL;
344 		}
345 	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
346 		switch (chan->type) {
347 		case IIO_ANGL_VEL:
348 			t = st->hpf_3db_freq_idx;
349 			*val = adxrs290_hpf_3db_freq_hz_table[t][0];
350 			*val2 = adxrs290_hpf_3db_freq_hz_table[t][1];
351 			return IIO_VAL_INT_PLUS_MICRO;
352 		default:
353 			return -EINVAL;
354 		}
355 	}
356 
357 	return -EINVAL;
358 }
359 
360 static int adxrs290_write_raw(struct iio_dev *indio_dev,
361 			      struct iio_chan_spec const *chan,
362 			      int val,
363 			      int val2,
364 			      long mask)
365 {
366 	struct adxrs290_state *st = iio_priv(indio_dev);
367 	int ret, lpf_idx, hpf_idx;
368 
369 	ret = iio_device_claim_direct_mode(indio_dev);
370 	if (ret)
371 		return ret;
372 
373 	switch (mask) {
374 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
375 		lpf_idx = adxrs290_find_match(adxrs290_lpf_3db_freq_hz_table,
376 					      ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table),
377 					      val, val2);
378 		if (lpf_idx < 0) {
379 			ret = -EINVAL;
380 			break;
381 		}
382 
383 		/* caching the updated state of the low-pass filter */
384 		st->lpf_3db_freq_idx = lpf_idx;
385 		/* retrieving the current state of the high-pass filter */
386 		hpf_idx = st->hpf_3db_freq_idx;
387 		ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
388 		break;
389 
390 	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
391 		hpf_idx = adxrs290_find_match(adxrs290_hpf_3db_freq_hz_table,
392 					      ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table),
393 					      val, val2);
394 		if (hpf_idx < 0) {
395 			ret = -EINVAL;
396 			break;
397 		}
398 
399 		/* caching the updated state of the high-pass filter */
400 		st->hpf_3db_freq_idx = hpf_idx;
401 		/* retrieving the current state of the low-pass filter */
402 		lpf_idx = st->lpf_3db_freq_idx;
403 		ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
404 		break;
405 
406 	default:
407 		ret = -EINVAL;
408 		break;
409 	}
410 
411 	iio_device_release_direct_mode(indio_dev);
412 	return ret;
413 }
414 
415 static int adxrs290_read_avail(struct iio_dev *indio_dev,
416 			       struct iio_chan_spec const *chan,
417 			       const int **vals, int *type, int *length,
418 			       long mask)
419 {
420 	switch (mask) {
421 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
422 		*vals = (const int *)adxrs290_lpf_3db_freq_hz_table;
423 		*type = IIO_VAL_INT_PLUS_MICRO;
424 		/* Values are stored in a 2D matrix */
425 		*length = ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table) * 2;
426 
427 		return IIO_AVAIL_LIST;
428 	case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
429 		*vals = (const int *)adxrs290_hpf_3db_freq_hz_table;
430 		*type = IIO_VAL_INT_PLUS_MICRO;
431 		/* Values are stored in a 2D matrix */
432 		*length = ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table) * 2;
433 
434 		return IIO_AVAIL_LIST;
435 	default:
436 		return -EINVAL;
437 	}
438 }
439 
440 static int adxrs290_reg_access_rw(struct spi_device *spi, unsigned int reg,
441 				  unsigned int *readval)
442 {
443 	int ret;
444 
445 	ret = spi_w8r8(spi, ADXRS290_READ_REG(reg));
446 	if (ret < 0)
447 		return ret;
448 
449 	*readval = ret;
450 
451 	return 0;
452 }
453 
454 static int adxrs290_reg_access(struct iio_dev *indio_dev, unsigned int reg,
455 			       unsigned int writeval, unsigned int *readval)
456 {
457 	struct adxrs290_state *st = iio_priv(indio_dev);
458 
459 	if (readval)
460 		return adxrs290_reg_access_rw(st->spi, reg, readval);
461 	else
462 		return adxrs290_spi_write_reg(st->spi, reg, writeval);
463 }
464 
465 static int adxrs290_data_rdy_trigger_set_state(struct iio_trigger *trig,
466 					       bool state)
467 {
468 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
469 	struct adxrs290_state *st = iio_priv(indio_dev);
470 	int ret;
471 	u8 val;
472 
473 	val = state ? ADXRS290_SYNC(ADXRS290_DATA_RDY_OUT) : 0;
474 
475 	ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_DATA_RDY, val);
476 	if (ret < 0)
477 		dev_err(&st->spi->dev, "failed to start data rdy interrupt\n");
478 
479 	return ret;
480 }
481 
482 static void adxrs290_reset_trig(struct iio_trigger *trig)
483 {
484 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
485 	int val;
486 
487 	/*
488 	 * Data ready interrupt is reset after a read of the data registers.
489 	 * Here, we only read the 16b DATAY registers as that marks the end of
490 	 * a read of the data registers and initiates a reset for the interrupt
491 	 * line.
492 	 */
493 	adxrs290_get_rate_data(indio_dev,
494 			       ADXRS290_READ_REG(ADXRS290_REG_DATAY0), &val);
495 }
496 
497 static const struct iio_trigger_ops adxrs290_trigger_ops = {
498 	.set_trigger_state = &adxrs290_data_rdy_trigger_set_state,
499 	.validate_device = &iio_trigger_validate_own_device,
500 	.reenable = &adxrs290_reset_trig,
501 };
502 
503 static irqreturn_t adxrs290_trigger_handler(int irq, void *p)
504 {
505 	struct iio_poll_func *pf = p;
506 	struct iio_dev *indio_dev = pf->indio_dev;
507 	struct adxrs290_state *st = iio_priv(indio_dev);
508 	u8 tx = ADXRS290_READ_REG(ADXRS290_REG_DATAX0);
509 	int ret;
510 
511 	mutex_lock(&st->lock);
512 
513 	/* exercise a bulk data capture starting from reg DATAX0... */
514 	ret = spi_write_then_read(st->spi, &tx, sizeof(tx), st->buffer.channels,
515 				  sizeof(st->buffer.channels));
516 	if (ret < 0)
517 		goto out_unlock_notify;
518 
519 	iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
520 					   pf->timestamp);
521 
522 out_unlock_notify:
523 	mutex_unlock(&st->lock);
524 	iio_trigger_notify_done(indio_dev->trig);
525 
526 	return IRQ_HANDLED;
527 }
528 
529 #define ADXRS290_ANGL_VEL_CHANNEL(reg, axis) {				\
530 	.type = IIO_ANGL_VEL,						\
531 	.address = reg,							\
532 	.modified = 1,							\
533 	.channel2 = IIO_MOD_##axis,					\
534 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
535 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
536 	BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |		\
537 	BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),		\
538 	.info_mask_shared_by_type_available =				\
539 	BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |		\
540 	BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),		\
541 	.scan_index = ADXRS290_IDX_##axis,				\
542 	.scan_type = {                                                  \
543 		.sign = 's',                                            \
544 		.realbits = 16,                                         \
545 		.storagebits = 16,                                      \
546 		.endianness = IIO_LE,					\
547 	},                                                              \
548 }
549 
550 static const struct iio_chan_spec adxrs290_channels[] = {
551 	ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAX0, X),
552 	ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAY0, Y),
553 	{
554 		.type = IIO_TEMP,
555 		.address = ADXRS290_REG_TEMP0,
556 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
557 		BIT(IIO_CHAN_INFO_SCALE),
558 		.scan_index = ADXRS290_IDX_TEMP,
559 		.scan_type = {
560 			.sign = 's',
561 			.realbits = 12,
562 			.storagebits = 16,
563 			.endianness = IIO_LE,
564 		},
565 	},
566 	IIO_CHAN_SOFT_TIMESTAMP(ADXRS290_IDX_TS),
567 };
568 
569 static const unsigned long adxrs290_avail_scan_masks[] = {
570 	BIT(ADXRS290_IDX_X) | BIT(ADXRS290_IDX_Y) | BIT(ADXRS290_IDX_TEMP),
571 	0
572 };
573 
574 static const struct iio_info adxrs290_info = {
575 	.read_raw = &adxrs290_read_raw,
576 	.write_raw = &adxrs290_write_raw,
577 	.read_avail = &adxrs290_read_avail,
578 	.debugfs_reg_access = &adxrs290_reg_access,
579 };
580 
581 static int adxrs290_probe_trigger(struct iio_dev *indio_dev)
582 {
583 	struct adxrs290_state *st = iio_priv(indio_dev);
584 	int ret;
585 
586 	if (!st->spi->irq) {
587 		dev_info(&st->spi->dev, "no irq, using polling\n");
588 		return 0;
589 	}
590 
591 	st->dready_trig = devm_iio_trigger_alloc(&st->spi->dev, "%s-dev%d",
592 						 indio_dev->name,
593 						 iio_device_id(indio_dev));
594 	if (!st->dready_trig)
595 		return -ENOMEM;
596 
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