1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Murata SCA3300 3-axis industrial accelerometer
4  *
5  * Copyright (c) 2021 Vaisala Oyj. All rights reserved.
6  */
7 
8 #include <linux/bitops.h>
9 #include <linux/crc8.h>
10 #include <linux/delay.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/spi/spi.h>
14 
15 #include <linux/unaligned.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_consumer.h>
21 #include <linux/iio/triggered_buffer.h>
22 
23 #define SCA3300_ALIAS "sca3300"
24 
25 #define SCA3300_CRC8_POLYNOMIAL 0x1d
26 
27 /* Device mode register */
28 #define SCA3300_REG_MODE	0xd
29 #define SCA3300_MODE_SW_RESET	0x20
30 
31 /* Last register in map */
32 #define SCA3300_REG_SELBANK	0x1f
33 
34 /* Device status and mask */
35 #define SCA3300_REG_STATUS	0x6
36 #define SCA3300_STATUS_MASK	GENMASK(8, 0)
37 
38 /* Device ID */
39 #define SCA3300_REG_WHOAMI	0x10
40 #define SCA3300_WHOAMI_ID	0x51
41 #define SCL3300_WHOAMI_ID	0xC1
42 
43 /* Device return status and mask */
44 #define SCA3300_VALUE_RS_ERROR	0x3
45 #define SCA3300_MASK_RS_STATUS	GENMASK(1, 0)
46 
47 #define SCL3300_REG_ANG_CTRL 0x0C
48 #define SCL3300_ANG_ENABLE   0x1F
49 
50 enum sca3300_scan_indexes {
51 	SCA3300_ACC_X = 0,
52 	SCA3300_ACC_Y,
53 	SCA3300_ACC_Z,
54 	SCA3300_TEMP,
55 	SCA3300_INCLI_X,
56 	SCA3300_INCLI_Y,
57 	SCA3300_INCLI_Z,
58 	SCA3300_SCAN_MAX
59 };
60 
61 #define SCA3300_ACCEL_CHANNEL(index, reg, axis) {			\
62 	.type = IIO_ACCEL,						\
63 	.address = reg,							\
64 	.modified = 1,							\
65 	.channel2 = IIO_MOD_##axis,					\
66 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
67 	.info_mask_shared_by_type =					\
68 	BIT(IIO_CHAN_INFO_SCALE) |					\
69 	BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),		\
70 	.info_mask_shared_by_type_available =				\
71 	BIT(IIO_CHAN_INFO_SCALE) |					\
72 	BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),		\
73 	.scan_index = index,						\
74 	.scan_type = {							\
75 		.sign = 's',						\
76 		.realbits = 16,						\
77 		.storagebits = 16,					\
78 		.endianness = IIO_CPU,					\
79 	},								\
80 }
81 
82 #define SCA3300_INCLI_CHANNEL(index, reg, axis) {			\
83 	.type = IIO_INCLI,						\
84 	.address = reg,							\
85 	.modified = 1,							\
86 	.channel2 = IIO_MOD_##axis,					\
87 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
88 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
89 	.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE), \
90 	.scan_index = index,						\
91 	.scan_type = {							\
92 		.sign = 's',						\
93 		.realbits = 16,						\
94 		.storagebits = 16,					\
95 		.endianness = IIO_CPU,					\
96 	},								\
97 }
98 
99 #define SCA3300_TEMP_CHANNEL(index, reg) {				\
100 		.type = IIO_TEMP,					\
101 		.address = reg,						\
102 		.scan_index = index,					\
103 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
104 		.scan_type = {						\
105 			.sign = 's',					\
106 			.realbits = 16,					\
107 			.storagebits = 16,				\
108 			.endianness = IIO_CPU,				\
109 		},							\
110 }
111 
112 static const struct iio_chan_spec sca3300_channels[] = {
113 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_X, 0x1, X),
114 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y),
115 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z),
116 	SCA3300_TEMP_CHANNEL(SCA3300_TEMP, 0x05),
117 	IIO_CHAN_SOFT_TIMESTAMP(4),
118 };
119 
120 static const int sca3300_lp_freq[] = {70, 10};
121 static const int sca3300_lp_freq_map[] = {0, 0, 0, 1};
122 
123 static const int scl3300_lp_freq[] = {40, 70, 10};
124 static const int scl3300_lp_freq_map[] = {0, 1, 2};
125 
126 static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}};
127 static const int sca3300_accel_scale_map[] = {0, 1, 2, 2};
128 
129 static const int scl3300_accel_scale[][2] = {{0, 167}, {0, 333}, {0, 83}};
130 static const int scl3300_accel_scale_map[] = {0, 1, 2};
131 
132 static const int scl3300_incli_scale[][2] = {{0, 5495}};
133 static const int scl3300_incli_scale_map[] = {0, 0, 0};
134 
135 static const int sca3300_avail_modes_map[] = {0, 1, 2, 3};
136 static const int scl3300_avail_modes_map[] = {0, 1, 3};
137 
138 static const struct iio_chan_spec scl3300_channels[] = {
139 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_X, 0x1, X),
140 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y),
141 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z),
142 	SCA3300_TEMP_CHANNEL(SCA3300_TEMP, 0x05),
143 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_X, 0x09, X),
144 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Y, 0x0A, Y),
145 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Z, 0x0B, Z),
146 	IIO_CHAN_SOFT_TIMESTAMP(7),
147 };
148 
149 static const unsigned long sca3300_scan_masks[] = {
150 	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
151 	BIT(SCA3300_TEMP),
152 	0
153 };
154 
155 static const unsigned long scl3300_scan_masks[] = {
156 	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
157 	BIT(SCA3300_TEMP) |
158 	BIT(SCA3300_INCLI_X) | BIT(SCA3300_INCLI_Y) | BIT(SCA3300_INCLI_Z),
159 	0
160 };
161 
162 struct sca3300_chip_info {
163 	const char *name;
164 	const unsigned long *scan_masks;
165 	const struct iio_chan_spec *channels;
166 	u8 num_channels;
167 	u8 num_accel_scales;
168 	const int (*accel_scale)[2];
169 	const int *accel_scale_map;
170 	const int (*incli_scale)[2];
171 	const int *incli_scale_map;
172 	u8 num_incli_scales;
173 	u8 num_freqs;
174 	const int *freq_table;
175 	const int *freq_map;
176 	const int *avail_modes_table;
177 	u8 num_avail_modes;
178 	u8 chip_id;
179 	bool angle_supported;
180 };
181 
182 /**
183  * struct sca3300_data - device data
184  * @spi: SPI device structure
185  * @lock: Data buffer lock
186  * @chip: Sensor chip specific information
187  * @txbuf: Transmit buffer
188  * @rxbuf: Receive buffer
189  */
190 struct sca3300_data {
191 	struct spi_device *spi;
192 	struct mutex lock;
193 	const struct sca3300_chip_info *chip;
194 	u8 txbuf[4] __aligned(IIO_DMA_MINALIGN);
195 	u8 rxbuf[4];
196 };
197 
198 static const struct sca3300_chip_info sca3300_chip_tbl[] = {
199 	{
200 		.name = "sca3300",
201 		.scan_masks = sca3300_scan_masks,
202 		.channels = sca3300_channels,
203 		.num_channels = ARRAY_SIZE(sca3300_channels),
204 		.num_accel_scales = ARRAY_SIZE(sca3300_accel_scale)*2,
205 		.accel_scale = sca3300_accel_scale,
206 		.accel_scale_map = sca3300_accel_scale_map,
207 		.num_freqs = ARRAY_SIZE(sca3300_lp_freq),
208 		.freq_table = sca3300_lp_freq,
209 		.freq_map = sca3300_lp_freq_map,
210 		.avail_modes_table = sca3300_avail_modes_map,
211 		.num_avail_modes = 4,
212 		.chip_id = SCA3300_WHOAMI_ID,
213 		.angle_supported = false,
214 	},
215 	{
216 		.name = "scl3300",
217 		.scan_masks = scl3300_scan_masks,
218 		.channels = scl3300_channels,
219 		.num_channels = ARRAY_SIZE(scl3300_channels),
220 		.num_accel_scales = ARRAY_SIZE(scl3300_accel_scale)*2,
221 		.accel_scale = scl3300_accel_scale,
222 		.accel_scale_map = scl3300_accel_scale_map,
223 		.incli_scale = scl3300_incli_scale,
224 		.incli_scale_map = scl3300_incli_scale_map,
225 		.num_incli_scales =  ARRAY_SIZE(scl3300_incli_scale)*2,
226 		.num_freqs = ARRAY_SIZE(scl3300_lp_freq),
227 		.freq_table = scl3300_lp_freq,
228 		.freq_map = scl3300_lp_freq_map,
229 		.avail_modes_table = scl3300_avail_modes_map,
230 		.num_avail_modes = 3,
231 		.chip_id = SCL3300_WHOAMI_ID,
232 		.angle_supported = true,
233 	},
234 };
235 
236 DECLARE_CRC8_TABLE(sca3300_crc_table);
237 
238 static int sca3300_transfer(struct sca3300_data *sca_data, int *val)
239 {
240 	/* Consecutive requests min. 10 us delay (Datasheet section 5.1.2) */
241 	struct spi_delay delay = { .value = 10, .unit = SPI_DELAY_UNIT_USECS };
242 	int32_t ret;
243 	int rs;
244 	u8 crc;
245 	struct spi_transfer xfers[2] = {
246 		{
247 			.tx_buf = sca_data->txbuf,
248 			.len = ARRAY_SIZE(sca_data->txbuf),
249 			.delay = delay,
250 			.cs_change = 1,
251 		},
252 		{
253 			.rx_buf = sca_data->rxbuf,
254 			.len = ARRAY_SIZE(sca_data->rxbuf),
255 			.delay = delay,
256 		}
257 	};
258 
259 	/* inverted crc value as described in device data sheet */
260 	crc = ~crc8(sca3300_crc_table, &sca_data->txbuf[0], 3, CRC8_INIT_VALUE);
261 	sca_data->txbuf[3] = crc;
262 
263 	ret = spi_sync_transfer(sca_data->spi, xfers, ARRAY_SIZE(xfers));
264 	if (ret) {
265 		dev_err(&sca_data->spi->dev,
266 			"transfer error, error: %d\n", ret);
267 		return -EIO;
268 	}
269 
270 	crc = ~crc8(sca3300_crc_table, &sca_data->rxbuf[0], 3, CRC8_INIT_VALUE);
271 	if (sca_data->rxbuf[3] != crc) {
272 		dev_err(&sca_data->spi->dev, "CRC checksum mismatch");
273 		return -EIO;
274 	}
275 
276 	/* get return status */
277 	rs = sca_data->rxbuf[0] & SCA3300_MASK_RS_STATUS;
278 	if (rs == SCA3300_VALUE_RS_ERROR)
279 		ret = -EINVAL;
280 
281 	*val = sign_extend32(get_unaligned_be16(&sca_data->rxbuf[1]), 15);
282 
283 	return ret;
284 }
285 
286 static int sca3300_error_handler(struct sca3300_data *sca_data)
287 {
288 	int ret;
289 	int val;
290 
291 	mutex_lock(&sca_data->lock);
292 	sca_data->txbuf[0] = SCA3300_REG_STATUS << 2;
293 	ret = sca3300_transfer(sca_data, &val);
294 	mutex_unlock(&sca_data->lock);
295 	/*
296 	 * Return status error is cleared after reading status register once,
297 	 * expect EINVAL here.
298 	 */
299 	if (ret != -EINVAL) {
300 		dev_err(&sca_data->spi->dev,
301 			"error reading device status: %d\n", ret);
302 		return ret;
303 	}
304 
305 	dev_err(&sca_data->spi->dev, "device status: 0x%lx\n",
306 		val & SCA3300_STATUS_MASK);
307 
308 	return 0;
309 }
310 
311 static int sca3300_read_reg(struct sca3300_data *sca_data, u8 reg, int *val)
312 {
313 	int ret;
314 
315 	mutex_lock(&sca_data->lock);
316 	sca_data->txbuf[0] = reg << 2;
317 	ret = sca3300_transfer(sca_data, val);
318 	mutex_unlock(&sca_data->lock);
319 	if (ret != -EINVAL)
320 		return ret;
321 
322 	return sca3300_error_handler(sca_data);
323 }
324 
325 static int sca3300_write_reg(struct sca3300_data *sca_data, u8 reg, int val)
326 {
327 	int reg_val = 0;
328 	int ret;
329 
330 	mutex_lock(&sca_data->lock);
331 	/* BIT(7) for write operation */
332 	sca_data->txbuf[0] = BIT(7) | (reg << 2);
333 	put_unaligned_be16(val, &sca_data->txbuf[1]);
334 	ret = sca3300_transfer(sca_data, &reg_val);
335 	mutex_unlock(&sca_data->lock);
336 	if (ret != -EINVAL)
337 		return ret;
338 
339 	return sca3300_error_handler(sca_data);
340 }
341 
342 static int sca3300_set_op_mode(struct sca3300_data *sca_data, int index)
343 {
344 	if ((index < 0) || (index >= sca_data->chip->num_avail_modes))
345 		return -EINVAL;
346 
347 	return sca3300_write_reg(sca_data, SCA3300_REG_MODE,
348 				 sca_data->chip->avail_modes_table[index]);
349 }
350 
351 static int sca3300_get_op_mode(struct sca3300_data *sca_data, int *index)
352 {
353 	int reg_val;
354 	int ret;
355 	int i;
356 
357 	ret = sca3300_read_reg(sca_data, SCA3300_REG_MODE, &reg_val);
358 	if (ret)
359 		return ret;
360 
361 	for (i = 0; i < sca_data->chip->num_avail_modes; i++) {
362 		if (sca_data->chip->avail_modes_table[i] == reg_val)
363 			break;
364 	}
365 	if (i == sca_data->chip->num_avail_modes)
366 		return -EINVAL;
367 
368 	*index = i;
369 	return 0;
370 }
371 
372 static int sca3300_set_frequency(struct sca3300_data *data, int val)
373 {
374 	const struct sca3300_chip_info *chip = data->chip;
375 	unsigned int index;
376 	int *opmode_scale;
377 	int *new_scale;
378 	unsigned int i;
379 
380 	if (sca3300_get_op_mode(data, &index))
381 		return -EINVAL;
382 
383 	/*
384 	 * Find a mode in which the requested sampling frequency is available
385 	 * and the scaling currently set is retained.
386 	 */
387 	opmode_scale = (int *)chip->accel_scale[chip->accel_scale_map[index]];
388 	for (i = 0; i < chip->num_avail_modes; i++) {
389 		new_scale = (int *)chip->accel_scale[chip->accel_scale_map[i]];
390 		if ((val == chip->freq_table[chip->freq_map[i]]) &&
391 		    (opmode_scale[1] == new_scale[1]) &&
392 		    (opmode_scale[0] == new_scale[0]))
393 			break;
394 	}
395 	if (i == chip->num_avail_modes)
396 		return -EINVAL;
397 
398 	return sca3300_set_op_mode(data, i);
399 }
400 
401 static int sca3300_write_raw(struct iio_dev *indio_dev,
402 			     struct iio_chan_spec const *chan,
403 			     int val, int val2, long mask)
404 {
405 	struct sca3300_data *data = iio_priv(indio_dev);
406 	int index;
407 	int i;
408 
409 	switch (mask) {
410 	case IIO_CHAN_INFO_SCALE:
411 		if (chan->type != IIO_ACCEL)
412 			return -EINVAL;
413 		/*
414 		 * Letting scale take priority over sampling frequency.
415 		 * That makes sense given we can only ever end up increasing
416 		 * the sampling frequency which is unlikely to be a problem.
417 		 */
418 		for (i = 0; i < data->chip->num_avail_modes; i++) {
419 			index = data->chip->accel_scale_map[i];
420 			if ((val  == data->chip->accel_scale[index][0]) &&
421 			    (val2 == data->chip->accel_scale[index][1]))
422 				return sca3300_set_op_mode(data, i);
423 		}
424 		return -EINVAL;
425 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
426 		return sca3300_set_frequency(data, val);
427 	default:
428 		return -EINVAL;
429 	}
430 }
431 
432 static int sca3300_read_raw(struct iio_dev *indio_dev,
433 			    struct iio_chan_spec const *chan,
434 			    int *val, int *val2, long mask)
435 {
436 	struct sca3300_data *data = iio_priv(indio_dev);
437 	int index;
438 	int ret;
439 
440 	switch (mask) {
441 	case IIO_CHAN_INFO_RAW:
442 		ret = sca3300_read_reg(data, chan->address, val);
443 		if (ret)
444 			return ret;
445 		return IIO_VAL_INT;
446 	case IIO_CHAN_INFO_SCALE:
447 		ret = sca3300_get_op_mode(data, &index);
448 		if (ret)
449 			return ret;
450 		switch (chan->type) {
451 		case IIO_INCLI:
452 			index = data->chip->incli_scale_map[index];
453 			*val  = data->chip->incli_scale[index][0];
454 			*val2 = data->chip->incli_scale[index][1];
455 			return IIO_VAL_INT_PLUS_MICRO;
456 		case IIO_ACCEL:
457 			index = data->chip->accel_scale_map[index];
458 			*val  = data->chip->accel_scale[index][0];
459 			*val2 = data->chip->accel_scale[index][1];
460 			return IIO_VAL_INT_PLUS_MICRO;
461 		default:
462 			return -EINVAL;
463 		}
464 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
465 		ret = sca3300_get_op_mode(data, &index);
466 		if (ret)
467 			return ret;
468 		index = data->chip->freq_map[index];
469 		*val = data->chip->freq_table[index];
470 		return IIO_VAL_INT;
471 	default:
472 		return -EINVAL;
473 	}
474 }
475 
476 static irqreturn_t sca3300_trigger_handler(int irq, void *p)
477 {
478 	struct iio_poll_func *pf = p;
479 	struct iio_dev *indio_dev = pf->indio_dev;
480 	struct sca3300_data *data = iio_priv(indio_dev);
481 	int bit, ret, val, i = 0;
482 	IIO_DECLARE_BUFFER_WITH_TS(s16, channels, SCA3300_SCAN_MAX);
483 
484 	iio_for_each_active_channel(indio_dev, bit) {
485 		ret = sca3300_read_reg(data, indio_dev->channels[bit].address, &val);
486 		if (ret) {
487 			dev_err_ratelimited(&data->spi->dev,
488 				"failed to read register, error: %d\n", ret);
489 			/* handled, but bailing out due to errors */
490 			goto out;
491 		}
492 		channels[i++] = val;
493 	}
494 
495 	iio_push_to_buffers_with_ts(indio_dev, channels, sizeof(channels),
496 				    iio_get_time_ns(indio_dev));
497 out:
498 	iio_trigger_notify_done(indio_dev->trig);
499 
500 	return IRQ_HANDLED;
501 }
502 
503 /*
504  * sca3300_init - Device init sequence. See datasheet rev 2 section
505  * 4.2 Start-Up Sequence for details.
506  */
507 static int sca3300_init(struct sca3300_data *sca_data,
508 			struct iio_dev *indio_dev)
509 {
510 	int value = 0;
511 	int ret;
512 	int i;
513 
514 	ret = sca3300_write_reg(sca_data, SCA3300_REG_MODE,
515 				SCA3300_MODE_SW_RESET);
516 	if (ret)
517 		return ret;
518 
519 	/*
520 	 * Wait 1ms after SW-reset command.
521 	 * Wait for the settling of signal paths,
522 	 * 15ms for SCA3300 and 25ms for SCL3300,
523 	 */
524 	usleep_range(26e3, 50e3);
525 
526 	ret = sca3300_read_reg(sca_data, SCA3300_REG_WHOAMI, &value);
527 	if (ret)
528 		return ret;
529 
530 	for (i = 0; i < ARRAY_SIZE(sca3300_chip_tbl); i++) {
531 		if (sca3300_chip_tbl[i].chip_id == value)
532 			break;
533 	}
534 	if (i == ARRAY_SIZE(sca3300_chip_tbl)) {
535 		dev_err(&sca_data->spi->dev, "unknown chip id %x\n", value);
536 		return -ENODEV;
537 	}
538 
539 	sca_data->chip = &sca3300_chip_tbl[i];
540 
541 	if (sca_data->chip->angle_supported) {
542 		ret = sca3300_write_reg(sca_data, SCL3300_REG_ANG_CTRL,
543 					SCL3300_ANG_ENABLE);
544 		if (ret)
545 			return ret;
546 	}
547 
548 	return 0;
549 }
550 
551 static int sca3300_debugfs_reg_access(struct iio_dev *indio_dev,
552 				      unsigned int reg, unsigned int writeval,
553 				      unsigned int *readval)
554 {
555 	struct sca3300_data *data = iio_priv(indio_dev);
556 	int value;
557 	int ret;
558 
559 	if (reg > SCA3300_REG_SELBANK)
560 		return -EINVAL;
561 
562 	if (!readval)
563 		return sca3300_write_reg(data, reg, writeval);
564 
565 	ret = sca3300_read_reg(data, reg, &value);
566 	if (ret)
567 		return ret;
568 
569 	*readval = value;
570 
571 	return 0;
572 }
573 
574 static int sca3300_read_avail(struct iio_dev *indio_dev,
575 			      struct iio_chan_spec const *chan,
576 			      const int **vals, int *type, int *length,
577 			      long mask)
578 {
579 	struct sca3300_data *data = iio_priv(indio_dev);
580 	switch (mask) {
581 	case IIO_CHAN_INFO_SCALE:
582 		switch (chan->type) {
583 		case IIO_INCLI:
584 			*vals = (const int *)data->chip->incli_scale;
585 			*length = data->chip->num_incli_scales;
586 			*type = IIO_VAL_INT_PLUS_MICRO;
587 			return IIO_AVAIL_LIST;
588 		case IIO_ACCEL:
589 			*vals = (const int *)data->chip->accel_scale;
590 			*length = data->chip->num_accel_scales;
591 			*type = IIO_VAL_INT_PLUS_MICRO;
592 			return IIO_AVAIL_LIST;
593 		default:
594 			return -EINVAL;
595 		}
596 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
597 		*vals = (const int *)data->chip->freq_table;
598 		*length = data->chip->num_freqs;
599 		*type = IIO_VAL_INT;
600 		return IIO_AVAIL_LIST;
601 	default:
602 		return -EINVAL;
603 	}
604 }
605 
606 static const struct iio_info sca3300_info = {
607 	.read_raw = sca3300_read_raw,
608 	.write_raw = sca3300_write_raw,
609 	.debugfs_reg_access = &sca3300_debugfs_reg_access,
610 	.read_avail = sca3300_read_avail,
611 };
612 
613 static int sca3300_probe(struct spi_device *spi)
614 {
615 	struct sca3300_data *sca_data;
616 	struct iio_dev *indio_dev;
617 	int ret;
618 
619 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*sca_data));
620 	if (!indio_dev)
621 		return -ENOMEM;
622 
623 	sca_data = iio_priv(indio_dev);
624 	mutex_init(&sca_data->lock);
625 	sca_data->spi = spi;
626 
627 	crc8_populate_msb(sca3300_crc_table, SCA3300_CRC8_POLYNOMIAL);
628 
629 	indio_dev->info = &sca3300_info;
630 
631 	ret = sca3300_init(sca_data, indio_dev);
632 	if (ret) {
633 		dev_err(&spi->dev, "failed to init device, error: %d\n", ret);
634 		return ret;
635 	}
636 
637 	indio_dev->name = sca_data->chip->name;
638 	indio_dev->modes = INDIO_DIRECT_MODE;
639 	indio_dev->channels = sca_data->chip->channels;
640 	indio_dev->num_channels = sca_data->chip->num_channels;
641 	indio_dev->available_scan_masks = sca_data->chip->scan_masks;
642 
643 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
644 					      iio_pollfunc_store_time,
645 					      sca3300_trigger_handler, NULL);
646 	if (ret) {
647 		dev_err(&spi->dev,
648 			"iio triggered buffer setup failed, error: %d\n", ret);
649 		return ret;
650 	}
651 
652 	ret = devm_iio_device_register(&spi->dev, indio_dev);
653 	if (ret) {
654 		dev_err(&spi->dev, "iio device register failed, error: %d\n",
655 			ret);
656 	}
657 
658 	return ret;
659 }
660 
661 static const struct of_device_id sca3300_dt_ids[] = {
662 	{ .compatible = "murata,sca3300"},
663 	{ .compatible = "murata,scl3300"},
664 	{ }
665 };
666 MODULE_DEVICE_TABLE(of, sca3300_dt_ids);
667 
668 static const struct spi_device_id sca3300_ids[] = {
669 	{ "sca3300" },
670 	{ "scl3300" },
671 	{ }
672 };
673 MODULE_DEVICE_TABLE(spi, sca3300_ids);
674 
675 static struct spi_driver sca3300_driver = {
676 	.driver   = {
677 		.name		= SCA3300_ALIAS,
678 		.of_match_table = sca3300_dt_ids,
679 	},
680 	.probe	  = sca3300_probe,
681 	.id_table = sca3300_ids,
682 };
683 module_spi_driver(sca3300_driver);
684 
685 MODULE_AUTHOR("Tomas Melin <tomas.melin@vaisala.com>");
686 MODULE_DESCRIPTION("Murata SCA3300 SPI Accelerometer");
687 MODULE_LICENSE("GPL v2");
688