xref: /openbmc/linux/drivers/iio/accel/sca3300.c (revision 35dab731)
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 <asm/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 /*
62  * Buffer size max case:
63  * Three accel channels, two bytes per channel.
64  * Temperature channel, two bytes.
65  * Three incli channels, two bytes per channel.
66  * Timestamp channel, eight bytes.
67  */
68 #define SCA3300_MAX_BUFFER_SIZE (ALIGN(sizeof(s16) * SCA3300_SCAN_MAX, sizeof(s64)) + sizeof(s64))
69 
70 #define SCA3300_ACCEL_CHANNEL(index, reg, axis) {			\
71 	.type = IIO_ACCEL,						\
72 	.address = reg,							\
73 	.modified = 1,							\
74 	.channel2 = IIO_MOD_##axis,					\
75 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
76 	.info_mask_shared_by_type =					\
77 	BIT(IIO_CHAN_INFO_SCALE) |					\
78 	BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),		\
79 	.info_mask_shared_by_type_available =				\
80 	BIT(IIO_CHAN_INFO_SCALE) |					\
81 	BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),		\
82 	.scan_index = index,						\
83 	.scan_type = {							\
84 		.sign = 's',						\
85 		.realbits = 16,						\
86 		.storagebits = 16,					\
87 		.endianness = IIO_CPU,					\
88 	},								\
89 }
90 
91 #define SCA3300_INCLI_CHANNEL(index, reg, axis) {			\
92 	.type = IIO_INCLI,						\
93 	.address = reg,							\
94 	.modified = 1,							\
95 	.channel2 = IIO_MOD_##axis,					\
96 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
97 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
98 	.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE), \
99 	.scan_index = index,						\
100 	.scan_type = {							\
101 		.sign = 's',						\
102 		.realbits = 16,						\
103 		.storagebits = 16,					\
104 		.endianness = IIO_CPU,					\
105 	},								\
106 }
107 
108 #define SCA3300_TEMP_CHANNEL(index, reg) {				\
109 		.type = IIO_TEMP,					\
110 		.address = reg,						\
111 		.scan_index = index,					\
112 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
113 		.scan_type = {						\
114 			.sign = 's',					\
115 			.realbits = 16,					\
116 			.storagebits = 16,				\
117 			.endianness = IIO_CPU,				\
118 		},							\
119 }
120 
121 static const struct iio_chan_spec sca3300_channels[] = {
122 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_X, 0x1, X),
123 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y),
124 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z),
125 	SCA3300_TEMP_CHANNEL(SCA3300_TEMP, 0x05),
126 	IIO_CHAN_SOFT_TIMESTAMP(4),
127 };
128 
129 static const int sca3300_lp_freq[] = {70, 10};
130 static const int sca3300_lp_freq_map[] = {0, 0, 0, 1};
131 
132 static const int scl3300_lp_freq[] = {40, 70, 10};
133 static const int scl3300_lp_freq_map[] = {0, 1, 2};
134 
135 static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}};
136 static const int sca3300_accel_scale_map[] = {0, 1, 2, 2};
137 
138 static const int scl3300_accel_scale[][2] = {{0, 167}, {0, 333}, {0, 83}};
139 static const int scl3300_accel_scale_map[] = {0, 1, 2};
140 
141 static const int scl3300_incli_scale[][2] = {{0, 5495}};
142 static const int scl3300_incli_scale_map[] = {0, 0, 0};
143 
144 static const int sca3300_avail_modes_map[] = {0, 1, 2, 3};
145 static const int scl3300_avail_modes_map[] = {0, 1, 3};
146 
147 static const struct iio_chan_spec scl3300_channels[] = {
148 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_X, 0x1, X),
149 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y),
150 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z),
151 	SCA3300_TEMP_CHANNEL(SCA3300_TEMP, 0x05),
152 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_X, 0x09, X),
153 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Y, 0x0A, Y),
154 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Z, 0x0B, Z),
155 	IIO_CHAN_SOFT_TIMESTAMP(7),
156 };
157 
158 static const unsigned long sca3300_scan_masks[] = {
159 	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
160 	BIT(SCA3300_TEMP),
161 	0
162 };
163 
164 static const unsigned long scl3300_scan_masks[] = {
165 	BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
166 	BIT(SCA3300_TEMP) |
167 	BIT(SCA3300_INCLI_X) | BIT(SCA3300_INCLI_Y) | BIT(SCA3300_INCLI_Z),
168 	0
169 };
170 
171 struct sca3300_chip_info {
172 	const char *name;
173 	const unsigned long *scan_masks;
174 	const struct iio_chan_spec *channels;
175 	u8 num_channels;
176 	u8 num_accel_scales;
177 	const int (*accel_scale)[2];
178 	const int *accel_scale_map;
179 	const int (*incli_scale)[2];
180 	const int *incli_scale_map;
181 	u8 num_incli_scales;
182 	u8 num_freqs;
183 	const int *freq_table;
184 	const int *freq_map;
185 	const int *avail_modes_table;
186 	u8 num_avail_modes;
187 	u8 chip_id;
188 	bool angle_supported;
189 };
190 
191 /**
192  * struct sca3300_data - device data
193  * @spi: SPI device structure
194  * @lock: Data buffer lock
195  * @chip: Sensor chip specific information
196  * @buffer: Triggered buffer:
197  *          -SCA3300: 4 channel 16-bit data + 64-bit timestamp
198  *          -SCL3300: 7 channel 16-bit data + 64-bit timestamp
199  * @txbuf: Transmit buffer
200  * @rxbuf: Receive buffer
201  */
202 struct sca3300_data {
203 	struct spi_device *spi;
204 	struct mutex lock;
205 	const struct sca3300_chip_info *chip;
206 	u8 buffer[SCA3300_MAX_BUFFER_SIZE] __aligned(sizeof(s64));
207 	u8 txbuf[4] __aligned(IIO_DMA_MINALIGN);
208 	u8 rxbuf[4];
209 };
210 
211 static const struct sca3300_chip_info sca3300_chip_tbl[] = {
212 	{
213 		.name = "sca3300",
214 		.scan_masks = sca3300_scan_masks,
215 		.channels = sca3300_channels,
216 		.num_channels = ARRAY_SIZE(sca3300_channels),
217 		.num_accel_scales = ARRAY_SIZE(sca3300_accel_scale)*2,
218 		.accel_scale = sca3300_accel_scale,
219 		.accel_scale_map = sca3300_accel_scale_map,
220 		.num_freqs = ARRAY_SIZE(sca3300_lp_freq),
221 		.freq_table = sca3300_lp_freq,
222 		.freq_map = sca3300_lp_freq_map,
223 		.avail_modes_table = sca3300_avail_modes_map,
224 		.num_avail_modes = 4,
225 		.chip_id = SCA3300_WHOAMI_ID,
226 		.angle_supported = false,
227 	},
228 	{
229 		.name = "scl3300",
230 		.scan_masks = scl3300_scan_masks,
231 		.channels = scl3300_channels,
232 		.num_channels = ARRAY_SIZE(scl3300_channels),
233 		.num_accel_scales = ARRAY_SIZE(scl3300_accel_scale)*2,
234 		.accel_scale = scl3300_accel_scale,
235 		.accel_scale_map = scl3300_accel_scale_map,
236 		.incli_scale = scl3300_incli_scale,
237 		.incli_scale_map = scl3300_incli_scale_map,
238 		.num_incli_scales =  ARRAY_SIZE(scl3300_incli_scale)*2,
239 		.num_freqs = ARRAY_SIZE(scl3300_lp_freq),
240 		.freq_table = scl3300_lp_freq,
241 		.freq_map = scl3300_lp_freq_map,
242 		.avail_modes_table = scl3300_avail_modes_map,
243 		.num_avail_modes = 3,
244 		.chip_id = SCL3300_WHOAMI_ID,
245 		.angle_supported = true,
246 	},
247 };
248 
249 DECLARE_CRC8_TABLE(sca3300_crc_table);
250 
sca3300_transfer(struct sca3300_data * sca_data,int * val)251 static int sca3300_transfer(struct sca3300_data *sca_data, int *val)
252 {
253 	/* Consecutive requests min. 10 us delay (Datasheet section 5.1.2) */
254 	struct spi_delay delay = { .value = 10, .unit = SPI_DELAY_UNIT_USECS };
255 	int32_t ret;
256 	int rs;
257 	u8 crc;
258 	struct spi_transfer xfers[2] = {
259 		{
260 			.tx_buf = sca_data->txbuf,
261 			.len = ARRAY_SIZE(sca_data->txbuf),
262 			.delay = delay,
263 			.cs_change = 1,
264 		},
265 		{
266 			.rx_buf = sca_data->rxbuf,
267 			.len = ARRAY_SIZE(sca_data->rxbuf),
268 			.delay = delay,
269 		}
270 	};
271 
272 	/* inverted crc value as described in device data sheet */
273 	crc = ~crc8(sca3300_crc_table, &sca_data->txbuf[0], 3, CRC8_INIT_VALUE);
274 	sca_data->txbuf[3] = crc;
275 
276 	ret = spi_sync_transfer(sca_data->spi, xfers, ARRAY_SIZE(xfers));
277 	if (ret) {
278 		dev_err(&sca_data->spi->dev,
279 			"transfer error, error: %d\n", ret);
280 		return -EIO;
281 	}
282 
283 	crc = ~crc8(sca3300_crc_table, &sca_data->rxbuf[0], 3, CRC8_INIT_VALUE);
284 	if (sca_data->rxbuf[3] != crc) {
285 		dev_err(&sca_data->spi->dev, "CRC checksum mismatch");
286 		return -EIO;
287 	}
288 
289 	/* get return status */
290 	rs = sca_data->rxbuf[0] & SCA3300_MASK_RS_STATUS;
291 	if (rs == SCA3300_VALUE_RS_ERROR)
292 		ret = -EINVAL;
293 
294 	*val = sign_extend32(get_unaligned_be16(&sca_data->rxbuf[1]), 15);
295 
296 	return ret;
297 }
298 
sca3300_error_handler(struct sca3300_data * sca_data)299 static int sca3300_error_handler(struct sca3300_data *sca_data)
300 {
301 	int ret;
302 	int val;
303 
304 	mutex_lock(&sca_data->lock);
305 	sca_data->txbuf[0] = SCA3300_REG_STATUS << 2;
306 	ret = sca3300_transfer(sca_data, &val);
307 	mutex_unlock(&sca_data->lock);
308 	/*
309 	 * Return status error is cleared after reading status register once,
310 	 * expect EINVAL here.
311 	 */
312 	if (ret != -EINVAL) {
313 		dev_err(&sca_data->spi->dev,
314 			"error reading device status: %d\n", ret);
315 		return ret;
316 	}
317 
318 	dev_err(&sca_data->spi->dev, "device status: 0x%lx\n",
319 		val & SCA3300_STATUS_MASK);
320 
321 	return 0;
322 }
323 
sca3300_read_reg(struct sca3300_data * sca_data,u8 reg,int * val)324 static int sca3300_read_reg(struct sca3300_data *sca_data, u8 reg, int *val)
325 {
326 	int ret;
327 
328 	mutex_lock(&sca_data->lock);
329 	sca_data->txbuf[0] = reg << 2;
330 	ret = sca3300_transfer(sca_data, val);
331 	mutex_unlock(&sca_data->lock);
332 	if (ret != -EINVAL)
333 		return ret;
334 
335 	return sca3300_error_handler(sca_data);
336 }
337 
sca3300_write_reg(struct sca3300_data * sca_data,u8 reg,int val)338 static int sca3300_write_reg(struct sca3300_data *sca_data, u8 reg, int val)
339 {
340 	int reg_val = 0;
341 	int ret;
342 
343 	mutex_lock(&sca_data->lock);
344 	/* BIT(7) for write operation */
345 	sca_data->txbuf[0] = BIT(7) | (reg << 2);
346 	put_unaligned_be16(val, &sca_data->txbuf[1]);
347 	ret = sca3300_transfer(sca_data, &reg_val);
348 	mutex_unlock(&sca_data->lock);
349 	if (ret != -EINVAL)
350 		return ret;
351 
352 	return sca3300_error_handler(sca_data);
353 }
354 
sca3300_set_op_mode(struct sca3300_data * sca_data,int index)355 static int sca3300_set_op_mode(struct sca3300_data *sca_data, int index)
356 {
357 	if ((index < 0) || (index >= sca_data->chip->num_avail_modes))
358 		return -EINVAL;
359 
360 	return sca3300_write_reg(sca_data, SCA3300_REG_MODE,
361 				 sca_data->chip->avail_modes_table[index]);
362 }
363 
sca3300_get_op_mode(struct sca3300_data * sca_data,int * index)364 static int sca3300_get_op_mode(struct sca3300_data *sca_data, int *index)
365 {
366 	int reg_val;
367 	int ret;
368 	int i;
369 
370 	ret = sca3300_read_reg(sca_data, SCA3300_REG_MODE, &reg_val);
371 	if (ret)
372 		return ret;
373 
374 	for (i = 0; i < sca_data->chip->num_avail_modes; i++) {
375 		if (sca_data->chip->avail_modes_table[i] == reg_val)
376 			break;
377 	}
378 	if (i == sca_data->chip->num_avail_modes)
379 		return -EINVAL;
380 
381 	*index = i;
382 	return 0;
383 }
384 
sca3300_set_frequency(struct sca3300_data * data,int val)385 static int sca3300_set_frequency(struct sca3300_data *data, int val)
386 {
387 	const struct sca3300_chip_info *chip = data->chip;
388 	unsigned int index;
389 	int *opmode_scale;
390 	int *new_scale;
391 	unsigned int i;
392 
393 	if (sca3300_get_op_mode(data, &index))
394 		return -EINVAL;
395 
396 	/*
397 	 * Find a mode in which the requested sampling frequency is available
398 	 * and the scaling currently set is retained.
399 	 */
400 	opmode_scale = (int *)chip->accel_scale[chip->accel_scale_map[index]];
401 	for (i = 0; i < chip->num_avail_modes; i++) {
402 		new_scale = (int *)chip->accel_scale[chip->accel_scale_map[i]];
403 		if ((val == chip->freq_table[chip->freq_map[i]]) &&
404 		    (opmode_scale[1] == new_scale[1]) &&
405 		    (opmode_scale[0] == new_scale[0]))
406 			break;
407 	}
408 	if (i == chip->num_avail_modes)
409 		return -EINVAL;
410 
411 	return sca3300_set_op_mode(data, i);
412 }
413 
sca3300_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)414 static int sca3300_write_raw(struct iio_dev *indio_dev,
415 			     struct iio_chan_spec const *chan,
416 			     int val, int val2, long mask)
417 {
418 	struct sca3300_data *data = iio_priv(indio_dev);
419 	int index;
420 	int i;
421 
422 	switch (mask) {
423 	case IIO_CHAN_INFO_SCALE:
424 		if (chan->type != IIO_ACCEL)
425 			return -EINVAL;
426 		/*
427 		 * Letting scale take priority over sampling frequency.
428 		 * That makes sense given we can only ever end up increasing
429 		 * the sampling frequency which is unlikely to be a problem.
430 		 */
431 		for (i = 0; i < data->chip->num_avail_modes; i++) {
432 			index = data->chip->accel_scale_map[i];
433 			if ((val  == data->chip->accel_scale[index][0]) &&
434 			    (val2 == data->chip->accel_scale[index][1]))
435 				return sca3300_set_op_mode(data, i);
436 		}
437 		return -EINVAL;
438 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
439 		return sca3300_set_frequency(data, val);
440 	default:
441 		return -EINVAL;
442 	}
443 }
444 
sca3300_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)445 static int sca3300_read_raw(struct iio_dev *indio_dev,
446 			    struct iio_chan_spec const *chan,
447 			    int *val, int *val2, long mask)
448 {
449 	struct sca3300_data *data = iio_priv(indio_dev);
450 	int index;
451 	int ret;
452 
453 	switch (mask) {
454 	case IIO_CHAN_INFO_RAW:
455 		ret = sca3300_read_reg(data, chan->address, val);
456 		if (ret)
457 			return ret;
458 		return IIO_VAL_INT;
459 	case IIO_CHAN_INFO_SCALE:
460 		ret = sca3300_get_op_mode(data, &index);
461 		if (ret)
462 			return ret;
463 		switch (chan->type) {
464 		case IIO_INCLI:
465 			index = data->chip->incli_scale_map[index];
466 			*val  = data->chip->incli_scale[index][0];
467 			*val2 = data->chip->incli_scale[index][1];
468 			return IIO_VAL_INT_PLUS_MICRO;
469 		case IIO_ACCEL:
470 			index = data->chip->accel_scale_map[index];
471 			*val  = data->chip->accel_scale[index][0];
472 			*val2 = data->chip->accel_scale[index][1];
473 			return IIO_VAL_INT_PLUS_MICRO;
474 		default:
475 			return -EINVAL;
476 		}
477 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
478 		ret = sca3300_get_op_mode(data, &index);
479 		if (ret)
480 			return ret;
481 		index = data->chip->freq_map[index];
482 		*val = data->chip->freq_table[index];
483 		return IIO_VAL_INT;
484 	default:
485 		return -EINVAL;
486 	}
487 }
488 
sca3300_trigger_handler(int irq,void * p)489 static irqreturn_t sca3300_trigger_handler(int irq, void *p)
490 {
491 	struct iio_poll_func *pf = p;
492 	struct iio_dev *indio_dev = pf->indio_dev;
493 	struct sca3300_data *data = iio_priv(indio_dev);
494 	int bit, ret, val, i = 0;
495 	s16 *channels = (s16 *)data->buffer;
496 
497 	for_each_set_bit(bit, indio_dev->active_scan_mask,
498 			 indio_dev->masklength) {
499 		ret = sca3300_read_reg(data, indio_dev->channels[bit].address, &val);
500 		if (ret) {
501 			dev_err_ratelimited(&data->spi->dev,
502 				"failed to read register, error: %d\n", ret);
503 			/* handled, but bailing out due to errors */
504 			goto out;
505 		}
506 		channels[i++] = val;
507 	}
508 
509 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
510 					   iio_get_time_ns(indio_dev));
511 out:
512 	iio_trigger_notify_done(indio_dev->trig);
513 
514 	return IRQ_HANDLED;
515 }
516 
517 /*
518  * sca3300_init - Device init sequence. See datasheet rev 2 section
519  * 4.2 Start-Up Sequence for details.
520  */
sca3300_init(struct sca3300_data * sca_data,struct iio_dev * indio_dev)521 static int sca3300_init(struct sca3300_data *sca_data,
522 			struct iio_dev *indio_dev)
523 {
524 	int value = 0;
525 	int ret;
526 	int i;
527 
528 	ret = sca3300_write_reg(sca_data, SCA3300_REG_MODE,
529 				SCA3300_MODE_SW_RESET);
530 	if (ret)
531 		return ret;
532 
533 	/*
534 	 * Wait 1ms after SW-reset command.
535 	 * Wait for the settling of signal paths,
536 	 * 15ms for SCA3300 and 25ms for SCL3300,
537 	 */
538 	usleep_range(26e3, 50e3);
539 
540 	ret = sca3300_read_reg(sca_data, SCA3300_REG_WHOAMI, &value);
541 	if (ret)
542 		return ret;
543 
544 	for (i = 0; i < ARRAY_SIZE(sca3300_chip_tbl); i++) {
545 		if (sca3300_chip_tbl[i].chip_id == value)
546 			break;
547 	}
548 	if (i == ARRAY_SIZE(sca3300_chip_tbl)) {
549 		dev_err(&sca_data->spi->dev, "unknown chip id %x\n", value);
550 		return -ENODEV;
551 	}
552 
553 	sca_data->chip = &sca3300_chip_tbl[i];
554 
555 	if (sca_data->chip->angle_supported) {
556 		ret = sca3300_write_reg(sca_data, SCL3300_REG_ANG_CTRL,
557 					SCL3300_ANG_ENABLE);
558 		if (ret)
559 			return ret;
560 	}
561 
562 	return 0;
563 }
564 
sca3300_debugfs_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)565 static int sca3300_debugfs_reg_access(struct iio_dev *indio_dev,
566 				      unsigned int reg, unsigned int writeval,
567 				      unsigned int *readval)
568 {
569 	struct sca3300_data *data = iio_priv(indio_dev);
570 	int value;
571 	int ret;
572 
573 	if (reg > SCA3300_REG_SELBANK)
574 		return -EINVAL;
575 
576 	if (!readval)
577 		return sca3300_write_reg(data, reg, writeval);
578 
579 	ret = sca3300_read_reg(data, reg, &value);
580 	if (ret)
581 		return ret;
582 
583 	*readval = value;
584 
585 	return 0;
586 }
587 
sca3300_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)588 static int sca3300_read_avail(struct iio_dev *indio_dev,
589 			      struct iio_chan_spec const *chan,
590 			      const int **vals, int *type, int *length,
591 			      long mask)
592 {
593 	struct sca3300_data *data = iio_priv(indio_dev);
594 	switch (mask) {
595 	case IIO_CHAN_INFO_SCALE:
596 		switch (chan->type) {
597 		case IIO_INCLI:
598 			*vals = (const int *)data->chip->incli_scale;
599 			*length = data->chip->num_incli_scales;
600 			*type = IIO_VAL_INT_PLUS_MICRO;
601 			return IIO_AVAIL_LIST;
602 		case IIO_ACCEL:
603 			*vals = (const int *)data->chip->accel_scale;
604 			*length = data->chip->num_accel_scales;
605 			*type = IIO_VAL_INT_PLUS_MICRO;
606 			return IIO_AVAIL_LIST;
607 		default:
608 			return -EINVAL;
609 		}
610 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
611 		*vals = (const int *)data->chip->freq_table;
612 		*length = data->chip->num_freqs;
613 		*type = IIO_VAL_INT;
614 		return IIO_AVAIL_LIST;
615 	default:
616 		return -EINVAL;
617 	}
618 }
619 
620 static const struct iio_info sca3300_info = {
621 	.read_raw = sca3300_read_raw,
622 	.write_raw = sca3300_write_raw,
623 	.debugfs_reg_access = &sca3300_debugfs_reg_access,
624 	.read_avail = sca3300_read_avail,
625 };
626 
sca3300_probe(struct spi_device * spi)627 static int sca3300_probe(struct spi_device *spi)
628 {
629 	struct sca3300_data *sca_data;
630 	struct iio_dev *indio_dev;
631 	int ret;
632 
633 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*sca_data));
634 	if (!indio_dev)
635 		return -ENOMEM;
636 
637 	sca_data = iio_priv(indio_dev);
638 	mutex_init(&sca_data->lock);
639 	sca_data->spi = spi;
640 
641 	crc8_populate_msb(sca3300_crc_table, SCA3300_CRC8_POLYNOMIAL);
642 
643 	indio_dev->info = &sca3300_info;
644 
645 	ret = sca3300_init(sca_data, indio_dev);
646 	if (ret) {
647 		dev_err(&spi->dev, "failed to init device, error: %d\n", ret);
648 		return ret;
649 	}
650 
651 	indio_dev->name = sca_data->chip->name;
652 	indio_dev->modes = INDIO_DIRECT_MODE;
653 	indio_dev->channels = sca_data->chip->channels;
654 	indio_dev->num_channels = sca_data->chip->num_channels;
655 	indio_dev->available_scan_masks = sca_data->chip->scan_masks;
656 
657 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
658 					      iio_pollfunc_store_time,
659 					      sca3300_trigger_handler, NULL);
660 	if (ret) {
661 		dev_err(&spi->dev,
662 			"iio triggered buffer setup failed, error: %d\n", ret);
663 		return ret;
664 	}
665 
666 	ret = devm_iio_device_register(&spi->dev, indio_dev);
667 	if (ret) {
668 		dev_err(&spi->dev, "iio device register failed, error: %d\n",
669 			ret);
670 	}
671 
672 	return ret;
673 }
674 
675 static const struct of_device_id sca3300_dt_ids[] = {
676 	{ .compatible = "murata,sca3300"},
677 	{ .compatible = "murata,scl3300"},
678 	{}
679 };
680 MODULE_DEVICE_TABLE(of, sca3300_dt_ids);
681 
682 static const struct spi_device_id sca3300_ids[] = {
683 	{ "sca3300" },
684 	{ "scl3300" },
685 	{}
686 };
687 MODULE_DEVICE_TABLE(spi, sca3300_ids);
688 
689 static struct spi_driver sca3300_driver = {
690 	.driver   = {
691 		.name		= SCA3300_ALIAS,
692 		.of_match_table = sca3300_dt_ids,
693 	},
694 	.probe	  = sca3300_probe,
695 	.id_table = sca3300_ids,
696 };
697 module_spi_driver(sca3300_driver);
698 
699 MODULE_AUTHOR("Tomas Melin <tomas.melin@vaisala.com>");
700 MODULE_DESCRIPTION("Murata SCA3300 SPI Accelerometer");
701 MODULE_LICENSE("GPL v2");
702