xref: /linux/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c (revision 5c75125672443a209a40033f0df5fb823e356452)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2020 Invensense, Inc.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/device.h>
8 #include <linux/minmax.h>
9 #include <linux/mutex.h>
10 #include <linux/pm_runtime.h>
11 #include <linux/regmap.h>
12 #include <linux/delay.h>
13 
14 #include <linux/iio/buffer.h>
15 #include <linux/iio/common/inv_sensors_timestamp.h>
16 #include <linux/iio/iio.h>
17 
18 #include "inv_icm42600.h"
19 #include "inv_icm42600_buffer.h"
20 
21 /* FIFO header: 1 byte */
22 #define INV_ICM42600_FIFO_HEADER_MSG		BIT(7)
23 #define INV_ICM42600_FIFO_HEADER_ACCEL		BIT(6)
24 #define INV_ICM42600_FIFO_HEADER_GYRO		BIT(5)
25 #define INV_ICM42600_FIFO_HEADER_TMST_FSYNC	GENMASK(3, 2)
26 #define INV_ICM42600_FIFO_HEADER_ODR_ACCEL	BIT(1)
27 #define INV_ICM42600_FIFO_HEADER_ODR_GYRO	BIT(0)
28 
29 struct inv_icm42600_fifo_1sensor_packet {
30 	u8 header;
31 	struct inv_icm42600_fifo_sensor_data data;
32 	s8 temp;
33 } __packed;
34 #define INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE		8
35 
36 struct inv_icm42600_fifo_2sensors_packet {
37 	u8 header;
38 	struct inv_icm42600_fifo_sensor_data accel;
39 	struct inv_icm42600_fifo_sensor_data gyro;
40 	s8 temp;
41 	__be16 timestamp;
42 } __packed;
43 #define INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE		16
44 
inv_icm42600_fifo_decode_packet(const void * packet,const void ** accel,const void ** gyro,const s8 ** temp,const void ** timestamp,unsigned int * odr)45 ssize_t inv_icm42600_fifo_decode_packet(const void *packet, const void **accel,
46 					const void **gyro, const s8 **temp,
47 					const void **timestamp, unsigned int *odr)
48 {
49 	const struct inv_icm42600_fifo_1sensor_packet *pack1 = packet;
50 	const struct inv_icm42600_fifo_2sensors_packet *pack2 = packet;
51 	u8 header = *((const u8 *)packet);
52 
53 	/* FIFO empty */
54 	if (header & INV_ICM42600_FIFO_HEADER_MSG) {
55 		*accel = NULL;
56 		*gyro = NULL;
57 		*temp = NULL;
58 		*timestamp = NULL;
59 		*odr = 0;
60 		return 0;
61 	}
62 
63 	/* handle odr flags */
64 	*odr = 0;
65 	if (header & INV_ICM42600_FIFO_HEADER_ODR_GYRO)
66 		*odr |= INV_ICM42600_SENSOR_GYRO;
67 	if (header & INV_ICM42600_FIFO_HEADER_ODR_ACCEL)
68 		*odr |= INV_ICM42600_SENSOR_ACCEL;
69 
70 	/* accel + gyro */
71 	if ((header & INV_ICM42600_FIFO_HEADER_ACCEL) &&
72 	    (header & INV_ICM42600_FIFO_HEADER_GYRO)) {
73 		*accel = &pack2->accel;
74 		*gyro = &pack2->gyro;
75 		*temp = &pack2->temp;
76 		*timestamp = &pack2->timestamp;
77 		return INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE;
78 	}
79 
80 	/* accel only */
81 	if (header & INV_ICM42600_FIFO_HEADER_ACCEL) {
82 		*accel = &pack1->data;
83 		*gyro = NULL;
84 		*temp = &pack1->temp;
85 		*timestamp = NULL;
86 		return INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
87 	}
88 
89 	/* gyro only */
90 	if (header & INV_ICM42600_FIFO_HEADER_GYRO) {
91 		*accel = NULL;
92 		*gyro = &pack1->data;
93 		*temp = &pack1->temp;
94 		*timestamp = NULL;
95 		return INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
96 	}
97 
98 	/* invalid packet if here */
99 	return -EINVAL;
100 }
101 
inv_icm42600_buffer_update_fifo_period(struct inv_icm42600_state * st)102 void inv_icm42600_buffer_update_fifo_period(struct inv_icm42600_state *st)
103 {
104 	u32 period_gyro, period_accel;
105 
106 	if (st->fifo.en & INV_ICM42600_SENSOR_GYRO)
107 		period_gyro = inv_icm42600_odr_to_period(st->conf.gyro.odr);
108 	else
109 		period_gyro = U32_MAX;
110 
111 	if (st->fifo.en & INV_ICM42600_SENSOR_ACCEL)
112 		period_accel = inv_icm42600_odr_to_period(st->conf.accel.odr);
113 	else
114 		period_accel = U32_MAX;
115 
116 	st->fifo.period = min(period_gyro, period_accel);
117 }
118 
inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state * st,unsigned int fifo_en)119 int inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state *st,
120 				    unsigned int fifo_en)
121 {
122 	unsigned int mask, val;
123 	int ret;
124 
125 	/* update only FIFO EN bits */
126 	mask = INV_ICM42600_FIFO_CONFIG1_TMST_FSYNC_EN |
127 		INV_ICM42600_FIFO_CONFIG1_TEMP_EN |
128 		INV_ICM42600_FIFO_CONFIG1_GYRO_EN |
129 		INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
130 
131 	val = 0;
132 	if (fifo_en & INV_ICM42600_SENSOR_GYRO)
133 		val |= INV_ICM42600_FIFO_CONFIG1_GYRO_EN;
134 	if (fifo_en & INV_ICM42600_SENSOR_ACCEL)
135 		val |= INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
136 	if (fifo_en & INV_ICM42600_SENSOR_TEMP)
137 		val |= INV_ICM42600_FIFO_CONFIG1_TEMP_EN;
138 
139 	ret = regmap_update_bits(st->map, INV_ICM42600_REG_FIFO_CONFIG1, mask, val);
140 	if (ret)
141 		return ret;
142 
143 	st->fifo.en = fifo_en;
144 	inv_icm42600_buffer_update_fifo_period(st);
145 
146 	return 0;
147 }
148 
inv_icm42600_get_packet_size(unsigned int fifo_en)149 static size_t inv_icm42600_get_packet_size(unsigned int fifo_en)
150 {
151 	size_t packet_size;
152 
153 	if ((fifo_en & INV_ICM42600_SENSOR_GYRO) &&
154 	    (fifo_en & INV_ICM42600_SENSOR_ACCEL))
155 		packet_size = INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE;
156 	else
157 		packet_size = INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
158 
159 	return packet_size;
160 }
161 
inv_icm42600_wm_truncate(unsigned int watermark,size_t packet_size)162 static unsigned int inv_icm42600_wm_truncate(unsigned int watermark,
163 					     size_t packet_size)
164 {
165 	size_t wm_size;
166 	unsigned int wm;
167 
168 	wm_size = watermark * packet_size;
169 	if (wm_size > INV_ICM42600_FIFO_WATERMARK_MAX)
170 		wm_size = INV_ICM42600_FIFO_WATERMARK_MAX;
171 
172 	wm = wm_size / packet_size;
173 
174 	return wm;
175 }
176 
177 /**
178  * inv_icm42600_buffer_update_watermark - update watermark FIFO threshold
179  * @st:	driver internal state
180  *
181  * Returns 0 on success, a negative error code otherwise.
182  *
183  * FIFO watermark threshold is computed based on the required watermark values
184  * set for gyro and accel sensors. Since watermark is all about acceptable data
185  * latency, use the smallest setting between the 2. It means choosing the
186  * smallest latency but this is not as simple as choosing the smallest watermark
187  * value. Latency depends on watermark and ODR. It requires several steps:
188  * 1) compute gyro and accel latencies and choose the smallest value.
189  * 2) adapt the choosen latency so that it is a multiple of both gyro and accel
190  *    ones. Otherwise it is possible that you don't meet a requirement. (for
191  *    example with gyro @100Hz wm 4 and accel @100Hz with wm 6, choosing the
192  *    value of 4 will not meet accel latency requirement because 6 is not a
193  *    multiple of 4. You need to use the value 2.)
194  * 3) Since all periods are multiple of each others, watermark is computed by
195  *    dividing this computed latency by the smallest period, which corresponds
196  *    to the FIFO frequency. Beware that this is only true because we are not
197  *    using 500Hz frequency which is not a multiple of the others.
198  */
inv_icm42600_buffer_update_watermark(struct inv_icm42600_state * st)199 int inv_icm42600_buffer_update_watermark(struct inv_icm42600_state *st)
200 {
201 	size_t packet_size, wm_size;
202 	unsigned int wm_gyro, wm_accel, watermark;
203 	u32 period_gyro, period_accel;
204 	u32 latency_gyro, latency_accel, latency;
205 	bool restore;
206 	__le16 raw_wm;
207 	int ret;
208 
209 	packet_size = inv_icm42600_get_packet_size(st->fifo.en);
210 
211 	/* compute sensors latency, depending on sensor watermark and odr */
212 	wm_gyro = inv_icm42600_wm_truncate(st->fifo.watermark.gyro, packet_size);
213 	wm_accel = inv_icm42600_wm_truncate(st->fifo.watermark.accel, packet_size);
214 	/* use us for odr to avoid overflow using 32 bits values */
215 	period_gyro = inv_icm42600_odr_to_period(st->conf.gyro.odr) / 1000UL;
216 	period_accel = inv_icm42600_odr_to_period(st->conf.accel.odr) / 1000UL;
217 	latency_gyro = period_gyro * wm_gyro;
218 	latency_accel = period_accel * wm_accel;
219 
220 	/* 0 value for watermark means that the sensor is turned off */
221 	if (wm_gyro == 0 && wm_accel == 0)
222 		return 0;
223 
224 	if (latency_gyro == 0) {
225 		watermark = wm_accel;
226 		st->fifo.watermark.eff_accel = wm_accel;
227 	} else if (latency_accel == 0) {
228 		watermark = wm_gyro;
229 		st->fifo.watermark.eff_gyro = wm_gyro;
230 	} else {
231 		/* compute the smallest latency that is a multiple of both */
232 		if (latency_gyro <= latency_accel)
233 			latency = latency_gyro - (latency_accel % latency_gyro);
234 		else
235 			latency = latency_accel - (latency_gyro % latency_accel);
236 		/* all this works because periods are multiple of each others */
237 		watermark = latency / min(period_gyro, period_accel);
238 		if (watermark < 1)
239 			watermark = 1;
240 		/* update effective watermark */
241 		st->fifo.watermark.eff_gyro = latency / period_gyro;
242 		if (st->fifo.watermark.eff_gyro < 1)
243 			st->fifo.watermark.eff_gyro = 1;
244 		st->fifo.watermark.eff_accel = latency / period_accel;
245 		if (st->fifo.watermark.eff_accel < 1)
246 			st->fifo.watermark.eff_accel = 1;
247 	}
248 
249 	/* compute watermark value in bytes */
250 	wm_size = watermark * packet_size;
251 
252 	/* changing FIFO watermark requires to turn off watermark interrupt */
253 	ret = regmap_update_bits_check(st->map, INV_ICM42600_REG_INT_SOURCE0,
254 				       INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN,
255 				       0, &restore);
256 	if (ret)
257 		return ret;
258 
259 	raw_wm = INV_ICM42600_FIFO_WATERMARK_VAL(wm_size);
260 	memcpy(st->buffer, &raw_wm, sizeof(raw_wm));
261 	ret = regmap_bulk_write(st->map, INV_ICM42600_REG_FIFO_WATERMARK,
262 				st->buffer, sizeof(raw_wm));
263 	if (ret)
264 		return ret;
265 
266 	/* restore watermark interrupt */
267 	if (restore) {
268 		ret = regmap_set_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
269 				      INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN);
270 		if (ret)
271 			return ret;
272 	}
273 
274 	return 0;
275 }
276 
inv_icm42600_buffer_preenable(struct iio_dev * indio_dev)277 static int inv_icm42600_buffer_preenable(struct iio_dev *indio_dev)
278 {
279 	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
280 	struct device *dev = regmap_get_device(st->map);
281 	struct inv_icm42600_sensor_state *sensor_st = iio_priv(indio_dev);
282 	struct inv_sensors_timestamp *ts = &sensor_st->ts;
283 
284 	pm_runtime_get_sync(dev);
285 
286 	guard(mutex)(&st->lock);
287 	inv_sensors_timestamp_reset(ts);
288 
289 	return 0;
290 }
291 
292 /*
293  * update_scan_mode callback is turning sensors on and setting data FIFO enable
294  * bits.
295  */
inv_icm42600_buffer_postenable(struct iio_dev * indio_dev)296 static int inv_icm42600_buffer_postenable(struct iio_dev *indio_dev)
297 {
298 	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
299 	int ret;
300 
301 	guard(mutex)(&st->lock);
302 
303 	if (st->fifo.on) {
304 		st->fifo.on++;
305 		return 0;
306 	}
307 
308 	/* set FIFO threshold interrupt */
309 	ret = regmap_set_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
310 			      INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN);
311 	if (ret)
312 		return ret;
313 
314 	/* flush FIFO data */
315 	ret = regmap_write(st->map, INV_ICM42600_REG_SIGNAL_PATH_RESET,
316 			   INV_ICM42600_SIGNAL_PATH_RESET_FIFO_FLUSH);
317 	if (ret)
318 		return ret;
319 
320 	/* set FIFO in streaming mode */
321 	ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,
322 			   INV_ICM42600_FIFO_CONFIG_STREAM);
323 	if (ret)
324 		return ret;
325 
326 	/* workaround: first read of FIFO count after reset is always 0 */
327 	ret = regmap_bulk_read(st->map, INV_ICM42600_REG_FIFO_COUNT, st->buffer, 2);
328 	if (ret)
329 		return ret;
330 
331 	st->fifo.on++;
332 
333 	return 0;
334 }
335 
inv_icm42600_buffer_predisable(struct iio_dev * indio_dev)336 static int inv_icm42600_buffer_predisable(struct iio_dev *indio_dev)
337 {
338 	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
339 	int ret;
340 
341 	guard(mutex)(&st->lock);
342 
343 	if (st->fifo.on > 1) {
344 		st->fifo.on--;
345 		return 0;
346 	}
347 
348 	/* set FIFO in bypass mode */
349 	ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,
350 			   INV_ICM42600_FIFO_CONFIG_BYPASS);
351 	if (ret)
352 		return ret;
353 
354 	/* flush FIFO data */
355 	ret = regmap_write(st->map, INV_ICM42600_REG_SIGNAL_PATH_RESET,
356 			   INV_ICM42600_SIGNAL_PATH_RESET_FIFO_FLUSH);
357 	if (ret)
358 		return ret;
359 
360 	/* disable FIFO threshold interrupt */
361 	ret = regmap_clear_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
362 				INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN);
363 	if (ret)
364 		return ret;
365 
366 	st->fifo.on--;
367 
368 	return 0;
369 }
370 
inv_icm42600_buffer_postdisable(struct iio_dev * indio_dev)371 static int inv_icm42600_buffer_postdisable(struct iio_dev *indio_dev)
372 {
373 	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
374 	struct inv_icm42600_sensor_state *sensor_st = iio_priv(indio_dev);
375 	struct inv_sensors_timestamp *ts = &sensor_st->ts;
376 	struct device *dev = regmap_get_device(st->map);
377 	unsigned int sensor;
378 	unsigned int *watermark;
379 	struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
380 	unsigned int sleep_temp = 0;
381 	unsigned int sleep_sensor = 0;
382 	unsigned int sleep;
383 	int ret;
384 
385 	if (indio_dev == st->indio_gyro) {
386 		sensor = INV_ICM42600_SENSOR_GYRO;
387 		watermark = &st->fifo.watermark.gyro;
388 	} else if (indio_dev == st->indio_accel) {
389 		sensor = INV_ICM42600_SENSOR_ACCEL;
390 		watermark = &st->fifo.watermark.accel;
391 	} else {
392 		return -EINVAL;
393 	}
394 
395 	mutex_lock(&st->lock);
396 
397 	inv_sensors_timestamp_apply_odr(ts, 0, 0, 0);
398 
399 	ret = inv_icm42600_buffer_set_fifo_en(st, st->fifo.en & ~sensor);
400 	if (ret)
401 		goto out_unlock;
402 
403 	*watermark = 0;
404 	ret = inv_icm42600_buffer_update_watermark(st);
405 	if (ret)
406 		goto out_unlock;
407 
408 	conf.mode = INV_ICM42600_SENSOR_MODE_OFF;
409 	if (sensor == INV_ICM42600_SENSOR_GYRO)
410 		ret = inv_icm42600_set_gyro_conf(st, &conf, &sleep_sensor);
411 	else if (!st->apex.on)
412 		ret = inv_icm42600_set_accel_conf(st, &conf, &sleep_sensor);
413 	if (ret)
414 		goto out_unlock;
415 
416 	/* if FIFO is off, turn temperature off */
417 	if (!st->fifo.on)
418 		ret = inv_icm42600_set_temp_conf(st, false, &sleep_temp);
419 
420 out_unlock:
421 	mutex_unlock(&st->lock);
422 
423 	/* sleep maximum required time */
424 	sleep = max(sleep_sensor, sleep_temp);
425 	if (sleep)
426 		msleep(sleep);
427 
428 	pm_runtime_put_autosuspend(dev);
429 
430 	return ret;
431 }
432 
433 const struct iio_buffer_setup_ops inv_icm42600_buffer_ops = {
434 	.preenable = inv_icm42600_buffer_preenable,
435 	.postenable = inv_icm42600_buffer_postenable,
436 	.predisable = inv_icm42600_buffer_predisable,
437 	.postdisable = inv_icm42600_buffer_postdisable,
438 };
439 
inv_icm42600_buffer_fifo_read(struct inv_icm42600_state * st,unsigned int max)440 int inv_icm42600_buffer_fifo_read(struct inv_icm42600_state *st,
441 				  unsigned int max)
442 {
443 	size_t max_count;
444 	__be16 *raw_fifo_count;
445 	ssize_t i, size;
446 	const void *accel, *gyro, *timestamp;
447 	const s8 *temp;
448 	unsigned int odr;
449 	int ret;
450 
451 	/* reset all samples counters */
452 	st->fifo.count = 0;
453 	st->fifo.nb.gyro = 0;
454 	st->fifo.nb.accel = 0;
455 	st->fifo.nb.total = 0;
456 
457 	/* compute maximum FIFO read size */
458 	if (max == 0)
459 		max_count = sizeof(st->fifo.data);
460 	else
461 		max_count = max * inv_icm42600_get_packet_size(st->fifo.en);
462 
463 	/* read FIFO count value */
464 	raw_fifo_count = (__be16 *)st->buffer;
465 	ret = regmap_bulk_read(st->map, INV_ICM42600_REG_FIFO_COUNT,
466 			       raw_fifo_count, sizeof(*raw_fifo_count));
467 	if (ret)
468 		return ret;
469 	st->fifo.count = be16_to_cpup(raw_fifo_count);
470 
471 	/* check and clamp FIFO count value */
472 	if (st->fifo.count == 0)
473 		return 0;
474 	if (st->fifo.count > max_count)
475 		st->fifo.count = max_count;
476 
477 	/* read all FIFO data in internal buffer */
478 	ret = regmap_noinc_read(st->map, INV_ICM42600_REG_FIFO_DATA,
479 				st->fifo.data, st->fifo.count);
480 	if (ret)
481 		return ret;
482 
483 	/* compute number of samples for each sensor */
484 	for (i = 0; i < st->fifo.count; i += size) {
485 		size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],
486 				&accel, &gyro, &temp, &timestamp, &odr);
487 		if (size <= 0)
488 			break;
489 		if (gyro != NULL && inv_icm42600_fifo_is_data_valid(gyro))
490 			st->fifo.nb.gyro++;
491 		if (accel != NULL && inv_icm42600_fifo_is_data_valid(accel))
492 			st->fifo.nb.accel++;
493 		st->fifo.nb.total++;
494 	}
495 
496 	return 0;
497 }
498 
inv_icm42600_buffer_fifo_parse(struct inv_icm42600_state * st)499 int inv_icm42600_buffer_fifo_parse(struct inv_icm42600_state *st)
500 {
501 	struct inv_icm42600_sensor_state *gyro_st = iio_priv(st->indio_gyro);
502 	struct inv_icm42600_sensor_state *accel_st = iio_priv(st->indio_accel);
503 	struct inv_sensors_timestamp *ts;
504 	int ret;
505 
506 	if (st->fifo.nb.total == 0)
507 		return 0;
508 
509 	/* handle gyroscope timestamp and FIFO data parsing */
510 	if (st->fifo.nb.gyro > 0) {
511 		ts = &gyro_st->ts;
512 		inv_sensors_timestamp_interrupt(ts, st->fifo.watermark.eff_gyro,
513 						st->timestamp.gyro);
514 		ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro);
515 		if (ret)
516 			return ret;
517 	}
518 
519 	/* handle accelerometer timestamp and FIFO data parsing */
520 	if (st->fifo.nb.accel > 0) {
521 		ts = &accel_st->ts;
522 		inv_sensors_timestamp_interrupt(ts, st->fifo.watermark.eff_accel,
523 						st->timestamp.accel);
524 		ret = inv_icm42600_accel_parse_fifo(st->indio_accel);
525 		if (ret)
526 			return ret;
527 	}
528 
529 	return 0;
530 }
531 
inv_icm42600_buffer_hwfifo_flush(struct inv_icm42600_state * st,unsigned int count)532 int inv_icm42600_buffer_hwfifo_flush(struct inv_icm42600_state *st,
533 				     unsigned int count)
534 {
535 	struct inv_icm42600_sensor_state *gyro_st = iio_priv(st->indio_gyro);
536 	struct inv_icm42600_sensor_state *accel_st = iio_priv(st->indio_accel);
537 	struct inv_sensors_timestamp *ts;
538 	s64 gyro_ts, accel_ts;
539 	int ret;
540 
541 	gyro_ts = iio_get_time_ns(st->indio_gyro);
542 	accel_ts = iio_get_time_ns(st->indio_accel);
543 
544 	ret = inv_icm42600_buffer_fifo_read(st, count);
545 	if (ret)
546 		return ret;
547 
548 	if (st->fifo.nb.total == 0)
549 		return 0;
550 
551 	if (st->fifo.nb.gyro > 0) {
552 		ts = &gyro_st->ts;
553 		inv_sensors_timestamp_interrupt(ts, st->fifo.nb.gyro, gyro_ts);
554 		ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro);
555 		if (ret)
556 			return ret;
557 	}
558 
559 	if (st->fifo.nb.accel > 0) {
560 		ts = &accel_st->ts;
561 		inv_sensors_timestamp_interrupt(ts, st->fifo.nb.accel, accel_ts);
562 		ret = inv_icm42600_accel_parse_fifo(st->indio_accel);
563 		if (ret)
564 			return ret;
565 	}
566 
567 	return 0;
568 }
569 
inv_icm42600_buffer_init(struct inv_icm42600_state * st)570 int inv_icm42600_buffer_init(struct inv_icm42600_state *st)
571 {
572 	unsigned int val;
573 	int ret;
574 
575 	st->fifo.watermark.eff_gyro = 1;
576 	st->fifo.watermark.eff_accel = 1;
577 
578 	/*
579 	 * Default FIFO configuration (bits 7 to 5)
580 	 * - use invalid value
581 	 * - FIFO count in bytes
582 	 * - FIFO count in big endian
583 	 */
584 	val = INV_ICM42600_INTF_CONFIG0_FIFO_COUNT_ENDIAN;
585 	ret = regmap_update_bits(st->map, INV_ICM42600_REG_INTF_CONFIG0,
586 				 GENMASK(7, 5), val);
587 	if (ret)
588 		return ret;
589 
590 	/*
591 	 * Enable FIFO partial read and continuous watermark interrupt.
592 	 * Disable all FIFO EN bits.
593 	 */
594 	val = INV_ICM42600_FIFO_CONFIG1_RESUME_PARTIAL_RD |
595 	      INV_ICM42600_FIFO_CONFIG1_WM_GT_TH;
596 	return regmap_update_bits(st->map, INV_ICM42600_REG_FIFO_CONFIG1,
597 				  GENMASK(6, 5) | GENMASK(3, 0), val);
598 }
599