1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * STMicroelectronics st_lsm6dsx FIFO buffer library driver
4 *
5 * Pattern FIFO:
6 * The FIFO buffer can be configured to store data from gyroscope and
7 * accelerometer. Samples are queued without any tag according to a
8 * specific pattern based on 'FIFO data sets' (6 bytes each):
9 * - 1st data set is reserved for gyroscope data
10 * - 2nd data set is reserved for accelerometer data
11 * The FIFO pattern changes depending on the ODRs and decimation factors
12 * assigned to the FIFO data sets. The first sequence of data stored in FIFO
13 * buffer contains the data of all the enabled FIFO data sets
14 * (e.g. Gx, Gy, Gz, Ax, Ay, Az), then data are repeated depending on the
15 * value of the decimation factor and ODR set for each FIFO data set.
16 *
17 * Supported devices:
18 * - ISM330DLC
19 * - LSM6DS3
20 * - LSM6DS3H
21 * - LSM6DS3TR-C
22 * - LSM6DSL
23 * - LSM6DSM
24 *
25 * Tagged FIFO:
26 * The FIFO buffer can be configured to store data from gyroscope and
27 * accelerometer. Each sample is queued with a tag (1B) indicating data
28 * source (gyroscope, accelerometer, hw timer).
29 *
30 * Supported devices:
31 * - ASM330LHB
32 * - ASM330LHH
33 * - ASM330LHHX
34 * - ASM330LHHXG1
35 * - ISM330DHCX
36 * - LSM6DSO
37 * - LSM6DSOP
38 * - LSM6DSOX
39 * - LSM6DSR
40 * - LSM6DSRX
41 * - LSM6DST
42 * - LSM6DSTX
43 * - LSM6DSV
44 *
45 * FIFO supported modes:
46 * - BYPASS: FIFO disabled
47 * - CONTINUOUS: FIFO enabled. When the buffer is full, the FIFO index
48 * restarts from the beginning and the oldest sample is overwritten
49 *
50 * Copyright 2016 STMicroelectronics Inc.
51 *
52 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
53 * Denis Ciocca <denis.ciocca@st.com>
54 */
55 #include <linux/module.h>
56 #include <linux/iio/kfifo_buf.h>
57 #include <linux/iio/iio.h>
58 #include <linux/iio/buffer.h>
59 #include <linux/regmap.h>
60 #include <linux/bitfield.h>
61
62 #include <linux/platform_data/st_sensors_pdata.h>
63
64 #include "st_lsm6dsx.h"
65
66 #define ST_LSM6DSX_REG_FIFO_MODE_ADDR 0x0a
67 #define ST_LSM6DSX_FIFO_MODE_MASK GENMASK(2, 0)
68 #define ST_LSM6DSX_FIFO_ODR_MASK GENMASK(6, 3)
69 #define ST_LSM6DSX_FIFO_EMPTY_MASK BIT(12)
70 #define ST_LSM6DSX_REG_FIFO_OUTL_ADDR 0x3e
71 #define ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR 0x78
72 #define ST_LSM6DSX_REG_TS_RESET_ADDR 0x42
73
74 #define ST_LSM6DSX_MAX_FIFO_ODR_VAL 0x08
75
76 #define ST_LSM6DSX_TS_RESET_VAL 0xaa
77
78 struct st_lsm6dsx_decimator_entry {
79 u8 decimator;
80 u8 val;
81 };
82
83 enum st_lsm6dsx_fifo_tag {
84 ST_LSM6DSX_GYRO_TAG = 0x01,
85 ST_LSM6DSX_ACC_TAG = 0x02,
86 ST_LSM6DSX_TS_TAG = 0x04,
87 ST_LSM6DSX_EXT0_TAG = 0x0f,
88 ST_LSM6DSX_EXT1_TAG = 0x10,
89 ST_LSM6DSX_EXT2_TAG = 0x11,
90 };
91
92 static const
93 struct st_lsm6dsx_decimator_entry st_lsm6dsx_decimator_table[] = {
94 { 0, 0x0 },
95 { 1, 0x1 },
96 { 2, 0x2 },
97 { 3, 0x3 },
98 { 4, 0x4 },
99 { 8, 0x5 },
100 { 16, 0x6 },
101 { 32, 0x7 },
102 };
103
104 static int
st_lsm6dsx_get_decimator_val(struct st_lsm6dsx_sensor * sensor,u32 max_odr)105 st_lsm6dsx_get_decimator_val(struct st_lsm6dsx_sensor *sensor, u32 max_odr)
106 {
107 const int max_size = ARRAY_SIZE(st_lsm6dsx_decimator_table);
108 u32 decimator = max_odr / sensor->odr;
109 int i;
110
111 if (decimator > 1)
112 decimator = round_down(decimator, 2);
113
114 for (i = 0; i < max_size; i++) {
115 if (st_lsm6dsx_decimator_table[i].decimator == decimator)
116 break;
117 }
118
119 sensor->decimator = decimator;
120 return i == max_size ? 0 : st_lsm6dsx_decimator_table[i].val;
121 }
122
st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw * hw,u32 * max_odr,u32 * min_odr)123 static void st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw *hw,
124 u32 *max_odr, u32 *min_odr)
125 {
126 struct st_lsm6dsx_sensor *sensor;
127 int i;
128
129 *max_odr = 0, *min_odr = ~0;
130 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
131 if (!hw->iio_devs[i])
132 continue;
133
134 sensor = iio_priv(hw->iio_devs[i]);
135
136 if (!(hw->enable_mask & BIT(sensor->id)))
137 continue;
138
139 *max_odr = max_t(u32, *max_odr, sensor->odr);
140 *min_odr = min_t(u32, *min_odr, sensor->odr);
141 }
142 }
143
st_lsm6dsx_get_sip(struct st_lsm6dsx_sensor * sensor,u32 min_odr)144 static u8 st_lsm6dsx_get_sip(struct st_lsm6dsx_sensor *sensor, u32 min_odr)
145 {
146 u8 sip = sensor->odr / min_odr;
147
148 return sip > 1 ? round_down(sip, 2) : sip;
149 }
150
st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw * hw)151 static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw)
152 {
153 const struct st_lsm6dsx_reg *ts_dec_reg;
154 struct st_lsm6dsx_sensor *sensor;
155 u16 sip = 0, ts_sip = 0;
156 u32 max_odr, min_odr;
157 int err = 0, i;
158 u8 data;
159
160 st_lsm6dsx_get_max_min_odr(hw, &max_odr, &min_odr);
161
162 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
163 const struct st_lsm6dsx_reg *dec_reg;
164
165 if (!hw->iio_devs[i])
166 continue;
167
168 sensor = iio_priv(hw->iio_devs[i]);
169 /* update fifo decimators and sample in pattern */
170 if (hw->enable_mask & BIT(sensor->id)) {
171 sensor->sip = st_lsm6dsx_get_sip(sensor, min_odr);
172 data = st_lsm6dsx_get_decimator_val(sensor, max_odr);
173 } else {
174 sensor->sip = 0;
175 data = 0;
176 }
177 ts_sip = max_t(u16, ts_sip, sensor->sip);
178
179 dec_reg = &hw->settings->decimator[sensor->id];
180 if (dec_reg->addr) {
181 int val = ST_LSM6DSX_SHIFT_VAL(data, dec_reg->mask);
182
183 err = st_lsm6dsx_update_bits_locked(hw, dec_reg->addr,
184 dec_reg->mask,
185 val);
186 if (err < 0)
187 return err;
188 }
189 sip += sensor->sip;
190 }
191 hw->sip = sip + ts_sip;
192 hw->ts_sip = ts_sip;
193
194 /*
195 * update hw ts decimator if necessary. Decimator for hw timestamp
196 * is always 1 or 0 in order to have a ts sample for each data
197 * sample in FIFO
198 */
199 ts_dec_reg = &hw->settings->ts_settings.decimator;
200 if (ts_dec_reg->addr) {
201 int val, ts_dec = !!hw->ts_sip;
202
203 val = ST_LSM6DSX_SHIFT_VAL(ts_dec, ts_dec_reg->mask);
204 err = st_lsm6dsx_update_bits_locked(hw, ts_dec_reg->addr,
205 ts_dec_reg->mask, val);
206 }
207 return err;
208 }
209
st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw * hw,enum st_lsm6dsx_fifo_mode fifo_mode)210 static int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
211 enum st_lsm6dsx_fifo_mode fifo_mode)
212 {
213 unsigned int data;
214
215 data = FIELD_PREP(ST_LSM6DSX_FIFO_MODE_MASK, fifo_mode);
216 return st_lsm6dsx_update_bits_locked(hw, ST_LSM6DSX_REG_FIFO_MODE_ADDR,
217 ST_LSM6DSX_FIFO_MODE_MASK, data);
218 }
219
st_lsm6dsx_set_fifo_odr(struct st_lsm6dsx_sensor * sensor,bool enable)220 static int st_lsm6dsx_set_fifo_odr(struct st_lsm6dsx_sensor *sensor,
221 bool enable)
222 {
223 struct st_lsm6dsx_hw *hw = sensor->hw;
224 const struct st_lsm6dsx_reg *batch_reg;
225 u8 data;
226
227 batch_reg = &hw->settings->batch[sensor->id];
228 if (batch_reg->addr) {
229 int val;
230
231 if (enable) {
232 int err;
233
234 err = st_lsm6dsx_check_odr(sensor, sensor->odr,
235 &data);
236 if (err < 0)
237 return err;
238 } else {
239 data = 0;
240 }
241 val = ST_LSM6DSX_SHIFT_VAL(data, batch_reg->mask);
242 return st_lsm6dsx_update_bits_locked(hw, batch_reg->addr,
243 batch_reg->mask, val);
244 } else {
245 data = hw->enable_mask ? ST_LSM6DSX_MAX_FIFO_ODR_VAL : 0;
246 return st_lsm6dsx_update_bits_locked(hw,
247 ST_LSM6DSX_REG_FIFO_MODE_ADDR,
248 ST_LSM6DSX_FIFO_ODR_MASK,
249 FIELD_PREP(ST_LSM6DSX_FIFO_ODR_MASK,
250 data));
251 }
252 }
253
st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor * sensor,u16 watermark)254 int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor, u16 watermark)
255 {
256 u16 fifo_watermark = ~0, cur_watermark, fifo_th_mask;
257 struct st_lsm6dsx_hw *hw = sensor->hw;
258 struct st_lsm6dsx_sensor *cur_sensor;
259 int i, err, data;
260 __le16 wdata;
261
262 if (!hw->sip)
263 return 0;
264
265 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
266 if (!hw->iio_devs[i])
267 continue;
268
269 cur_sensor = iio_priv(hw->iio_devs[i]);
270
271 if (!(hw->enable_mask & BIT(cur_sensor->id)))
272 continue;
273
274 cur_watermark = (cur_sensor == sensor) ? watermark
275 : cur_sensor->watermark;
276
277 fifo_watermark = min_t(u16, fifo_watermark, cur_watermark);
278 }
279
280 fifo_watermark = max_t(u16, fifo_watermark, hw->sip);
281 fifo_watermark = (fifo_watermark / hw->sip) * hw->sip;
282 fifo_watermark = fifo_watermark * hw->settings->fifo_ops.th_wl;
283
284 mutex_lock(&hw->page_lock);
285 err = regmap_read(hw->regmap, hw->settings->fifo_ops.fifo_th.addr + 1,
286 &data);
287 if (err < 0)
288 goto out;
289
290 fifo_th_mask = hw->settings->fifo_ops.fifo_th.mask;
291 fifo_watermark = ((data << 8) & ~fifo_th_mask) |
292 (fifo_watermark & fifo_th_mask);
293
294 wdata = cpu_to_le16(fifo_watermark);
295 err = regmap_bulk_write(hw->regmap,
296 hw->settings->fifo_ops.fifo_th.addr,
297 &wdata, sizeof(wdata));
298 out:
299 mutex_unlock(&hw->page_lock);
300 return err;
301 }
302
st_lsm6dsx_reset_hw_ts(struct st_lsm6dsx_hw * hw)303 static int st_lsm6dsx_reset_hw_ts(struct st_lsm6dsx_hw *hw)
304 {
305 struct st_lsm6dsx_sensor *sensor;
306 int i, err;
307
308 /* reset hw ts counter */
309 err = st_lsm6dsx_write_locked(hw, ST_LSM6DSX_REG_TS_RESET_ADDR,
310 ST_LSM6DSX_TS_RESET_VAL);
311 if (err < 0)
312 return err;
313
314 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
315 if (!hw->iio_devs[i])
316 continue;
317
318 sensor = iio_priv(hw->iio_devs[i]);
319 /*
320 * store enable buffer timestamp as reference for
321 * hw timestamp
322 */
323 sensor->ts_ref = iio_get_time_ns(hw->iio_devs[i]);
324 }
325 return 0;
326 }
327
st_lsm6dsx_resume_fifo(struct st_lsm6dsx_hw * hw)328 int st_lsm6dsx_resume_fifo(struct st_lsm6dsx_hw *hw)
329 {
330 int err;
331
332 /* reset hw ts counter */
333 err = st_lsm6dsx_reset_hw_ts(hw);
334 if (err < 0)
335 return err;
336
337 return st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
338 }
339
340 /*
341 * Set max bulk read to ST_LSM6DSX_MAX_WORD_LEN/ST_LSM6DSX_MAX_TAGGED_WORD_LEN
342 * in order to avoid a kmalloc for each bus access
343 */
st_lsm6dsx_read_block(struct st_lsm6dsx_hw * hw,u8 addr,u8 * data,unsigned int data_len,unsigned int max_word_len)344 static inline int st_lsm6dsx_read_block(struct st_lsm6dsx_hw *hw, u8 addr,
345 u8 *data, unsigned int data_len,
346 unsigned int max_word_len)
347 {
348 unsigned int word_len, read_len = 0;
349 int err;
350
351 while (read_len < data_len) {
352 word_len = min_t(unsigned int, data_len - read_len,
353 max_word_len);
354 err = st_lsm6dsx_read_locked(hw, addr, data + read_len,
355 word_len);
356 if (err < 0)
357 return err;
358 read_len += word_len;
359 }
360 return 0;
361 }
362
363 #define ST_LSM6DSX_IIO_BUFF_SIZE (ALIGN(ST_LSM6DSX_SAMPLE_SIZE, \
364 sizeof(s64)) + sizeof(s64))
365 /**
366 * st_lsm6dsx_read_fifo() - hw FIFO read routine
367 * @hw: Pointer to instance of struct st_lsm6dsx_hw.
368 *
369 * Read samples from the hw FIFO and push them to IIO buffers.
370 *
371 * Return: Number of bytes read from the FIFO
372 */
st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw * hw)373 int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
374 {
375 struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor, *ext_sensor = NULL;
376 int err, sip, acc_sip, gyro_sip, ts_sip, ext_sip, read_len, offset;
377 u16 fifo_len, pattern_len = hw->sip * ST_LSM6DSX_SAMPLE_SIZE;
378 u16 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
379 bool reset_ts = false;
380 __le16 fifo_status;
381 s64 ts = 0;
382
383 err = st_lsm6dsx_read_locked(hw,
384 hw->settings->fifo_ops.fifo_diff.addr,
385 &fifo_status, sizeof(fifo_status));
386 if (err < 0) {
387 dev_err(hw->dev, "failed to read fifo status (err=%d)\n",
388 err);
389 return err;
390 }
391
392 if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
393 return 0;
394
395 if (!pattern_len)
396 pattern_len = ST_LSM6DSX_SAMPLE_SIZE;
397
398 fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
399 ST_LSM6DSX_CHAN_SIZE;
400 fifo_len = (fifo_len / pattern_len) * pattern_len;
401
402 acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
403 gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]);
404 if (hw->iio_devs[ST_LSM6DSX_ID_EXT0])
405 ext_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_EXT0]);
406
407 for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
408 err = st_lsm6dsx_read_block(hw, ST_LSM6DSX_REG_FIFO_OUTL_ADDR,
409 hw->buff, pattern_len,
410 ST_LSM6DSX_MAX_WORD_LEN);
411 if (err < 0) {
412 dev_err(hw->dev,
413 "failed to read pattern from fifo (err=%d)\n",
414 err);
415 return err;
416 }
417
418 /*
419 * Data are written to the FIFO with a specific pattern
420 * depending on the configured ODRs. The first sequence of data
421 * stored in FIFO contains the data of all enabled sensors
422 * (e.g. Gx, Gy, Gz, Ax, Ay, Az, Ts), then data are repeated
423 * depending on the value of the decimation factor set for each
424 * sensor.
425 *
426 * Supposing the FIFO is storing data from gyroscope and
427 * accelerometer at different ODRs:
428 * - gyroscope ODR = 208Hz, accelerometer ODR = 104Hz
429 * Since the gyroscope ODR is twice the accelerometer one, the
430 * following pattern is repeated every 9 samples:
431 * - Gx, Gy, Gz, Ax, Ay, Az, Ts, Gx, Gy, Gz, Ts, Gx, ..
432 */
433 ext_sip = ext_sensor ? ext_sensor->sip : 0;
434 gyro_sip = gyro_sensor->sip;
435 acc_sip = acc_sensor->sip;
436 ts_sip = hw->ts_sip;
437 offset = 0;
438 sip = 0;
439
440 while (acc_sip > 0 || gyro_sip > 0 || ext_sip > 0) {
441 if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
442 memcpy(hw->scan[ST_LSM6DSX_ID_GYRO].channels,
443 &hw->buff[offset],
444 sizeof(hw->scan[ST_LSM6DSX_ID_GYRO].channels));
445 offset += sizeof(hw->scan[ST_LSM6DSX_ID_GYRO].channels);
446 }
447 if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
448 memcpy(hw->scan[ST_LSM6DSX_ID_ACC].channels,
449 &hw->buff[offset],
450 sizeof(hw->scan[ST_LSM6DSX_ID_ACC].channels));
451 offset += sizeof(hw->scan[ST_LSM6DSX_ID_ACC].channels);
452 }
453 if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
454 memcpy(hw->scan[ST_LSM6DSX_ID_EXT0].channels,
455 &hw->buff[offset],
456 sizeof(hw->scan[ST_LSM6DSX_ID_EXT0].channels));
457 offset += sizeof(hw->scan[ST_LSM6DSX_ID_EXT0].channels);
458 }
459
460 if (ts_sip-- > 0) {
461 u8 data[ST_LSM6DSX_SAMPLE_SIZE];
462
463 memcpy(data, &hw->buff[offset], sizeof(data));
464 /*
465 * hw timestamp is 3B long and it is stored
466 * in FIFO using 6B as 4th FIFO data set
467 * according to this schema:
468 * B0 = ts[15:8], B1 = ts[23:16], B3 = ts[7:0]
469 */
470 ts = data[1] << 16 | data[0] << 8 | data[3];
471 /*
472 * check if hw timestamp engine is going to
473 * reset (the sensor generates an interrupt
474 * to signal the hw timestamp will reset in
475 * 1.638s)
476 */
477 if (!reset_ts && ts >= 0xff0000)
478 reset_ts = true;
479 ts *= hw->ts_gain;
480
481 offset += ST_LSM6DSX_SAMPLE_SIZE;
482 }
483
484 if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
485 /*
486 * We need to discards gyro samples during
487 * filters settling time
488 */
489 if (gyro_sensor->samples_to_discard > 0)
490 gyro_sensor->samples_to_discard--;
491 else
492 iio_push_to_buffers_with_timestamp(
493 hw->iio_devs[ST_LSM6DSX_ID_GYRO],
494 &hw->scan[ST_LSM6DSX_ID_GYRO],
495 gyro_sensor->ts_ref + ts);
496 gyro_sip--;
497 }
498 if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
499 /*
500 * We need to discards accel samples during
501 * filters settling time
502 */
503 if (acc_sensor->samples_to_discard > 0)
504 acc_sensor->samples_to_discard--;
505 else
506 iio_push_to_buffers_with_timestamp(
507 hw->iio_devs[ST_LSM6DSX_ID_ACC],
508 &hw->scan[ST_LSM6DSX_ID_ACC],
509 acc_sensor->ts_ref + ts);
510 acc_sip--;
511 }
512 if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
513 iio_push_to_buffers_with_timestamp(
514 hw->iio_devs[ST_LSM6DSX_ID_EXT0],
515 &hw->scan[ST_LSM6DSX_ID_EXT0],
516 ext_sensor->ts_ref + ts);
517 ext_sip--;
518 }
519 sip++;
520 }
521 }
522
523 if (unlikely(reset_ts)) {
524 err = st_lsm6dsx_reset_hw_ts(hw);
525 if (err < 0) {
526 dev_err(hw->dev, "failed to reset hw ts (err=%d)\n",
527 err);
528 return err;
529 }
530 }
531 return read_len;
532 }
533
534 #define ST_LSM6DSX_INVALID_SAMPLE 0x7ffd
535 static int
st_lsm6dsx_push_tagged_data(struct st_lsm6dsx_hw * hw,u8 tag,u8 * data,s64 ts)536 st_lsm6dsx_push_tagged_data(struct st_lsm6dsx_hw *hw, u8 tag,
537 u8 *data, s64 ts)
538 {
539 s16 val = le16_to_cpu(*(__le16 *)data);
540 struct st_lsm6dsx_sensor *sensor;
541 struct iio_dev *iio_dev;
542
543 /* invalid sample during bootstrap phase */
544 if (val >= ST_LSM6DSX_INVALID_SAMPLE)
545 return -EINVAL;
546
547 /*
548 * EXT_TAG are managed in FIFO fashion so ST_LSM6DSX_EXT0_TAG
549 * corresponds to the first enabled channel, ST_LSM6DSX_EXT1_TAG
550 * to the second one and ST_LSM6DSX_EXT2_TAG to the last enabled
551 * channel
552 */
553 switch (tag) {
554 case ST_LSM6DSX_GYRO_TAG:
555 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_GYRO];
556 break;
557 case ST_LSM6DSX_ACC_TAG:
558 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_ACC];
559 break;
560 case ST_LSM6DSX_EXT0_TAG:
561 if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0))
562 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT0];
563 else if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1))
564 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1];
565 else
566 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
567 break;
568 case ST_LSM6DSX_EXT1_TAG:
569 if ((hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0)) &&
570 (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1)))
571 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1];
572 else
573 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
574 break;
575 case ST_LSM6DSX_EXT2_TAG:
576 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
577 break;
578 default:
579 return -EINVAL;
580 }
581
582 sensor = iio_priv(iio_dev);
583 iio_push_to_buffers_with_timestamp(iio_dev, data,
584 ts + sensor->ts_ref);
585
586 return 0;
587 }
588
589 /**
590 * st_lsm6dsx_read_tagged_fifo() - tagged hw FIFO read routine
591 * @hw: Pointer to instance of struct st_lsm6dsx_hw.
592 *
593 * Read samples from the hw FIFO and push them to IIO buffers.
594 *
595 * Return: Number of bytes read from the FIFO
596 */
st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw * hw)597 int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw)
598 {
599 u16 pattern_len = hw->sip * ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
600 u16 fifo_len, fifo_diff_mask;
601 /*
602 * Alignment needed as this can ultimately be passed to a
603 * call to iio_push_to_buffers_with_timestamp() which
604 * must be passed a buffer that is aligned to 8 bytes so
605 * as to allow insertion of a naturally aligned timestamp.
606 */
607 u8 iio_buff[ST_LSM6DSX_IIO_BUFF_SIZE] __aligned(8);
608 u8 tag;
609 bool reset_ts = false;
610 int i, err, read_len;
611 __le16 fifo_status;
612 s64 ts = 0;
613
614 err = st_lsm6dsx_read_locked(hw,
615 hw->settings->fifo_ops.fifo_diff.addr,
616 &fifo_status, sizeof(fifo_status));
617 if (err < 0) {
618 dev_err(hw->dev, "failed to read fifo status (err=%d)\n",
619 err);
620 return err;
621 }
622
623 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
624 fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
625 ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
626 if (!fifo_len)
627 return 0;
628
629 if (!pattern_len)
630 pattern_len = ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
631
632 for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
633 err = st_lsm6dsx_read_block(hw,
634 ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR,
635 hw->buff, pattern_len,
636 ST_LSM6DSX_MAX_TAGGED_WORD_LEN);
637 if (err < 0) {
638 dev_err(hw->dev,
639 "failed to read pattern from fifo (err=%d)\n",
640 err);
641 return err;
642 }
643
644 for (i = 0; i < pattern_len;
645 i += ST_LSM6DSX_TAGGED_SAMPLE_SIZE) {
646 memcpy(iio_buff, &hw->buff[i + ST_LSM6DSX_TAG_SIZE],
647 ST_LSM6DSX_SAMPLE_SIZE);
648
649 tag = hw->buff[i] >> 3;
650 if (tag == ST_LSM6DSX_TS_TAG) {
651 /*
652 * hw timestamp is 4B long and it is stored
653 * in FIFO according to this schema:
654 * B0 = ts[7:0], B1 = ts[15:8], B2 = ts[23:16],
655 * B3 = ts[31:24]
656 */
657 ts = le32_to_cpu(*((__le32 *)iio_buff));
658 /*
659 * check if hw timestamp engine is going to
660 * reset (the sensor generates an interrupt
661 * to signal the hw timestamp will reset in
662 * 1.638s)
663 */
664 if (!reset_ts && ts >= 0xffff0000)
665 reset_ts = true;
666 ts *= hw->ts_gain;
667 } else {
668 st_lsm6dsx_push_tagged_data(hw, tag, iio_buff,
669 ts);
670 }
671 }
672 }
673
674 if (unlikely(reset_ts)) {
675 err = st_lsm6dsx_reset_hw_ts(hw);
676 if (err < 0)
677 return err;
678 }
679 return read_len;
680 }
681
st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw * hw)682 int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw)
683 {
684 int err;
685
686 if (!hw->settings->fifo_ops.read_fifo)
687 return -ENOTSUPP;
688
689 mutex_lock(&hw->fifo_lock);
690
691 hw->settings->fifo_ops.read_fifo(hw);
692 err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_BYPASS);
693
694 mutex_unlock(&hw->fifo_lock);
695
696 return err;
697 }
698
699 static void
st_lsm6dsx_update_samples_to_discard(struct st_lsm6dsx_sensor * sensor)700 st_lsm6dsx_update_samples_to_discard(struct st_lsm6dsx_sensor *sensor)
701 {
702 const struct st_lsm6dsx_samples_to_discard *data;
703 struct st_lsm6dsx_hw *hw = sensor->hw;
704 int i;
705
706 if (sensor->id != ST_LSM6DSX_ID_GYRO &&
707 sensor->id != ST_LSM6DSX_ID_ACC)
708 return;
709
710 /* check if drdy mask is supported in hw */
711 if (hw->settings->drdy_mask.addr)
712 return;
713
714 data = &hw->settings->samples_to_discard[sensor->id];
715 for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++) {
716 if (data->val[i].milli_hz == sensor->odr) {
717 sensor->samples_to_discard = data->val[i].samples;
718 return;
719 }
720 }
721 }
722
st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor * sensor,bool enable)723 int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable)
724 {
725 struct st_lsm6dsx_hw *hw = sensor->hw;
726 u8 fifo_mask;
727 int err;
728
729 mutex_lock(&hw->conf_lock);
730
731 if (enable)
732 fifo_mask = hw->fifo_mask | BIT(sensor->id);
733 else
734 fifo_mask = hw->fifo_mask & ~BIT(sensor->id);
735
736 if (hw->fifo_mask) {
737 err = st_lsm6dsx_flush_fifo(hw);
738 if (err < 0)
739 goto out;
740 }
741
742 if (enable)
743 st_lsm6dsx_update_samples_to_discard(sensor);
744
745 err = st_lsm6dsx_device_set_enable(sensor, enable);
746 if (err < 0)
747 goto out;
748
749 err = st_lsm6dsx_set_fifo_odr(sensor, enable);
750 if (err < 0)
751 goto out;
752
753 err = st_lsm6dsx_update_decimators(hw);
754 if (err < 0)
755 goto out;
756
757 err = st_lsm6dsx_update_watermark(sensor, sensor->watermark);
758 if (err < 0)
759 goto out;
760
761 if (fifo_mask) {
762 err = st_lsm6dsx_resume_fifo(hw);
763 if (err < 0)
764 goto out;
765 }
766
767 hw->fifo_mask = fifo_mask;
768
769 out:
770 mutex_unlock(&hw->conf_lock);
771
772 return err;
773 }
774
st_lsm6dsx_buffer_preenable(struct iio_dev * iio_dev)775 static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev)
776 {
777 struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
778 struct st_lsm6dsx_hw *hw = sensor->hw;
779
780 if (!hw->settings->fifo_ops.update_fifo)
781 return -ENOTSUPP;
782
783 return hw->settings->fifo_ops.update_fifo(sensor, true);
784 }
785
st_lsm6dsx_buffer_postdisable(struct iio_dev * iio_dev)786 static int st_lsm6dsx_buffer_postdisable(struct iio_dev *iio_dev)
787 {
788 struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
789 struct st_lsm6dsx_hw *hw = sensor->hw;
790
791 if (!hw->settings->fifo_ops.update_fifo)
792 return -ENOTSUPP;
793
794 return hw->settings->fifo_ops.update_fifo(sensor, false);
795 }
796
797 static const struct iio_buffer_setup_ops st_lsm6dsx_buffer_ops = {
798 .preenable = st_lsm6dsx_buffer_preenable,
799 .postdisable = st_lsm6dsx_buffer_postdisable,
800 };
801
st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw * hw)802 int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw)
803 {
804 int i, ret;
805
806 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
807 if (!hw->iio_devs[i])
808 continue;
809
810 ret = devm_iio_kfifo_buffer_setup(hw->dev, hw->iio_devs[i],
811 &st_lsm6dsx_buffer_ops);
812 if (ret)
813 return ret;
814 }
815
816 return 0;
817 }
818