1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * STMicroelectronics st_lsm6dsx FIFO buffer library driver
4 *
5 * LSM6DS3/LSM6DS3H/LSM6DSL/LSM6DSM/ISM330DLC/LSM6DS3TR-C:
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 * LSM6DSO/LSM6DSOX/ASM330LHH/LSM6DSR/LSM6DSRX/ISM330DHCX:
18 * The FIFO buffer can be configured to store data from gyroscope and
19 * accelerometer. Each sample is queued with a tag (1B) indicating data
20 * source (gyroscope, accelerometer, hw timer).
21 *
22 * FIFO supported modes:
23 * - BYPASS: FIFO disabled
24 * - CONTINUOUS: FIFO enabled. When the buffer is full, the FIFO index
25 * restarts from the beginning and the oldest sample is overwritten
26 *
27 * Copyright 2016 STMicroelectronics Inc.
28 *
29 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
30 * Denis Ciocca <denis.ciocca@st.com>
31 */
32 #include <linux/module.h>
33 #include <linux/iio/kfifo_buf.h>
34 #include <linux/iio/iio.h>
35 #include <linux/iio/buffer.h>
36 #include <linux/regmap.h>
37 #include <linux/bitfield.h>
38
39 #include <linux/platform_data/st_sensors_pdata.h>
40
41 #include "st_lsm6dsx.h"
42
43 #define ST_LSM6DSX_REG_FIFO_MODE_ADDR 0x0a
44 #define ST_LSM6DSX_FIFO_MODE_MASK GENMASK(2, 0)
45 #define ST_LSM6DSX_FIFO_ODR_MASK GENMASK(6, 3)
46 #define ST_LSM6DSX_FIFO_EMPTY_MASK BIT(12)
47 #define ST_LSM6DSX_REG_FIFO_OUTL_ADDR 0x3e
48 #define ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR 0x78
49 #define ST_LSM6DSX_REG_TS_RESET_ADDR 0x42
50
51 #define ST_LSM6DSX_MAX_FIFO_ODR_VAL 0x08
52
53 #define ST_LSM6DSX_TS_RESET_VAL 0xaa
54
55 struct st_lsm6dsx_decimator_entry {
56 u8 decimator;
57 u8 val;
58 };
59
60 enum st_lsm6dsx_fifo_tag {
61 ST_LSM6DSX_GYRO_TAG = 0x01,
62 ST_LSM6DSX_ACC_TAG = 0x02,
63 ST_LSM6DSX_TS_TAG = 0x04,
64 ST_LSM6DSX_EXT0_TAG = 0x0f,
65 ST_LSM6DSX_EXT1_TAG = 0x10,
66 ST_LSM6DSX_EXT2_TAG = 0x11,
67 };
68
69 static const
70 struct st_lsm6dsx_decimator_entry st_lsm6dsx_decimator_table[] = {
71 { 0, 0x0 },
72 { 1, 0x1 },
73 { 2, 0x2 },
74 { 3, 0x3 },
75 { 4, 0x4 },
76 { 8, 0x5 },
77 { 16, 0x6 },
78 { 32, 0x7 },
79 };
80
81 static int
st_lsm6dsx_get_decimator_val(struct st_lsm6dsx_sensor * sensor,u32 max_odr)82 st_lsm6dsx_get_decimator_val(struct st_lsm6dsx_sensor *sensor, u32 max_odr)
83 {
84 const int max_size = ARRAY_SIZE(st_lsm6dsx_decimator_table);
85 u32 decimator = max_odr / sensor->odr;
86 int i;
87
88 if (decimator > 1)
89 decimator = round_down(decimator, 2);
90
91 for (i = 0; i < max_size; i++) {
92 if (st_lsm6dsx_decimator_table[i].decimator == decimator)
93 break;
94 }
95
96 sensor->decimator = decimator;
97 return i == max_size ? 0 : st_lsm6dsx_decimator_table[i].val;
98 }
99
st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw * hw,u32 * max_odr,u32 * min_odr)100 static void st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw *hw,
101 u32 *max_odr, u32 *min_odr)
102 {
103 struct st_lsm6dsx_sensor *sensor;
104 int i;
105
106 *max_odr = 0, *min_odr = ~0;
107 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
108 if (!hw->iio_devs[i])
109 continue;
110
111 sensor = iio_priv(hw->iio_devs[i]);
112
113 if (!(hw->enable_mask & BIT(sensor->id)))
114 continue;
115
116 *max_odr = max_t(u32, *max_odr, sensor->odr);
117 *min_odr = min_t(u32, *min_odr, sensor->odr);
118 }
119 }
120
st_lsm6dsx_get_sip(struct st_lsm6dsx_sensor * sensor,u32 min_odr)121 static u8 st_lsm6dsx_get_sip(struct st_lsm6dsx_sensor *sensor, u32 min_odr)
122 {
123 u8 sip = sensor->odr / min_odr;
124
125 return sip > 1 ? round_down(sip, 2) : sip;
126 }
127
st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw * hw)128 static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw)
129 {
130 const struct st_lsm6dsx_reg *ts_dec_reg;
131 struct st_lsm6dsx_sensor *sensor;
132 u16 sip = 0, ts_sip = 0;
133 u32 max_odr, min_odr;
134 int err = 0, i;
135 u8 data;
136
137 st_lsm6dsx_get_max_min_odr(hw, &max_odr, &min_odr);
138
139 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
140 const struct st_lsm6dsx_reg *dec_reg;
141
142 if (!hw->iio_devs[i])
143 continue;
144
145 sensor = iio_priv(hw->iio_devs[i]);
146 /* update fifo decimators and sample in pattern */
147 if (hw->enable_mask & BIT(sensor->id)) {
148 sensor->sip = st_lsm6dsx_get_sip(sensor, min_odr);
149 data = st_lsm6dsx_get_decimator_val(sensor, max_odr);
150 } else {
151 sensor->sip = 0;
152 data = 0;
153 }
154 ts_sip = max_t(u16, ts_sip, sensor->sip);
155
156 dec_reg = &hw->settings->decimator[sensor->id];
157 if (dec_reg->addr) {
158 int val = ST_LSM6DSX_SHIFT_VAL(data, dec_reg->mask);
159
160 err = st_lsm6dsx_update_bits_locked(hw, dec_reg->addr,
161 dec_reg->mask,
162 val);
163 if (err < 0)
164 return err;
165 }
166 sip += sensor->sip;
167 }
168 hw->sip = sip + ts_sip;
169 hw->ts_sip = ts_sip;
170
171 /*
172 * update hw ts decimator if necessary. Decimator for hw timestamp
173 * is always 1 or 0 in order to have a ts sample for each data
174 * sample in FIFO
175 */
176 ts_dec_reg = &hw->settings->ts_settings.decimator;
177 if (ts_dec_reg->addr) {
178 int val, ts_dec = !!hw->ts_sip;
179
180 val = ST_LSM6DSX_SHIFT_VAL(ts_dec, ts_dec_reg->mask);
181 err = st_lsm6dsx_update_bits_locked(hw, ts_dec_reg->addr,
182 ts_dec_reg->mask, val);
183 }
184 return err;
185 }
186
st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw * hw,enum st_lsm6dsx_fifo_mode fifo_mode)187 static int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
188 enum st_lsm6dsx_fifo_mode fifo_mode)
189 {
190 unsigned int data;
191
192 data = FIELD_PREP(ST_LSM6DSX_FIFO_MODE_MASK, fifo_mode);
193 return st_lsm6dsx_update_bits_locked(hw, ST_LSM6DSX_REG_FIFO_MODE_ADDR,
194 ST_LSM6DSX_FIFO_MODE_MASK, data);
195 }
196
st_lsm6dsx_set_fifo_odr(struct st_lsm6dsx_sensor * sensor,bool enable)197 static int st_lsm6dsx_set_fifo_odr(struct st_lsm6dsx_sensor *sensor,
198 bool enable)
199 {
200 struct st_lsm6dsx_hw *hw = sensor->hw;
201 const struct st_lsm6dsx_reg *batch_reg;
202 u8 data;
203
204 batch_reg = &hw->settings->batch[sensor->id];
205 if (batch_reg->addr) {
206 int val;
207
208 if (enable) {
209 int err;
210
211 err = st_lsm6dsx_check_odr(sensor, sensor->odr,
212 &data);
213 if (err < 0)
214 return err;
215 } else {
216 data = 0;
217 }
218 val = ST_LSM6DSX_SHIFT_VAL(data, batch_reg->mask);
219 return st_lsm6dsx_update_bits_locked(hw, batch_reg->addr,
220 batch_reg->mask, val);
221 } else {
222 data = hw->enable_mask ? ST_LSM6DSX_MAX_FIFO_ODR_VAL : 0;
223 return st_lsm6dsx_update_bits_locked(hw,
224 ST_LSM6DSX_REG_FIFO_MODE_ADDR,
225 ST_LSM6DSX_FIFO_ODR_MASK,
226 FIELD_PREP(ST_LSM6DSX_FIFO_ODR_MASK,
227 data));
228 }
229 }
230
st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor * sensor,u16 watermark)231 int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor, u16 watermark)
232 {
233 u16 fifo_watermark = ~0, cur_watermark, fifo_th_mask;
234 struct st_lsm6dsx_hw *hw = sensor->hw;
235 struct st_lsm6dsx_sensor *cur_sensor;
236 int i, err, data;
237 __le16 wdata;
238
239 if (!hw->sip)
240 return 0;
241
242 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
243 if (!hw->iio_devs[i])
244 continue;
245
246 cur_sensor = iio_priv(hw->iio_devs[i]);
247
248 if (!(hw->enable_mask & BIT(cur_sensor->id)))
249 continue;
250
251 cur_watermark = (cur_sensor == sensor) ? watermark
252 : cur_sensor->watermark;
253
254 fifo_watermark = min_t(u16, fifo_watermark, cur_watermark);
255 }
256
257 fifo_watermark = max_t(u16, fifo_watermark, hw->sip);
258 fifo_watermark = (fifo_watermark / hw->sip) * hw->sip;
259 fifo_watermark = fifo_watermark * hw->settings->fifo_ops.th_wl;
260
261 mutex_lock(&hw->page_lock);
262 err = regmap_read(hw->regmap, hw->settings->fifo_ops.fifo_th.addr + 1,
263 &data);
264 if (err < 0)
265 goto out;
266
267 fifo_th_mask = hw->settings->fifo_ops.fifo_th.mask;
268 fifo_watermark = ((data << 8) & ~fifo_th_mask) |
269 (fifo_watermark & fifo_th_mask);
270
271 wdata = cpu_to_le16(fifo_watermark);
272 err = regmap_bulk_write(hw->regmap,
273 hw->settings->fifo_ops.fifo_th.addr,
274 &wdata, sizeof(wdata));
275 out:
276 mutex_unlock(&hw->page_lock);
277 return err;
278 }
279
st_lsm6dsx_reset_hw_ts(struct st_lsm6dsx_hw * hw)280 static int st_lsm6dsx_reset_hw_ts(struct st_lsm6dsx_hw *hw)
281 {
282 struct st_lsm6dsx_sensor *sensor;
283 int i, err;
284
285 /* reset hw ts counter */
286 err = st_lsm6dsx_write_locked(hw, ST_LSM6DSX_REG_TS_RESET_ADDR,
287 ST_LSM6DSX_TS_RESET_VAL);
288 if (err < 0)
289 return err;
290
291 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
292 if (!hw->iio_devs[i])
293 continue;
294
295 sensor = iio_priv(hw->iio_devs[i]);
296 /*
297 * store enable buffer timestamp as reference for
298 * hw timestamp
299 */
300 sensor->ts_ref = iio_get_time_ns(hw->iio_devs[i]);
301 }
302 return 0;
303 }
304
st_lsm6dsx_resume_fifo(struct st_lsm6dsx_hw * hw)305 int st_lsm6dsx_resume_fifo(struct st_lsm6dsx_hw *hw)
306 {
307 int err;
308
309 /* reset hw ts counter */
310 err = st_lsm6dsx_reset_hw_ts(hw);
311 if (err < 0)
312 return err;
313
314 return st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
315 }
316
317 /*
318 * Set max bulk read to ST_LSM6DSX_MAX_WORD_LEN/ST_LSM6DSX_MAX_TAGGED_WORD_LEN
319 * in order to avoid a kmalloc for each bus access
320 */
st_lsm6dsx_read_block(struct st_lsm6dsx_hw * hw,u8 addr,u8 * data,unsigned int data_len,unsigned int max_word_len)321 static inline int st_lsm6dsx_read_block(struct st_lsm6dsx_hw *hw, u8 addr,
322 u8 *data, unsigned int data_len,
323 unsigned int max_word_len)
324 {
325 unsigned int word_len, read_len = 0;
326 int err;
327
328 while (read_len < data_len) {
329 word_len = min_t(unsigned int, data_len - read_len,
330 max_word_len);
331 err = st_lsm6dsx_read_locked(hw, addr, data + read_len,
332 word_len);
333 if (err < 0)
334 return err;
335 read_len += word_len;
336 }
337 return 0;
338 }
339
340 #define ST_LSM6DSX_IIO_BUFF_SIZE (ALIGN(ST_LSM6DSX_SAMPLE_SIZE, \
341 sizeof(s64)) + sizeof(s64))
342 /**
343 * st_lsm6dsx_read_fifo() - hw FIFO read routine
344 * @hw: Pointer to instance of struct st_lsm6dsx_hw.
345 *
346 * Read samples from the hw FIFO and push them to IIO buffers.
347 *
348 * Return: Number of bytes read from the FIFO
349 */
st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw * hw)350 int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
351 {
352 struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor, *ext_sensor = NULL;
353 int err, sip, acc_sip, gyro_sip, ts_sip, ext_sip, read_len, offset;
354 u16 fifo_len, pattern_len = hw->sip * ST_LSM6DSX_SAMPLE_SIZE;
355 u16 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
356 bool reset_ts = false;
357 __le16 fifo_status;
358 s64 ts = 0;
359
360 err = st_lsm6dsx_read_locked(hw,
361 hw->settings->fifo_ops.fifo_diff.addr,
362 &fifo_status, sizeof(fifo_status));
363 if (err < 0) {
364 dev_err(hw->dev, "failed to read fifo status (err=%d)\n",
365 err);
366 return err;
367 }
368
369 if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
370 return 0;
371
372 fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
373 ST_LSM6DSX_CHAN_SIZE;
374 fifo_len = (fifo_len / pattern_len) * pattern_len;
375
376 acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
377 gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]);
378 if (hw->iio_devs[ST_LSM6DSX_ID_EXT0])
379 ext_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_EXT0]);
380
381 for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
382 err = st_lsm6dsx_read_block(hw, ST_LSM6DSX_REG_FIFO_OUTL_ADDR,
383 hw->buff, pattern_len,
384 ST_LSM6DSX_MAX_WORD_LEN);
385 if (err < 0) {
386 dev_err(hw->dev,
387 "failed to read pattern from fifo (err=%d)\n",
388 err);
389 return err;
390 }
391
392 /*
393 * Data are written to the FIFO with a specific pattern
394 * depending on the configured ODRs. The first sequence of data
395 * stored in FIFO contains the data of all enabled sensors
396 * (e.g. Gx, Gy, Gz, Ax, Ay, Az, Ts), then data are repeated
397 * depending on the value of the decimation factor set for each
398 * sensor.
399 *
400 * Supposing the FIFO is storing data from gyroscope and
401 * accelerometer at different ODRs:
402 * - gyroscope ODR = 208Hz, accelerometer ODR = 104Hz
403 * Since the gyroscope ODR is twice the accelerometer one, the
404 * following pattern is repeated every 9 samples:
405 * - Gx, Gy, Gz, Ax, Ay, Az, Ts, Gx, Gy, Gz, Ts, Gx, ..
406 */
407 ext_sip = ext_sensor ? ext_sensor->sip : 0;
408 gyro_sip = gyro_sensor->sip;
409 acc_sip = acc_sensor->sip;
410 ts_sip = hw->ts_sip;
411 offset = 0;
412 sip = 0;
413
414 while (acc_sip > 0 || gyro_sip > 0 || ext_sip > 0) {
415 if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
416 memcpy(hw->scan[ST_LSM6DSX_ID_GYRO].channels,
417 &hw->buff[offset],
418 sizeof(hw->scan[ST_LSM6DSX_ID_GYRO].channels));
419 offset += sizeof(hw->scan[ST_LSM6DSX_ID_GYRO].channels);
420 }
421 if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
422 memcpy(hw->scan[ST_LSM6DSX_ID_ACC].channels,
423 &hw->buff[offset],
424 sizeof(hw->scan[ST_LSM6DSX_ID_ACC].channels));
425 offset += sizeof(hw->scan[ST_LSM6DSX_ID_ACC].channels);
426 }
427 if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
428 memcpy(hw->scan[ST_LSM6DSX_ID_EXT0].channels,
429 &hw->buff[offset],
430 sizeof(hw->scan[ST_LSM6DSX_ID_EXT0].channels));
431 offset += sizeof(hw->scan[ST_LSM6DSX_ID_EXT0].channels);
432 }
433
434 if (ts_sip-- > 0) {
435 u8 data[ST_LSM6DSX_SAMPLE_SIZE];
436
437 memcpy(data, &hw->buff[offset], sizeof(data));
438 /*
439 * hw timestamp is 3B long and it is stored
440 * in FIFO using 6B as 4th FIFO data set
441 * according to this schema:
442 * B0 = ts[15:8], B1 = ts[23:16], B3 = ts[7:0]
443 */
444 ts = data[1] << 16 | data[0] << 8 | data[3];
445 /*
446 * check if hw timestamp engine is going to
447 * reset (the sensor generates an interrupt
448 * to signal the hw timestamp will reset in
449 * 1.638s)
450 */
451 if (!reset_ts && ts >= 0xff0000)
452 reset_ts = true;
453 ts *= hw->ts_gain;
454
455 offset += ST_LSM6DSX_SAMPLE_SIZE;
456 }
457
458 if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
459 iio_push_to_buffers_with_timestamp(
460 hw->iio_devs[ST_LSM6DSX_ID_GYRO],
461 &hw->scan[ST_LSM6DSX_ID_GYRO],
462 gyro_sensor->ts_ref + ts);
463 gyro_sip--;
464 }
465 if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
466 iio_push_to_buffers_with_timestamp(
467 hw->iio_devs[ST_LSM6DSX_ID_ACC],
468 &hw->scan[ST_LSM6DSX_ID_ACC],
469 acc_sensor->ts_ref + ts);
470 acc_sip--;
471 }
472 if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
473 iio_push_to_buffers_with_timestamp(
474 hw->iio_devs[ST_LSM6DSX_ID_EXT0],
475 &hw->scan[ST_LSM6DSX_ID_EXT0],
476 ext_sensor->ts_ref + ts);
477 ext_sip--;
478 }
479 sip++;
480 }
481 }
482
483 if (unlikely(reset_ts)) {
484 err = st_lsm6dsx_reset_hw_ts(hw);
485 if (err < 0) {
486 dev_err(hw->dev, "failed to reset hw ts (err=%d)\n",
487 err);
488 return err;
489 }
490 }
491 return read_len;
492 }
493
494 #define ST_LSM6DSX_INVALID_SAMPLE 0x7ffd
495 static int
st_lsm6dsx_push_tagged_data(struct st_lsm6dsx_hw * hw,u8 tag,u8 * data,s64 ts)496 st_lsm6dsx_push_tagged_data(struct st_lsm6dsx_hw *hw, u8 tag,
497 u8 *data, s64 ts)
498 {
499 s16 val = le16_to_cpu(*(__le16 *)data);
500 struct st_lsm6dsx_sensor *sensor;
501 struct iio_dev *iio_dev;
502
503 /* invalid sample during bootstrap phase */
504 if (val >= ST_LSM6DSX_INVALID_SAMPLE)
505 return -EINVAL;
506
507 /*
508 * EXT_TAG are managed in FIFO fashion so ST_LSM6DSX_EXT0_TAG
509 * corresponds to the first enabled channel, ST_LSM6DSX_EXT1_TAG
510 * to the second one and ST_LSM6DSX_EXT2_TAG to the last enabled
511 * channel
512 */
513 switch (tag) {
514 case ST_LSM6DSX_GYRO_TAG:
515 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_GYRO];
516 break;
517 case ST_LSM6DSX_ACC_TAG:
518 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_ACC];
519 break;
520 case ST_LSM6DSX_EXT0_TAG:
521 if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0))
522 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT0];
523 else if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1))
524 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1];
525 else
526 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
527 break;
528 case ST_LSM6DSX_EXT1_TAG:
529 if ((hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0)) &&
530 (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1)))
531 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1];
532 else
533 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
534 break;
535 case ST_LSM6DSX_EXT2_TAG:
536 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
537 break;
538 default:
539 return -EINVAL;
540 }
541
542 sensor = iio_priv(iio_dev);
543 iio_push_to_buffers_with_timestamp(iio_dev, data,
544 ts + sensor->ts_ref);
545
546 return 0;
547 }
548
549 /**
550 * st_lsm6dsx_read_tagged_fifo() - tagged hw FIFO read routine
551 * @hw: Pointer to instance of struct st_lsm6dsx_hw.
552 *
553 * Read samples from the hw FIFO and push them to IIO buffers.
554 *
555 * Return: Number of bytes read from the FIFO
556 */
st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw * hw)557 int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw)
558 {
559 u16 pattern_len = hw->sip * ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
560 u16 fifo_len, fifo_diff_mask;
561 /*
562 * Alignment needed as this can ultimately be passed to a
563 * call to iio_push_to_buffers_with_timestamp() which
564 * must be passed a buffer that is aligned to 8 bytes so
565 * as to allow insertion of a naturally aligned timestamp.
566 */
567 u8 iio_buff[ST_LSM6DSX_IIO_BUFF_SIZE] __aligned(8);
568 u8 tag;
569 bool reset_ts = false;
570 int i, err, read_len;
571 __le16 fifo_status;
572 s64 ts = 0;
573
574 err = st_lsm6dsx_read_locked(hw,
575 hw->settings->fifo_ops.fifo_diff.addr,
576 &fifo_status, sizeof(fifo_status));
577 if (err < 0) {
578 dev_err(hw->dev, "failed to read fifo status (err=%d)\n",
579 err);
580 return err;
581 }
582
583 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
584 fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
585 ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
586 if (!fifo_len)
587 return 0;
588
589 for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
590 err = st_lsm6dsx_read_block(hw,
591 ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR,
592 hw->buff, pattern_len,
593 ST_LSM6DSX_MAX_TAGGED_WORD_LEN);
594 if (err < 0) {
595 dev_err(hw->dev,
596 "failed to read pattern from fifo (err=%d)\n",
597 err);
598 return err;
599 }
600
601 for (i = 0; i < pattern_len;
602 i += ST_LSM6DSX_TAGGED_SAMPLE_SIZE) {
603 memcpy(iio_buff, &hw->buff[i + ST_LSM6DSX_TAG_SIZE],
604 ST_LSM6DSX_SAMPLE_SIZE);
605
606 tag = hw->buff[i] >> 3;
607 if (tag == ST_LSM6DSX_TS_TAG) {
608 /*
609 * hw timestamp is 4B long and it is stored
610 * in FIFO according to this schema:
611 * B0 = ts[7:0], B1 = ts[15:8], B2 = ts[23:16],
612 * B3 = ts[31:24]
613 */
614 ts = le32_to_cpu(*((__le32 *)iio_buff));
615 /*
616 * check if hw timestamp engine is going to
617 * reset (the sensor generates an interrupt
618 * to signal the hw timestamp will reset in
619 * 1.638s)
620 */
621 if (!reset_ts && ts >= 0xffff0000)
622 reset_ts = true;
623 ts *= hw->ts_gain;
624 } else {
625 st_lsm6dsx_push_tagged_data(hw, tag, iio_buff,
626 ts);
627 }
628 }
629 }
630
631 if (unlikely(reset_ts)) {
632 err = st_lsm6dsx_reset_hw_ts(hw);
633 if (err < 0)
634 return err;
635 }
636 return read_len;
637 }
638
st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw * hw)639 int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw)
640 {
641 int err;
642
643 if (!hw->settings->fifo_ops.read_fifo)
644 return -ENOTSUPP;
645
646 mutex_lock(&hw->fifo_lock);
647
648 hw->settings->fifo_ops.read_fifo(hw);
649 err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_BYPASS);
650
651 mutex_unlock(&hw->fifo_lock);
652
653 return err;
654 }
655
st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor * sensor,bool enable)656 int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable)
657 {
658 struct st_lsm6dsx_hw *hw = sensor->hw;
659 u8 fifo_mask;
660 int err;
661
662 mutex_lock(&hw->conf_lock);
663
664 if (enable)
665 fifo_mask = hw->fifo_mask | BIT(sensor->id);
666 else
667 fifo_mask = hw->fifo_mask & ~BIT(sensor->id);
668
669 if (hw->fifo_mask) {
670 err = st_lsm6dsx_flush_fifo(hw);
671 if (err < 0)
672 goto out;
673 }
674
675 if (sensor->id == ST_LSM6DSX_ID_EXT0 ||
676 sensor->id == ST_LSM6DSX_ID_EXT1 ||
677 sensor->id == ST_LSM6DSX_ID_EXT2) {
678 err = st_lsm6dsx_shub_set_enable(sensor, enable);
679 if (err < 0)
680 goto out;
681 } else {
682 err = st_lsm6dsx_sensor_set_enable(sensor, enable);
683 if (err < 0)
684 goto out;
685 }
686
687 err = st_lsm6dsx_set_fifo_odr(sensor, enable);
688 if (err < 0)
689 goto out;
690
691 err = st_lsm6dsx_update_decimators(hw);
692 if (err < 0)
693 goto out;
694
695 err = st_lsm6dsx_update_watermark(sensor, sensor->watermark);
696 if (err < 0)
697 goto out;
698
699 if (fifo_mask) {
700 err = st_lsm6dsx_resume_fifo(hw);
701 if (err < 0)
702 goto out;
703 }
704
705 hw->fifo_mask = fifo_mask;
706
707 out:
708 mutex_unlock(&hw->conf_lock);
709
710 return err;
711 }
712
st_lsm6dsx_buffer_preenable(struct iio_dev * iio_dev)713 static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev)
714 {
715 struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
716 struct st_lsm6dsx_hw *hw = sensor->hw;
717
718 if (!hw->settings->fifo_ops.update_fifo)
719 return -ENOTSUPP;
720
721 return hw->settings->fifo_ops.update_fifo(sensor, true);
722 }
723
st_lsm6dsx_buffer_postdisable(struct iio_dev * iio_dev)724 static int st_lsm6dsx_buffer_postdisable(struct iio_dev *iio_dev)
725 {
726 struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
727 struct st_lsm6dsx_hw *hw = sensor->hw;
728
729 if (!hw->settings->fifo_ops.update_fifo)
730 return -ENOTSUPP;
731
732 return hw->settings->fifo_ops.update_fifo(sensor, false);
733 }
734
735 static const struct iio_buffer_setup_ops st_lsm6dsx_buffer_ops = {
736 .preenable = st_lsm6dsx_buffer_preenable,
737 .postdisable = st_lsm6dsx_buffer_postdisable,
738 };
739
st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw * hw)740 int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw)
741 {
742 struct iio_buffer *buffer;
743 int i;
744
745 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
746 if (!hw->iio_devs[i])
747 continue;
748
749 buffer = devm_iio_kfifo_allocate(hw->dev);
750 if (!buffer)
751 return -ENOMEM;
752
753 iio_device_attach_buffer(hw->iio_devs[i], buffer);
754 hw->iio_devs[i]->modes |= INDIO_BUFFER_SOFTWARE;
755 hw->iio_devs[i]->setup_ops = &st_lsm6dsx_buffer_ops;
756 }
757
758 return 0;
759 }
760