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 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 } 99 100 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 } 120 121 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 } 127 128 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 } 186 187 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 } 196 197 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 } 230 231 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 } 279 280 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 } 304 305 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 */ 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 */ 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 u8 gyro_buff[ST_LSM6DSX_IIO_BUFF_SIZE]; 357 u8 acc_buff[ST_LSM6DSX_IIO_BUFF_SIZE]; 358 u8 ext_buff[ST_LSM6DSX_IIO_BUFF_SIZE]; 359 bool reset_ts = false; 360 __le16 fifo_status; 361 s64 ts = 0; 362 363 err = st_lsm6dsx_read_locked(hw, 364 hw->settings->fifo_ops.fifo_diff.addr, 365 &fifo_status, sizeof(fifo_status)); 366 if (err < 0) { 367 dev_err(hw->dev, "failed to read fifo status (err=%d)\n", 368 err); 369 return err; 370 } 371 372 if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK)) 373 return 0; 374 375 fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) * 376 ST_LSM6DSX_CHAN_SIZE; 377 fifo_len = (fifo_len / pattern_len) * pattern_len; 378 379 acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]); 380 gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]); 381 if (hw->iio_devs[ST_LSM6DSX_ID_EXT0]) 382 ext_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_EXT0]); 383 384 for (read_len = 0; read_len < fifo_len; read_len += pattern_len) { 385 err = st_lsm6dsx_read_block(hw, ST_LSM6DSX_REG_FIFO_OUTL_ADDR, 386 hw->buff, pattern_len, 387 ST_LSM6DSX_MAX_WORD_LEN); 388 if (err < 0) { 389 dev_err(hw->dev, 390 "failed to read pattern from fifo (err=%d)\n", 391 err); 392 return err; 393 } 394 395 /* 396 * Data are written to the FIFO with a specific pattern 397 * depending on the configured ODRs. The first sequence of data 398 * stored in FIFO contains the data of all enabled sensors 399 * (e.g. Gx, Gy, Gz, Ax, Ay, Az, Ts), then data are repeated 400 * depending on the value of the decimation factor set for each 401 * sensor. 402 * 403 * Supposing the FIFO is storing data from gyroscope and 404 * accelerometer at different ODRs: 405 * - gyroscope ODR = 208Hz, accelerometer ODR = 104Hz 406 * Since the gyroscope ODR is twice the accelerometer one, the 407 * following pattern is repeated every 9 samples: 408 * - Gx, Gy, Gz, Ax, Ay, Az, Ts, Gx, Gy, Gz, Ts, Gx, .. 409 */ 410 ext_sip = ext_sensor ? ext_sensor->sip : 0; 411 gyro_sip = gyro_sensor->sip; 412 acc_sip = acc_sensor->sip; 413 ts_sip = hw->ts_sip; 414 offset = 0; 415 sip = 0; 416 417 while (acc_sip > 0 || gyro_sip > 0 || ext_sip > 0) { 418 if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) { 419 memcpy(gyro_buff, &hw->buff[offset], 420 ST_LSM6DSX_SAMPLE_SIZE); 421 offset += ST_LSM6DSX_SAMPLE_SIZE; 422 } 423 if (acc_sip > 0 && !(sip % acc_sensor->decimator)) { 424 memcpy(acc_buff, &hw->buff[offset], 425 ST_LSM6DSX_SAMPLE_SIZE); 426 offset += ST_LSM6DSX_SAMPLE_SIZE; 427 } 428 if (ext_sip > 0 && !(sip % ext_sensor->decimator)) { 429 memcpy(ext_buff, &hw->buff[offset], 430 ST_LSM6DSX_SAMPLE_SIZE); 431 offset += ST_LSM6DSX_SAMPLE_SIZE; 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 gyro_buff, gyro_sensor->ts_ref + ts); 462 gyro_sip--; 463 } 464 if (acc_sip > 0 && !(sip % acc_sensor->decimator)) { 465 iio_push_to_buffers_with_timestamp( 466 hw->iio_devs[ST_LSM6DSX_ID_ACC], 467 acc_buff, acc_sensor->ts_ref + ts); 468 acc_sip--; 469 } 470 if (ext_sip > 0 && !(sip % ext_sensor->decimator)) { 471 iio_push_to_buffers_with_timestamp( 472 hw->iio_devs[ST_LSM6DSX_ID_EXT0], 473 ext_buff, ext_sensor->ts_ref + ts); 474 ext_sip--; 475 } 476 sip++; 477 } 478 } 479 480 if (unlikely(reset_ts)) { 481 err = st_lsm6dsx_reset_hw_ts(hw); 482 if (err < 0) { 483 dev_err(hw->dev, "failed to reset hw ts (err=%d)\n", 484 err); 485 return err; 486 } 487 } 488 return read_len; 489 } 490 491 #define ST_LSM6DSX_INVALID_SAMPLE 0x7ffd 492 static int 493 st_lsm6dsx_push_tagged_data(struct st_lsm6dsx_hw *hw, u8 tag, 494 u8 *data, s64 ts) 495 { 496 s16 val = le16_to_cpu(*(__le16 *)data); 497 struct st_lsm6dsx_sensor *sensor; 498 struct iio_dev *iio_dev; 499 500 /* invalid sample during bootstrap phase */ 501 if (val >= ST_LSM6DSX_INVALID_SAMPLE) 502 return -EINVAL; 503 504 /* 505 * EXT_TAG are managed in FIFO fashion so ST_LSM6DSX_EXT0_TAG 506 * corresponds to the first enabled channel, ST_LSM6DSX_EXT1_TAG 507 * to the second one and ST_LSM6DSX_EXT2_TAG to the last enabled 508 * channel 509 */ 510 switch (tag) { 511 case ST_LSM6DSX_GYRO_TAG: 512 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_GYRO]; 513 break; 514 case ST_LSM6DSX_ACC_TAG: 515 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_ACC]; 516 break; 517 case ST_LSM6DSX_EXT0_TAG: 518 if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0)) 519 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT0]; 520 else if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1)) 521 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1]; 522 else 523 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2]; 524 break; 525 case ST_LSM6DSX_EXT1_TAG: 526 if ((hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0)) && 527 (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1))) 528 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1]; 529 else 530 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2]; 531 break; 532 case ST_LSM6DSX_EXT2_TAG: 533 iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2]; 534 break; 535 default: 536 return -EINVAL; 537 } 538 539 sensor = iio_priv(iio_dev); 540 iio_push_to_buffers_with_timestamp(iio_dev, data, 541 ts + sensor->ts_ref); 542 543 return 0; 544 } 545 546 /** 547 * st_lsm6dsx_read_tagged_fifo() - tagged hw FIFO read routine 548 * @hw: Pointer to instance of struct st_lsm6dsx_hw. 549 * 550 * Read samples from the hw FIFO and push them to IIO buffers. 551 * 552 * Return: Number of bytes read from the FIFO 553 */ 554 int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw) 555 { 556 u16 pattern_len = hw->sip * ST_LSM6DSX_TAGGED_SAMPLE_SIZE; 557 u16 fifo_len, fifo_diff_mask; 558 u8 iio_buff[ST_LSM6DSX_IIO_BUFF_SIZE], tag; 559 bool reset_ts = false; 560 int i, err, read_len; 561 __le16 fifo_status; 562 s64 ts = 0; 563 564 err = st_lsm6dsx_read_locked(hw, 565 hw->settings->fifo_ops.fifo_diff.addr, 566 &fifo_status, sizeof(fifo_status)); 567 if (err < 0) { 568 dev_err(hw->dev, "failed to read fifo status (err=%d)\n", 569 err); 570 return err; 571 } 572 573 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask; 574 fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) * 575 ST_LSM6DSX_TAGGED_SAMPLE_SIZE; 576 if (!fifo_len) 577 return 0; 578 579 for (read_len = 0; read_len < fifo_len; read_len += pattern_len) { 580 err = st_lsm6dsx_read_block(hw, 581 ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR, 582 hw->buff, pattern_len, 583 ST_LSM6DSX_MAX_TAGGED_WORD_LEN); 584 if (err < 0) { 585 dev_err(hw->dev, 586 "failed to read pattern from fifo (err=%d)\n", 587 err); 588 return err; 589 } 590 591 for (i = 0; i < pattern_len; 592 i += ST_LSM6DSX_TAGGED_SAMPLE_SIZE) { 593 memcpy(iio_buff, &hw->buff[i + ST_LSM6DSX_TAG_SIZE], 594 ST_LSM6DSX_SAMPLE_SIZE); 595 596 tag = hw->buff[i] >> 3; 597 if (tag == ST_LSM6DSX_TS_TAG) { 598 /* 599 * hw timestamp is 4B long and it is stored 600 * in FIFO according to this schema: 601 * B0 = ts[7:0], B1 = ts[15:8], B2 = ts[23:16], 602 * B3 = ts[31:24] 603 */ 604 ts = le32_to_cpu(*((__le32 *)iio_buff)); 605 /* 606 * check if hw timestamp engine is going to 607 * reset (the sensor generates an interrupt 608 * to signal the hw timestamp will reset in 609 * 1.638s) 610 */ 611 if (!reset_ts && ts >= 0xffff0000) 612 reset_ts = true; 613 ts *= hw->ts_gain; 614 } else { 615 st_lsm6dsx_push_tagged_data(hw, tag, iio_buff, 616 ts); 617 } 618 } 619 } 620 621 if (unlikely(reset_ts)) { 622 err = st_lsm6dsx_reset_hw_ts(hw); 623 if (err < 0) 624 return err; 625 } 626 return read_len; 627 } 628 629 int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw) 630 { 631 int err; 632 633 if (!hw->settings->fifo_ops.read_fifo) 634 return -ENOTSUPP; 635 636 mutex_lock(&hw->fifo_lock); 637 638 hw->settings->fifo_ops.read_fifo(hw); 639 err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_BYPASS); 640 641 mutex_unlock(&hw->fifo_lock); 642 643 return err; 644 } 645 646 int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable) 647 { 648 struct st_lsm6dsx_hw *hw = sensor->hw; 649 u8 fifo_mask; 650 int err; 651 652 mutex_lock(&hw->conf_lock); 653 654 if (enable) 655 fifo_mask = hw->fifo_mask | BIT(sensor->id); 656 else 657 fifo_mask = hw->fifo_mask & ~BIT(sensor->id); 658 659 if (hw->fifo_mask) { 660 err = st_lsm6dsx_flush_fifo(hw); 661 if (err < 0) 662 goto out; 663 } 664 665 if (sensor->id == ST_LSM6DSX_ID_EXT0 || 666 sensor->id == ST_LSM6DSX_ID_EXT1 || 667 sensor->id == ST_LSM6DSX_ID_EXT2) { 668 err = st_lsm6dsx_shub_set_enable(sensor, enable); 669 if (err < 0) 670 goto out; 671 } else { 672 err = st_lsm6dsx_sensor_set_enable(sensor, enable); 673 if (err < 0) 674 goto out; 675 } 676 677 err = st_lsm6dsx_set_fifo_odr(sensor, enable); 678 if (err < 0) 679 goto out; 680 681 err = st_lsm6dsx_update_decimators(hw); 682 if (err < 0) 683 goto out; 684 685 err = st_lsm6dsx_update_watermark(sensor, sensor->watermark); 686 if (err < 0) 687 goto out; 688 689 if (fifo_mask) { 690 err = st_lsm6dsx_resume_fifo(hw); 691 if (err < 0) 692 goto out; 693 } 694 695 hw->fifo_mask = fifo_mask; 696 697 out: 698 mutex_unlock(&hw->conf_lock); 699 700 return err; 701 } 702 703 static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev) 704 { 705 struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev); 706 struct st_lsm6dsx_hw *hw = sensor->hw; 707 708 if (!hw->settings->fifo_ops.update_fifo) 709 return -ENOTSUPP; 710 711 return hw->settings->fifo_ops.update_fifo(sensor, true); 712 } 713 714 static int st_lsm6dsx_buffer_postdisable(struct iio_dev *iio_dev) 715 { 716 struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev); 717 struct st_lsm6dsx_hw *hw = sensor->hw; 718 719 if (!hw->settings->fifo_ops.update_fifo) 720 return -ENOTSUPP; 721 722 return hw->settings->fifo_ops.update_fifo(sensor, false); 723 } 724 725 static const struct iio_buffer_setup_ops st_lsm6dsx_buffer_ops = { 726 .preenable = st_lsm6dsx_buffer_preenable, 727 .postdisable = st_lsm6dsx_buffer_postdisable, 728 }; 729 730 int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw) 731 { 732 struct iio_buffer *buffer; 733 int i; 734 735 for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) { 736 if (!hw->iio_devs[i]) 737 continue; 738 739 buffer = devm_iio_kfifo_allocate(hw->dev); 740 if (!buffer) 741 return -ENOMEM; 742 743 iio_device_attach_buffer(hw->iio_devs[i], buffer); 744 hw->iio_devs[i]->modes |= INDIO_BUFFER_SOFTWARE; 745 hw->iio_devs[i]->setup_ops = &st_lsm6dsx_buffer_ops; 746 } 747 748 return 0; 749 } 750