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