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