drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c

   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         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
 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  */
 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
 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
 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
 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
 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
 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 }