drivers/iio/gyro/adxrs290.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * ADXRS290 SPI Gyroscope Driver
   4  *
   5  * Copyright (C) 2020 Nishant Malpani <nish.malpani25@gmail.com>
   6  * Copyright (C) 2020 Analog Devices, Inc.
   7  */
   8
   9 #include <linux/bitfield.h>
  10 #include <linux/delay.h>
  11 #include <linux/device.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/spi/spi.h>
  15
  16 #include <linux/iio/buffer.h>
  17 #include <linux/iio/iio.h>
  18 #include <linux/iio/sysfs.h>
  19 #include <linux/iio/trigger.h>
  20 #include <linux/iio/triggered_buffer.h>
  21 #include <linux/iio/trigger_consumer.h>
  22
  23 #define ADXRS290_ADI_ID         0xAD
  24 #define ADXRS290_MEMS_ID        0x1D
  25 #define ADXRS290_DEV_ID         0x92
  26
  27 #define ADXRS290_REG_ADI_ID     0x00
  28 #define ADXRS290_REG_MEMS_ID    0x01
  29 #define ADXRS290_REG_DEV_ID     0x02
  30 #define ADXRS290_REG_REV_ID     0x03
  31 #define ADXRS290_REG_SN0        0x04 /* Serial Number Registers, 4 bytes */
  32 #define ADXRS290_REG_DATAX0     0x08 /* Roll Rate o/p Data Regs, 2 bytes */
  33 #define ADXRS290_REG_DATAY0     0x0A /* Pitch Rate o/p Data Regs, 2 bytes */
  34 #define ADXRS290_REG_TEMP0      0x0C
  35 #define ADXRS290_REG_POWER_CTL  0x10
  36 #define ADXRS290_REG_FILTER     0x11
  37 #define ADXRS290_REG_DATA_RDY   0x12
  38
  39 #define ADXRS290_READ           BIT(7)
  40 #define ADXRS290_TSM            BIT(0)
  41 #define ADXRS290_MEASUREMENT    BIT(1)
  42 #define ADXRS290_DATA_RDY_OUT   BIT(0)
  43 #define ADXRS290_SYNC_MASK      GENMASK(1, 0)
  44 #define ADXRS290_SYNC(x)        FIELD_PREP(ADXRS290_SYNC_MASK, x)
  45 #define ADXRS290_LPF_MASK       GENMASK(2, 0)
  46 #define ADXRS290_LPF(x)         FIELD_PREP(ADXRS290_LPF_MASK, x)
  47 #define ADXRS290_HPF_MASK       GENMASK(7, 4)
  48 #define ADXRS290_HPF(x)         FIELD_PREP(ADXRS290_HPF_MASK, x)
  49
  50 #define ADXRS290_READ_REG(reg)  (ADXRS290_READ | (reg))
  51
  52 #define ADXRS290_MAX_TRANSITION_TIME_MS 100
  53
  54 enum adxrs290_mode {
  55         ADXRS290_MODE_STANDBY,
  56         ADXRS290_MODE_MEASUREMENT,
  57 };
  58
  59 enum adxrs290_scan_index {
  60         ADXRS290_IDX_X,
  61         ADXRS290_IDX_Y,
  62         ADXRS290_IDX_TEMP,
  63         ADXRS290_IDX_TS,
  64 };
  65
  66 struct adxrs290_state {
  67         struct spi_device       *spi;
  68         /* Serialize reads and their subsequent processing */
  69         struct mutex            lock;
  70         enum adxrs290_mode      mode;
  71         unsigned int            lpf_3db_freq_idx;
  72         unsigned int            hpf_3db_freq_idx;
  73         struct iio_trigger      *dready_trig;
  74         /* Ensure correct alignment of timestamp when present */
  75         struct {
  76                 s16 channels[3];
  77                 s64 ts __aligned(8);
  78         } buffer;
  79 };
  80
  81 /*
  82  * Available cut-off frequencies of the low pass filter in Hz.
  83  * The integer part and fractional part are represented separately.
  84  */
  85 static const int adxrs290_lpf_3db_freq_hz_table[][2] = {
  86         [0] = {480, 0},
  87         [1] = {320, 0},
  88         [2] = {160, 0},
  89         [3] = {80, 0},
  90         [4] = {56, 600000},
  91         [5] = {40, 0},
  92         [6] = {28, 300000},
  93         [7] = {20, 0},
  94 };
  95
  96 /*
  97  * Available cut-off frequencies of the high pass filter in Hz.
  98  * The integer part and fractional part are represented separately.
  99  */
 100 static const int adxrs290_hpf_3db_freq_hz_table[][2] = {
 101         [0] = {0, 0},
 102         [1] = {0, 11000},
 103         [2] = {0, 22000},
 104         [3] = {0, 44000},
 105         [4] = {0, 87000},
 106         [5] = {0, 175000},
 107         [6] = {0, 350000},
 108         [7] = {0, 700000},
 109         [8] = {1, 400000},
 110         [9] = {2, 800000},
 111         [10] = {11, 300000},
 112 };
 113
 114 static int adxrs290_get_rate_data(struct iio_dev *indio_dev, const u8 cmd, int *val)
 115 {
 116         struct adxrs290_state *st = iio_priv(indio_dev);
 117         int ret = 0;
 118         int temp;
 119
 120         mutex_lock(&st->lock);
 121         temp = spi_w8r16(st->spi, cmd);
 122         if (temp < 0) {
 123                 ret = temp;
 124                 goto err_unlock;
 125         }
 126
 127         *val = temp;
 128
 129 err_unlock:
 130         mutex_unlock(&st->lock);
 131         return ret;
 132 }
 133
 134 static int adxrs290_get_temp_data(struct iio_dev *indio_dev, int *val)
 135 {
 136         const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_TEMP0);
 137         struct adxrs290_state *st = iio_priv(indio_dev);
 138         int ret = 0;
 139         int temp;
 140
 141         mutex_lock(&st->lock);
 142         temp = spi_w8r16(st->spi, cmd);
 143         if (temp < 0) {
 144                 ret = temp;
 145                 goto err_unlock;
 146         }
 147
 148         /* extract lower 12 bits temperature reading */
 149         *val = temp & 0x0FFF;
 150
 151 err_unlock:
 152         mutex_unlock(&st->lock);
 153         return ret;
 154 }
 155
 156 static int adxrs290_get_3db_freq(struct iio_dev *indio_dev, u8 *val, u8 *val2)
 157 {
 158         const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_FILTER);
 159         struct adxrs290_state *st = iio_priv(indio_dev);
 160         int ret = 0;
 161         short temp;
 162
 163         mutex_lock(&st->lock);
 164         temp = spi_w8r8(st->spi, cmd);
 165         if (temp < 0) {
 166                 ret = temp;
 167                 goto err_unlock;
 168         }
 169
 170         *val = FIELD_GET(ADXRS290_LPF_MASK, temp);
 171         *val2 = FIELD_GET(ADXRS290_HPF_MASK, temp);
 172
 173 err_unlock:
 174         mutex_unlock(&st->lock);
 175         return ret;
 176 }
 177
 178 static int adxrs290_spi_write_reg(struct spi_device *spi, const u8 reg,
 179                                   const u8 val)
 180 {
 181         u8 buf[2];
 182
 183         buf[0] = reg;
 184         buf[1] = val;
 185
 186         return spi_write_then_read(spi, buf, ARRAY_SIZE(buf), NULL, 0);
 187 }
 188
 189 static int adxrs290_find_match(const int (*freq_tbl)[2], const int n,
 190                                const int val, const int val2)
 191 {
 192         int i;
 193
 194         for (i = 0; i < n; i++) {
 195                 if (freq_tbl[i][0] == val && freq_tbl[i][1] == val2)
 196                         return i;
 197         }
 198
 199         return -EINVAL;
 200 }
 201
 202 static int adxrs290_set_filter_freq(struct iio_dev *indio_dev,
 203                                     const unsigned int lpf_idx,
 204                                     const unsigned int hpf_idx)
 205 {
 206         struct adxrs290_state *st = iio_priv(indio_dev);
 207         u8 val;
 208
 209         val = ADXRS290_HPF(hpf_idx) | ADXRS290_LPF(lpf_idx);
 210
 211         return adxrs290_spi_write_reg(st->spi, ADXRS290_REG_FILTER, val);
 212 }
 213
 214 static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
 215 {
 216         struct adxrs290_state *st = iio_priv(indio_dev);
 217         int val, ret;
 218
 219         if (st->mode == mode)
 220                 return 0;
 221
 222         mutex_lock(&st->lock);
 223
 224         ret = spi_w8r8(st->spi, ADXRS290_READ_REG(ADXRS290_REG_POWER_CTL));
 225         if (ret < 0)
 226                 goto out_unlock;
 227
 228         val = ret;
 229
 230         switch (mode) {
 231         case ADXRS290_MODE_STANDBY:
 232                 val &= ~ADXRS290_MEASUREMENT;
 233                 break;
 234         case ADXRS290_MODE_MEASUREMENT:
 235                 val |= ADXRS290_MEASUREMENT;
 236                 break;
 237         default:
 238                 ret = -EINVAL;
 239                 goto out_unlock;
 240         }
 241
 242         ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_POWER_CTL, val);
 243         if (ret < 0) {
 244                 dev_err(&st->spi->dev, "unable to set mode: %d\n", ret);
 245                 goto out_unlock;
 246         }
 247
 248         /* update cached mode */
 249         st->mode = mode;
 250
 251 out_unlock:
 252         mutex_unlock(&st->lock);
 253         return ret;
 254 }
 255
 256 static void adxrs290_chip_off_action(void *data)
 257 {
 258         struct iio_dev *indio_dev = data;
 259
 260         adxrs290_set_mode(indio_dev, ADXRS290_MODE_STANDBY);
 261 }
 262
 263 static int adxrs290_initial_setup(struct iio_dev *indio_dev)
 264 {
 265         struct adxrs290_state *st = iio_priv(indio_dev);
 266         struct spi_device *spi = st->spi;
 267         int ret;
 268
 269         ret = adxrs290_spi_write_reg(spi, ADXRS290_REG_POWER_CTL,
 270                                      ADXRS290_MEASUREMENT | ADXRS290_TSM);
 271         if (ret < 0)
 272                 return ret;
 273
 274         st->mode = ADXRS290_MODE_MEASUREMENT;
 275
 276         return devm_add_action_or_reset(&spi->dev, adxrs290_chip_off_action,
 277                                         indio_dev);
 278 }
 279
 280 static int adxrs290_read_raw(struct iio_dev *indio_dev,
 281                              struct iio_chan_spec const *chan,
 282                              int *val,
 283                              int *val2,
 284                              long mask)
 285 {
 286         struct adxrs290_state *st = iio_priv(indio_dev);
 287         unsigned int t;
 288         int ret;
 289
 290         switch (mask) {
 291         case IIO_CHAN_INFO_RAW:
 292                 ret = iio_device_claim_direct_mode(indio_dev);
 293                 if (ret)
 294                         return ret;
 295
 296                 switch (chan->type) {
 297                 case IIO_ANGL_VEL:
 298                         ret = adxrs290_get_rate_data(indio_dev,
 299                                                      ADXRS290_READ_REG(chan->address),
 300                                                      val);
 301                         if (ret < 0)
 302                                 break;
 303
 304                         ret = IIO_VAL_INT;
 305                         break;
 306                 case IIO_TEMP:
 307                         ret = adxrs290_get_temp_data(indio_dev, val);
 308                         if (ret < 0)
 309                                 break;
 310
 311                         ret = IIO_VAL_INT;
 312                         break;
 313                 default:
 314                         ret = -EINVAL;
 315                         break;
 316                 }
 317
 318                 iio_device_release_direct_mode(indio_dev);
 319                 return ret;
 320         case IIO_CHAN_INFO_SCALE:
 321                 switch (chan->type) {
 322                 case IIO_ANGL_VEL:
 323                         /* 1 LSB = 0.005 degrees/sec */
 324                         *val = 0;
 325                         *val2 = 87266;
 326                         return IIO_VAL_INT_PLUS_NANO;
 327                 case IIO_TEMP:
 328                         /* 1 LSB = 0.1 degrees Celsius */
 329                         *val = 100;
 330                         return IIO_VAL_INT;
 331                 default:
 332                         return -EINVAL;
 333                 }
 334         case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 335                 switch (chan->type) {
 336                 case IIO_ANGL_VEL:
 337                         t = st->lpf_3db_freq_idx;
 338                         *val = adxrs290_lpf_3db_freq_hz_table[t][0];
 339                         *val2 = adxrs290_lpf_3db_freq_hz_table[t][1];
 340                         return IIO_VAL_INT_PLUS_MICRO;
 341                 default:
 342                         return -EINVAL;
 343                 }
 344         case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
 345                 switch (chan->type) {
 346                 case IIO_ANGL_VEL:
 347                         t = st->hpf_3db_freq_idx;
 348                         *val = adxrs290_hpf_3db_freq_hz_table[t][0];
 349                         *val2 = adxrs290_hpf_3db_freq_hz_table[t][1];
 350                         return IIO_VAL_INT_PLUS_MICRO;
 351                 default:
 352                         return -EINVAL;
 353                 }
 354         }
 355
 356         return -EINVAL;
 357 }
 358
 359 static int adxrs290_write_raw(struct iio_dev *indio_dev,
 360                               struct iio_chan_spec const *chan,
 361                               int val,
 362                               int val2,
 363                               long mask)
 364 {
 365         struct adxrs290_state *st = iio_priv(indio_dev);
 366         int ret, lpf_idx, hpf_idx;
 367
 368         ret = iio_device_claim_direct_mode(indio_dev);
 369         if (ret)
 370                 return ret;
 371
 372         switch (mask) {
 373         case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 374                 lpf_idx = adxrs290_find_match(adxrs290_lpf_3db_freq_hz_table,
 375                                               ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table),
 376                                               val, val2);
 377                 if (lpf_idx < 0) {
 378                         ret = -EINVAL;
 379                         break;
 380                 }
 381
 382                 /* caching the updated state of the low-pass filter */
 383                 st->lpf_3db_freq_idx = lpf_idx;
 384                 /* retrieving the current state of the high-pass filter */
 385                 hpf_idx = st->hpf_3db_freq_idx;
 386                 ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
 387                 break;
 388
 389         case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
 390                 hpf_idx = adxrs290_find_match(adxrs290_hpf_3db_freq_hz_table,
 391                                               ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table),
 392                                               val, val2);
 393                 if (hpf_idx < 0) {
 394                         ret = -EINVAL;
 395                         break;
 396                 }
 397
 398                 /* caching the updated state of the high-pass filter */
 399                 st->hpf_3db_freq_idx = hpf_idx;
 400                 /* retrieving the current state of the low-pass filter */
 401                 lpf_idx = st->lpf_3db_freq_idx;
 402                 ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
 403                 break;
 404
 405         default:
 406                 ret = -EINVAL;
 407                 break;
 408         }
 409
 410         iio_device_release_direct_mode(indio_dev);
 411         return ret;
 412 }
 413
 414 static int adxrs290_read_avail(struct iio_dev *indio_dev,
 415                                struct iio_chan_spec const *chan,
 416                                const int **vals, int *type, int *length,
 417                                long mask)
 418 {
 419         switch (mask) {
 420         case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 421                 *vals = (const int *)adxrs290_lpf_3db_freq_hz_table;
 422                 *type = IIO_VAL_INT_PLUS_MICRO;
 423                 /* Values are stored in a 2D matrix */
 424                 *length = ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table) * 2;
 425
 426                 return IIO_AVAIL_LIST;
 427         case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
 428                 *vals = (const int *)adxrs290_hpf_3db_freq_hz_table;
 429                 *type = IIO_VAL_INT_PLUS_MICRO;
 430                 /* Values are stored in a 2D matrix */
 431                 *length = ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table) * 2;
 432
 433                 return IIO_AVAIL_LIST;
 434         default:
 435                 return -EINVAL;
 436         }
 437 }
 438
 439 static int adxrs290_reg_access_rw(struct spi_device *spi, unsigned int reg,
 440                                   unsigned int *readval)
 441 {
 442         int ret;
 443
 444         ret = spi_w8r8(spi, ADXRS290_READ_REG(reg));
 445         if (ret < 0)
 446                 return ret;
 447
 448         *readval = ret;
 449
 450         return 0;
 451 }
 452
 453 static int adxrs290_reg_access(struct iio_dev *indio_dev, unsigned int reg,
 454                                unsigned int writeval, unsigned int *readval)
 455 {
 456         struct adxrs290_state *st = iio_priv(indio_dev);
 457
 458         if (readval)
 459                 return adxrs290_reg_access_rw(st->spi, reg, readval);
 460         else
 461                 return adxrs290_spi_write_reg(st->spi, reg, writeval);
 462 }
 463
 464 static int adxrs290_data_rdy_trigger_set_state(struct iio_trigger *trig,
 465                                                bool state)
 466 {
 467         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 468         struct adxrs290_state *st = iio_priv(indio_dev);
 469         int ret;
 470         u8 val;
 471
 472         val = state ? ADXRS290_SYNC(ADXRS290_DATA_RDY_OUT) : 0;
 473
 474         ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_DATA_RDY, val);
 475         if (ret < 0)
 476                 dev_err(&st->spi->dev, "failed to start data rdy interrupt\n");
 477
 478         return ret;
 479 }
 480
 481 static void adxrs290_reset_trig(struct iio_trigger *trig)
 482 {
 483         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 484         int val;
 485
 486         /*
 487          * Data ready interrupt is reset after a read of the data registers.
 488          * Here, we only read the 16b DATAY registers as that marks the end of
 489          * a read of the data registers and initiates a reset for the interrupt
 490          * line.
 491          */
 492         adxrs290_get_rate_data(indio_dev,
 493                                ADXRS290_READ_REG(ADXRS290_REG_DATAY0), &val);
 494 }
 495
 496 static const struct iio_trigger_ops adxrs290_trigger_ops = {
 497         .set_trigger_state = &adxrs290_data_rdy_trigger_set_state,
 498         .validate_device = &iio_trigger_validate_own_device,
 499         .reenable = &adxrs290_reset_trig,
 500 };
 501
 502 static irqreturn_t adxrs290_trigger_handler(int irq, void *p)
 503 {
 504         struct iio_poll_func *pf = p;
 505         struct iio_dev *indio_dev = pf->indio_dev;
 506         struct adxrs290_state *st = iio_priv(indio_dev);
 507         u8 tx = ADXRS290_READ_REG(ADXRS290_REG_DATAX0);
 508         int ret;
 509
 510         mutex_lock(&st->lock);
 511
 512         /* exercise a bulk data capture starting from reg DATAX0... */
 513         ret = spi_write_then_read(st->spi, &tx, sizeof(tx), st->buffer.channels,
 514                                   sizeof(st->buffer.channels));
 515         if (ret < 0)
 516                 goto out_unlock_notify;
 517
 518         iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
 519                                            pf->timestamp);
 520
 521 out_unlock_notify:
 522         mutex_unlock(&st->lock);
 523         iio_trigger_notify_done(indio_dev->trig);
 524
 525         return IRQ_HANDLED;
 526 }
 527
 528 #define ADXRS290_ANGL_VEL_CHANNEL(reg, axis) {                          \
 529         .type = IIO_ANGL_VEL,                                           \
 530         .address = reg,                                                 \
 531         .modified = 1,                                                  \
 532         .channel2 = IIO_MOD_##axis,                                     \
 533         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
 534         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
 535         BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |              \
 536         BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),              \
 537         .info_mask_shared_by_type_available =                           \
 538         BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |              \
 539         BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),              \
 540         .scan_index = ADXRS290_IDX_##axis,                              \
 541         .scan_type = {                                                  \
 542                 .sign = 's',                                            \
 543                 .realbits = 16,                                         \
 544                 .storagebits = 16,                                      \
 545                 .endianness = IIO_LE,                                   \
 546         },                                                              \
 547 }
 548
 549 static const struct iio_chan_spec adxrs290_channels[] = {
 550         ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAX0, X),
 551         ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAY0, Y),
 552         {
 553                 .type = IIO_TEMP,
 554                 .address = ADXRS290_REG_TEMP0,
 555                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 556                 BIT(IIO_CHAN_INFO_SCALE),
 557                 .scan_index = ADXRS290_IDX_TEMP,
 558                 .scan_type = {
 559                         .sign = 's',
 560                         .realbits = 12,
 561                         .storagebits = 16,
 562                         .endianness = IIO_LE,
 563                 },
 564         },
 565         IIO_CHAN_SOFT_TIMESTAMP(ADXRS290_IDX_TS),
 566 };
 567
 568 static const unsigned long adxrs290_avail_scan_masks[] = {
 569         BIT(ADXRS290_IDX_X) | BIT(ADXRS290_IDX_Y) | BIT(ADXRS290_IDX_TEMP),
 570         0
 571 };
 572
 573 static const struct iio_info adxrs290_info = {
 574         .read_raw = &adxrs290_read_raw,
 575         .write_raw = &adxrs290_write_raw,
 576         .read_avail = &adxrs290_read_avail,
 577         .debugfs_reg_access = &adxrs290_reg_access,
 578 };
 579
 580 static int adxrs290_probe_trigger(struct iio_dev *indio_dev)
 581 {
 582         struct adxrs290_state *st = iio_priv(indio_dev);
 583         int ret;
 584
 585         if (!st->spi->irq) {
 586                 dev_info(&st->spi->dev, "no irq, using polling\n");
 587                 return 0;
 588         }
 589
 590         st->dready_trig = devm_iio_trigger_alloc(&st->spi->dev, "%s-dev%d",
 591                                                  indio_dev->name,
 592                                                  iio_device_id(indio_dev));
 593         if (!st->dready_trig)
 594                 return -ENOMEM;
 595
 596         st->dready_trig->ops = &adxrs290_trigger_ops;
 597         iio_trigger_set_drvdata(st->dready_trig, indio_dev);
 598
 599         ret = devm_request_irq(&st->spi->dev, st->spi->irq,
 600                                &iio_trigger_generic_data_rdy_poll,
 601                                IRQF_ONESHOT, "adxrs290_irq", st->dready_trig);
 602         if (ret < 0)
 603                 return dev_err_probe(&st->spi->dev, ret,
 604                                      "request irq %d failed\n", st->spi->irq);
 605
 606         ret = devm_iio_trigger_register(&st->spi->dev, st->dready_trig);
 607         if (ret) {
 608                 dev_err(&st->spi->dev, "iio trigger register failed\n");
 609                 return ret;
 610         }
 611
 612         indio_dev->trig = iio_trigger_get(st->dready_trig);
 613
 614         return 0;
 615 }
 616
 617 static int adxrs290_probe(struct spi_device *spi)
 618 {
 619         struct iio_dev *indio_dev;
 620         struct adxrs290_state *st;
 621         u8 val, val2;
 622         int ret;
 623
 624         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 625         if (!indio_dev)
 626                 return -ENOMEM;
 627
 628         st = iio_priv(indio_dev);
 629         st->spi = spi;
 630
 631         indio_dev->name = "adxrs290";
 632         indio_dev->modes = INDIO_DIRECT_MODE;
 633         indio_dev->channels = adxrs290_channels;
 634         indio_dev->num_channels = ARRAY_SIZE(adxrs290_channels);
 635         indio_dev->info = &adxrs290_info;
 636         indio_dev->available_scan_masks = adxrs290_avail_scan_masks;
 637
 638         mutex_init(&st->lock);
 639
 640         val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_ADI_ID));
 641         if (val != ADXRS290_ADI_ID) {
 642                 dev_err(&spi->dev, "Wrong ADI ID 0x%02x\n", val);
 643                 return -ENODEV;
 644         }
 645
 646         val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_MEMS_ID));
 647         if (val != ADXRS290_MEMS_ID) {
 648                 dev_err(&spi->dev, "Wrong MEMS ID 0x%02x\n", val);
 649                 return -ENODEV;
 650         }
 651
 652         val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_DEV_ID));
 653         if (val != ADXRS290_DEV_ID) {
 654                 dev_err(&spi->dev, "Wrong DEV ID 0x%02x\n", val);
 655                 return -ENODEV;
 656         }
 657
 658         /* default mode the gyroscope starts in */
 659         st->mode = ADXRS290_MODE_STANDBY;
 660
 661         /* switch to measurement mode and switch on the temperature sensor */
 662         ret = adxrs290_initial_setup(indio_dev);
 663         if (ret < 0)
 664                 return ret;
 665
 666         /* max transition time to measurement mode */
 667         msleep(ADXRS290_MAX_TRANSITION_TIME_MS);
 668
 669         ret = adxrs290_get_3db_freq(indio_dev, &val, &val2);
 670         if (ret < 0)
 671                 return ret;
 672
 673         st->lpf_3db_freq_idx = val;
 674         st->hpf_3db_freq_idx = val2;
 675
 676         ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
 677                                               &iio_pollfunc_store_time,
 678                                               &adxrs290_trigger_handler, NULL);
 679         if (ret < 0)
 680                 return dev_err_probe(&spi->dev, ret,
 681                                      "iio triggered buffer setup failed\n");
 682
 683         ret = adxrs290_probe_trigger(indio_dev);
 684         if (ret < 0)
 685                 return ret;
 686
 687         return devm_iio_device_register(&spi->dev, indio_dev);
 688 }
 689
 690 static const struct of_device_id adxrs290_of_match[] = {
 691         { .compatible = "adi,adxrs290" },
 692         { }
 693 };
 694 MODULE_DEVICE_TABLE(of, adxrs290_of_match);
 695
 696 static struct spi_driver adxrs290_driver = {
 697         .driver = {
 698                 .name = "adxrs290",
 699                 .of_match_table = adxrs290_of_match,
 700         },
 701         .probe = adxrs290_probe,
 702 };
 703 module_spi_driver(adxrs290_driver);
 704
 705 MODULE_AUTHOR("Nishant Malpani <nish.malpani25@gmail.com>");
 706 MODULE_DESCRIPTION("Analog Devices ADXRS290 Gyroscope SPI driver");
 707 MODULE_LICENSE("GPL");