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/bitops.h>
  11 #include <linux/delay.h>
  12 #include <linux/device.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/spi/spi.h>
  16
  17 #include <linux/iio/buffer.h>
  18 #include <linux/iio/iio.h>
  19 #include <linux/iio/sysfs.h>
  20 #include <linux/iio/trigger.h>
  21 #include <linux/iio/triggered_buffer.h>
  22 #include <linux/iio/trigger_consumer.h>
  23
  24 #define ADXRS290_ADI_ID         0xAD
  25 #define ADXRS290_MEMS_ID        0x1D
  26 #define ADXRS290_DEV_ID         0x92
  27
  28 #define ADXRS290_REG_ADI_ID     0x00
  29 #define ADXRS290_REG_MEMS_ID    0x01
  30 #define ADXRS290_REG_DEV_ID     0x02
  31 #define ADXRS290_REG_REV_ID     0x03
  32 #define ADXRS290_REG_SN0        0x04 /* Serial Number Registers, 4 bytes */
  33 #define ADXRS290_REG_DATAX0     0x08 /* Roll Rate o/p Data Regs, 2 bytes */
  34 #define ADXRS290_REG_DATAY0     0x0A /* Pitch Rate o/p Data Regs, 2 bytes */
  35 #define ADXRS290_REG_TEMP0      0x0C
  36 #define ADXRS290_REG_POWER_CTL  0x10
  37 #define ADXRS290_REG_FILTER     0x11
  38 #define ADXRS290_REG_DATA_RDY   0x12
  39
  40 #define ADXRS290_READ           BIT(7)
  41 #define ADXRS290_TSM            BIT(0)
  42 #define ADXRS290_MEASUREMENT    BIT(1)
  43 #define ADXRS290_DATA_RDY_OUT   BIT(0)
  44 #define ADXRS290_SYNC_MASK      GENMASK(1, 0)
  45 #define ADXRS290_SYNC(x)        FIELD_PREP(ADXRS290_SYNC_MASK, x)
  46 #define ADXRS290_LPF_MASK       GENMASK(2, 0)
  47 #define ADXRS290_LPF(x)         FIELD_PREP(ADXRS290_LPF_MASK, x)
  48 #define ADXRS290_HPF_MASK       GENMASK(7, 4)
  49 #define ADXRS290_HPF(x)         FIELD_PREP(ADXRS290_HPF_MASK, x)
  50
  51 #define ADXRS290_READ_REG(reg)  (ADXRS290_READ | (reg))
  52
  53 #define ADXRS290_MAX_TRANSITION_TIME_MS 100
  54
  55 enum adxrs290_mode {
  56         ADXRS290_MODE_STANDBY,
  57         ADXRS290_MODE_MEASUREMENT,
  58 };
  59
  60 enum adxrs290_scan_index {
  61         ADXRS290_IDX_X,
  62         ADXRS290_IDX_Y,
  63         ADXRS290_IDX_TEMP,
  64         ADXRS290_IDX_TS,
  65 };
  66
  67 struct adxrs290_state {
  68         struct spi_device       *spi;
  69         /* Serialize reads and their subsequent processing */
  70         struct mutex            lock;
  71         enum adxrs290_mode      mode;
  72         unsigned int            lpf_3db_freq_idx;
  73         unsigned int            hpf_3db_freq_idx;
  74         struct iio_trigger      *dready_trig;
  75         /* Ensure correct alignment of timestamp when present */
  76         struct {
  77                 s16 channels[3];
  78                 s64 ts __aligned(8);
  79         } buffer;
  80 };
  81
  82 /*
  83  * Available cut-off frequencies of the low pass filter in Hz.
  84  * The integer part and fractional part are represented separately.
  85  */
  86 static const int adxrs290_lpf_3db_freq_hz_table[][2] = {
  87         [0] = {480, 0},
  88         [1] = {320, 0},
  89         [2] = {160, 0},
  90         [3] = {80, 0},
  91         [4] = {56, 600000},
  92         [5] = {40, 0},
  93         [6] = {28, 300000},
  94         [7] = {20, 0},
  95 };
  96
  97 /*
  98  * Available cut-off frequencies of the high pass filter in Hz.
  99  * The integer part and fractional part are represented separately.
 100  */
 101 static const int adxrs290_hpf_3db_freq_hz_table[][2] = {
 102         [0] = {0, 0},
 103         [1] = {0, 11000},
 104         [2] = {0, 22000},
 105         [3] = {0, 44000},
 106         [4] = {0, 87000},
 107         [5] = {0, 175000},
 108         [6] = {0, 350000},
 109         [7] = {0, 700000},
 110         [8] = {1, 400000},
 111         [9] = {2, 800000},
 112         [10] = {11, 300000},
 113 };
 114
 115 static int adxrs290_get_rate_data(struct iio_dev *indio_dev, const u8 cmd, int *val)
 116 {
 117         struct adxrs290_state *st = iio_priv(indio_dev);
 118         int ret = 0;
 119         int temp;
 120
 121         mutex_lock(&st->lock);
 122         temp = spi_w8r16(st->spi, cmd);
 123         if (temp < 0) {
 124                 ret = temp;
 125                 goto err_unlock;
 126         }
 127
 128         *val = sign_extend32(temp, 15);
 129
 130 err_unlock:
 131         mutex_unlock(&st->lock);
 132         return ret;
 133 }
 134
 135 static int adxrs290_get_temp_data(struct iio_dev *indio_dev, int *val)
 136 {
 137         const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_TEMP0);
 138         struct adxrs290_state *st = iio_priv(indio_dev);
 139         int ret = 0;
 140         int temp;
 141
 142         mutex_lock(&st->lock);
 143         temp = spi_w8r16(st->spi, cmd);
 144         if (temp < 0) {
 145                 ret = temp;
 146                 goto err_unlock;
 147         }
 148
 149         /* extract lower 12 bits temperature reading */
 150         *val = sign_extend32(temp, 11);
 151
 152 err_unlock:
 153         mutex_unlock(&st->lock);
 154         return ret;
 155 }
 156
 157 static int adxrs290_get_3db_freq(struct iio_dev *indio_dev, u8 *val, u8 *val2)
 158 {
 159         const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_FILTER);
 160         struct adxrs290_state *st = iio_priv(indio_dev);
 161         int ret = 0;
 162         short temp;
 163
 164         mutex_lock(&st->lock);
 165         temp = spi_w8r8(st->spi, cmd);
 166         if (temp < 0) {
 167                 ret = temp;
 168                 goto err_unlock;
 169         }
 170
 171         *val = FIELD_GET(ADXRS290_LPF_MASK, temp);
 172         *val2 = FIELD_GET(ADXRS290_HPF_MASK, temp);
 173
 174 err_unlock:
 175         mutex_unlock(&st->lock);
 176         return ret;
 177 }
 178
 179 static int adxrs290_spi_write_reg(struct spi_device *spi, const u8 reg,
 180                                   const u8 val)
 181 {
 182         u8 buf[2];
 183
 184         buf[0] = reg;
 185         buf[1] = val;
 186
 187         return spi_write_then_read(spi, buf, ARRAY_SIZE(buf), NULL, 0);
 188 }
 189
 190 static int adxrs290_find_match(const int (*freq_tbl)[2], const int n,
 191                                const int val, const int val2)
 192 {
 193         int i;
 194
 195         for (i = 0; i < n; i++) {
 196                 if (freq_tbl[i][0] == val && freq_tbl[i][1] == val2)
 197                         return i;
 198         }
 199
 200         return -EINVAL;
 201 }
 202
 203 static int adxrs290_set_filter_freq(struct iio_dev *indio_dev,
 204                                     const unsigned int lpf_idx,
 205                                     const unsigned int hpf_idx)
 206 {
 207         struct adxrs290_state *st = iio_priv(indio_dev);
 208         u8 val;
 209
 210         val = ADXRS290_HPF(hpf_idx) | ADXRS290_LPF(lpf_idx);
 211
 212         return adxrs290_spi_write_reg(st->spi, ADXRS290_REG_FILTER, val);
 213 }
 214
 215 static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
 216 {
 217         struct adxrs290_state *st = iio_priv(indio_dev);
 218         int val, ret;
 219
 220         if (st->mode == mode)
 221                 return 0;
 222
 223         mutex_lock(&st->lock);
 224
 225         ret = spi_w8r8(st->spi, ADXRS290_READ_REG(ADXRS290_REG_POWER_CTL));
 226         if (ret < 0)
 227                 goto out_unlock;
 228
 229         val = ret;
 230
 231         switch (mode) {
 232         case ADXRS290_MODE_STANDBY:
 233                 val &= ~ADXRS290_MEASUREMENT;
 234                 break;
 235         case ADXRS290_MODE_MEASUREMENT:
 236                 val |= ADXRS290_MEASUREMENT;
 237                 break;
 238         default:
 239                 ret = -EINVAL;
 240                 goto out_unlock;
 241         }
 242
 243         ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_POWER_CTL, val);
 244         if (ret < 0) {
 245                 dev_err(&st->spi->dev, "unable to set mode: %d\n", ret);
 246                 goto out_unlock;
 247         }
 248
 249         /* update cached mode */
 250         st->mode = mode;
 251
 252 out_unlock:
 253         mutex_unlock(&st->lock);
 254         return ret;
 255 }
 256
 257 static void adxrs290_chip_off_action(void *data)
 258 {
 259         struct iio_dev *indio_dev = data;
 260
 261         adxrs290_set_mode(indio_dev, ADXRS290_MODE_STANDBY);
 262 }
 263
 264 static int adxrs290_initial_setup(struct iio_dev *indio_dev)
 265 {
 266         struct adxrs290_state *st = iio_priv(indio_dev);
 267         struct spi_device *spi = st->spi;
 268         int ret;
 269
 270         ret = adxrs290_spi_write_reg(spi, ADXRS290_REG_POWER_CTL,
 271                                      ADXRS290_MEASUREMENT | ADXRS290_TSM);
 272         if (ret < 0)
 273                 return ret;
 274
 275         st->mode = ADXRS290_MODE_MEASUREMENT;
 276
 277         return devm_add_action_or_reset(&spi->dev, adxrs290_chip_off_action,
 278                                         indio_dev);
 279 }
 280
 281 static int adxrs290_read_raw(struct iio_dev *indio_dev,
 282                              struct iio_chan_spec const *chan,
 283                              int *val,
 284                              int *val2,
 285                              long mask)
 286 {
 287         struct adxrs290_state *st = iio_priv(indio_dev);
 288         unsigned int t;
 289         int ret;
 290
 291         switch (mask) {
 292         case IIO_CHAN_INFO_RAW:
 293                 ret = iio_device_claim_direct_mode(indio_dev);
 294                 if (ret)
 295                         return ret;
 296
 297                 switch (chan->type) {
 298                 case IIO_ANGL_VEL:
 299                         ret = adxrs290_get_rate_data(indio_dev,
 300                                                      ADXRS290_READ_REG(chan->address),
 301                                                      val);
 302                         if (ret < 0)
 303                                 break;
 304
 305                         ret = IIO_VAL_INT;
 306                         break;
 307                 case IIO_TEMP:
 308                         ret = adxrs290_get_temp_data(indio_dev, val);
 309                         if (ret < 0)
 310                                 break;
 311
 312                         ret = IIO_VAL_INT;
 313                         break;
 314                 default:
 315                         ret = -EINVAL;
 316                         break;
 317                 }
 318
 319                 iio_device_release_direct_mode(indio_dev);
 320                 return ret;
 321         case IIO_CHAN_INFO_SCALE:
 322                 switch (chan->type) {
 323                 case IIO_ANGL_VEL:
 324                         /* 1 LSB = 0.005 degrees/sec */
 325                         *val = 0;
 326                         *val2 = 87266;
 327                         return IIO_VAL_INT_PLUS_NANO;
 328                 case IIO_TEMP:
 329                         /* 1 LSB = 0.1 degrees Celsius */
 330                         *val = 100;
 331                         return IIO_VAL_INT;
 332                 default:
 333                         return -EINVAL;
 334                 }
 335         case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 336                 switch (chan->type) {
 337                 case IIO_ANGL_VEL:
 338                         t = st->lpf_3db_freq_idx;
 339                         *val = adxrs290_lpf_3db_freq_hz_table[t][0];
 340                         *val2 = adxrs290_lpf_3db_freq_hz_table[t][1];
 341                         return IIO_VAL_INT_PLUS_MICRO;
 342                 default:
 343                         return -EINVAL;
 344                 }
 345         case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
 346                 switch (chan->type) {
 347                 case IIO_ANGL_VEL:
 348                         t = st->hpf_3db_freq_idx;
 349                         *val = adxrs290_hpf_3db_freq_hz_table[t][0];
 350                         *val2 = adxrs290_hpf_3db_freq_hz_table[t][1];
 351                         return IIO_VAL_INT_PLUS_MICRO;
 352                 default:
 353                         return -EINVAL;
 354                 }
 355         }
 356
 357         return -EINVAL;
 358 }
 359
 360 static int adxrs290_write_raw(struct iio_dev *indio_dev,
 361                               struct iio_chan_spec const *chan,
 362                               int val,
 363                               int val2,
 364                               long mask)
 365 {
 366         struct adxrs290_state *st = iio_priv(indio_dev);
 367         int ret, lpf_idx, hpf_idx;
 368
 369         ret = iio_device_claim_direct_mode(indio_dev);
 370         if (ret)
 371                 return ret;
 372
 373         switch (mask) {
 374         case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 375                 lpf_idx = adxrs290_find_match(adxrs290_lpf_3db_freq_hz_table,
 376                                               ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table),
 377                                               val, val2);
 378                 if (lpf_idx < 0) {
 379                         ret = -EINVAL;
 380                         break;
 381                 }
 382
 383                 /* caching the updated state of the low-pass filter */
 384                 st->lpf_3db_freq_idx = lpf_idx;
 385                 /* retrieving the current state of the high-pass filter */
 386                 hpf_idx = st->hpf_3db_freq_idx;
 387                 ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
 388                 break;
 389
 390         case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
 391                 hpf_idx = adxrs290_find_match(adxrs290_hpf_3db_freq_hz_table,
 392                                               ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table),
 393                                               val, val2);
 394                 if (hpf_idx < 0) {
 395                         ret = -EINVAL;
 396                         break;
 397                 }
 398
 399                 /* caching the updated state of the high-pass filter */
 400                 st->hpf_3db_freq_idx = hpf_idx;
 401                 /* retrieving the current state of the low-pass filter */
 402                 lpf_idx = st->lpf_3db_freq_idx;
 403                 ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
 404                 break;
 405
 406         default:
 407                 ret = -EINVAL;
 408                 break;
 409         }
 410
 411         iio_device_release_direct_mode(indio_dev);
 412         return ret;
 413 }
 414
 415 static int adxrs290_read_avail(struct iio_dev *indio_dev,
 416                                struct iio_chan_spec const *chan,
 417                                const int **vals, int *type, int *length,
 418                                long mask)
 419 {
 420         switch (mask) {
 421         case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 422                 *vals = (const int *)adxrs290_lpf_3db_freq_hz_table;
 423                 *type = IIO_VAL_INT_PLUS_MICRO;
 424                 /* Values are stored in a 2D matrix */
 425                 *length = ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table) * 2;
 426
 427                 return IIO_AVAIL_LIST;
 428         case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
 429                 *vals = (const int *)adxrs290_hpf_3db_freq_hz_table;
 430                 *type = IIO_VAL_INT_PLUS_MICRO;
 431                 /* Values are stored in a 2D matrix */
 432                 *length = ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table) * 2;
 433
 434                 return IIO_AVAIL_LIST;
 435         default:
 436                 return -EINVAL;
 437         }
 438 }
 439
 440 static int adxrs290_reg_access_rw(struct spi_device *spi, unsigned int reg,
 441                                   unsigned int *readval)
 442 {
 443         int ret;
 444
 445         ret = spi_w8r8(spi, ADXRS290_READ_REG(reg));
 446         if (ret < 0)
 447                 return ret;
 448
 449         *readval = ret;
 450
 451         return 0;
 452 }
 453
 454 static int adxrs290_reg_access(struct iio_dev *indio_dev, unsigned int reg,
 455                                unsigned int writeval, unsigned int *readval)
 456 {
 457         struct adxrs290_state *st = iio_priv(indio_dev);
 458
 459         if (readval)
 460                 return adxrs290_reg_access_rw(st->spi, reg, readval);
 461         else
 462                 return adxrs290_spi_write_reg(st->spi, reg, writeval);
 463 }
 464
 465 static int adxrs290_data_rdy_trigger_set_state(struct iio_trigger *trig,
 466                                                bool state)
 467 {
 468         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 469         struct adxrs290_state *st = iio_priv(indio_dev);
 470         int ret;
 471         u8 val;
 472
 473         val = state ? ADXRS290_SYNC(ADXRS290_DATA_RDY_OUT) : 0;
 474
 475         ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_DATA_RDY, val);
 476         if (ret < 0)
 477                 dev_err(&st->spi->dev, "failed to start data rdy interrupt\n");
 478
 479         return ret;
 480 }
 481
 482 static void adxrs290_reset_trig(struct iio_trigger *trig)
 483 {
 484         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 485         int val;
 486
 487         /*
 488          * Data ready interrupt is reset after a read of the data registers.
 489          * Here, we only read the 16b DATAY registers as that marks the end of
 490          * a read of the data registers and initiates a reset for the interrupt
 491          * line.
 492          */
 493         adxrs290_get_rate_data(indio_dev,
 494                                ADXRS290_READ_REG(ADXRS290_REG_DATAY0), &val);
 495 }
 496
 497 static const struct iio_trigger_ops adxrs290_trigger_ops = {
 498         .set_trigger_state = &adxrs290_data_rdy_trigger_set_state,
 499         .validate_device = &iio_trigger_validate_own_device,
 500         .reenable = &adxrs290_reset_trig,
 501 };
 502
 503 static irqreturn_t adxrs290_trigger_handler(int irq, void *p)
 504 {
 505         struct iio_poll_func *pf = p;
 506         struct iio_dev *indio_dev = pf->indio_dev;
 507         struct adxrs290_state *st = iio_priv(indio_dev);
 508         u8 tx = ADXRS290_READ_REG(ADXRS290_REG_DATAX0);
 509         int ret;
 510
 511         mutex_lock(&st->lock);
 512
 513         /* exercise a bulk data capture starting from reg DATAX0... */
 514         ret = spi_write_then_read(st->spi, &tx, sizeof(tx), st->buffer.channels,
 515                                   sizeof(st->buffer.channels));
 516         if (ret < 0)
 517                 goto out_unlock_notify;
 518
 519         iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
 520                                            pf->timestamp);
 521
 522 out_unlock_notify:
 523         mutex_unlock(&st->lock);
 524         iio_trigger_notify_done(indio_dev->trig);
 525
 526         return IRQ_HANDLED;
 527 }
 528
 529 #define ADXRS290_ANGL_VEL_CHANNEL(reg, axis) {                          \
 530         .type = IIO_ANGL_VEL,                                           \
 531         .address = reg,                                                 \
 532         .modified = 1,                                                  \
 533         .channel2 = IIO_MOD_##axis,                                     \
 534         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
 535         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
 536         BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |              \
 537         BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),              \
 538         .info_mask_shared_by_type_available =                           \
 539         BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |              \
 540         BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY),              \
 541         .scan_index = ADXRS290_IDX_##axis,                              \
 542         .scan_type = {                                                  \
 543                 .sign = 's',                                            \
 544                 .realbits = 16,                                         \
 545                 .storagebits = 16,                                      \
 546                 .endianness = IIO_LE,                                   \
 547         },                                                              \
 548 }
 549
 550 static const struct iio_chan_spec adxrs290_channels[] = {
 551         ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAX0, X),
 552         ADXRS290_ANGL_VEL_CHANNEL(ADXRS290_REG_DATAY0, Y),
 553         {
 554                 .type = IIO_TEMP,
 555                 .address = ADXRS290_REG_TEMP0,
 556                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 557                 BIT(IIO_CHAN_INFO_SCALE),
 558                 .scan_index = ADXRS290_IDX_TEMP,
 559                 .scan_type = {
 560                         .sign = 's',
 561                         .realbits = 12,
 562                         .storagebits = 16,
 563                         .endianness = IIO_LE,
 564                 },
 565         },
 566         IIO_CHAN_SOFT_TIMESTAMP(ADXRS290_IDX_TS),
 567 };
 568
 569 static const unsigned long adxrs290_avail_scan_masks[] = {
 570         BIT(ADXRS290_IDX_X) | BIT(ADXRS290_IDX_Y) | BIT(ADXRS290_IDX_TEMP),
 571         0
 572 };
 573
 574 static const struct iio_info adxrs290_info = {
 575         .read_raw = &adxrs290_read_raw,
 576         .write_raw = &adxrs290_write_raw,
 577         .read_avail = &adxrs290_read_avail,
 578         .debugfs_reg_access = &adxrs290_reg_access,
 579 };
 580
 581 static int adxrs290_probe_trigger(struct iio_dev *indio_dev)
 582 {
 583         struct adxrs290_state *st = iio_priv(indio_dev);
 584         int ret;
 585
 586         if (!st->spi->irq) {
 587                 dev_info(&st->spi->dev, "no irq, using polling\n");
 588                 return 0;
 589         }
 590
 591         st->dready_trig = devm_iio_trigger_alloc(&st->spi->dev, "%s-dev%d",
 592                                                  indio_dev->name,
 593                                                  iio_device_id(indio_dev));
 594         if (!st->dready_trig)
 595                 return -ENOMEM;
 596
 597         st->dready_trig->ops = &adxrs290_trigger_ops;
 598         iio_trigger_set_drvdata(st->dready_trig, indio_dev);
 599
 600         ret = devm_request_irq(&st->spi->dev, st->spi->irq,
 601                                &iio_trigger_generic_data_rdy_poll,
 602                                IRQF_ONESHOT, "adxrs290_irq", st->dready_trig);
 603         if (ret < 0)
 604                 return dev_err_probe(&st->spi->dev, ret,
 605                                      "request irq %d failed\n", st->spi->irq);
 606
 607         ret = devm_iio_trigger_register(&st->spi->dev, st->dready_trig);
 608         if (ret) {
 609                 dev_err(&st->spi->dev, "iio trigger register failed\n");
 610                 return ret;
 611         }
 612
 613         indio_dev->trig = iio_trigger_get(st->dready_trig);
 614
 615         return 0;
 616 }
 617
 618 static int adxrs290_probe(struct spi_device *spi)
 619 {
 620         struct iio_dev *indio_dev;
 621         struct adxrs290_state *st;
 622         u8 val, val2;
 623         int ret;
 624
 625         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 626         if (!indio_dev)
 627                 return -ENOMEM;
 628
 629         st = iio_priv(indio_dev);
 630         st->spi = spi;
 631
 632         indio_dev->name = "adxrs290";
 633         indio_dev->modes = INDIO_DIRECT_MODE;
 634         indio_dev->channels = adxrs290_channels;
 635         indio_dev->num_channels = ARRAY_SIZE(adxrs290_channels);
 636         indio_dev->info = &adxrs290_info;
 637         indio_dev->available_scan_masks = adxrs290_avail_scan_masks;
 638
 639         mutex_init(&st->lock);
 640
 641         val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_ADI_ID));
 642         if (val != ADXRS290_ADI_ID) {
 643                 dev_err(&spi->dev, "Wrong ADI ID 0x%02x\n", val);
 644                 return -ENODEV;
 645         }
 646
 647         val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_MEMS_ID));
 648         if (val != ADXRS290_MEMS_ID) {
 649                 dev_err(&spi->dev, "Wrong MEMS ID 0x%02x\n", val);
 650                 return -ENODEV;
 651         }
 652
 653         val = spi_w8r8(spi, ADXRS290_READ_REG(ADXRS290_REG_DEV_ID));
 654         if (val != ADXRS290_DEV_ID) {
 655                 dev_err(&spi->dev, "Wrong DEV ID 0x%02x\n", val);
 656                 return -ENODEV;
 657         }
 658
 659         /* default mode the gyroscope starts in */
 660         st->mode = ADXRS290_MODE_STANDBY;
 661
 662         /* switch to measurement mode and switch on the temperature sensor */
 663         ret = adxrs290_initial_setup(indio_dev);
 664         if (ret < 0)
 665                 return ret;
 666
 667         /* max transition time to measurement mode */
 668         msleep(ADXRS290_MAX_TRANSITION_TIME_MS);
 669
 670         ret = adxrs290_get_3db_freq(indio_dev, &val, &val2);
 671         if (ret < 0)
 672                 return ret;
 673
 674         st->lpf_3db_freq_idx = val;
 675         st->hpf_3db_freq_idx = val2;
 676
 677         ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
 678                                               &iio_pollfunc_store_time,
 679                                               &adxrs290_trigger_handler, NULL);
 680         if (ret < 0)
 681                 return dev_err_probe(&spi->dev, ret,
 682                                      "iio triggered buffer setup failed\n");
 683
 684         ret = adxrs290_probe_trigger(indio_dev);
 685         if (ret < 0)
 686                 return ret;
 687
 688         return devm_iio_device_register(&spi->dev, indio_dev);
 689 }
 690
 691 static const struct of_device_id adxrs290_of_match[] = {
 692         { .compatible = "adi,adxrs290" },
 693         { }
 694 };
 695 MODULE_DEVICE_TABLE(of, adxrs290_of_match);
 696
 697 static struct spi_driver adxrs290_driver = {
 698         .driver = {
 699                 .name = "adxrs290",
 700                 .of_match_table = adxrs290_of_match,
 701         },
 702         .probe = adxrs290_probe,
 703 };
 704 module_spi_driver(adxrs290_driver);
 705
 706 MODULE_AUTHOR("Nishant Malpani <nish.malpani25@gmail.com>");
 707 MODULE_DESCRIPTION("Analog Devices ADXRS290 Gyroscope SPI driver");
 708 MODULE_LICENSE("GPL");