linux/drivers/iio/gyro/adxrs290.c
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   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
  54enum adxrs290_mode {
  55        ADXRS290_MODE_STANDBY,
  56        ADXRS290_MODE_MEASUREMENT,
  57};
  58
  59enum adxrs290_scan_index {
  60        ADXRS290_IDX_X,
  61        ADXRS290_IDX_Y,
  62        ADXRS290_IDX_TEMP,
  63        ADXRS290_IDX_TS,
  64};
  65
  66struct 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 */
  85static 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 */
 100static 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
 114static 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
 129err_unlock:
 130        mutex_unlock(&st->lock);
 131        return ret;
 132}
 133
 134static 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
 151err_unlock:
 152        mutex_unlock(&st->lock);
 153        return ret;
 154}
 155
 156static 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
 173err_unlock:
 174        mutex_unlock(&st->lock);
 175        return ret;
 176}
 177
 178static 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
 189static 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
 202static 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
 214static 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
 251out_unlock:
 252        mutex_unlock(&st->lock);
 253        return ret;
 254}
 255
 256static 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
 263static 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
 280static 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
 359static 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
 414static 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
 439static 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
 453static 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
 464static 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
 481static 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
 496static 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
 502static 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
 521out_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
 549static 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
 568static const unsigned long adxrs290_avail_scan_masks[] = {
 569        BIT(ADXRS290_IDX_X) | BIT(ADXRS290_IDX_Y) | BIT(ADXRS290_IDX_TEMP),
 570        0
 571};
 572
 573static 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
 580static 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
 617static 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
 690static const struct of_device_id adxrs290_of_match[] = {
 691        { .compatible = "adi,adxrs290" },
 692        { }
 693};
 694MODULE_DEVICE_TABLE(of, adxrs290_of_match);
 695
 696static struct spi_driver adxrs290_driver = {
 697        .driver = {
 698                .name = "adxrs290",
 699                .of_match_table = adxrs290_of_match,
 700        },
 701        .probe = adxrs290_probe,
 702};
 703module_spi_driver(adxrs290_driver);
 704
 705MODULE_AUTHOR("Nishant Malpani <nish.malpani25@gmail.com>");
 706MODULE_DESCRIPTION("Analog Devices ADXRS290 Gyroscope SPI driver");
 707MODULE_LICENSE("GPL");
 708