drivers/iio/accel/stk8312.c

   1 /**
   2  * Sensortek STK8312 3-Axis Accelerometer
   3  *
   4  * Copyright (c) 2015, Intel Corporation.
   5  *
   6  * This file is subject to the terms and conditions of version 2 of
   7  * the GNU General Public License. See the file COPYING in the main
   8  * directory of this archive for more details.
   9  *
  10  * IIO driver for STK8312; 7-bit I2C address: 0x3D.
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/i2c.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/delay.h>
  19 #include <linux/iio/buffer.h>
  20 #include <linux/iio/iio.h>
  21 #include <linux/iio/sysfs.h>
  22 #include <linux/iio/trigger.h>
  23 #include <linux/iio/triggered_buffer.h>
  24 #include <linux/iio/trigger_consumer.h>
  25
  26 #define STK8312_REG_XOUT                0x00
  27 #define STK8312_REG_YOUT                0x01
  28 #define STK8312_REG_ZOUT                0x02
  29 #define STK8312_REG_INTSU               0x06
  30 #define STK8312_REG_MODE                0x07
  31 #define STK8312_REG_SR                  0x08
  32 #define STK8312_REG_STH                 0x13
  33 #define STK8312_REG_RESET               0x20
  34 #define STK8312_REG_AFECTRL             0x24
  35 #define STK8312_REG_OTPADDR             0x3D
  36 #define STK8312_REG_OTPDATA             0x3E
  37 #define STK8312_REG_OTPCTRL             0x3F
  38
  39 #define STK8312_MODE_ACTIVE             BIT(0)
  40 #define STK8312_MODE_STANDBY            0x00
  41 #define STK8312_MODE_INT_AH_PP          0xC0    /* active-high, push-pull */
  42 #define STK8312_DREADY_BIT              BIT(4)
  43 #define STK8312_RNG_6G                  1
  44 #define STK8312_RNG_SHIFT               6
  45 #define STK8312_RNG_MASK                GENMASK(7, 6)
  46 #define STK8312_SR_MASK                 GENMASK(2, 0)
  47 #define STK8312_SR_400HZ_IDX            0
  48 #define STK8312_ALL_CHANNEL_MASK        GENMASK(2, 0)
  49 #define STK8312_ALL_CHANNEL_SIZE        3
  50
  51 #define STK8312_DRIVER_NAME             "stk8312"
  52 #define STK8312_IRQ_NAME                "stk8312_event"
  53
  54 /*
  55  * The accelerometer has two measurement ranges:
  56  *
  57  * -6g - +6g (8-bit, signed)
  58  * -16g - +16g (8-bit, signed)
  59  *
  60  * scale1 = (6 + 6) * 9.81 / (2^8 - 1)     = 0.4616
  61  * scale2 = (16 + 16) * 9.81 / (2^8 - 1)   = 1.2311
  62  */
  63 #define STK8312_SCALE_AVAIL             "0.4616 1.2311"
  64
  65 static const int stk8312_scale_table[][2] = {
  66         {0, 461600}, {1, 231100}
  67 };
  68
  69 static const struct {
  70         int val;
  71         int val2;
  72 } stk8312_samp_freq_table[] = {
  73         {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
  74         {12, 500000}, {6, 250000}, {3, 125000}
  75 };
  76
  77 #define STK8312_ACCEL_CHANNEL(index, reg, axis) {                       \
  78         .type = IIO_ACCEL,                                              \
  79         .address = reg,                                                 \
  80         .modified = 1,                                                  \
  81         .channel2 = IIO_MOD_##axis,                                     \
  82         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
  83         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
  84                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
  85         .scan_index = index,                                            \
  86         .scan_type = {                                                  \
  87                 .sign = 's',                                            \
  88                 .realbits = 8,                                          \
  89                 .storagebits = 8,                                       \
  90                 .endianness = IIO_CPU,                                  \
  91         },                                                              \
  92 }
  93
  94 static const struct iio_chan_spec stk8312_channels[] = {
  95         STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),
  96         STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),
  97         STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),
  98         IIO_CHAN_SOFT_TIMESTAMP(3),
  99 };
 100
 101 struct stk8312_data {
 102         struct i2c_client *client;
 103         struct mutex lock;
 104         u8 range;
 105         u8 sample_rate_idx;
 106         u8 mode;
 107         struct iio_trigger *dready_trig;
 108         bool dready_trigger_on;
 109         s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
 110 };
 111
 112 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
 113
 114 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
 115
 116 static struct attribute *stk8312_attributes[] = {
 117         &iio_const_attr_in_accel_scale_available.dev_attr.attr,
 118         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 119         NULL,
 120 };
 121
 122 static const struct attribute_group stk8312_attribute_group = {
 123         .attrs = stk8312_attributes
 124 };
 125
 126 static int stk8312_otp_init(struct stk8312_data *data)
 127 {
 128         int ret;
 129         int count = 10;
 130         struct i2c_client *client = data->client;
 131
 132         ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
 133         if (ret < 0)
 134                 goto exit_err;
 135         ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
 136         if (ret < 0)
 137                 goto exit_err;
 138
 139         do {
 140                 usleep_range(1000, 5000);
 141                 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
 142                 if (ret < 0)
 143                         goto exit_err;
 144                 count--;
 145         } while (!(ret & BIT(7)) && count > 0);
 146
 147         if (count == 0) {
 148                 ret = -ETIMEDOUT;
 149                 goto exit_err;
 150         }
 151
 152         ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
 153         if (ret == 0)
 154                 ret = -EINVAL;
 155         if (ret < 0)
 156                 goto exit_err;
 157
 158         ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret);
 159         if (ret < 0)
 160                 goto exit_err;
 161         msleep(150);
 162
 163         return 0;
 164
 165 exit_err:
 166         dev_err(&client->dev, "failed to initialize sensor\n");
 167         return ret;
 168 }
 169
 170 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
 171 {
 172         int ret;
 173         struct i2c_client *client = data->client;
 174
 175         if (mode == data->mode)
 176                 return 0;
 177
 178         ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
 179         if (ret < 0) {
 180                 dev_err(&client->dev, "failed to change sensor mode\n");
 181                 return ret;
 182         }
 183
 184         data->mode = mode;
 185         if (mode & STK8312_MODE_ACTIVE) {
 186                 /* Need to run OTP sequence before entering active mode */
 187                 usleep_range(1000, 5000);
 188                 ret = stk8312_otp_init(data);
 189         }
 190
 191         return ret;
 192 }
 193
 194 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
 195 {
 196         int ret;
 197         u8 mode;
 198         struct i2c_client *client = data->client;
 199
 200         mode = data->mode;
 201         /* We need to go in standby mode to modify registers */
 202         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
 203         if (ret < 0)
 204                 return ret;
 205
 206         ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
 207         if (ret < 0) {
 208                 dev_err(&client->dev, "failed to set interrupts\n");
 209                 stk8312_set_mode(data, mode);
 210                 return ret;
 211         }
 212
 213         return stk8312_set_mode(data, mode);
 214 }
 215
 216 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
 217                                               bool state)
 218 {
 219         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 220         struct stk8312_data *data = iio_priv(indio_dev);
 221         int ret;
 222
 223         if (state)
 224                 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
 225         else
 226                 ret = stk8312_set_interrupts(data, 0x00);
 227
 228         if (ret < 0) {
 229                 dev_err(&data->client->dev, "failed to set trigger state\n");
 230                 return ret;
 231         }
 232
 233         data->dready_trigger_on = state;
 234
 235         return 0;
 236 }
 237
 238 static const struct iio_trigger_ops stk8312_trigger_ops = {
 239         .set_trigger_state = stk8312_data_rdy_trigger_set_state,
 240 };
 241
 242 static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)
 243 {
 244         int ret;
 245         u8 masked_reg;
 246         u8 mode;
 247         struct i2c_client *client = data->client;
 248
 249         if (rate == data->sample_rate_idx)
 250                 return 0;
 251
 252         mode = data->mode;
 253         /* We need to go in standby mode to modify registers */
 254         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
 255         if (ret < 0)
 256                 return ret;
 257
 258         ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
 259         if (ret < 0)
 260                 goto err_activate;
 261
 262         masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
 263
 264         ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
 265         if (ret < 0)
 266                 goto err_activate;
 267
 268         data->sample_rate_idx = rate;
 269
 270         return stk8312_set_mode(data, mode);
 271
 272 err_activate:
 273         dev_err(&client->dev, "failed to set sampling rate\n");
 274         stk8312_set_mode(data, mode);
 275
 276         return ret;
 277 }
 278
 279 static int stk8312_set_range(struct stk8312_data *data, u8 range)
 280 {
 281         int ret;
 282         u8 masked_reg;
 283         u8 mode;
 284         struct i2c_client *client = data->client;
 285
 286         if (range != 1 && range != 2)
 287                 return -EINVAL;
 288         else if (range == data->range)
 289                 return 0;
 290
 291         mode = data->mode;
 292         /* We need to go in standby mode to modify registers */
 293         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
 294         if (ret < 0)
 295                 return ret;
 296
 297         ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
 298         if (ret < 0)
 299                 goto err_activate;
 300
 301         masked_reg = ret & (~STK8312_RNG_MASK);
 302         masked_reg |= range << STK8312_RNG_SHIFT;
 303
 304         ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
 305         if (ret < 0)
 306                 goto err_activate;
 307
 308         data->range = range;
 309
 310         return stk8312_set_mode(data, mode);
 311
 312 err_activate:
 313         dev_err(&client->dev, "failed to change sensor range\n");
 314         stk8312_set_mode(data, mode);
 315
 316         return ret;
 317 }
 318
 319 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
 320 {
 321         int ret;
 322         struct i2c_client *client = data->client;
 323
 324         if (address > 2)
 325                 return -EINVAL;
 326
 327         ret = i2c_smbus_read_byte_data(client, address);
 328         if (ret < 0)
 329                 dev_err(&client->dev, "register read failed\n");
 330
 331         return ret;
 332 }
 333
 334 static int stk8312_read_raw(struct iio_dev *indio_dev,
 335                             struct iio_chan_spec const *chan,
 336                             int *val, int *val2, long mask)
 337 {
 338         struct stk8312_data *data = iio_priv(indio_dev);
 339         int ret;
 340
 341         switch (mask) {
 342         case IIO_CHAN_INFO_RAW:
 343                 if (iio_buffer_enabled(indio_dev))
 344                         return -EBUSY;
 345                 mutex_lock(&data->lock);
 346                 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
 347                 if (ret < 0) {
 348                         mutex_unlock(&data->lock);
 349                         return ret;
 350                 }
 351                 ret = stk8312_read_accel(data, chan->address);
 352                 if (ret < 0) {
 353                         stk8312_set_mode(data,
 354                                          data->mode & (~STK8312_MODE_ACTIVE));
 355                         mutex_unlock(&data->lock);
 356                         return ret;
 357                 }
 358                 *val = sign_extend32(ret, 7);
 359                 ret = stk8312_set_mode(data,
 360                                        data->mode & (~STK8312_MODE_ACTIVE));
 361                 mutex_unlock(&data->lock);
 362                 if (ret < 0)
 363                         return ret;
 364                 return IIO_VAL_INT;
 365         case IIO_CHAN_INFO_SCALE:
 366                 *val = stk8312_scale_table[data->range - 1][0];
 367                 *val2 = stk8312_scale_table[data->range - 1][1];
 368                 return IIO_VAL_INT_PLUS_MICRO;
 369         case IIO_CHAN_INFO_SAMP_FREQ:
 370                 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
 371                 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
 372                 return IIO_VAL_INT_PLUS_MICRO;
 373         }
 374
 375         return -EINVAL;
 376 }
 377
 378 static int stk8312_write_raw(struct iio_dev *indio_dev,
 379                              struct iio_chan_spec const *chan,
 380                              int val, int val2, long mask)
 381 {
 382         int i;
 383         int index = -1;
 384         int ret;
 385         struct stk8312_data *data = iio_priv(indio_dev);
 386
 387         switch (mask) {
 388         case IIO_CHAN_INFO_SCALE:
 389                 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
 390                         if (val == stk8312_scale_table[i][0] &&
 391                             val2 == stk8312_scale_table[i][1]) {
 392                                 index = i + 1;
 393                                 break;
 394                         }
 395                 if (index < 0)
 396                         return -EINVAL;
 397
 398                 mutex_lock(&data->lock);
 399                 ret = stk8312_set_range(data, index);
 400                 mutex_unlock(&data->lock);
 401
 402                 return ret;
 403         case IIO_CHAN_INFO_SAMP_FREQ:
 404                 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
 405                         if (val == stk8312_samp_freq_table[i].val &&
 406                             val2 == stk8312_samp_freq_table[i].val2) {
 407                                 index = i;
 408                                 break;
 409                         }
 410                 if (index < 0)
 411                         return -EINVAL;
 412                 mutex_lock(&data->lock);
 413                 ret = stk8312_set_sample_rate(data, index);
 414                 mutex_unlock(&data->lock);
 415
 416                 return ret;
 417         }
 418
 419         return -EINVAL;
 420 }
 421
 422 static const struct iio_info stk8312_info = {
 423         .read_raw               = stk8312_read_raw,
 424         .write_raw              = stk8312_write_raw,
 425         .attrs                  = &stk8312_attribute_group,
 426 };
 427
 428 static irqreturn_t stk8312_trigger_handler(int irq, void *p)
 429 {
 430         struct iio_poll_func *pf = p;
 431         struct iio_dev *indio_dev = pf->indio_dev;
 432         struct stk8312_data *data = iio_priv(indio_dev);
 433         int bit, ret, i = 0;
 434
 435         mutex_lock(&data->lock);
 436         /*
 437          * Do a bulk read if all channels are requested,
 438          * from 0x00 (XOUT) to 0x02 (ZOUT)
 439          */
 440         if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
 441                 ret = i2c_smbus_read_i2c_block_data(data->client,
 442                                                     STK8312_REG_XOUT,
 443                                                     STK8312_ALL_CHANNEL_SIZE,
 444                                                     data->buffer);
 445                 if (ret < STK8312_ALL_CHANNEL_SIZE) {
 446                         dev_err(&data->client->dev, "register read failed\n");
 447                         mutex_unlock(&data->lock);
 448                         goto err;
 449                 }
 450         } else {
 451                 for_each_set_bit(bit, indio_dev->active_scan_mask,
 452                                  indio_dev->masklength) {
 453                         ret = stk8312_read_accel(data, bit);
 454                         if (ret < 0) {
 455                                 mutex_unlock(&data->lock);
 456                                 goto err;
 457                         }
 458                         data->buffer[i++] = ret;
 459                 }
 460         }
 461         mutex_unlock(&data->lock);
 462
 463         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 464                                            pf->timestamp);
 465 err:
 466         iio_trigger_notify_done(indio_dev->trig);
 467
 468         return IRQ_HANDLED;
 469 }
 470
 471 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
 472 {
 473         struct iio_dev *indio_dev = private;
 474         struct stk8312_data *data = iio_priv(indio_dev);
 475
 476         if (data->dready_trigger_on)
 477                 iio_trigger_poll(data->dready_trig);
 478
 479         return IRQ_HANDLED;
 480 }
 481
 482 static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
 483 {
 484         struct stk8312_data *data = iio_priv(indio_dev);
 485
 486         return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
 487 }
 488
 489 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
 490 {
 491         struct stk8312_data *data = iio_priv(indio_dev);
 492
 493         return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
 494 }
 495
 496 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
 497         .preenable   = stk8312_buffer_preenable,
 498         .postenable  = iio_triggered_buffer_postenable,
 499         .predisable  = iio_triggered_buffer_predisable,
 500         .postdisable = stk8312_buffer_postdisable,
 501 };
 502
 503 static int stk8312_probe(struct i2c_client *client,
 504                          const struct i2c_device_id *id)
 505 {
 506         int ret;
 507         struct iio_dev *indio_dev;
 508         struct stk8312_data *data;
 509
 510         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 511         if (!indio_dev) {
 512                 dev_err(&client->dev, "iio allocation failed!\n");
 513                 return -ENOMEM;
 514         }
 515
 516         data = iio_priv(indio_dev);
 517         data->client = client;
 518         i2c_set_clientdata(client, indio_dev);
 519         mutex_init(&data->lock);
 520
 521         indio_dev->dev.parent = &client->dev;
 522         indio_dev->info = &stk8312_info;
 523         indio_dev->name = STK8312_DRIVER_NAME;
 524         indio_dev->modes = INDIO_DIRECT_MODE;
 525         indio_dev->channels = stk8312_channels;
 526         indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
 527
 528         /* A software reset is recommended at power-on */
 529         ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
 530         if (ret < 0) {
 531                 dev_err(&client->dev, "failed to reset sensor\n");
 532                 return ret;
 533         }
 534         data->sample_rate_idx = STK8312_SR_400HZ_IDX;
 535         ret = stk8312_set_range(data, STK8312_RNG_6G);
 536         if (ret < 0)
 537                 return ret;
 538
 539         ret = stk8312_set_mode(data,
 540                                STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE);
 541         if (ret < 0)
 542                 return ret;
 543
 544         if (client->irq > 0) {
 545                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 546                                                 stk8312_data_rdy_trig_poll,
 547                                                 NULL,
 548                                                 IRQF_TRIGGER_RISING |
 549                                                 IRQF_ONESHOT,
 550                                                 STK8312_IRQ_NAME,
 551                                                 indio_dev);
 552                 if (ret < 0) {
 553                         dev_err(&client->dev, "request irq %d failed\n",
 554                                 client->irq);
 555                         goto err_power_off;
 556                 }
 557
 558                 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
 559                                                            "%s-dev%d",
 560                                                            indio_dev->name,
 561                                                            indio_dev->id);
 562                 if (!data->dready_trig) {
 563                         ret = -ENOMEM;
 564                         goto err_power_off;
 565                 }
 566
 567                 data->dready_trig->dev.parent = &client->dev;
 568                 data->dready_trig->ops = &stk8312_trigger_ops;
 569                 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
 570                 ret = iio_trigger_register(data->dready_trig);
 571                 if (ret) {
 572                         dev_err(&client->dev, "iio trigger register failed\n");
 573                         goto err_power_off;
 574                 }
 575         }
 576
 577         ret = iio_triggered_buffer_setup(indio_dev,
 578                                          iio_pollfunc_store_time,
 579                                          stk8312_trigger_handler,
 580                                          &stk8312_buffer_setup_ops);
 581         if (ret < 0) {
 582                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 583                 goto err_trigger_unregister;
 584         }
 585
 586         ret = iio_device_register(indio_dev);
 587         if (ret < 0) {
 588                 dev_err(&client->dev, "device_register failed\n");
 589                 goto err_buffer_cleanup;
 590         }
 591
 592         return 0;
 593
 594 err_buffer_cleanup:
 595         iio_triggered_buffer_cleanup(indio_dev);
 596 err_trigger_unregister:
 597         if (data->dready_trig)
 598                 iio_trigger_unregister(data->dready_trig);
 599 err_power_off:
 600         stk8312_set_mode(data, STK8312_MODE_STANDBY);
 601         return ret;
 602 }
 603
 604 static int stk8312_remove(struct i2c_client *client)
 605 {
 606         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 607         struct stk8312_data *data = iio_priv(indio_dev);
 608
 609         iio_device_unregister(indio_dev);
 610         iio_triggered_buffer_cleanup(indio_dev);
 611
 612         if (data->dready_trig)
 613                 iio_trigger_unregister(data->dready_trig);
 614
 615         return stk8312_set_mode(data, STK8312_MODE_STANDBY);
 616 }
 617
 618 #ifdef CONFIG_PM_SLEEP
 619 static int stk8312_suspend(struct device *dev)
 620 {
 621         struct stk8312_data *data;
 622
 623         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 624
 625         return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
 626 }
 627
 628 static int stk8312_resume(struct device *dev)
 629 {
 630         struct stk8312_data *data;
 631
 632         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 633
 634         return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
 635 }
 636
 637 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
 638
 639 #define STK8312_PM_OPS (&stk8312_pm_ops)
 640 #else
 641 #define STK8312_PM_OPS NULL
 642 #endif
 643
 644 static const struct i2c_device_id stk8312_i2c_id[] = {
 645         {"STK8312", 0},
 646         {}
 647 };
 648 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
 649
 650 static const struct acpi_device_id stk8312_acpi_id[] = {
 651         {"STK8312", 0},
 652         {}
 653 };
 654
 655 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
 656
 657 static struct i2c_driver stk8312_driver = {
 658         .driver = {
 659                 .name = STK8312_DRIVER_NAME,
 660                 .pm = STK8312_PM_OPS,
 661                 .acpi_match_table = ACPI_PTR(stk8312_acpi_id),
 662         },
 663         .probe =            stk8312_probe,
 664         .remove =           stk8312_remove,
 665         .id_table =         stk8312_i2c_id,
 666 };
 667
 668 module_i2c_driver(stk8312_driver);
 669
 670 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
 671 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
 672 MODULE_LICENSE("GPL v2");