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/gpio/consumer.h>
  15 #include <linux/i2c.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/delay.h>
  20 #include <linux/iio/buffer.h>
  21 #include <linux/iio/iio.h>
  22 #include <linux/iio/sysfs.h>
  23 #include <linux/iio/trigger.h>
  24 #include <linux/iio/triggered_buffer.h>
  25 #include <linux/iio/trigger_consumer.h>
  26
  27 #define STK8312_REG_XOUT                0x00
  28 #define STK8312_REG_YOUT                0x01
  29 #define STK8312_REG_ZOUT                0x02
  30 #define STK8312_REG_INTSU               0x06
  31 #define STK8312_REG_MODE                0x07
  32 #define STK8312_REG_SR                  0x08
  33 #define STK8312_REG_STH                 0x13
  34 #define STK8312_REG_RESET               0x20
  35 #define STK8312_REG_AFECTRL             0x24
  36 #define STK8312_REG_OTPADDR             0x3D
  37 #define STK8312_REG_OTPDATA             0x3E
  38 #define STK8312_REG_OTPCTRL             0x3F
  39
  40 #define STK8312_MODE_ACTIVE             0x01
  41 #define STK8312_MODE_STANDBY            0x00
  42 #define STK8312_DREADY_BIT              0x10
  43 #define STK8312_INT_MODE                0xC0
  44 #define STK8312_RNG_MASK                0xC0
  45 #define STK8312_SR_MASK                 0x07
  46 #define STK8312_SR_400HZ_IDX            0
  47 #define STK8312_RNG_SHIFT               6
  48 #define STK8312_READ_RETRIES            16
  49 #define STK8312_ALL_CHANNEL_MASK        7
  50 #define STK8312_ALL_CHANNEL_SIZE        3
  51
  52 #define STK8312_DRIVER_NAME             "stk8312"
  53 #define STK8312_GPIO                    "stk8312_gpio"
  54 #define STK8312_IRQ_NAME                "stk8312_event"
  55
  56 /*
  57  * The accelerometer has two measurement ranges:
  58  *
  59  * -6g - +6g (8-bit, signed)
  60  * -16g - +16g (8-bit, signed)
  61  *
  62  * scale1 = (6 + 6) * 9.81 / (2^8 - 1)     = 0.4616
  63  * scale2 = (16 + 16) * 9.81 / (2^8 - 1)   = 1.2311
  64  */
  65 #define STK8312_SCALE_AVAIL             "0.4616 1.2311"
  66
  67 static const int stk8312_scale_table[][2] = {
  68         {0, 461600}, {1, 231100}
  69 };
  70
  71 static const struct {
  72         u16 val;
  73         u32 val2;
  74 } stk8312_samp_freq_table[] = {
  75         {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
  76         {12, 500000}, {6, 250000}, {3, 125000}
  77 };
  78
  79 #define STK8312_ACCEL_CHANNEL(index, reg, axis) {                       \
  80         .type = IIO_ACCEL,                                              \
  81         .address = reg,                                                 \
  82         .modified = 1,                                                  \
  83         .channel2 = IIO_MOD_##axis,                                     \
  84         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
  85         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
  86                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
  87         .scan_index = index,                                            \
  88         .scan_type = {                                                  \
  89                 .sign = 's',                                            \
  90                 .realbits = 8,                                          \
  91                 .storagebits = 8,                                       \
  92                 .endianness = IIO_CPU,                                  \
  93         },                                                              \
  94 }
  95
  96 static const struct iio_chan_spec stk8312_channels[] = {
  97         STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),
  98         STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),
  99         STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),
 100         IIO_CHAN_SOFT_TIMESTAMP(3),
 101 };
 102
 103 struct stk8312_data {
 104         struct i2c_client *client;
 105         struct mutex lock;
 106         int range;
 107         u8 sample_rate_idx;
 108         u8 mode;
 109         struct iio_trigger *dready_trig;
 110         bool dready_trigger_on;
 111         s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
 112 };
 113
 114 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
 115
 116 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
 117
 118 static struct attribute *stk8312_attributes[] = {
 119         &iio_const_attr_in_accel_scale_available.dev_attr.attr,
 120         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 121         NULL,
 122 };
 123
 124 static const struct attribute_group stk8312_attribute_group = {
 125         .attrs = stk8312_attributes
 126 };
 127
 128 static int stk8312_otp_init(struct stk8312_data *data)
 129 {
 130         int ret;
 131         int count = 10;
 132         struct i2c_client *client = data->client;
 133
 134         ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
 135         if (ret < 0)
 136                 goto exit_err;
 137         ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
 138         if (ret < 0)
 139                 goto exit_err;
 140
 141         do {
 142                 usleep_range(1000, 5000);
 143                 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
 144                 if (ret < 0)
 145                         goto exit_err;
 146                 count--;
 147         } while (!(ret & 0x80) && count > 0);
 148
 149         if (count == 0)
 150                 goto exit_err;
 151
 152         ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
 153         if (ret < 0)
 154                 goto exit_err;
 155
 156         ret = i2c_smbus_write_byte_data(data->client,
 157                         STK8312_REG_AFECTRL, ret);
 158         if (ret < 0)
 159                 goto exit_err;
 160         msleep(150);
 161
 162         return ret;
 163
 164 exit_err:
 165         dev_err(&client->dev, "failed to initialize sensor\n");
 166         return ret;
 167 }
 168
 169 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
 170 {
 171         int ret;
 172         struct i2c_client *client = data->client;
 173
 174         if (mode == data->mode)
 175                 return 0;
 176
 177         ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
 178         if (ret < 0) {
 179                 dev_err(&client->dev, "failed to change sensor mode\n");
 180                 return ret;
 181         }
 182
 183         data->mode = mode;
 184         if (mode & STK8312_MODE_ACTIVE) {
 185                 /* Need to run OTP sequence before entering active mode */
 186                 usleep_range(1000, 5000);
 187                 ret = stk8312_otp_init(data);
 188         }
 189
 190         return ret;
 191 }
 192
 193 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
 194 {
 195         int ret;
 196         u8 mode;
 197         struct i2c_client *client = data->client;
 198
 199         mode = data->mode;
 200         /* We need to go in standby mode to modify registers */
 201         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
 202         if (ret < 0)
 203                 return ret;
 204
 205         ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
 206         if (ret < 0)
 207                 dev_err(&client->dev, "failed to set interrupts\n");
 208
 209         return stk8312_set_mode(data, mode);
 210 }
 211
 212 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
 213                                               bool state)
 214 {
 215         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 216         struct stk8312_data *data = iio_priv(indio_dev);
 217         int ret;
 218
 219         if (state)
 220                 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
 221         else
 222                 ret = stk8312_set_interrupts(data, 0x00);
 223
 224         if (ret < 0) {
 225                 dev_err(&data->client->dev, "failed to set trigger state\n");
 226                 return ret;
 227         }
 228
 229         data->dready_trigger_on = state;
 230
 231         return ret;
 232 }
 233
 234 static const struct iio_trigger_ops stk8312_trigger_ops = {
 235         .set_trigger_state = stk8312_data_rdy_trigger_set_state,
 236         .owner = THIS_MODULE,
 237 };
 238
 239 static int stk8312_set_sample_rate(struct stk8312_data *data, int rate)
 240 {
 241         int ret;
 242         u8 masked_reg;
 243         u8 mode;
 244         struct i2c_client *client = data->client;
 245
 246         if (rate == data->sample_rate_idx)
 247                 return 0;
 248
 249         mode = data->mode;
 250         /* We need to go in standby mode to modify registers */
 251         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
 252         if (ret < 0)
 253                 return ret;
 254
 255         ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
 256         if (ret < 0) {
 257                 dev_err(&client->dev, "failed to set sampling rate\n");
 258                 return ret;
 259         }
 260
 261         masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
 262
 263         ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
 264         if (ret < 0)
 265                 dev_err(&client->dev, "failed to set sampling rate\n");
 266         else
 267                 data->sample_rate_idx = rate;
 268
 269         return stk8312_set_mode(data, mode);
 270 }
 271
 272 static int stk8312_set_range(struct stk8312_data *data, u8 range)
 273 {
 274         int ret;
 275         u8 masked_reg;
 276         u8 mode;
 277         struct i2c_client *client = data->client;
 278
 279         if (range != 1 && range != 2)
 280                 return -EINVAL;
 281         else if (range == data->range)
 282                 return 0;
 283
 284         mode = data->mode;
 285         /* We need to go in standby mode to modify registers */
 286         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
 287         if (ret < 0)
 288                 return ret;
 289
 290         ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
 291         if (ret < 0) {
 292                 dev_err(&client->dev, "failed to change sensor range\n");
 293                 return ret;
 294         }
 295
 296         masked_reg = ret & (~STK8312_RNG_MASK);
 297         masked_reg |= range << STK8312_RNG_SHIFT;
 298
 299         ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
 300         if (ret < 0)
 301                 dev_err(&client->dev, "failed to change sensor range\n");
 302         else
 303                 data->range = range;
 304
 305         return stk8312_set_mode(data, mode);
 306 }
 307
 308 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
 309 {
 310         int ret;
 311         struct i2c_client *client = data->client;
 312
 313         if (address > 2)
 314                 return -EINVAL;
 315
 316         ret = i2c_smbus_read_byte_data(client, address);
 317         if (ret < 0)
 318                 dev_err(&client->dev, "register read failed\n");
 319
 320         return ret;
 321 }
 322
 323 static int stk8312_read_raw(struct iio_dev *indio_dev,
 324                             struct iio_chan_spec const *chan,
 325                             int *val, int *val2, long mask)
 326 {
 327         struct stk8312_data *data = iio_priv(indio_dev);
 328         int ret;
 329
 330         switch (mask) {
 331         case IIO_CHAN_INFO_RAW:
 332                 if (iio_buffer_enabled(indio_dev))
 333                         return -EBUSY;
 334                 mutex_lock(&data->lock);
 335                 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
 336                 if (ret < 0) {
 337                         mutex_unlock(&data->lock);
 338                         return -EINVAL;
 339                 }
 340                 ret = stk8312_read_accel(data, chan->address);
 341                 if (ret < 0) {
 342                         stk8312_set_mode(data,
 343                                          data->mode & (~STK8312_MODE_ACTIVE));
 344                         mutex_unlock(&data->lock);
 345                         return -EINVAL;
 346                 }
 347                 *val = sign_extend32(ret, 7);
 348                 stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
 349                 mutex_unlock(&data->lock);
 350                 return IIO_VAL_INT;
 351         case IIO_CHAN_INFO_SCALE:
 352                 *val = stk8312_scale_table[data->range - 1][0];
 353                 *val2 = stk8312_scale_table[data->range - 1][1];
 354                 return IIO_VAL_INT_PLUS_MICRO;
 355         case IIO_CHAN_INFO_SAMP_FREQ:
 356                 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
 357                 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
 358                 return IIO_VAL_INT_PLUS_MICRO;
 359         }
 360
 361         return -EINVAL;
 362 }
 363
 364 static int stk8312_write_raw(struct iio_dev *indio_dev,
 365                              struct iio_chan_spec const *chan,
 366                              int val, int val2, long mask)
 367 {
 368         int i;
 369         int index = -1;
 370         int ret;
 371         struct stk8312_data *data = iio_priv(indio_dev);
 372
 373         switch (mask) {
 374         case IIO_CHAN_INFO_SCALE:
 375                 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
 376                         if (val == stk8312_scale_table[i][0] &&
 377                             val2 == stk8312_scale_table[i][1]) {
 378                                 index = i + 1;
 379                                 break;
 380                         }
 381                 if (index < 0)
 382                         return -EINVAL;
 383
 384                 mutex_lock(&data->lock);
 385                 ret = stk8312_set_range(data, index);
 386                 mutex_unlock(&data->lock);
 387
 388                 return ret;
 389         case IIO_CHAN_INFO_SAMP_FREQ:
 390                 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
 391                         if (val == stk8312_samp_freq_table[i].val &&
 392                             val2 == stk8312_samp_freq_table[i].val2) {
 393                                 index = i;
 394                                 break;
 395                         }
 396                 if (index < 0)
 397                         return -EINVAL;
 398                 mutex_lock(&data->lock);
 399                 ret = stk8312_set_sample_rate(data, index);
 400                 mutex_unlock(&data->lock);
 401
 402                 return ret;
 403         }
 404
 405         return -EINVAL;
 406 }
 407
 408 static const struct iio_info stk8312_info = {
 409         .driver_module          = THIS_MODULE,
 410         .read_raw               = stk8312_read_raw,
 411         .write_raw              = stk8312_write_raw,
 412         .attrs                  = &stk8312_attribute_group,
 413 };
 414
 415 static irqreturn_t stk8312_trigger_handler(int irq, void *p)
 416 {
 417         struct iio_poll_func *pf = p;
 418         struct iio_dev *indio_dev = pf->indio_dev;
 419         struct stk8312_data *data = iio_priv(indio_dev);
 420         int bit, ret, i = 0;
 421         u8 buffer[STK8312_ALL_CHANNEL_SIZE];
 422
 423         mutex_lock(&data->lock);
 424         /*
 425          * Do a bulk read if all channels are requested,
 426          * from 0x00 (XOUT) to 0x02 (ZOUT)
 427          */
 428         if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
 429                 ret = i2c_smbus_read_i2c_block_data(data->client,
 430                                                     STK8312_REG_XOUT,
 431                                                     STK8312_ALL_CHANNEL_SIZE,
 432                                                     buffer);
 433                 if (ret < STK8312_ALL_CHANNEL_SIZE) {
 434                         dev_err(&data->client->dev, "register read failed\n");
 435                         mutex_unlock(&data->lock);
 436                         goto err;
 437                 }
 438                 data->buffer[0] = buffer[0];
 439                 data->buffer[1] = buffer[1];
 440                 data->buffer[2] = buffer[2];
 441         } else {
 442                 for_each_set_bit(bit, indio_dev->active_scan_mask,
 443                            indio_dev->masklength) {
 444                         ret = stk8312_read_accel(data, bit);
 445                         if (ret < 0) {
 446                                 mutex_unlock(&data->lock);
 447                                 goto err;
 448                         }
 449                         data->buffer[i++] = ret;
 450                 }
 451         }
 452         mutex_unlock(&data->lock);
 453
 454         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 455                                            pf->timestamp);
 456 err:
 457         iio_trigger_notify_done(indio_dev->trig);
 458
 459         return IRQ_HANDLED;
 460 }
 461
 462 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
 463 {
 464         struct iio_dev *indio_dev = private;
 465         struct stk8312_data *data = iio_priv(indio_dev);
 466
 467         if (data->dready_trigger_on)
 468                 iio_trigger_poll(data->dready_trig);
 469
 470         return IRQ_HANDLED;
 471 }
 472
 473 static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
 474 {
 475         struct stk8312_data *data = iio_priv(indio_dev);
 476
 477         return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
 478 }
 479
 480 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
 481 {
 482         struct stk8312_data *data = iio_priv(indio_dev);
 483
 484         return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
 485 }
 486
 487 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
 488         .preenable   = stk8312_buffer_preenable,
 489         .postenable  = iio_triggered_buffer_postenable,
 490         .predisable  = iio_triggered_buffer_predisable,
 491         .postdisable = stk8312_buffer_postdisable,
 492 };
 493
 494 static int stk8312_gpio_probe(struct i2c_client *client)
 495 {
 496         struct device *dev;
 497         struct gpio_desc *gpio;
 498         int ret;
 499
 500         if (!client)
 501                 return -EINVAL;
 502
 503         dev = &client->dev;
 504
 505         /* data ready gpio interrupt pin */
 506         gpio = devm_gpiod_get_index(dev, STK8312_GPIO, 0, GPIOD_IN);
 507         if (IS_ERR(gpio)) {
 508                 dev_err(dev, "acpi gpio get index failed\n");
 509                 return PTR_ERR(gpio);
 510         }
 511
 512         ret = gpiod_to_irq(gpio);
 513         dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
 514
 515         return ret;
 516 }
 517
 518 static int stk8312_probe(struct i2c_client *client,
 519                          const struct i2c_device_id *id)
 520 {
 521         int ret;
 522         struct iio_dev *indio_dev;
 523         struct stk8312_data *data;
 524
 525         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 526         if (!indio_dev) {
 527                 dev_err(&client->dev, "iio allocation failed!\n");
 528                 return -ENOMEM;
 529         }
 530
 531         data = iio_priv(indio_dev);
 532         data->client = client;
 533         i2c_set_clientdata(client, indio_dev);
 534         mutex_init(&data->lock);
 535
 536         indio_dev->dev.parent = &client->dev;
 537         indio_dev->info = &stk8312_info;
 538         indio_dev->name = STK8312_DRIVER_NAME;
 539         indio_dev->modes = INDIO_DIRECT_MODE;
 540         indio_dev->channels = stk8312_channels;
 541         indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
 542
 543         /* A software reset is recommended at power-on */
 544         ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
 545         if (ret < 0) {
 546                 dev_err(&client->dev, "failed to reset sensor\n");
 547                 return ret;
 548         }
 549         data->sample_rate_idx = STK8312_SR_400HZ_IDX;
 550         ret = stk8312_set_range(data, 1);
 551         if (ret < 0)
 552                 return ret;
 553
 554         ret = stk8312_set_mode(data, STK8312_INT_MODE | STK8312_MODE_ACTIVE);
 555         if (ret < 0)
 556                 return ret;
 557
 558         if (client->irq < 0)
 559                 client->irq = stk8312_gpio_probe(client);
 560
 561         if (client->irq >= 0) {
 562                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 563                                                 stk8312_data_rdy_trig_poll,
 564                                                 NULL,
 565                                                 IRQF_TRIGGER_RISING |
 566                                                 IRQF_ONESHOT,
 567                                                 STK8312_IRQ_NAME,
 568                                                 indio_dev);
 569                 if (ret < 0) {
 570                         dev_err(&client->dev, "request irq %d failed\n",
 571                                 client->irq);
 572                         goto err_power_off;
 573                 }
 574
 575                 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
 576                                                            "%s-dev%d",
 577                                                            indio_dev->name,
 578                                                            indio_dev->id);
 579                 if (!data->dready_trig) {
 580                         ret = -ENOMEM;
 581                         goto err_power_off;
 582                 }
 583
 584                 data->dready_trig->dev.parent = &client->dev;
 585                 data->dready_trig->ops = &stk8312_trigger_ops;
 586                 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
 587                 ret = iio_trigger_register(data->dready_trig);
 588                 if (ret) {
 589                         dev_err(&client->dev, "iio trigger register failed\n");
 590                         goto err_power_off;
 591                 }
 592         }
 593
 594         ret = iio_triggered_buffer_setup(indio_dev,
 595                                          iio_pollfunc_store_time,
 596                                          stk8312_trigger_handler,
 597                                          &stk8312_buffer_setup_ops);
 598         if (ret < 0) {
 599                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 600                 goto err_trigger_unregister;
 601         }
 602
 603         ret = iio_device_register(indio_dev);
 604         if (ret < 0) {
 605                 dev_err(&client->dev, "device_register failed\n");
 606                 goto err_buffer_cleanup;
 607         }
 608
 609         return ret;
 610
 611 err_buffer_cleanup:
 612         iio_triggered_buffer_cleanup(indio_dev);
 613 err_trigger_unregister:
 614         if (data->dready_trig)
 615                 iio_trigger_unregister(data->dready_trig);
 616 err_power_off:
 617         stk8312_set_mode(data, STK8312_MODE_STANDBY);
 618         return ret;
 619 }
 620
 621 static int stk8312_remove(struct i2c_client *client)
 622 {
 623         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 624         struct stk8312_data *data = iio_priv(indio_dev);
 625
 626         iio_device_unregister(indio_dev);
 627         iio_triggered_buffer_cleanup(indio_dev);
 628
 629         if (data->dready_trig)
 630                 iio_trigger_unregister(data->dready_trig);
 631
 632         return stk8312_set_mode(data, STK8312_MODE_STANDBY);
 633 }
 634
 635 #ifdef CONFIG_PM_SLEEP
 636 static int stk8312_suspend(struct device *dev)
 637 {
 638         struct stk8312_data *data;
 639
 640         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 641
 642         return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
 643 }
 644
 645 static int stk8312_resume(struct device *dev)
 646 {
 647         struct stk8312_data *data;
 648
 649         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 650
 651         return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
 652 }
 653
 654 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
 655
 656 #define STK8312_PM_OPS (&stk8312_pm_ops)
 657 #else
 658 #define STK8312_PM_OPS NULL
 659 #endif
 660
 661 static const struct i2c_device_id stk8312_i2c_id[] = {
 662         {"STK8312", 0},
 663         {}
 664 };
 665 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
 666
 667 static const struct acpi_device_id stk8312_acpi_id[] = {
 668         {"STK8312", 0},
 669         {}
 670 };
 671
 672 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
 673
 674 static struct i2c_driver stk8312_driver = {
 675         .driver = {
 676                 .name = "stk8312",
 677                 .pm = STK8312_PM_OPS,
 678                 .acpi_match_table = ACPI_PTR(stk8312_acpi_id),
 679         },
 680         .probe =            stk8312_probe,
 681         .remove =           stk8312_remove,
 682         .id_table =         stk8312_i2c_id,
 683 };
 684
 685 module_i2c_driver(stk8312_driver);
 686
 687 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
 688 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
 689 MODULE_LICENSE("GPL v2");