drivers/iio/light/max44000.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * MAX44000 Ambient and Infrared Proximity Sensor
   4  *
   5  * Copyright (c) 2016, Intel Corporation.
   6  *
   7  * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
   8  *
   9  * 7-bit I2C slave address 0x4a
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/i2c.h>
  15 #include <linux/regmap.h>
  16 #include <linux/util_macros.h>
  17 #include <linux/iio/iio.h>
  18 #include <linux/iio/sysfs.h>
  19 #include <linux/iio/buffer.h>
  20 #include <linux/iio/trigger_consumer.h>
  21 #include <linux/iio/triggered_buffer.h>
  22 #include <linux/acpi.h>
  23
  24 #define MAX44000_DRV_NAME               "max44000"
  25
  26 /* Registers in datasheet order */
  27 #define MAX44000_REG_STATUS             0x00
  28 #define MAX44000_REG_CFG_MAIN           0x01
  29 #define MAX44000_REG_CFG_RX             0x02
  30 #define MAX44000_REG_CFG_TX             0x03
  31 #define MAX44000_REG_ALS_DATA_HI        0x04
  32 #define MAX44000_REG_ALS_DATA_LO        0x05
  33 #define MAX44000_REG_PRX_DATA           0x16
  34 #define MAX44000_REG_ALS_UPTHR_HI       0x06
  35 #define MAX44000_REG_ALS_UPTHR_LO       0x07
  36 #define MAX44000_REG_ALS_LOTHR_HI       0x08
  37 #define MAX44000_REG_ALS_LOTHR_LO       0x09
  38 #define MAX44000_REG_PST                0x0a
  39 #define MAX44000_REG_PRX_IND            0x0b
  40 #define MAX44000_REG_PRX_THR            0x0c
  41 #define MAX44000_REG_TRIM_GAIN_GREEN    0x0f
  42 #define MAX44000_REG_TRIM_GAIN_IR       0x10
  43
  44 /* REG_CFG bits */
  45 #define MAX44000_CFG_ALSINTE            0x01
  46 #define MAX44000_CFG_PRXINTE            0x02
  47 #define MAX44000_CFG_MASK               0x1c
  48 #define MAX44000_CFG_MODE_SHUTDOWN      0x00
  49 #define MAX44000_CFG_MODE_ALS_GIR       0x04
  50 #define MAX44000_CFG_MODE_ALS_G         0x08
  51 #define MAX44000_CFG_MODE_ALS_IR        0x0c
  52 #define MAX44000_CFG_MODE_ALS_PRX       0x10
  53 #define MAX44000_CFG_MODE_PRX           0x14
  54 #define MAX44000_CFG_TRIM               0x20
  55
  56 /*
  57  * Upper 4 bits are not documented but start as 1 on powerup
  58  * Setting them to 0 causes proximity to misbehave so set them to 1
  59  */
  60 #define MAX44000_REG_CFG_RX_DEFAULT 0xf0
  61
  62 /* REG_RX bits */
  63 #define MAX44000_CFG_RX_ALSTIM_MASK     0x0c
  64 #define MAX44000_CFG_RX_ALSTIM_SHIFT    2
  65 #define MAX44000_CFG_RX_ALSPGA_MASK     0x03
  66 #define MAX44000_CFG_RX_ALSPGA_SHIFT    0
  67
  68 /* REG_TX bits */
  69 #define MAX44000_LED_CURRENT_MASK       0xf
  70 #define MAX44000_LED_CURRENT_MAX        11
  71 #define MAX44000_LED_CURRENT_DEFAULT    6
  72
  73 #define MAX44000_ALSDATA_OVERFLOW       0x4000
  74
  75 struct max44000_data {
  76         struct mutex lock;
  77         struct regmap *regmap;
  78         /* Ensure naturally aligned timestamp */
  79         struct {
  80                 u16 channels[2];
  81                 s64 ts __aligned(8);
  82         } scan;
  83 };
  84
  85 /* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
  86 #define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5
  87
  88 /* Scale can be multiplied by up to 128x via ALSPGA for measurement gain */
  89 static const int max44000_alspga_shift[] = {0, 2, 4, 7};
  90 #define MAX44000_ALSPGA_MAX_SHIFT 7
  91
  92 /*
  93  * Scale can be multiplied by up to 64x via ALSTIM because of lost resolution
  94  *
  95  * This scaling factor is hidden from userspace and instead accounted for when
  96  * reading raw values from the device.
  97  *
  98  * This makes it possible to cleanly expose ALSPGA as IIO_CHAN_INFO_SCALE and
  99  * ALSTIM as IIO_CHAN_INFO_INT_TIME without the values affecting each other.
 100  *
 101  * Handling this internally is also required for buffer support because the
 102  * channel's scan_type can't be modified dynamically.
 103  */
 104 #define MAX44000_ALSTIM_SHIFT(alstim) (2 * (alstim))
 105
 106 /* Available integration times with pretty manual alignment: */
 107 static const int max44000_int_time_avail_ns_array[] = {
 108            100000000,
 109             25000000,
 110              6250000,
 111              1562500,
 112 };
 113 static const char max44000_int_time_avail_str[] =
 114         "0.100 "
 115         "0.025 "
 116         "0.00625 "
 117         "0.0015625";
 118
 119 /* Available scales (internal to ulux) with pretty manual alignment: */
 120 static const int max44000_scale_avail_ulux_array[] = {
 121             31250,
 122            125000,
 123            500000,
 124           4000000,
 125 };
 126 static const char max44000_scale_avail_str[] =
 127         "0.03125 "
 128         "0.125 "
 129         "0.5 "
 130          "4";
 131
 132 #define MAX44000_SCAN_INDEX_ALS 0
 133 #define MAX44000_SCAN_INDEX_PRX 1
 134
 135 static const struct iio_chan_spec max44000_channels[] = {
 136         {
 137                 .type = IIO_LIGHT,
 138                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 139                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
 140                                             BIT(IIO_CHAN_INFO_INT_TIME),
 141                 .scan_index = MAX44000_SCAN_INDEX_ALS,
 142                 .scan_type = {
 143                         .sign           = 'u',
 144                         .realbits       = 14,
 145                         .storagebits    = 16,
 146                 }
 147         },
 148         {
 149                 .type = IIO_PROXIMITY,
 150                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 151                 .scan_index = MAX44000_SCAN_INDEX_PRX,
 152                 .scan_type = {
 153                         .sign           = 'u',
 154                         .realbits       = 8,
 155                         .storagebits    = 16,
 156                 }
 157         },
 158         IIO_CHAN_SOFT_TIMESTAMP(2),
 159         {
 160                 .type = IIO_CURRENT,
 161                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 162                                       BIT(IIO_CHAN_INFO_SCALE),
 163                 .extend_name = "led",
 164                 .output = 1,
 165                 .scan_index = -1,
 166         },
 167 };
 168
 169 static int max44000_read_alstim(struct max44000_data *data)
 170 {
 171         unsigned int val;
 172         int ret;
 173
 174         ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
 175         if (ret < 0)
 176                 return ret;
 177         return (val & MAX44000_CFG_RX_ALSTIM_MASK) >> MAX44000_CFG_RX_ALSTIM_SHIFT;
 178 }
 179
 180 static int max44000_write_alstim(struct max44000_data *data, int val)
 181 {
 182         return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
 183                                  MAX44000_CFG_RX_ALSTIM_MASK,
 184                                  val << MAX44000_CFG_RX_ALSTIM_SHIFT);
 185 }
 186
 187 static int max44000_read_alspga(struct max44000_data *data)
 188 {
 189         unsigned int val;
 190         int ret;
 191
 192         ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
 193         if (ret < 0)
 194                 return ret;
 195         return (val & MAX44000_CFG_RX_ALSPGA_MASK) >> MAX44000_CFG_RX_ALSPGA_SHIFT;
 196 }
 197
 198 static int max44000_write_alspga(struct max44000_data *data, int val)
 199 {
 200         return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
 201                                  MAX44000_CFG_RX_ALSPGA_MASK,
 202                                  val << MAX44000_CFG_RX_ALSPGA_SHIFT);
 203 }
 204
 205 static int max44000_read_alsval(struct max44000_data *data)
 206 {
 207         u16 regval;
 208         __be16 val;
 209         int alstim, ret;
 210
 211         ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
 212                                &val, sizeof(val));
 213         if (ret < 0)
 214                 return ret;
 215         alstim = ret = max44000_read_alstim(data);
 216         if (ret < 0)
 217                 return ret;
 218
 219         regval = be16_to_cpu(val);
 220
 221         /*
 222          * Overflow is explained on datasheet page 17.
 223          *
 224          * It's a warning that either the G or IR channel has become saturated
 225          * and that the value in the register is likely incorrect.
 226          *
 227          * The recommendation is to change the scale (ALSPGA).
 228          * The driver just returns the max representable value.
 229          */
 230         if (regval & MAX44000_ALSDATA_OVERFLOW)
 231                 return 0x3FFF;
 232
 233         return regval << MAX44000_ALSTIM_SHIFT(alstim);
 234 }
 235
 236 static int max44000_write_led_current_raw(struct max44000_data *data, int val)
 237 {
 238         /* Maybe we should clamp the value instead? */
 239         if (val < 0 || val > MAX44000_LED_CURRENT_MAX)
 240                 return -ERANGE;
 241         if (val >= 8)
 242                 val += 4;
 243         return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,
 244                                  MAX44000_LED_CURRENT_MASK, val);
 245 }
 246
 247 static int max44000_read_led_current_raw(struct max44000_data *data)
 248 {
 249         unsigned int regval;
 250         int ret;
 251
 252         ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, &regval);
 253         if (ret < 0)
 254                 return ret;
 255         regval &= MAX44000_LED_CURRENT_MASK;
 256         if (regval >= 8)
 257                 regval -= 4;
 258         return regval;
 259 }
 260
 261 static int max44000_read_raw(struct iio_dev *indio_dev,
 262                              struct iio_chan_spec const *chan,
 263                              int *val, int *val2, long mask)
 264 {
 265         struct max44000_data *data = iio_priv(indio_dev);
 266         int alstim, alspga;
 267         unsigned int regval;
 268         int ret;
 269
 270         switch (mask) {
 271         case IIO_CHAN_INFO_RAW:
 272                 switch (chan->type) {
 273                 case IIO_LIGHT:
 274                         mutex_lock(&data->lock);
 275                         ret = max44000_read_alsval(data);
 276                         mutex_unlock(&data->lock);
 277                         if (ret < 0)
 278                                 return ret;
 279                         *val = ret;
 280                         return IIO_VAL_INT;
 281
 282                 case IIO_PROXIMITY:
 283                         mutex_lock(&data->lock);
 284                         ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
 285                         mutex_unlock(&data->lock);
 286                         if (ret < 0)
 287                                 return ret;
 288                         *val = regval;
 289                         return IIO_VAL_INT;
 290
 291                 case IIO_CURRENT:
 292                         mutex_lock(&data->lock);
 293                         ret = max44000_read_led_current_raw(data);
 294                         mutex_unlock(&data->lock);
 295                         if (ret < 0)
 296                                 return ret;
 297                         *val = ret;
 298                         return IIO_VAL_INT;
 299
 300                 default:
 301                         return -EINVAL;
 302                 }
 303
 304         case IIO_CHAN_INFO_SCALE:
 305                 switch (chan->type) {
 306                 case IIO_CURRENT:
 307                         /* Output register is in 10s of miliamps */
 308                         *val = 10;
 309                         return IIO_VAL_INT;
 310
 311                 case IIO_LIGHT:
 312                         mutex_lock(&data->lock);
 313                         alspga = ret = max44000_read_alspga(data);
 314                         mutex_unlock(&data->lock);
 315                         if (ret < 0)
 316                                 return ret;
 317
 318                         /* Avoid negative shifts */
 319                         *val = (1 << MAX44000_ALSPGA_MAX_SHIFT);
 320                         *val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2
 321                                         + MAX44000_ALSPGA_MAX_SHIFT
 322                                         - max44000_alspga_shift[alspga];
 323                         return IIO_VAL_FRACTIONAL_LOG2;
 324
 325                 default:
 326                         return -EINVAL;
 327                 }
 328
 329         case IIO_CHAN_INFO_INT_TIME:
 330                 mutex_lock(&data->lock);
 331                 alstim = ret = max44000_read_alstim(data);
 332                 mutex_unlock(&data->lock);
 333
 334                 if (ret < 0)
 335                         return ret;
 336                 *val = 0;
 337                 *val2 = max44000_int_time_avail_ns_array[alstim];
 338                 return IIO_VAL_INT_PLUS_NANO;
 339
 340         default:
 341                 return -EINVAL;
 342         }
 343 }
 344
 345 static int max44000_write_raw(struct iio_dev *indio_dev,
 346                               struct iio_chan_spec const *chan,
 347                               int val, int val2, long mask)
 348 {
 349         struct max44000_data *data = iio_priv(indio_dev);
 350         int ret;
 351
 352         if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {
 353                 mutex_lock(&data->lock);
 354                 ret = max44000_write_led_current_raw(data, val);
 355                 mutex_unlock(&data->lock);
 356                 return ret;
 357         } else if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) {
 358                 s64 valns = val * NSEC_PER_SEC + val2;
 359                 int alstim = find_closest_descending(valns,
 360                                 max44000_int_time_avail_ns_array,
 361                                 ARRAY_SIZE(max44000_int_time_avail_ns_array));
 362                 mutex_lock(&data->lock);
 363                 ret = max44000_write_alstim(data, alstim);
 364                 mutex_unlock(&data->lock);
 365                 return ret;
 366         } else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT) {
 367                 s64 valus = val * USEC_PER_SEC + val2;
 368                 int alspga = find_closest(valus,
 369                                 max44000_scale_avail_ulux_array,
 370                                 ARRAY_SIZE(max44000_scale_avail_ulux_array));
 371                 mutex_lock(&data->lock);
 372                 ret = max44000_write_alspga(data, alspga);
 373                 mutex_unlock(&data->lock);
 374                 return ret;
 375         }
 376
 377         return -EINVAL;
 378 }
 379
 380 static int max44000_write_raw_get_fmt(struct iio_dev *indio_dev,
 381                                       struct iio_chan_spec const *chan,
 382                                       long mask)
 383 {
 384         if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT)
 385                 return IIO_VAL_INT_PLUS_NANO;
 386         else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT)
 387                 return IIO_VAL_INT_PLUS_MICRO;
 388         else
 389                 return IIO_VAL_INT;
 390 }
 391
 392 static IIO_CONST_ATTR(illuminance_integration_time_available, max44000_int_time_avail_str);
 393 static IIO_CONST_ATTR(illuminance_scale_available, max44000_scale_avail_str);
 394
 395 static struct attribute *max44000_attributes[] = {
 396         &iio_const_attr_illuminance_integration_time_available.dev_attr.attr,
 397         &iio_const_attr_illuminance_scale_available.dev_attr.attr,
 398         NULL
 399 };
 400
 401 static const struct attribute_group max44000_attribute_group = {
 402         .attrs = max44000_attributes,
 403 };
 404
 405 static const struct iio_info max44000_info = {
 406         .read_raw               = max44000_read_raw,
 407         .write_raw              = max44000_write_raw,
 408         .write_raw_get_fmt      = max44000_write_raw_get_fmt,
 409         .attrs                  = &max44000_attribute_group,
 410 };
 411
 412 static bool max44000_readable_reg(struct device *dev, unsigned int reg)
 413 {
 414         switch (reg) {
 415         case MAX44000_REG_STATUS:
 416         case MAX44000_REG_CFG_MAIN:
 417         case MAX44000_REG_CFG_RX:
 418         case MAX44000_REG_CFG_TX:
 419         case MAX44000_REG_ALS_DATA_HI:
 420         case MAX44000_REG_ALS_DATA_LO:
 421         case MAX44000_REG_PRX_DATA:
 422         case MAX44000_REG_ALS_UPTHR_HI:
 423         case MAX44000_REG_ALS_UPTHR_LO:
 424         case MAX44000_REG_ALS_LOTHR_HI:
 425         case MAX44000_REG_ALS_LOTHR_LO:
 426         case MAX44000_REG_PST:
 427         case MAX44000_REG_PRX_IND:
 428         case MAX44000_REG_PRX_THR:
 429         case MAX44000_REG_TRIM_GAIN_GREEN:
 430         case MAX44000_REG_TRIM_GAIN_IR:
 431                 return true;
 432         default:
 433                 return false;
 434         }
 435 }
 436
 437 static bool max44000_writeable_reg(struct device *dev, unsigned int reg)
 438 {
 439         switch (reg) {
 440         case MAX44000_REG_CFG_MAIN:
 441         case MAX44000_REG_CFG_RX:
 442         case MAX44000_REG_CFG_TX:
 443         case MAX44000_REG_ALS_UPTHR_HI:
 444         case MAX44000_REG_ALS_UPTHR_LO:
 445         case MAX44000_REG_ALS_LOTHR_HI:
 446         case MAX44000_REG_ALS_LOTHR_LO:
 447         case MAX44000_REG_PST:
 448         case MAX44000_REG_PRX_IND:
 449         case MAX44000_REG_PRX_THR:
 450         case MAX44000_REG_TRIM_GAIN_GREEN:
 451         case MAX44000_REG_TRIM_GAIN_IR:
 452                 return true;
 453         default:
 454                 return false;
 455         }
 456 }
 457
 458 static bool max44000_volatile_reg(struct device *dev, unsigned int reg)
 459 {
 460         switch (reg) {
 461         case MAX44000_REG_STATUS:
 462         case MAX44000_REG_ALS_DATA_HI:
 463         case MAX44000_REG_ALS_DATA_LO:
 464         case MAX44000_REG_PRX_DATA:
 465                 return true;
 466         default:
 467                 return false;
 468         }
 469 }
 470
 471 static bool max44000_precious_reg(struct device *dev, unsigned int reg)
 472 {
 473         return reg == MAX44000_REG_STATUS;
 474 }
 475
 476 static const struct regmap_config max44000_regmap_config = {
 477         .reg_bits               = 8,
 478         .val_bits               = 8,
 479
 480         .max_register           = MAX44000_REG_PRX_DATA,
 481         .readable_reg           = max44000_readable_reg,
 482         .writeable_reg          = max44000_writeable_reg,
 483         .volatile_reg           = max44000_volatile_reg,
 484         .precious_reg           = max44000_precious_reg,
 485
 486         .use_single_read        = true,
 487         .use_single_write       = true,
 488         .cache_type             = REGCACHE_RBTREE,
 489 };
 490
 491 static irqreturn_t max44000_trigger_handler(int irq, void *p)
 492 {
 493         struct iio_poll_func *pf = p;
 494         struct iio_dev *indio_dev = pf->indio_dev;
 495         struct max44000_data *data = iio_priv(indio_dev);
 496         int index = 0;
 497         unsigned int regval;
 498         int ret;
 499
 500         mutex_lock(&data->lock);
 501         if (test_bit(MAX44000_SCAN_INDEX_ALS, indio_dev->active_scan_mask)) {
 502                 ret = max44000_read_alsval(data);
 503                 if (ret < 0)
 504                         goto out_unlock;
 505                 data->scan.channels[index++] = ret;
 506         }
 507         if (test_bit(MAX44000_SCAN_INDEX_PRX, indio_dev->active_scan_mask)) {
 508                 ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
 509                 if (ret < 0)
 510                         goto out_unlock;
 511                 data->scan.channels[index] = regval;
 512         }
 513         mutex_unlock(&data->lock);
 514
 515         iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 516                                            iio_get_time_ns(indio_dev));
 517         iio_trigger_notify_done(indio_dev->trig);
 518         return IRQ_HANDLED;
 519
 520 out_unlock:
 521         mutex_unlock(&data->lock);
 522         iio_trigger_notify_done(indio_dev->trig);
 523         return IRQ_HANDLED;
 524 }
 525
 526 static int max44000_probe(struct i2c_client *client,
 527                           const struct i2c_device_id *id)
 528 {
 529         struct max44000_data *data;
 530         struct iio_dev *indio_dev;
 531         int ret, reg;
 532
 533         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 534         if (!indio_dev)
 535                 return -ENOMEM;
 536         data = iio_priv(indio_dev);
 537         data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config);
 538         if (IS_ERR(data->regmap)) {
 539                 dev_err(&client->dev, "regmap_init failed!\n");
 540                 return PTR_ERR(data->regmap);
 541         }
 542
 543         i2c_set_clientdata(client, indio_dev);
 544         mutex_init(&data->lock);
 545         indio_dev->info = &max44000_info;
 546         indio_dev->name = MAX44000_DRV_NAME;
 547         indio_dev->channels = max44000_channels;
 548         indio_dev->num_channels = ARRAY_SIZE(max44000_channels);
 549
 550         /*
 551          * The device doesn't have a reset function so we just clear some
 552          * important bits at probe time to ensure sane operation.
 553          *
 554          * Since we don't support interrupts/events the threshold values are
 555          * not important. We also don't touch trim values.
 556          */
 557
 558         /* Reset ALS scaling bits */
 559         ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX,
 560                            MAX44000_REG_CFG_RX_DEFAULT);
 561         if (ret < 0) {
 562                 dev_err(&client->dev, "failed to write default CFG_RX: %d\n",
 563                         ret);
 564                 return ret;
 565         }
 566
 567         /*
 568          * By default the LED pulse used for the proximity sensor is disabled.
 569          * Set a middle value so that we get some sort of valid data by default.
 570          */
 571         ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
 572         if (ret < 0) {
 573                 dev_err(&client->dev, "failed to write init config: %d\n", ret);
 574                 return ret;
 575         }
 576
 577         /* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
 578         reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
 579         ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
 580         if (ret < 0) {
 581                 dev_err(&client->dev, "failed to write init config: %d\n", ret);
 582                 return ret;
 583         }
 584
 585         /* Read status at least once to clear any stale interrupt bits. */
 586         ret = regmap_read(data->regmap, MAX44000_REG_STATUS, &reg);
 587         if (ret < 0) {
 588                 dev_err(&client->dev, "failed to read init status: %d\n", ret);
 589                 return ret;
 590         }
 591
 592         ret = iio_triggered_buffer_setup(indio_dev, NULL, max44000_trigger_handler, NULL);
 593         if (ret < 0) {
 594                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 595                 return ret;
 596         }
 597
 598         return iio_device_register(indio_dev);
 599 }
 600
 601 static int max44000_remove(struct i2c_client *client)
 602 {
 603         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 604
 605         iio_device_unregister(indio_dev);
 606         iio_triggered_buffer_cleanup(indio_dev);
 607
 608         return 0;
 609 }
 610
 611 static const struct i2c_device_id max44000_id[] = {
 612         {"max44000", 0},
 613         { }
 614 };
 615 MODULE_DEVICE_TABLE(i2c, max44000_id);
 616
 617 #ifdef CONFIG_ACPI
 618 static const struct acpi_device_id max44000_acpi_match[] = {
 619         {"MAX44000", 0},
 620         { }
 621 };
 622 MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);
 623 #endif
 624
 625 static struct i2c_driver max44000_driver = {
 626         .driver = {
 627                 .name   = MAX44000_DRV_NAME,
 628                 .acpi_match_table = ACPI_PTR(max44000_acpi_match),
 629         },
 630         .probe          = max44000_probe,
 631         .remove         = max44000_remove,
 632         .id_table       = max44000_id,
 633 };
 634
 635 module_i2c_driver(max44000_driver);
 636
 637 MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");
 638 MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");
 639 MODULE_LICENSE("GPL v2");