drivers/iio/light/max44000.c

   1 /*
   2  * MAX44000 Ambient and Infrared Proximity Sensor
   3  *
   4  * Copyright (c) 2016, 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  * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
  11  *
  12  * 7-bit I2C slave address 0x4a
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/i2c.h>
  18 #include <linux/regmap.h>
  19 #include <linux/util_macros.h>
  20 #include <linux/iio/iio.h>
  21 #include <linux/iio/sysfs.h>
  22 #include <linux/iio/buffer.h>
  23 #include <linux/iio/trigger_consumer.h>
  24 #include <linux/iio/triggered_buffer.h>
  25 #include <linux/acpi.h>
  26
  27 #define MAX44000_DRV_NAME               "max44000"
  28
  29 /* Registers in datasheet order */
  30 #define MAX44000_REG_STATUS             0x00
  31 #define MAX44000_REG_CFG_MAIN           0x01
  32 #define MAX44000_REG_CFG_RX             0x02
  33 #define MAX44000_REG_CFG_TX             0x03
  34 #define MAX44000_REG_ALS_DATA_HI        0x04
  35 #define MAX44000_REG_ALS_DATA_LO        0x05
  36 #define MAX44000_REG_PRX_DATA           0x16
  37 #define MAX44000_REG_ALS_UPTHR_HI       0x06
  38 #define MAX44000_REG_ALS_UPTHR_LO       0x07
  39 #define MAX44000_REG_ALS_LOTHR_HI       0x08
  40 #define MAX44000_REG_ALS_LOTHR_LO       0x09
  41 #define MAX44000_REG_PST                0x0a
  42 #define MAX44000_REG_PRX_IND            0x0b
  43 #define MAX44000_REG_PRX_THR            0x0c
  44 #define MAX44000_REG_TRIM_GAIN_GREEN    0x0f
  45 #define MAX44000_REG_TRIM_GAIN_IR       0x10
  46
  47 /* REG_CFG bits */
  48 #define MAX44000_CFG_ALSINTE            0x01
  49 #define MAX44000_CFG_PRXINTE            0x02
  50 #define MAX44000_CFG_MASK               0x1c
  51 #define MAX44000_CFG_MODE_SHUTDOWN      0x00
  52 #define MAX44000_CFG_MODE_ALS_GIR       0x04
  53 #define MAX44000_CFG_MODE_ALS_G         0x08
  54 #define MAX44000_CFG_MODE_ALS_IR        0x0c
  55 #define MAX44000_CFG_MODE_ALS_PRX       0x10
  56 #define MAX44000_CFG_MODE_PRX           0x14
  57 #define MAX44000_CFG_TRIM               0x20
  58
  59 /*
  60  * Upper 4 bits are not documented but start as 1 on powerup
  61  * Setting them to 0 causes proximity to misbehave so set them to 1
  62  */
  63 #define MAX44000_REG_CFG_RX_DEFAULT 0xf0
  64
  65 /* REG_RX bits */
  66 #define MAX44000_CFG_RX_ALSTIM_MASK     0x0c
  67 #define MAX44000_CFG_RX_ALSTIM_SHIFT    2
  68 #define MAX44000_CFG_RX_ALSPGA_MASK     0x03
  69 #define MAX44000_CFG_RX_ALSPGA_SHIFT    0
  70
  71 /* REG_TX bits */
  72 #define MAX44000_LED_CURRENT_MASK       0xf
  73 #define MAX44000_LED_CURRENT_MAX        11
  74 #define MAX44000_LED_CURRENT_DEFAULT    6
  75
  76 #define MAX44000_ALSDATA_OVERFLOW       0x4000
  77
  78 struct max44000_data {
  79         struct mutex lock;
  80         struct regmap *regmap;
  81 };
  82
  83 /* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
  84 #define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5
  85
  86 /* Scale can be multiplied by up to 128x via ALSPGA for measurement gain */
  87 static const int max44000_alspga_shift[] = {0, 2, 4, 7};
  88 #define MAX44000_ALSPGA_MAX_SHIFT 7
  89
  90 /*
  91  * Scale can be multiplied by up to 64x via ALSTIM because of lost resolution
  92  *
  93  * This scaling factor is hidden from userspace and instead accounted for when
  94  * reading raw values from the device.
  95  *
  96  * This makes it possible to cleanly expose ALSPGA as IIO_CHAN_INFO_SCALE and
  97  * ALSTIM as IIO_CHAN_INFO_INT_TIME without the values affecting each other.
  98  *
  99  * Handling this internally is also required for buffer support because the
 100  * channel's scan_type can't be modified dynamically.
 101  */
 102 static const int max44000_alstim_shift[] = {0, 2, 4, 6};
 103 #define MAX44000_ALSTIM_SHIFT(alstim) (2 * (alstim))
 104
 105 /* Available integration times with pretty manual alignment: */
 106 static const int max44000_int_time_avail_ns_array[] = {
 107            100000000,
 108             25000000,
 109              6250000,
 110              1562500,
 111 };
 112 static const char max44000_int_time_avail_str[] =
 113         "0.100 "
 114         "0.025 "
 115         "0.00625 "
 116         "0.0015625";
 117
 118 /* Available scales (internal to ulux) with pretty manual alignment: */
 119 static const int max44000_scale_avail_ulux_array[] = {
 120             31250,
 121            125000,
 122            500000,
 123           4000000,
 124 };
 125 static const char max44000_scale_avail_str[] =
 126         "0.03125 "
 127         "0.125 "
 128         "0.5 "
 129          "4";
 130
 131 #define MAX44000_SCAN_INDEX_ALS 0
 132 #define MAX44000_SCAN_INDEX_PRX 1
 133
 134 static const struct iio_chan_spec max44000_channels[] = {
 135         {
 136                 .type = IIO_LIGHT,
 137                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 138                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
 139                                             BIT(IIO_CHAN_INFO_INT_TIME),
 140                 .scan_index = MAX44000_SCAN_INDEX_ALS,
 141                 .scan_type = {
 142                         .sign           = 'u',
 143                         .realbits       = 14,
 144                         .storagebits    = 16,
 145                 }
 146         },
 147         {
 148                 .type = IIO_PROXIMITY,
 149                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 150                 .scan_index = MAX44000_SCAN_INDEX_PRX,
 151                 .scan_type = {
 152                         .sign           = 'u',
 153                         .realbits       = 8,
 154                         .storagebits    = 16,
 155                 }
 156         },
 157         IIO_CHAN_SOFT_TIMESTAMP(2),
 158         {
 159                 .type = IIO_CURRENT,
 160                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 161                                       BIT(IIO_CHAN_INFO_SCALE),
 162                 .extend_name = "led",
 163                 .output = 1,
 164                 .scan_index = -1,
 165         },
 166 };
 167
 168 static int max44000_read_alstim(struct max44000_data *data)
 169 {
 170         unsigned int val;
 171         int ret;
 172
 173         ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
 174         if (ret < 0)
 175                 return ret;
 176         return (val & MAX44000_CFG_RX_ALSTIM_MASK) >> MAX44000_CFG_RX_ALSTIM_SHIFT;
 177 }
 178
 179 static int max44000_write_alstim(struct max44000_data *data, int val)
 180 {
 181         return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
 182                                  MAX44000_CFG_RX_ALSTIM_MASK,
 183                                  val << MAX44000_CFG_RX_ALSTIM_SHIFT);
 184 }
 185
 186 static int max44000_read_alspga(struct max44000_data *data)
 187 {
 188         unsigned int val;
 189         int ret;
 190
 191         ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
 192         if (ret < 0)
 193                 return ret;
 194         return (val & MAX44000_CFG_RX_ALSPGA_MASK) >> MAX44000_CFG_RX_ALSPGA_SHIFT;
 195 }
 196
 197 static int max44000_write_alspga(struct max44000_data *data, int val)
 198 {
 199         return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
 200                                  MAX44000_CFG_RX_ALSPGA_MASK,
 201                                  val << MAX44000_CFG_RX_ALSPGA_SHIFT);
 202 }
 203
 204 static int max44000_read_alsval(struct max44000_data *data)
 205 {
 206         u16 regval;
 207         __be16 val;
 208         int alstim, ret;
 209
 210         ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
 211                                &val, sizeof(val));
 212         if (ret < 0)
 213                 return ret;
 214         alstim = ret = max44000_read_alstim(data);
 215         if (ret < 0)
 216                 return ret;
 217
 218         regval = be16_to_cpu(val);
 219
 220         /*
 221          * Overflow is explained on datasheet page 17.
 222          *
 223          * It's a warning that either the G or IR channel has become saturated
 224          * and that the value in the register is likely incorrect.
 225          *
 226          * The recommendation is to change the scale (ALSPGA).
 227          * The driver just returns the max representable value.
 228          */
 229         if (regval & MAX44000_ALSDATA_OVERFLOW)
 230                 return 0x3FFF;
 231
 232         return regval << MAX44000_ALSTIM_SHIFT(alstim);
 233 }
 234
 235 static int max44000_write_led_current_raw(struct max44000_data *data, int val)
 236 {
 237         /* Maybe we should clamp the value instead? */
 238         if (val < 0 || val > MAX44000_LED_CURRENT_MAX)
 239                 return -ERANGE;
 240         if (val >= 8)
 241                 val += 4;
 242         return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,
 243                                  MAX44000_LED_CURRENT_MASK, val);
 244 }
 245
 246 static int max44000_read_led_current_raw(struct max44000_data *data)
 247 {
 248         unsigned int regval;
 249         int ret;
 250
 251         ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, &regval);
 252         if (ret < 0)
 253                 return ret;
 254         regval &= MAX44000_LED_CURRENT_MASK;
 255         if (regval >= 8)
 256                 regval -= 4;
 257         return regval;
 258 }
 259
 260 static int max44000_read_raw(struct iio_dev *indio_dev,
 261                              struct iio_chan_spec const *chan,
 262                              int *val, int *val2, long mask)
 263 {
 264         struct max44000_data *data = iio_priv(indio_dev);
 265         int alstim, alspga;
 266         unsigned int regval;
 267         int ret;
 268
 269         switch (mask) {
 270         case IIO_CHAN_INFO_RAW:
 271                 switch (chan->type) {
 272                 case IIO_LIGHT:
 273                         mutex_lock(&data->lock);
 274                         ret = max44000_read_alsval(data);
 275                         mutex_unlock(&data->lock);
 276                         if (ret < 0)
 277                                 return ret;
 278                         *val = ret;
 279                         return IIO_VAL_INT;
 280
 281                 case IIO_PROXIMITY:
 282                         mutex_lock(&data->lock);
 283                         ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
 284                         mutex_unlock(&data->lock);
 285                         if (ret < 0)
 286                                 return ret;
 287                         *val = regval;
 288                         return IIO_VAL_INT;
 289
 290                 case IIO_CURRENT:
 291                         mutex_lock(&data->lock);
 292                         ret = max44000_read_led_current_raw(data);
 293                         mutex_unlock(&data->lock);
 294                         if (ret < 0)
 295                                 return ret;
 296                         *val = ret;
 297                         return IIO_VAL_INT;
 298
 299                 default:
 300                         return -EINVAL;
 301                 }
 302
 303         case IIO_CHAN_INFO_SCALE:
 304                 switch (chan->type) {
 305                 case IIO_CURRENT:
 306                         /* Output register is in 10s of miliamps */
 307                         *val = 10;
 308                         return IIO_VAL_INT;
 309
 310                 case IIO_LIGHT:
 311                         mutex_lock(&data->lock);
 312                         alspga = ret = max44000_read_alspga(data);
 313                         mutex_unlock(&data->lock);
 314                         if (ret < 0)
 315                                 return ret;
 316
 317                         /* Avoid negative shifts */
 318                         *val = (1 << MAX44000_ALSPGA_MAX_SHIFT);
 319                         *val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2
 320                                         + MAX44000_ALSPGA_MAX_SHIFT
 321                                         - max44000_alspga_shift[alspga];
 322                         return IIO_VAL_FRACTIONAL_LOG2;
 323
 324                 default:
 325                         return -EINVAL;
 326                 }
 327
 328         case IIO_CHAN_INFO_INT_TIME:
 329                 mutex_lock(&data->lock);
 330                 alstim = ret = max44000_read_alstim(data);
 331                 mutex_unlock(&data->lock);
 332
 333                 if (ret < 0)
 334                         return ret;
 335                 *val = 0;
 336                 *val2 = max44000_int_time_avail_ns_array[alstim];
 337                 return IIO_VAL_INT_PLUS_NANO;
 338
 339         default:
 340                 return -EINVAL;
 341         }
 342 }
 343
 344 static int max44000_write_raw(struct iio_dev *indio_dev,
 345                               struct iio_chan_spec const *chan,
 346                               int val, int val2, long mask)
 347 {
 348         struct max44000_data *data = iio_priv(indio_dev);
 349         int ret;
 350
 351         if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {
 352                 mutex_lock(&data->lock);
 353                 ret = max44000_write_led_current_raw(data, val);
 354                 mutex_unlock(&data->lock);
 355                 return ret;
 356         } else if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) {
 357                 s64 valns = val * NSEC_PER_SEC + val2;
 358                 int alstim = find_closest_descending(valns,
 359                                 max44000_int_time_avail_ns_array,
 360                                 ARRAY_SIZE(max44000_int_time_avail_ns_array));
 361                 mutex_lock(&data->lock);
 362                 ret = max44000_write_alstim(data, alstim);
 363                 mutex_unlock(&data->lock);
 364                 return ret;
 365         } else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT) {
 366                 s64 valus = val * USEC_PER_SEC + val2;
 367                 int alspga = find_closest(valus,
 368                                 max44000_scale_avail_ulux_array,
 369                                 ARRAY_SIZE(max44000_scale_avail_ulux_array));
 370                 mutex_lock(&data->lock);
 371                 ret = max44000_write_alspga(data, alspga);
 372                 mutex_unlock(&data->lock);
 373                 return ret;
 374         }
 375
 376         return -EINVAL;
 377 }
 378
 379 static int max44000_write_raw_get_fmt(struct iio_dev *indio_dev,
 380                                       struct iio_chan_spec const *chan,
 381                                       long mask)
 382 {
 383         if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT)
 384                 return IIO_VAL_INT_PLUS_NANO;
 385         else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT)
 386                 return IIO_VAL_INT_PLUS_MICRO;
 387         else
 388                 return IIO_VAL_INT;
 389 }
 390
 391 static IIO_CONST_ATTR(illuminance_integration_time_available, max44000_int_time_avail_str);
 392 static IIO_CONST_ATTR(illuminance_scale_available, max44000_scale_avail_str);
 393
 394 static struct attribute *max44000_attributes[] = {
 395         &iio_const_attr_illuminance_integration_time_available.dev_attr.attr,
 396         &iio_const_attr_illuminance_scale_available.dev_attr.attr,
 397         NULL
 398 };
 399
 400 static const struct attribute_group max44000_attribute_group = {
 401         .attrs = max44000_attributes,
 402 };
 403
 404 static const struct iio_info max44000_info = {
 405         .driver_module          = THIS_MODULE,
 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_rw  = 1,
 487         .cache_type     = REGCACHE_RBTREE,
 488 };
 489
 490 static irqreturn_t max44000_trigger_handler(int irq, void *p)
 491 {
 492         struct iio_poll_func *pf = p;
 493         struct iio_dev *indio_dev = pf->indio_dev;
 494         struct max44000_data *data = iio_priv(indio_dev);
 495         u16 buf[8]; /* 2x u16 + padding + 8 bytes timestamp */
 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                 buf[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                 buf[index] = regval;
 512         }
 513         mutex_unlock(&data->lock);
 514
 515         iio_push_to_buffers_with_timestamp(indio_dev, buf,
 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->dev.parent = &client->dev;
 546         indio_dev->info = &max44000_info;
 547         indio_dev->name = MAX44000_DRV_NAME;
 548         indio_dev->channels = max44000_channels;
 549         indio_dev->num_channels = ARRAY_SIZE(max44000_channels);
 550
 551         /*
 552          * The device doesn't have a reset function so we just clear some
 553          * important bits at probe time to ensure sane operation.
 554          *
 555          * Since we don't support interrupts/events the threshold values are
 556          * not important. We also don't touch trim values.
 557          */
 558
 559         /* Reset ALS scaling bits */
 560         ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX,
 561                            MAX44000_REG_CFG_RX_DEFAULT);
 562         if (ret < 0) {
 563                 dev_err(&client->dev, "failed to write default CFG_RX: %d\n",
 564                         ret);
 565                 return ret;
 566         }
 567
 568         /*
 569          * By default the LED pulse used for the proximity sensor is disabled.
 570          * Set a middle value so that we get some sort of valid data by default.
 571          */
 572         ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
 573         if (ret < 0) {
 574                 dev_err(&client->dev, "failed to write init config: %d\n", ret);
 575                 return ret;
 576         }
 577
 578         /* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
 579         reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
 580         ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
 581         if (ret < 0) {
 582                 dev_err(&client->dev, "failed to write init config: %d\n", ret);
 583                 return ret;
 584         }
 585
 586         /* Read status at least once to clear any stale interrupt bits. */
 587         ret = regmap_read(data->regmap, MAX44000_REG_STATUS, &reg);
 588         if (ret < 0) {
 589                 dev_err(&client->dev, "failed to read init status: %d\n", ret);
 590                 return ret;
 591         }
 592
 593         ret = iio_triggered_buffer_setup(indio_dev, NULL, max44000_trigger_handler, NULL);
 594         if (ret < 0) {
 595                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 596                 return ret;
 597         }
 598
 599         return iio_device_register(indio_dev);
 600 }
 601
 602 static int max44000_remove(struct i2c_client *client)
 603 {
 604         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 605
 606         iio_device_unregister(indio_dev);
 607         iio_triggered_buffer_cleanup(indio_dev);
 608
 609         return 0;
 610 }
 611
 612 static const struct i2c_device_id max44000_id[] = {
 613         {"max44000", 0},
 614         { }
 615 };
 616 MODULE_DEVICE_TABLE(i2c, max44000_id);
 617
 618 #ifdef CONFIG_ACPI
 619 static const struct acpi_device_id max44000_acpi_match[] = {
 620         {"MAX44000", 0},
 621         { }
 622 };
 623 MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);
 624 #endif
 625
 626 static struct i2c_driver max44000_driver = {
 627         .driver = {
 628                 .name   = MAX44000_DRV_NAME,
 629                 .acpi_match_table = ACPI_PTR(max44000_acpi_match),
 630         },
 631         .probe          = max44000_probe,
 632         .remove         = max44000_remove,
 633         .id_table       = max44000_id,
 634 };
 635
 636 module_i2c_driver(max44000_driver);
 637
 638 MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");
 639 MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");
 640 MODULE_LICENSE("GPL v2");