drivers/iio/light/ltr390.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * IIO driver for Lite-On LTR390 ALS and UV sensor
   4  * (7-bit I2C slave address 0x53)
   5  *
   6  * Based on the work of:
   7  *   Shreeya Patel and Shi Zhigang (LTRF216 Driver)
   8  *
   9  * Copyright (C) 2023 Anshul Dalal <[email protected]>
  10  *
  11  * Datasheet:
  12  *   https://optoelectronics.liteon.com/upload/download/DS86-2015-0004/LTR-390UV_Final_%20DS_V1%201.pdf
  13  *
  14  * TODO:
  15  *   - Support for configurable gain and resolution
  16  *   - Sensor suspend/resume support
  17  *   - Add support for reading the ALS
  18  *   - Interrupt support
  19  */
  20
  21 #include <linux/bitfield.h>
  22 #include <linux/device.h>
  23 #include <linux/i2c.h>
  24 #include <linux/irq.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/math.h>
  27 #include <linux/module.h>
  28 #include <linux/mutex.h>
  29 #include <linux/regmap.h>
  30
  31 #include <linux/iio/iio.h>
  32 #include <linux/iio/events.h>
  33
  34 #include <linux/unaligned.h>
  35
  36 #define LTR390_MAIN_CTRL                0x00
  37 #define LTR390_ALS_UVS_MEAS_RATE        0x04
  38 #define LTR390_ALS_UVS_GAIN             0x05
  39 #define LTR390_PART_ID                  0x06
  40 #define LTR390_MAIN_STATUS              0x07
  41 #define LTR390_ALS_DATA                 0x0D
  42 #define LTR390_UVS_DATA                 0x10
  43 #define LTR390_INT_CFG                  0x19
  44 #define LTR390_INT_PST                  0x1A
  45 #define LTR390_THRESH_UP                0x21
  46 #define LTR390_THRESH_LOW               0x24
  47
  48 #define LTR390_PART_NUMBER_ID           0xb
  49 #define LTR390_ALS_UVS_GAIN_MASK        GENMASK(2, 0)
  50 #define LTR390_ALS_UVS_MEAS_RATE_MASK   GENMASK(2, 0)
  51 #define LTR390_ALS_UVS_INT_TIME_MASK    GENMASK(6, 4)
  52 #define LTR390_ALS_UVS_INT_TIME(x)      FIELD_PREP(LTR390_ALS_UVS_INT_TIME_MASK, (x))
  53 #define LTR390_INT_PST_MASK             GENMASK(7, 4)
  54 #define LTR390_INT_PST_VAL(x)           FIELD_PREP(LTR390_INT_PST_MASK, (x))
  55
  56 #define LTR390_SW_RESET       BIT(4)
  57 #define LTR390_UVS_MODE       BIT(3)
  58 #define LTR390_SENSOR_ENABLE  BIT(1)
  59 #define LTR390_LS_INT_EN      BIT(2)
  60 #define LTR390_LS_INT_SEL_UVS BIT(5)
  61
  62 #define LTR390_FRACTIONAL_PRECISION 100
  63
  64 /*
  65  * At 20-bit resolution (integration time: 400ms) and 18x gain, 2300 counts of
  66  * the sensor are equal to 1 UV Index [Datasheet Page#8].
  67  *
  68  * For the default resolution of 18-bit (integration time: 100ms) and default
  69  * gain of 3x, the counts/uvi are calculated as follows:
  70  * 2300 / ((3/18) * (100/400)) = 95.83
  71  */
  72 #define LTR390_COUNTS_PER_UVI 96
  73
  74 /*
  75  * Window Factor is needed when the device is under Window glass with coated
  76  * tinted ink. This is to compensate for the light loss due to the lower
  77  * transmission rate of the window glass and helps * in calculating lux.
  78  */
  79 #define LTR390_WINDOW_FACTOR 1
  80
  81 enum ltr390_mode {
  82         LTR390_SET_ALS_MODE,
  83         LTR390_SET_UVS_MODE,
  84 };
  85
  86 enum ltr390_meas_rate {
  87         LTR390_GET_FREQ,
  88         LTR390_GET_PERIOD,
  89 };
  90
  91 struct ltr390_data {
  92         struct regmap *regmap;
  93         struct i2c_client *client;
  94         /* Protects device from simulataneous reads */
  95         struct mutex lock;
  96         enum ltr390_mode mode;
  97         int gain;
  98         int int_time_us;
  99 };
 100
 101 static const struct regmap_config ltr390_regmap_config = {
 102         .name = "ltr390",
 103         .reg_bits = 8,
 104         .reg_stride = 1,
 105         .val_bits = 8,
 106 };
 107
 108 /* Sampling frequency is in mili Hz and mili Seconds */
 109 static const int ltr390_samp_freq_table[][2] = {
 110                 [0] = { 40000, 25 },
 111                 [1] = { 20000, 50 },
 112                 [2] = { 10000, 100 },
 113                 [3] = { 5000, 200 },
 114                 [4] = { 2000, 500 },
 115                 [5] = { 1000, 1000 },
 116                 [6] = { 500, 2000 },
 117                 [7] = { 500, 2000 },
 118 };
 119
 120 static int ltr390_register_read(struct ltr390_data *data, u8 register_address)
 121 {
 122         struct device *dev = &data->client->dev;
 123         int ret;
 124         u8 recieve_buffer[3];
 125
 126         ret = regmap_bulk_read(data->regmap, register_address, recieve_buffer,
 127                                sizeof(recieve_buffer));
 128         if (ret) {
 129                 dev_err(dev, "failed to read measurement data");
 130                 return ret;
 131         }
 132
 133         return get_unaligned_le24(recieve_buffer);
 134 }
 135
 136 static int ltr390_set_mode(struct ltr390_data *data, enum ltr390_mode mode)
 137 {
 138         int ret;
 139
 140         if (data->mode == mode)
 141                 return 0;
 142
 143         switch (mode) {
 144         case LTR390_SET_ALS_MODE:
 145                 ret = regmap_clear_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_UVS_MODE);
 146                 break;
 147
 148         case LTR390_SET_UVS_MODE:
 149                 ret = regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_UVS_MODE);
 150                 break;
 151         }
 152
 153         if (ret)
 154                 return ret;
 155
 156         data->mode = mode;
 157         return 0;
 158 }
 159
 160 static int ltr390_counts_per_uvi(struct ltr390_data *data)
 161 {
 162         const int orig_gain = 18;
 163         const int orig_int_time = 400;
 164
 165         return DIV_ROUND_CLOSEST(23 * data->gain * data->int_time_us, 10 * orig_gain * orig_int_time);
 166 }
 167
 168 static int ltr390_get_samp_freq_or_period(struct ltr390_data *data,
 169                                         enum ltr390_meas_rate option)
 170 {
 171         int ret, value;
 172
 173         ret = regmap_read(data->regmap, LTR390_ALS_UVS_MEAS_RATE, &value);
 174         if (ret < 0)
 175                 return ret;
 176         value = FIELD_GET(LTR390_ALS_UVS_MEAS_RATE_MASK, value);
 177
 178         return ltr390_samp_freq_table[value][option];
 179 }
 180
 181 static int ltr390_read_raw(struct iio_dev *iio_device,
 182                            struct iio_chan_spec const *chan, int *val,
 183                            int *val2, long mask)
 184 {
 185         int ret;
 186         struct ltr390_data *data = iio_priv(iio_device);
 187
 188         guard(mutex)(&data->lock);
 189         switch (mask) {
 190         case IIO_CHAN_INFO_RAW:
 191                 switch (chan->type) {
 192                 case IIO_UVINDEX:
 193                         ret = ltr390_set_mode(data, LTR390_SET_UVS_MODE);
 194                         if (ret < 0)
 195                                 return ret;
 196
 197                         ret = ltr390_register_read(data, LTR390_UVS_DATA);
 198                         if (ret < 0)
 199                                 return ret;
 200                         break;
 201
 202                 case IIO_LIGHT:
 203                         ret = ltr390_set_mode(data, LTR390_SET_ALS_MODE);
 204                         if (ret < 0)
 205                                 return ret;
 206
 207                         ret = ltr390_register_read(data, LTR390_ALS_DATA);
 208                         if (ret < 0)
 209                                 return ret;
 210                         break;
 211
 212                 default:
 213                         return -EINVAL;
 214                 }
 215                 *val = ret;
 216                 return IIO_VAL_INT;
 217         case IIO_CHAN_INFO_SCALE:
 218                 switch (chan->type) {
 219                 case IIO_UVINDEX:
 220                         *val = LTR390_WINDOW_FACTOR * LTR390_FRACTIONAL_PRECISION;
 221                         *val2 = ltr390_counts_per_uvi(data);
 222                         return IIO_VAL_FRACTIONAL;
 223
 224                 case IIO_LIGHT:
 225                         *val = LTR390_WINDOW_FACTOR * 6 * 100;
 226                         *val2 = data->gain * data->int_time_us;
 227                         return IIO_VAL_FRACTIONAL;
 228
 229                 default:
 230                         return -EINVAL;
 231                 }
 232
 233         case IIO_CHAN_INFO_INT_TIME:
 234                 *val = data->int_time_us;
 235                 return IIO_VAL_INT;
 236
 237         case IIO_CHAN_INFO_SAMP_FREQ:
 238                 *val = ltr390_get_samp_freq_or_period(data, LTR390_GET_FREQ);
 239                 return IIO_VAL_INT;
 240
 241         default:
 242                 return -EINVAL;
 243         }
 244 }
 245
 246 /* integration time in us */
 247 static const int ltr390_int_time_map_us[] = { 400000, 200000, 100000, 50000, 25000, 12500 };
 248 static const int ltr390_gain_map[] = { 1, 3, 6, 9, 18 };
 249 static const int ltr390_freq_map[] = { 40000, 20000, 10000, 5000, 2000, 1000, 500, 500 };
 250
 251 static const struct iio_event_spec ltr390_event_spec[] = {
 252         {
 253                 .type = IIO_EV_TYPE_THRESH,
 254                 .dir = IIO_EV_DIR_RISING,
 255                 .mask_separate = BIT(IIO_EV_INFO_VALUE),
 256         }, {
 257                 .type = IIO_EV_TYPE_THRESH,
 258                 .dir = IIO_EV_DIR_FALLING,
 259                 .mask_separate = BIT(IIO_EV_INFO_VALUE),
 260         }, {
 261                 .type = IIO_EV_TYPE_THRESH,
 262                 .dir = IIO_EV_DIR_EITHER,
 263                 .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
 264                                 BIT(IIO_EV_INFO_PERIOD),
 265         }
 266 };
 267
 268 static const struct iio_chan_spec ltr390_channels[] = {
 269         /* UV sensor */
 270         {
 271                 .type = IIO_UVINDEX,
 272                 .scan_index = 0,
 273                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
 274                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 275                 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) |
 276                                                         BIT(IIO_CHAN_INFO_SCALE) |
 277                                                         BIT(IIO_CHAN_INFO_SAMP_FREQ),
 278                 .event_spec = ltr390_event_spec,
 279                 .num_event_specs = ARRAY_SIZE(ltr390_event_spec),
 280         },
 281         /* ALS sensor */
 282         {
 283                 .type = IIO_LIGHT,
 284                 .scan_index = 1,
 285                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
 286                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 287                 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) |
 288                                                         BIT(IIO_CHAN_INFO_SCALE) |
 289                                                         BIT(IIO_CHAN_INFO_SAMP_FREQ),
 290                 .event_spec = ltr390_event_spec,
 291                 .num_event_specs = ARRAY_SIZE(ltr390_event_spec),
 292         },
 293 };
 294
 295 static int ltr390_set_gain(struct ltr390_data *data, int val)
 296 {
 297         int ret, idx;
 298
 299         for (idx = 0; idx < ARRAY_SIZE(ltr390_gain_map); idx++) {
 300                 if (ltr390_gain_map[idx] != val)
 301                         continue;
 302
 303                 guard(mutex)(&data->lock);
 304                 ret = regmap_update_bits(data->regmap,
 305                                         LTR390_ALS_UVS_GAIN,
 306                                         LTR390_ALS_UVS_GAIN_MASK, idx);
 307                 if (ret)
 308                         return ret;
 309
 310                 data->gain = ltr390_gain_map[idx];
 311                 return 0;
 312         }
 313
 314         return -EINVAL;
 315 }
 316
 317 static int ltr390_set_int_time(struct ltr390_data *data, int val)
 318 {
 319         int ret, idx;
 320
 321         for (idx = 0; idx < ARRAY_SIZE(ltr390_int_time_map_us); idx++) {
 322                 if (ltr390_int_time_map_us[idx] != val)
 323                         continue;
 324
 325                 guard(mutex)(&data->lock);
 326                 ret = regmap_update_bits(data->regmap,
 327                                         LTR390_ALS_UVS_MEAS_RATE,
 328                                         LTR390_ALS_UVS_INT_TIME_MASK,
 329                                         LTR390_ALS_UVS_INT_TIME(idx));
 330                 if (ret)
 331                         return ret;
 332
 333                 data->int_time_us = ltr390_int_time_map_us[idx];
 334                 return 0;
 335         }
 336
 337         return -EINVAL;
 338 }
 339
 340 static int ltr390_set_samp_freq(struct ltr390_data *data, int val)
 341 {
 342         int idx;
 343
 344         for (idx = 0; idx < ARRAY_SIZE(ltr390_samp_freq_table); idx++) {
 345                 if (ltr390_samp_freq_table[idx][0] != val)
 346                         continue;
 347
 348                 guard(mutex)(&data->lock);
 349                 return regmap_update_bits(data->regmap,
 350                                         LTR390_ALS_UVS_MEAS_RATE,
 351                                         LTR390_ALS_UVS_MEAS_RATE_MASK, idx);
 352         }
 353
 354         return -EINVAL;
 355 }
 356
 357 static int ltr390_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
 358                                 const int **vals, int *type, int *length, long mask)
 359 {
 360         switch (mask) {
 361         case IIO_CHAN_INFO_SCALE:
 362                 *length = ARRAY_SIZE(ltr390_gain_map);
 363                 *type = IIO_VAL_INT;
 364                 *vals = ltr390_gain_map;
 365                 return IIO_AVAIL_LIST;
 366         case IIO_CHAN_INFO_INT_TIME:
 367                 *length = ARRAY_SIZE(ltr390_int_time_map_us);
 368                 *type = IIO_VAL_INT;
 369                 *vals = ltr390_int_time_map_us;
 370                 return IIO_AVAIL_LIST;
 371         case IIO_CHAN_INFO_SAMP_FREQ:
 372                 *length = ARRAY_SIZE(ltr390_freq_map);
 373                 *type = IIO_VAL_INT;
 374                 *vals = ltr390_freq_map;
 375                 return IIO_AVAIL_LIST;
 376         default:
 377                 return -EINVAL;
 378         }
 379 }
 380
 381 static int ltr390_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
 382                                 int val, int val2, long mask)
 383 {
 384         struct ltr390_data *data = iio_priv(indio_dev);
 385
 386         switch (mask) {
 387         case IIO_CHAN_INFO_SCALE:
 388                 if (val2 != 0)
 389                         return -EINVAL;
 390
 391                 return ltr390_set_gain(data, val);
 392
 393         case IIO_CHAN_INFO_INT_TIME:
 394                 if (val2 != 0)
 395                         return -EINVAL;
 396
 397                 return ltr390_set_int_time(data, val);
 398
 399         case IIO_CHAN_INFO_SAMP_FREQ:
 400                 if (val2 != 0)
 401                         return -EINVAL;
 402
 403                 return ltr390_set_samp_freq(data, val);
 404
 405         default:
 406                 return -EINVAL;
 407         }
 408 }
 409
 410 static int ltr390_read_intr_prst(struct ltr390_data *data, int *val)
 411 {
 412         int ret, prst, samp_period;
 413
 414         samp_period = ltr390_get_samp_freq_or_period(data, LTR390_GET_PERIOD);
 415         ret = regmap_read(data->regmap, LTR390_INT_PST, &prst);
 416         if (ret < 0)
 417                 return ret;
 418         *val = prst * samp_period;
 419
 420         return IIO_VAL_INT;
 421 }
 422
 423 static int ltr390_write_intr_prst(struct ltr390_data *data, int val)
 424 {
 425         int ret, samp_period, new_val;
 426
 427         samp_period = ltr390_get_samp_freq_or_period(data, LTR390_GET_PERIOD);
 428
 429         /* persist period should be greater than or equal to samp period */
 430         if (val < samp_period)
 431                 return -EINVAL;
 432
 433         new_val = DIV_ROUND_UP(val, samp_period);
 434         if (new_val < 0 || new_val > 0x0f)
 435                 return -EINVAL;
 436
 437         guard(mutex)(&data->lock);
 438         ret = regmap_update_bits(data->regmap,
 439                                 LTR390_INT_PST,
 440                                 LTR390_INT_PST_MASK,
 441                                 LTR390_INT_PST_VAL(new_val));
 442         if (ret)
 443                 return ret;
 444
 445         return 0;
 446 }
 447
 448 static int ltr390_read_threshold(struct iio_dev *indio_dev,
 449                                 enum iio_event_direction dir,
 450                                 int *val, int *val2)
 451 {
 452         struct ltr390_data *data = iio_priv(indio_dev);
 453         int ret;
 454
 455         switch (dir) {
 456         case IIO_EV_DIR_RISING:
 457                 ret = ltr390_register_read(data, LTR390_THRESH_UP);
 458                 if (ret < 0)
 459                         return ret;
 460                 *val = ret;
 461                 return IIO_VAL_INT;
 462
 463         case IIO_EV_DIR_FALLING:
 464                 ret = ltr390_register_read(data, LTR390_THRESH_LOW);
 465                 if (ret < 0)
 466                         return ret;
 467                 *val = ret;
 468                 return IIO_VAL_INT;
 469         default:
 470                 return -EINVAL;
 471         }
 472 }
 473
 474 static int ltr390_write_threshold(struct iio_dev *indio_dev,
 475                                 enum iio_event_direction dir,
 476                                 int val, int val2)
 477 {
 478         struct ltr390_data *data = iio_priv(indio_dev);
 479
 480         guard(mutex)(&data->lock);
 481         switch (dir) {
 482         case IIO_EV_DIR_RISING:
 483                 return regmap_bulk_write(data->regmap, LTR390_THRESH_UP, &val, 3);
 484
 485         case IIO_EV_DIR_FALLING:
 486                 return regmap_bulk_write(data->regmap, LTR390_THRESH_LOW, &val, 3);
 487
 488         default:
 489                 return -EINVAL;
 490         }
 491 }
 492
 493 static int ltr390_read_event_value(struct iio_dev *indio_dev,
 494                                 const struct iio_chan_spec *chan,
 495                                 enum iio_event_type type,
 496                                 enum iio_event_direction dir,
 497                                 enum iio_event_info info,
 498                                 int *val, int *val2)
 499 {
 500         switch (info) {
 501         case IIO_EV_INFO_VALUE:
 502                 return ltr390_read_threshold(indio_dev, dir, val, val2);
 503
 504         case IIO_EV_INFO_PERIOD:
 505                 return ltr390_read_intr_prst(iio_priv(indio_dev), val);
 506
 507         default:
 508                 return -EINVAL;
 509         }
 510 }
 511
 512 static int ltr390_write_event_value(struct iio_dev *indio_dev,
 513                                 const struct iio_chan_spec *chan,
 514                                 enum iio_event_type type,
 515                                 enum iio_event_direction dir,
 516                                 enum iio_event_info info,
 517                                 int val, int val2)
 518 {
 519         switch (info) {
 520         case IIO_EV_INFO_VALUE:
 521                 if (val2 != 0)
 522                         return -EINVAL;
 523
 524                 return ltr390_write_threshold(indio_dev, dir, val, val2);
 525
 526         case IIO_EV_INFO_PERIOD:
 527                 if (val2 != 0)
 528                         return -EINVAL;
 529
 530                 return ltr390_write_intr_prst(iio_priv(indio_dev), val);
 531
 532         default:
 533                 return -EINVAL;
 534         }
 535 }
 536
 537 static int ltr390_read_event_config(struct iio_dev *indio_dev,
 538                                 const struct iio_chan_spec *chan,
 539                                 enum iio_event_type type,
 540                                 enum iio_event_direction dir)
 541 {
 542         struct ltr390_data *data = iio_priv(indio_dev);
 543         int ret, status;
 544
 545         ret = regmap_read(data->regmap, LTR390_INT_CFG, &status);
 546         if (ret < 0)
 547                 return ret;
 548
 549         return FIELD_GET(LTR390_LS_INT_EN, status);
 550 }
 551
 552 static int ltr390_write_event_config(struct iio_dev *indio_dev,
 553                                 const struct iio_chan_spec *chan,
 554                                 enum iio_event_type type,
 555                                 enum iio_event_direction dir,
 556                                 bool state)
 557 {
 558         struct ltr390_data *data = iio_priv(indio_dev);
 559         int ret;
 560
 561         if (!state)
 562                 return regmap_clear_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_EN);
 563
 564         guard(mutex)(&data->lock);
 565         ret = regmap_set_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_EN);
 566         if (ret < 0)
 567                 return ret;
 568
 569         switch (chan->type) {
 570         case IIO_LIGHT:
 571                 ret = ltr390_set_mode(data, LTR390_SET_ALS_MODE);
 572                 if (ret < 0)
 573                         return ret;
 574
 575                 return regmap_clear_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_SEL_UVS);
 576
 577         case IIO_UVINDEX:
 578                 ret = ltr390_set_mode(data, LTR390_SET_UVS_MODE);
 579                 if (ret < 0)
 580                         return ret;
 581
 582                 return regmap_set_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_SEL_UVS);
 583
 584         default:
 585                 return -EINVAL;
 586         }
 587 }
 588
 589 static const struct iio_info ltr390_info = {
 590         .read_raw = ltr390_read_raw,
 591         .write_raw = ltr390_write_raw,
 592         .read_avail = ltr390_read_avail,
 593         .read_event_value = ltr390_read_event_value,
 594         .read_event_config = ltr390_read_event_config,
 595         .write_event_value = ltr390_write_event_value,
 596         .write_event_config = ltr390_write_event_config,
 597 };
 598
 599 static irqreturn_t ltr390_interrupt_handler(int irq, void *private)
 600 {
 601         struct iio_dev *indio_dev = private;
 602         struct ltr390_data *data = iio_priv(indio_dev);
 603         int ret, status;
 604
 605         /* Reading the status register to clear the interrupt flag, Datasheet pg: 17*/
 606         ret = regmap_read(data->regmap, LTR390_MAIN_STATUS, &status);
 607         if (ret < 0)
 608                 return ret;
 609
 610         switch (data->mode) {
 611         case LTR390_SET_ALS_MODE:
 612                 iio_push_event(indio_dev,
 613                                 IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
 614                                 IIO_EV_TYPE_THRESH,
 615                                 IIO_EV_DIR_EITHER),
 616                                 iio_get_time_ns(indio_dev));
 617                 break;
 618
 619         case LTR390_SET_UVS_MODE:
 620                 iio_push_event(indio_dev,
 621                                 IIO_UNMOD_EVENT_CODE(IIO_UVINDEX, 0,
 622                                 IIO_EV_TYPE_THRESH,
 623                                 IIO_EV_DIR_EITHER),
 624                                 iio_get_time_ns(indio_dev));
 625                 break;
 626         }
 627
 628         return IRQ_HANDLED;
 629 }
 630
 631 static int ltr390_probe(struct i2c_client *client)
 632 {
 633         struct ltr390_data *data;
 634         struct iio_dev *indio_dev;
 635         struct device *dev;
 636         int ret, part_number;
 637
 638         dev = &client->dev;
 639         indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 640         if (!indio_dev)
 641                 return -ENOMEM;
 642
 643         data = iio_priv(indio_dev);
 644
 645         data->regmap = devm_regmap_init_i2c(client, &ltr390_regmap_config);
 646         if (IS_ERR(data->regmap))
 647                 return dev_err_probe(dev, PTR_ERR(data->regmap),
 648                                      "regmap initialization failed\n");
 649
 650         data->client = client;
 651         /* default value of integration time from pg: 15 of the datasheet */
 652         data->int_time_us = 100000;
 653         /* default value of gain from pg: 16 of the datasheet */
 654         data->gain = 3;
 655         /* default mode for ltr390 is ALS mode */
 656         data->mode = LTR390_SET_ALS_MODE;
 657
 658         mutex_init(&data->lock);
 659
 660         indio_dev->info = &ltr390_info;
 661         indio_dev->channels = ltr390_channels;
 662         indio_dev->num_channels = ARRAY_SIZE(ltr390_channels);
 663         indio_dev->name = "ltr390";
 664
 665         ret = regmap_read(data->regmap, LTR390_PART_ID, &part_number);
 666         if (ret)
 667                 return dev_err_probe(dev, ret,
 668                                      "failed to get sensor's part id\n");
 669         /* Lower 4 bits of `part_number` change with hardware revisions */
 670         if (part_number >> 4 != LTR390_PART_NUMBER_ID)
 671                 dev_info(dev, "received invalid product id: 0x%x", part_number);
 672         dev_dbg(dev, "LTR390, product id: 0x%x\n", part_number);
 673
 674         /* reset sensor, chip fails to respond to this, so ignore any errors */
 675         regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SW_RESET);
 676
 677         /* Wait for the registers to reset before proceeding */
 678         usleep_range(1000, 2000);
 679
 680         ret = regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
 681         if (ret)
 682                 return dev_err_probe(dev, ret, "failed to enable the sensor\n");
 683
 684         if (client->irq) {
 685                 ret = devm_request_threaded_irq(dev, client->irq,
 686                                                 NULL, ltr390_interrupt_handler,
 687                                                 IRQF_ONESHOT,
 688                                                 "ltr390_thresh_event",
 689                                                 indio_dev);
 690                 if (ret)
 691                         return dev_err_probe(dev, ret,
 692                                              "request irq (%d) failed\n", client->irq);
 693         }
 694
 695         return devm_iio_device_register(dev, indio_dev);
 696 }
 697
 698 static int ltr390_suspend(struct device *dev)
 699 {
 700         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 701         struct ltr390_data *data = iio_priv(indio_dev);
 702
 703         return regmap_clear_bits(data->regmap, LTR390_MAIN_CTRL,
 704                                 LTR390_SENSOR_ENABLE);
 705 }
 706
 707 static int ltr390_resume(struct device *dev)
 708 {
 709         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 710         struct ltr390_data *data = iio_priv(indio_dev);
 711
 712         return regmap_set_bits(data->regmap, LTR390_MAIN_CTRL,
 713                                 LTR390_SENSOR_ENABLE);
 714 }
 715
 716 static DEFINE_SIMPLE_DEV_PM_OPS(ltr390_pm_ops, ltr390_suspend, ltr390_resume);
 717
 718 static const struct i2c_device_id ltr390_id[] = {
 719         { "ltr390" },
 720         { /* Sentinel */ }
 721 };
 722 MODULE_DEVICE_TABLE(i2c, ltr390_id);
 723
 724 static const struct of_device_id ltr390_of_table[] = {
 725         { .compatible = "liteon,ltr390" },
 726         { /* Sentinel */ }
 727 };
 728 MODULE_DEVICE_TABLE(of, ltr390_of_table);
 729
 730 static struct i2c_driver ltr390_driver = {
 731         .driver = {
 732                 .name = "ltr390",
 733                 .of_match_table = ltr390_of_table,
 734                 .pm = pm_sleep_ptr(&ltr390_pm_ops),
 735         },
 736         .probe = ltr390_probe,
 737         .id_table = ltr390_id,
 738 };
 739 module_i2c_driver(ltr390_driver);
 740
 741 MODULE_AUTHOR("Anshul Dalal <[email protected]>");
 742 MODULE_DESCRIPTION("Lite-On LTR390 ALS and UV sensor Driver");
 743 MODULE_LICENSE("GPL");