drivers/iio/light/opt3001.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /**
   3  * opt3001.c - Texas Instruments OPT3001 Light Sensor
   4  *
   5  * Copyright (C) 2014 Texas Instruments Incorporated - https://www.ti.com
   6  *
   7  * Author: Andreas Dannenberg <dannenberg@ti.com>
   8  * Based on previous work from: Felipe Balbi <balbi@ti.com>
   9  */
  10
  11 #include <linux/bitops.h>
  12 #include <linux/delay.h>
  13 #include <linux/device.h>
  14 #include <linux/i2c.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/mod_devicetable.h>
  20 #include <linux/mutex.h>
  21 #include <linux/slab.h>
  22 #include <linux/types.h>
  23
  24 #include <linux/iio/events.h>
  25 #include <linux/iio/iio.h>
  26 #include <linux/iio/sysfs.h>
  27
  28 #define OPT3001_RESULT          0x00
  29 #define OPT3001_CONFIGURATION   0x01
  30 #define OPT3001_LOW_LIMIT       0x02
  31 #define OPT3001_HIGH_LIMIT      0x03
  32 #define OPT3001_MANUFACTURER_ID 0x7e
  33 #define OPT3001_DEVICE_ID       0x7f
  34
  35 #define OPT3001_CONFIGURATION_RN_MASK   (0xf << 12)
  36 #define OPT3001_CONFIGURATION_RN_AUTO   (0xc << 12)
  37
  38 #define OPT3001_CONFIGURATION_CT        BIT(11)
  39
  40 #define OPT3001_CONFIGURATION_M_MASK    (3 << 9)
  41 #define OPT3001_CONFIGURATION_M_SHUTDOWN (0 << 9)
  42 #define OPT3001_CONFIGURATION_M_SINGLE  (1 << 9)
  43 #define OPT3001_CONFIGURATION_M_CONTINUOUS (2 << 9) /* also 3 << 9 */
  44
  45 #define OPT3001_CONFIGURATION_OVF       BIT(8)
  46 #define OPT3001_CONFIGURATION_CRF       BIT(7)
  47 #define OPT3001_CONFIGURATION_FH        BIT(6)
  48 #define OPT3001_CONFIGURATION_FL        BIT(5)
  49 #define OPT3001_CONFIGURATION_L         BIT(4)
  50 #define OPT3001_CONFIGURATION_POL       BIT(3)
  51 #define OPT3001_CONFIGURATION_ME        BIT(2)
  52
  53 #define OPT3001_CONFIGURATION_FC_MASK   (3 << 0)
  54
  55 /* The end-of-conversion enable is located in the low-limit register */
  56 #define OPT3001_LOW_LIMIT_EOC_ENABLE    0xc000
  57
  58 #define OPT3001_REG_EXPONENT(n)         ((n) >> 12)
  59 #define OPT3001_REG_MANTISSA(n)         ((n) & 0xfff)
  60
  61 #define OPT3001_INT_TIME_LONG           800000
  62 #define OPT3001_INT_TIME_SHORT          100000
  63
  64 /*
  65  * Time to wait for conversion result to be ready. The device datasheet
  66  * sect. 6.5 states results are ready after total integration time plus 3ms.
  67  * This results in worst-case max values of 113ms or 883ms, respectively.
  68  * Add some slack to be on the safe side.
  69  */
  70 #define OPT3001_RESULT_READY_SHORT      150
  71 #define OPT3001_RESULT_READY_LONG       1000
  72
  73 struct opt3001 {
  74         struct i2c_client       *client;
  75         struct device           *dev;
  76
  77         struct mutex            lock;
  78         bool                    ok_to_ignore_lock;
  79         bool                    result_ready;
  80         wait_queue_head_t       result_ready_queue;
  81         u16                     result;
  82
  83         u32                     int_time;
  84         u32                     mode;
  85
  86         u16                     high_thresh_mantissa;
  87         u16                     low_thresh_mantissa;
  88
  89         u8                      high_thresh_exp;
  90         u8                      low_thresh_exp;
  91
  92         bool                    use_irq;
  93 };
  94
  95 struct opt3001_scale {
  96         int     val;
  97         int     val2;
  98 };
  99
 100 static const struct opt3001_scale opt3001_scales[] = {
 101         {
 102                 .val = 40,
 103                 .val2 = 950000,
 104         },
 105         {
 106                 .val = 81,
 107                 .val2 = 900000,
 108         },
 109         {
 110                 .val = 163,
 111                 .val2 = 800000,
 112         },
 113         {
 114                 .val = 327,
 115                 .val2 = 600000,
 116         },
 117         {
 118                 .val = 655,
 119                 .val2 = 200000,
 120         },
 121         {
 122                 .val = 1310,
 123                 .val2 = 400000,
 124         },
 125         {
 126                 .val = 2620,
 127                 .val2 = 800000,
 128         },
 129         {
 130                 .val = 5241,
 131                 .val2 = 600000,
 132         },
 133         {
 134                 .val = 10483,
 135                 .val2 = 200000,
 136         },
 137         {
 138                 .val = 20966,
 139                 .val2 = 400000,
 140         },
 141         {
 142                 .val = 83865,
 143                 .val2 = 600000,
 144         },
 145 };
 146
 147 static int opt3001_find_scale(const struct opt3001 *opt, int val,
 148                 int val2, u8 *exponent)
 149 {
 150         int i;
 151
 152         for (i = 0; i < ARRAY_SIZE(opt3001_scales); i++) {
 153                 const struct opt3001_scale *scale = &opt3001_scales[i];
 154
 155                 /*
 156                  * Combine the integer and micro parts for comparison
 157                  * purposes. Use milli lux precision to avoid 32-bit integer
 158                  * overflows.
 159                  */
 160                 if ((val * 1000 + val2 / 1000) <=
 161                                 (scale->val * 1000 + scale->val2 / 1000)) {
 162                         *exponent = i;
 163                         return 0;
 164                 }
 165         }
 166
 167         return -EINVAL;
 168 }
 169
 170 static void opt3001_to_iio_ret(struct opt3001 *opt, u8 exponent,
 171                 u16 mantissa, int *val, int *val2)
 172 {
 173         int lux;
 174
 175         lux = 10 * (mantissa << exponent);
 176         *val = lux / 1000;
 177         *val2 = (lux - (*val * 1000)) * 1000;
 178 }
 179
 180 static void opt3001_set_mode(struct opt3001 *opt, u16 *reg, u16 mode)
 181 {
 182         *reg &= ~OPT3001_CONFIGURATION_M_MASK;
 183         *reg |= mode;
 184         opt->mode = mode;
 185 }
 186
 187 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.8");
 188
 189 static struct attribute *opt3001_attributes[] = {
 190         &iio_const_attr_integration_time_available.dev_attr.attr,
 191         NULL
 192 };
 193
 194 static const struct attribute_group opt3001_attribute_group = {
 195         .attrs = opt3001_attributes,
 196 };
 197
 198 static const struct iio_event_spec opt3001_event_spec[] = {
 199         {
 200                 .type = IIO_EV_TYPE_THRESH,
 201                 .dir = IIO_EV_DIR_RISING,
 202                 .mask_separate = BIT(IIO_EV_INFO_VALUE) |
 203                         BIT(IIO_EV_INFO_ENABLE),
 204         },
 205         {
 206                 .type = IIO_EV_TYPE_THRESH,
 207                 .dir = IIO_EV_DIR_FALLING,
 208                 .mask_separate = BIT(IIO_EV_INFO_VALUE) |
 209                         BIT(IIO_EV_INFO_ENABLE),
 210         },
 211 };
 212
 213 static const struct iio_chan_spec opt3001_channels[] = {
 214         {
 215                 .type = IIO_LIGHT,
 216                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
 217                                 BIT(IIO_CHAN_INFO_INT_TIME),
 218                 .event_spec = opt3001_event_spec,
 219                 .num_event_specs = ARRAY_SIZE(opt3001_event_spec),
 220         },
 221         IIO_CHAN_SOFT_TIMESTAMP(1),
 222 };
 223
 224 static int opt3001_get_lux(struct opt3001 *opt, int *val, int *val2)
 225 {
 226         int ret;
 227         u16 mantissa;
 228         u16 reg;
 229         u8 exponent;
 230         u16 value;
 231         long timeout;
 232
 233         if (opt->use_irq) {
 234                 /*
 235                  * Enable the end-of-conversion interrupt mechanism. Note that
 236                  * doing so will overwrite the low-level limit value however we
 237                  * will restore this value later on.
 238                  */
 239                 ret = i2c_smbus_write_word_swapped(opt->client,
 240                                         OPT3001_LOW_LIMIT,
 241                                         OPT3001_LOW_LIMIT_EOC_ENABLE);
 242                 if (ret < 0) {
 243                         dev_err(opt->dev, "failed to write register %02x\n",
 244                                         OPT3001_LOW_LIMIT);
 245                         return ret;
 246                 }
 247
 248                 /* Allow IRQ to access the device despite lock being set */
 249                 opt->ok_to_ignore_lock = true;
 250         }
 251
 252         /* Reset data-ready indicator flag */
 253         opt->result_ready = false;
 254
 255         /* Configure for single-conversion mode and start a new conversion */
 256         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 257         if (ret < 0) {
 258                 dev_err(opt->dev, "failed to read register %02x\n",
 259                                 OPT3001_CONFIGURATION);
 260                 goto err;
 261         }
 262
 263         reg = ret;
 264         opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SINGLE);
 265
 266         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 267                         reg);
 268         if (ret < 0) {
 269                 dev_err(opt->dev, "failed to write register %02x\n",
 270                                 OPT3001_CONFIGURATION);
 271                 goto err;
 272         }
 273
 274         if (opt->use_irq) {
 275                 /* Wait for the IRQ to indicate the conversion is complete */
 276                 ret = wait_event_timeout(opt->result_ready_queue,
 277                                 opt->result_ready,
 278                                 msecs_to_jiffies(OPT3001_RESULT_READY_LONG));
 279         } else {
 280                 /* Sleep for result ready time */
 281                 timeout = (opt->int_time == OPT3001_INT_TIME_SHORT) ?
 282                         OPT3001_RESULT_READY_SHORT : OPT3001_RESULT_READY_LONG;
 283                 msleep(timeout);
 284
 285                 /* Check result ready flag */
 286                 ret = i2c_smbus_read_word_swapped(opt->client,
 287                                                   OPT3001_CONFIGURATION);
 288                 if (ret < 0) {
 289                         dev_err(opt->dev, "failed to read register %02x\n",
 290                                 OPT3001_CONFIGURATION);
 291                         goto err;
 292                 }
 293
 294                 if (!(ret & OPT3001_CONFIGURATION_CRF)) {
 295                         ret = -ETIMEDOUT;
 296                         goto err;
 297                 }
 298
 299                 /* Obtain value */
 300                 ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_RESULT);
 301                 if (ret < 0) {
 302                         dev_err(opt->dev, "failed to read register %02x\n",
 303                                 OPT3001_RESULT);
 304                         goto err;
 305                 }
 306                 opt->result = ret;
 307                 opt->result_ready = true;
 308         }
 309
 310 err:
 311         if (opt->use_irq)
 312                 /* Disallow IRQ to access the device while lock is active */
 313                 opt->ok_to_ignore_lock = false;
 314
 315         if (ret == 0)
 316                 return -ETIMEDOUT;
 317         else if (ret < 0)
 318                 return ret;
 319
 320         if (opt->use_irq) {
 321                 /*
 322                  * Disable the end-of-conversion interrupt mechanism by
 323                  * restoring the low-level limit value (clearing
 324                  * OPT3001_LOW_LIMIT_EOC_ENABLE). Note that selectively clearing
 325                  * those enable bits would affect the actual limit value due to
 326                  * bit-overlap and therefore can't be done.
 327                  */
 328                 value = (opt->low_thresh_exp << 12) | opt->low_thresh_mantissa;
 329                 ret = i2c_smbus_write_word_swapped(opt->client,
 330                                                    OPT3001_LOW_LIMIT,
 331                                                    value);
 332                 if (ret < 0) {
 333                         dev_err(opt->dev, "failed to write register %02x\n",
 334                                         OPT3001_LOW_LIMIT);
 335                         return ret;
 336                 }
 337         }
 338
 339         exponent = OPT3001_REG_EXPONENT(opt->result);
 340         mantissa = OPT3001_REG_MANTISSA(opt->result);
 341
 342         opt3001_to_iio_ret(opt, exponent, mantissa, val, val2);
 343
 344         return IIO_VAL_INT_PLUS_MICRO;
 345 }
 346
 347 static int opt3001_get_int_time(struct opt3001 *opt, int *val, int *val2)
 348 {
 349         *val = 0;
 350         *val2 = opt->int_time;
 351
 352         return IIO_VAL_INT_PLUS_MICRO;
 353 }
 354
 355 static int opt3001_set_int_time(struct opt3001 *opt, int time)
 356 {
 357         int ret;
 358         u16 reg;
 359
 360         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 361         if (ret < 0) {
 362                 dev_err(opt->dev, "failed to read register %02x\n",
 363                                 OPT3001_CONFIGURATION);
 364                 return ret;
 365         }
 366
 367         reg = ret;
 368
 369         switch (time) {
 370         case OPT3001_INT_TIME_SHORT:
 371                 reg &= ~OPT3001_CONFIGURATION_CT;
 372                 opt->int_time = OPT3001_INT_TIME_SHORT;
 373                 break;
 374         case OPT3001_INT_TIME_LONG:
 375                 reg |= OPT3001_CONFIGURATION_CT;
 376                 opt->int_time = OPT3001_INT_TIME_LONG;
 377                 break;
 378         default:
 379                 return -EINVAL;
 380         }
 381
 382         return i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 383                         reg);
 384 }
 385
 386 static int opt3001_read_raw(struct iio_dev *iio,
 387                 struct iio_chan_spec const *chan, int *val, int *val2,
 388                 long mask)
 389 {
 390         struct opt3001 *opt = iio_priv(iio);
 391         int ret;
 392
 393         if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
 394                 return -EBUSY;
 395
 396         if (chan->type != IIO_LIGHT)
 397                 return -EINVAL;
 398
 399         mutex_lock(&opt->lock);
 400
 401         switch (mask) {
 402         case IIO_CHAN_INFO_PROCESSED:
 403                 ret = opt3001_get_lux(opt, val, val2);
 404                 break;
 405         case IIO_CHAN_INFO_INT_TIME:
 406                 ret = opt3001_get_int_time(opt, val, val2);
 407                 break;
 408         default:
 409                 ret = -EINVAL;
 410         }
 411
 412         mutex_unlock(&opt->lock);
 413
 414         return ret;
 415 }
 416
 417 static int opt3001_write_raw(struct iio_dev *iio,
 418                 struct iio_chan_spec const *chan, int val, int val2,
 419                 long mask)
 420 {
 421         struct opt3001 *opt = iio_priv(iio);
 422         int ret;
 423
 424         if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
 425                 return -EBUSY;
 426
 427         if (chan->type != IIO_LIGHT)
 428                 return -EINVAL;
 429
 430         if (mask != IIO_CHAN_INFO_INT_TIME)
 431                 return -EINVAL;
 432
 433         if (val != 0)
 434                 return -EINVAL;
 435
 436         mutex_lock(&opt->lock);
 437         ret = opt3001_set_int_time(opt, val2);
 438         mutex_unlock(&opt->lock);
 439
 440         return ret;
 441 }
 442
 443 static int opt3001_read_event_value(struct iio_dev *iio,
 444                 const struct iio_chan_spec *chan, enum iio_event_type type,
 445                 enum iio_event_direction dir, enum iio_event_info info,
 446                 int *val, int *val2)
 447 {
 448         struct opt3001 *opt = iio_priv(iio);
 449         int ret = IIO_VAL_INT_PLUS_MICRO;
 450
 451         mutex_lock(&opt->lock);
 452
 453         switch (dir) {
 454         case IIO_EV_DIR_RISING:
 455                 opt3001_to_iio_ret(opt, opt->high_thresh_exp,
 456                                 opt->high_thresh_mantissa, val, val2);
 457                 break;
 458         case IIO_EV_DIR_FALLING:
 459                 opt3001_to_iio_ret(opt, opt->low_thresh_exp,
 460                                 opt->low_thresh_mantissa, val, val2);
 461                 break;
 462         default:
 463                 ret = -EINVAL;
 464         }
 465
 466         mutex_unlock(&opt->lock);
 467
 468         return ret;
 469 }
 470
 471 static int opt3001_write_event_value(struct iio_dev *iio,
 472                 const struct iio_chan_spec *chan, enum iio_event_type type,
 473                 enum iio_event_direction dir, enum iio_event_info info,
 474                 int val, int val2)
 475 {
 476         struct opt3001 *opt = iio_priv(iio);
 477         int ret;
 478
 479         u16 mantissa;
 480         u16 value;
 481         u16 reg;
 482
 483         u8 exponent;
 484
 485         if (val < 0)
 486                 return -EINVAL;
 487
 488         mutex_lock(&opt->lock);
 489
 490         ret = opt3001_find_scale(opt, val, val2, &exponent);
 491         if (ret < 0) {
 492                 dev_err(opt->dev, "can't find scale for %d.%06u\n", val, val2);
 493                 goto err;
 494         }
 495
 496         mantissa = (((val * 1000) + (val2 / 1000)) / 10) >> exponent;
 497         value = (exponent << 12) | mantissa;
 498
 499         switch (dir) {
 500         case IIO_EV_DIR_RISING:
 501                 reg = OPT3001_HIGH_LIMIT;
 502                 opt->high_thresh_mantissa = mantissa;
 503                 opt->high_thresh_exp = exponent;
 504                 break;
 505         case IIO_EV_DIR_FALLING:
 506                 reg = OPT3001_LOW_LIMIT;
 507                 opt->low_thresh_mantissa = mantissa;
 508                 opt->low_thresh_exp = exponent;
 509                 break;
 510         default:
 511                 ret = -EINVAL;
 512                 goto err;
 513         }
 514
 515         ret = i2c_smbus_write_word_swapped(opt->client, reg, value);
 516         if (ret < 0) {
 517                 dev_err(opt->dev, "failed to write register %02x\n", reg);
 518                 goto err;
 519         }
 520
 521 err:
 522         mutex_unlock(&opt->lock);
 523
 524         return ret;
 525 }
 526
 527 static int opt3001_read_event_config(struct iio_dev *iio,
 528                 const struct iio_chan_spec *chan, enum iio_event_type type,
 529                 enum iio_event_direction dir)
 530 {
 531         struct opt3001 *opt = iio_priv(iio);
 532
 533         return opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS;
 534 }
 535
 536 static int opt3001_write_event_config(struct iio_dev *iio,
 537                 const struct iio_chan_spec *chan, enum iio_event_type type,
 538                 enum iio_event_direction dir, int state)
 539 {
 540         struct opt3001 *opt = iio_priv(iio);
 541         int ret;
 542         u16 mode;
 543         u16 reg;
 544
 545         if (state && opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
 546                 return 0;
 547
 548         if (!state && opt->mode == OPT3001_CONFIGURATION_M_SHUTDOWN)
 549                 return 0;
 550
 551         mutex_lock(&opt->lock);
 552
 553         mode = state ? OPT3001_CONFIGURATION_M_CONTINUOUS
 554                 : OPT3001_CONFIGURATION_M_SHUTDOWN;
 555
 556         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 557         if (ret < 0) {
 558                 dev_err(opt->dev, "failed to read register %02x\n",
 559                                 OPT3001_CONFIGURATION);
 560                 goto err;
 561         }
 562
 563         reg = ret;
 564         opt3001_set_mode(opt, &reg, mode);
 565
 566         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 567                         reg);
 568         if (ret < 0) {
 569                 dev_err(opt->dev, "failed to write register %02x\n",
 570                                 OPT3001_CONFIGURATION);
 571                 goto err;
 572         }
 573
 574 err:
 575         mutex_unlock(&opt->lock);
 576
 577         return ret;
 578 }
 579
 580 static const struct iio_info opt3001_info = {
 581         .attrs = &opt3001_attribute_group,
 582         .read_raw = opt3001_read_raw,
 583         .write_raw = opt3001_write_raw,
 584         .read_event_value = opt3001_read_event_value,
 585         .write_event_value = opt3001_write_event_value,
 586         .read_event_config = opt3001_read_event_config,
 587         .write_event_config = opt3001_write_event_config,
 588 };
 589
 590 static int opt3001_read_id(struct opt3001 *opt)
 591 {
 592         char manufacturer[2];
 593         u16 device_id;
 594         int ret;
 595
 596         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_MANUFACTURER_ID);
 597         if (ret < 0) {
 598                 dev_err(opt->dev, "failed to read register %02x\n",
 599                                 OPT3001_MANUFACTURER_ID);
 600                 return ret;
 601         }
 602
 603         manufacturer[0] = ret >> 8;
 604         manufacturer[1] = ret & 0xff;
 605
 606         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_DEVICE_ID);
 607         if (ret < 0) {
 608                 dev_err(opt->dev, "failed to read register %02x\n",
 609                                 OPT3001_DEVICE_ID);
 610                 return ret;
 611         }
 612
 613         device_id = ret;
 614
 615         dev_info(opt->dev, "Found %c%c OPT%04x\n", manufacturer[0],
 616                         manufacturer[1], device_id);
 617
 618         return 0;
 619 }
 620
 621 static int opt3001_configure(struct opt3001 *opt)
 622 {
 623         int ret;
 624         u16 reg;
 625
 626         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 627         if (ret < 0) {
 628                 dev_err(opt->dev, "failed to read register %02x\n",
 629                                 OPT3001_CONFIGURATION);
 630                 return ret;
 631         }
 632
 633         reg = ret;
 634
 635         /* Enable automatic full-scale setting mode */
 636         reg &= ~OPT3001_CONFIGURATION_RN_MASK;
 637         reg |= OPT3001_CONFIGURATION_RN_AUTO;
 638
 639         /* Reflect status of the device's integration time setting */
 640         if (reg & OPT3001_CONFIGURATION_CT)
 641                 opt->int_time = OPT3001_INT_TIME_LONG;
 642         else
 643                 opt->int_time = OPT3001_INT_TIME_SHORT;
 644
 645         /* Ensure device is in shutdown initially */
 646         opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
 647
 648         /* Configure for latched window-style comparison operation */
 649         reg |= OPT3001_CONFIGURATION_L;
 650         reg &= ~OPT3001_CONFIGURATION_POL;
 651         reg &= ~OPT3001_CONFIGURATION_ME;
 652         reg &= ~OPT3001_CONFIGURATION_FC_MASK;
 653
 654         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 655                         reg);
 656         if (ret < 0) {
 657                 dev_err(opt->dev, "failed to write register %02x\n",
 658                                 OPT3001_CONFIGURATION);
 659                 return ret;
 660         }
 661
 662         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_LOW_LIMIT);
 663         if (ret < 0) {
 664                 dev_err(opt->dev, "failed to read register %02x\n",
 665                                 OPT3001_LOW_LIMIT);
 666                 return ret;
 667         }
 668
 669         opt->low_thresh_mantissa = OPT3001_REG_MANTISSA(ret);
 670         opt->low_thresh_exp = OPT3001_REG_EXPONENT(ret);
 671
 672         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_HIGH_LIMIT);
 673         if (ret < 0) {
 674                 dev_err(opt->dev, "failed to read register %02x\n",
 675                                 OPT3001_HIGH_LIMIT);
 676                 return ret;
 677         }
 678
 679         opt->high_thresh_mantissa = OPT3001_REG_MANTISSA(ret);
 680         opt->high_thresh_exp = OPT3001_REG_EXPONENT(ret);
 681
 682         return 0;
 683 }
 684
 685 static irqreturn_t opt3001_irq(int irq, void *_iio)
 686 {
 687         struct iio_dev *iio = _iio;
 688         struct opt3001 *opt = iio_priv(iio);
 689         int ret;
 690         bool wake_result_ready_queue = false;
 691
 692         if (!opt->ok_to_ignore_lock)
 693                 mutex_lock(&opt->lock);
 694
 695         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 696         if (ret < 0) {
 697                 dev_err(opt->dev, "failed to read register %02x\n",
 698                                 OPT3001_CONFIGURATION);
 699                 goto out;
 700         }
 701
 702         if ((ret & OPT3001_CONFIGURATION_M_MASK) ==
 703                         OPT3001_CONFIGURATION_M_CONTINUOUS) {
 704                 if (ret & OPT3001_CONFIGURATION_FH)
 705                         iio_push_event(iio,
 706                                         IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
 707                                                         IIO_EV_TYPE_THRESH,
 708                                                         IIO_EV_DIR_RISING),
 709                                         iio_get_time_ns(iio));
 710                 if (ret & OPT3001_CONFIGURATION_FL)
 711                         iio_push_event(iio,
 712                                         IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
 713                                                         IIO_EV_TYPE_THRESH,
 714                                                         IIO_EV_DIR_FALLING),
 715                                         iio_get_time_ns(iio));
 716         } else if (ret & OPT3001_CONFIGURATION_CRF) {
 717                 ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_RESULT);
 718                 if (ret < 0) {
 719                         dev_err(opt->dev, "failed to read register %02x\n",
 720                                         OPT3001_RESULT);
 721                         goto out;
 722                 }
 723                 opt->result = ret;
 724                 opt->result_ready = true;
 725                 wake_result_ready_queue = true;
 726         }
 727
 728 out:
 729         if (!opt->ok_to_ignore_lock)
 730                 mutex_unlock(&opt->lock);
 731
 732         if (wake_result_ready_queue)
 733                 wake_up(&opt->result_ready_queue);
 734
 735         return IRQ_HANDLED;
 736 }
 737
 738 static int opt3001_probe(struct i2c_client *client,
 739                 const struct i2c_device_id *id)
 740 {
 741         struct device *dev = &client->dev;
 742
 743         struct iio_dev *iio;
 744         struct opt3001 *opt;
 745         int irq = client->irq;
 746         int ret;
 747
 748         iio = devm_iio_device_alloc(dev, sizeof(*opt));
 749         if (!iio)
 750                 return -ENOMEM;
 751
 752         opt = iio_priv(iio);
 753         opt->client = client;
 754         opt->dev = dev;
 755
 756         mutex_init(&opt->lock);
 757         init_waitqueue_head(&opt->result_ready_queue);
 758         i2c_set_clientdata(client, iio);
 759
 760         ret = opt3001_read_id(opt);
 761         if (ret)
 762                 return ret;
 763
 764         ret = opt3001_configure(opt);
 765         if (ret)
 766                 return ret;
 767
 768         iio->name = client->name;
 769         iio->channels = opt3001_channels;
 770         iio->num_channels = ARRAY_SIZE(opt3001_channels);
 771         iio->modes = INDIO_DIRECT_MODE;
 772         iio->info = &opt3001_info;
 773
 774         ret = devm_iio_device_register(dev, iio);
 775         if (ret) {
 776                 dev_err(dev, "failed to register IIO device\n");
 777                 return ret;
 778         }
 779
 780         /* Make use of INT pin only if valid IRQ no. is given */
 781         if (irq > 0) {
 782                 ret = request_threaded_irq(irq, NULL, opt3001_irq,
 783                                 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 784                                 "opt3001", iio);
 785                 if (ret) {
 786                         dev_err(dev, "failed to request IRQ #%d\n", irq);
 787                         return ret;
 788                 }
 789                 opt->use_irq = true;
 790         } else {
 791                 dev_dbg(opt->dev, "enabling interrupt-less operation\n");
 792         }
 793
 794         return 0;
 795 }
 796
 797 static int opt3001_remove(struct i2c_client *client)
 798 {
 799         struct iio_dev *iio = i2c_get_clientdata(client);
 800         struct opt3001 *opt = iio_priv(iio);
 801         int ret;
 802         u16 reg;
 803
 804         if (opt->use_irq)
 805                 free_irq(client->irq, iio);
 806
 807         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 808         if (ret < 0) {
 809                 dev_err(opt->dev, "failed to read register %02x\n",
 810                                 OPT3001_CONFIGURATION);
 811                 return ret;
 812         }
 813
 814         reg = ret;
 815         opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
 816
 817         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 818                         reg);
 819         if (ret < 0) {
 820                 dev_err(opt->dev, "failed to write register %02x\n",
 821                                 OPT3001_CONFIGURATION);
 822                 return ret;
 823         }
 824
 825         return 0;
 826 }
 827
 828 static const struct i2c_device_id opt3001_id[] = {
 829         { "opt3001", 0 },
 830         { } /* Terminating Entry */
 831 };
 832 MODULE_DEVICE_TABLE(i2c, opt3001_id);
 833
 834 static const struct of_device_id opt3001_of_match[] = {
 835         { .compatible = "ti,opt3001" },
 836         { }
 837 };
 838 MODULE_DEVICE_TABLE(of, opt3001_of_match);
 839
 840 static struct i2c_driver opt3001_driver = {
 841         .probe = opt3001_probe,
 842         .remove = opt3001_remove,
 843         .id_table = opt3001_id,
 844
 845         .driver = {
 846                 .name = "opt3001",
 847                 .of_match_table = opt3001_of_match,
 848         },
 849 };
 850
 851 module_i2c_driver(opt3001_driver);
 852
 853 MODULE_LICENSE("GPL v2");
 854 MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");
 855 MODULE_DESCRIPTION("Texas Instruments OPT3001 Light Sensor Driver");