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