drivers/iio/light/opt3001.c

   1 /**
   2  * opt3001.c - Texas Instruments OPT3001 Light Sensor
   3  *
   4  * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com
   5  *
   6  * Author: Andreas Dannenberg <dannenberg@ti.com>
   7  * Based on previous work from: Felipe Balbi <balbi@ti.com>
   8  *
   9  * This program is free software: you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License version 2 of the License
  11  * as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  16  * more details.
  17  */
  18
  19 #include <linux/bitops.h>
  20 #include <linux/delay.h>
  21 #include <linux/device.h>
  22 #include <linux/i2c.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/irq.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/mutex.h>
  28 #include <linux/slab.h>
  29 #include <linux/types.h>
  30
  31 #include <linux/iio/events.h>
  32 #include <linux/iio/iio.h>
  33 #include <linux/iio/sysfs.h>
  34
  35 #define OPT3001_RESULT          0x00
  36 #define OPT3001_CONFIGURATION   0x01
  37 #define OPT3001_LOW_LIMIT       0x02
  38 #define OPT3001_HIGH_LIMIT      0x03
  39 #define OPT3001_MANUFACTURER_ID 0x7e
  40 #define OPT3001_DEVICE_ID       0x7f
  41
  42 #define OPT3001_CONFIGURATION_RN_MASK   (0xf << 12)
  43 #define OPT3001_CONFIGURATION_RN_AUTO   (0xc << 12)
  44
  45 #define OPT3001_CONFIGURATION_CT        BIT(11)
  46
  47 #define OPT3001_CONFIGURATION_M_MASK    (3 << 9)
  48 #define OPT3001_CONFIGURATION_M_SHUTDOWN (0 << 9)
  49 #define OPT3001_CONFIGURATION_M_SINGLE  (1 << 9)
  50 #define OPT3001_CONFIGURATION_M_CONTINUOUS (2 << 9) /* also 3 << 9 */
  51
  52 #define OPT3001_CONFIGURATION_OVF       BIT(8)
  53 #define OPT3001_CONFIGURATION_CRF       BIT(7)
  54 #define OPT3001_CONFIGURATION_FH        BIT(6)
  55 #define OPT3001_CONFIGURATION_FL        BIT(5)
  56 #define OPT3001_CONFIGURATION_L         BIT(4)
  57 #define OPT3001_CONFIGURATION_POL       BIT(3)
  58 #define OPT3001_CONFIGURATION_ME        BIT(2)
  59
  60 #define OPT3001_CONFIGURATION_FC_MASK   (3 << 0)
  61
  62 /* The end-of-conversion enable is located in the low-limit register */
  63 #define OPT3001_LOW_LIMIT_EOC_ENABLE    0xc000
  64
  65 #define OPT3001_REG_EXPONENT(n)         ((n) >> 12)
  66 #define OPT3001_REG_MANTISSA(n)         ((n) & 0xfff)
  67
  68 /*
  69  * Time to wait for conversion result to be ready. The device datasheet
  70  * worst-case max value is 880ms. Add some slack to be on the safe side.
  71  */
  72 #define OPT3001_RESULT_READY_TIMEOUT    msecs_to_jiffies(1000)
  73
  74 struct opt3001 {
  75         struct i2c_client       *client;
  76         struct device           *dev;
  77
  78         struct mutex            lock;
  79         u16                     ok_to_ignore_lock:1;
  80         u16                     result_ready:1;
  81         wait_queue_head_t       result_ready_queue;
  82         u16                     result;
  83
  84         u32                     int_time;
  85         u32                     mode;
  86
  87         u16                     high_thresh_mantissa;
  88         u16                     low_thresh_mantissa;
  89
  90         u8                      high_thresh_exp;
  91         u8                      low_thresh_exp;
  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
 231         /*
 232          * Enable the end-of-conversion interrupt mechanism. Note that doing
 233          * so will overwrite the low-level limit value however we will restore
 234          * this value later on.
 235          */
 236         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT,
 237                         OPT3001_LOW_LIMIT_EOC_ENABLE);
 238         if (ret < 0) {
 239                 dev_err(opt->dev, "failed to write register %02x\n",
 240                                 OPT3001_LOW_LIMIT);
 241                 return ret;
 242         }
 243
 244         /* Reset data-ready indicator flag (will be set in the IRQ routine) */
 245         opt->result_ready = false;
 246
 247         /* Allow IRQ to access the device despite lock being set */
 248         opt->ok_to_ignore_lock = true;
 249
 250         /* Configure for single-conversion mode and start a new conversion */
 251         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 252         if (ret < 0) {
 253                 dev_err(opt->dev, "failed to read register %02x\n",
 254                                 OPT3001_CONFIGURATION);
 255                 goto err;
 256         }
 257
 258         reg = ret;
 259         opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SINGLE);
 260
 261         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 262                         reg);
 263         if (ret < 0) {
 264                 dev_err(opt->dev, "failed to write register %02x\n",
 265                                 OPT3001_CONFIGURATION);
 266                 goto err;
 267         }
 268
 269         /* Wait for the IRQ to indicate the conversion is complete */
 270         ret = wait_event_timeout(opt->result_ready_queue, opt->result_ready,
 271                         OPT3001_RESULT_READY_TIMEOUT);
 272
 273 err:
 274         /* Disallow IRQ to access the device while lock is active */
 275         opt->ok_to_ignore_lock = false;
 276
 277         if (ret == 0)
 278                 return -ETIMEDOUT;
 279         else if (ret < 0)
 280                 return ret;
 281
 282         /*
 283          * Disable the end-of-conversion interrupt mechanism by restoring the
 284          * low-level limit value (clearing OPT3001_LOW_LIMIT_EOC_ENABLE). Note
 285          * that selectively clearing those enable bits would affect the actual
 286          * limit value due to bit-overlap and therefore can't be done.
 287          */
 288         value = (opt->low_thresh_exp << 12) | opt->low_thresh_mantissa;
 289         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT,
 290                         value);
 291         if (ret < 0) {
 292                 dev_err(opt->dev, "failed to write register %02x\n",
 293                                 OPT3001_LOW_LIMIT);
 294                 return ret;
 295         }
 296
 297         exponent = OPT3001_REG_EXPONENT(opt->result);
 298         mantissa = OPT3001_REG_MANTISSA(opt->result);
 299
 300         opt3001_to_iio_ret(opt, exponent, mantissa, val, val2);
 301
 302         return IIO_VAL_INT_PLUS_MICRO;
 303 }
 304
 305 static int opt3001_get_int_time(struct opt3001 *opt, int *val, int *val2)
 306 {
 307         *val = 0;
 308         *val2 = opt->int_time;
 309
 310         return IIO_VAL_INT_PLUS_MICRO;
 311 }
 312
 313 static int opt3001_set_int_time(struct opt3001 *opt, int time)
 314 {
 315         int ret;
 316         u16 reg;
 317
 318         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 319         if (ret < 0) {
 320                 dev_err(opt->dev, "failed to read register %02x\n",
 321                                 OPT3001_CONFIGURATION);
 322                 return ret;
 323         }
 324
 325         reg = ret;
 326
 327         switch (time) {
 328         case 100000:
 329                 reg &= ~OPT3001_CONFIGURATION_CT;
 330                 opt->int_time = 100000;
 331                 break;
 332         case 800000:
 333                 reg |= OPT3001_CONFIGURATION_CT;
 334                 opt->int_time = 800000;
 335                 break;
 336         default:
 337                 return -EINVAL;
 338         }
 339
 340         return i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 341                         reg);
 342 }
 343
 344 static int opt3001_read_raw(struct iio_dev *iio,
 345                 struct iio_chan_spec const *chan, int *val, int *val2,
 346                 long mask)
 347 {
 348         struct opt3001 *opt = iio_priv(iio);
 349         int ret;
 350
 351         if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
 352                 return -EBUSY;
 353
 354         if (chan->type != IIO_LIGHT)
 355                 return -EINVAL;
 356
 357         mutex_lock(&opt->lock);
 358
 359         switch (mask) {
 360         case IIO_CHAN_INFO_PROCESSED:
 361                 ret = opt3001_get_lux(opt, val, val2);
 362                 break;
 363         case IIO_CHAN_INFO_INT_TIME:
 364                 ret = opt3001_get_int_time(opt, val, val2);
 365                 break;
 366         default:
 367                 ret = -EINVAL;
 368         }
 369
 370         mutex_unlock(&opt->lock);
 371
 372         return ret;
 373 }
 374
 375 static int opt3001_write_raw(struct iio_dev *iio,
 376                 struct iio_chan_spec const *chan, int val, int val2,
 377                 long mask)
 378 {
 379         struct opt3001 *opt = iio_priv(iio);
 380         int ret;
 381
 382         if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
 383                 return -EBUSY;
 384
 385         if (chan->type != IIO_LIGHT)
 386                 return -EINVAL;
 387
 388         if (mask != IIO_CHAN_INFO_INT_TIME)
 389                 return -EINVAL;
 390
 391         if (val != 0)
 392                 return -EINVAL;
 393
 394         mutex_lock(&opt->lock);
 395         ret = opt3001_set_int_time(opt, val2);
 396         mutex_unlock(&opt->lock);
 397
 398         return ret;
 399 }
 400
 401 static int opt3001_read_event_value(struct iio_dev *iio,
 402                 const struct iio_chan_spec *chan, enum iio_event_type type,
 403                 enum iio_event_direction dir, enum iio_event_info info,
 404                 int *val, int *val2)
 405 {
 406         struct opt3001 *opt = iio_priv(iio);
 407         int ret = IIO_VAL_INT_PLUS_MICRO;
 408
 409         mutex_lock(&opt->lock);
 410
 411         switch (dir) {
 412         case IIO_EV_DIR_RISING:
 413                 opt3001_to_iio_ret(opt, opt->high_thresh_exp,
 414                                 opt->high_thresh_mantissa, val, val2);
 415                 break;
 416         case IIO_EV_DIR_FALLING:
 417                 opt3001_to_iio_ret(opt, opt->low_thresh_exp,
 418                                 opt->low_thresh_mantissa, val, val2);
 419                 break;
 420         default:
 421                 ret = -EINVAL;
 422         }
 423
 424         mutex_unlock(&opt->lock);
 425
 426         return ret;
 427 }
 428
 429 static int opt3001_write_event_value(struct iio_dev *iio,
 430                 const struct iio_chan_spec *chan, enum iio_event_type type,
 431                 enum iio_event_direction dir, enum iio_event_info info,
 432                 int val, int val2)
 433 {
 434         struct opt3001 *opt = iio_priv(iio);
 435         int ret;
 436
 437         u16 mantissa;
 438         u16 value;
 439         u16 reg;
 440
 441         u8 exponent;
 442
 443         if (val < 0)
 444                 return -EINVAL;
 445
 446         mutex_lock(&opt->lock);
 447
 448         ret = opt3001_find_scale(opt, val, val2, &exponent);
 449         if (ret < 0) {
 450                 dev_err(opt->dev, "can't find scale for %d.%06u\n", val, val2);
 451                 goto err;
 452         }
 453
 454         mantissa = (((val * 1000) + (val2 / 1000)) / 10) >> exponent;
 455         value = (exponent << 12) | mantissa;
 456
 457         switch (dir) {
 458         case IIO_EV_DIR_RISING:
 459                 reg = OPT3001_HIGH_LIMIT;
 460                 opt->high_thresh_mantissa = mantissa;
 461                 opt->high_thresh_exp = exponent;
 462                 break;
 463         case IIO_EV_DIR_FALLING:
 464                 reg = OPT3001_LOW_LIMIT;
 465                 opt->low_thresh_mantissa = mantissa;
 466                 opt->low_thresh_exp = exponent;
 467                 break;
 468         default:
 469                 ret = -EINVAL;
 470                 goto err;
 471         }
 472
 473         ret = i2c_smbus_write_word_swapped(opt->client, reg, value);
 474         if (ret < 0) {
 475                 dev_err(opt->dev, "failed to write register %02x\n", reg);
 476                 goto err;
 477         }
 478
 479 err:
 480         mutex_unlock(&opt->lock);
 481
 482         return ret;
 483 }
 484
 485 static int opt3001_read_event_config(struct iio_dev *iio,
 486                 const struct iio_chan_spec *chan, enum iio_event_type type,
 487                 enum iio_event_direction dir)
 488 {
 489         struct opt3001 *opt = iio_priv(iio);
 490
 491         return opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS;
 492 }
 493
 494 static int opt3001_write_event_config(struct iio_dev *iio,
 495                 const struct iio_chan_spec *chan, enum iio_event_type type,
 496                 enum iio_event_direction dir, int state)
 497 {
 498         struct opt3001 *opt = iio_priv(iio);
 499         int ret;
 500         u16 mode;
 501         u16 reg;
 502
 503         if (state && opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
 504                 return 0;
 505
 506         if (!state && opt->mode == OPT3001_CONFIGURATION_M_SHUTDOWN)
 507                 return 0;
 508
 509         mutex_lock(&opt->lock);
 510
 511         mode = state ? OPT3001_CONFIGURATION_M_CONTINUOUS
 512                 : OPT3001_CONFIGURATION_M_SHUTDOWN;
 513
 514         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 515         if (ret < 0) {
 516                 dev_err(opt->dev, "failed to read register %02x\n",
 517                                 OPT3001_CONFIGURATION);
 518                 goto err;
 519         }
 520
 521         reg = ret;
 522         opt3001_set_mode(opt, &reg, mode);
 523
 524         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 525                         reg);
 526         if (ret < 0) {
 527                 dev_err(opt->dev, "failed to write register %02x\n",
 528                                 OPT3001_CONFIGURATION);
 529                 goto err;
 530         }
 531
 532 err:
 533         mutex_unlock(&opt->lock);
 534
 535         return ret;
 536 }
 537
 538 static const struct iio_info opt3001_info = {
 539         .driver_module = THIS_MODULE,
 540         .attrs = &opt3001_attribute_group,
 541         .read_raw = opt3001_read_raw,
 542         .write_raw = opt3001_write_raw,
 543         .read_event_value = opt3001_read_event_value,
 544         .write_event_value = opt3001_write_event_value,
 545         .read_event_config = opt3001_read_event_config,
 546         .write_event_config = opt3001_write_event_config,
 547 };
 548
 549 static int opt3001_read_id(struct opt3001 *opt)
 550 {
 551         char manufacturer[2];
 552         u16 device_id;
 553         int ret;
 554
 555         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_MANUFACTURER_ID);
 556         if (ret < 0) {
 557                 dev_err(opt->dev, "failed to read register %02x\n",
 558                                 OPT3001_MANUFACTURER_ID);
 559                 return ret;
 560         }
 561
 562         manufacturer[0] = ret >> 8;
 563         manufacturer[1] = ret & 0xff;
 564
 565         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_DEVICE_ID);
 566         if (ret < 0) {
 567                 dev_err(opt->dev, "failed to read register %02x\n",
 568                                 OPT3001_DEVICE_ID);
 569                 return ret;
 570         }
 571
 572         device_id = ret;
 573
 574         dev_info(opt->dev, "Found %c%c OPT%04x\n", manufacturer[0],
 575                         manufacturer[1], device_id);
 576
 577         return 0;
 578 }
 579
 580 static int opt3001_configure(struct opt3001 *opt)
 581 {
 582         int ret;
 583         u16 reg;
 584
 585         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 586         if (ret < 0) {
 587                 dev_err(opt->dev, "failed to read register %02x\n",
 588                                 OPT3001_CONFIGURATION);
 589                 return ret;
 590         }
 591
 592         reg = ret;
 593
 594         /* Enable automatic full-scale setting mode */
 595         reg &= ~OPT3001_CONFIGURATION_RN_MASK;
 596         reg |= OPT3001_CONFIGURATION_RN_AUTO;
 597
 598         /* Reflect status of the device's integration time setting */
 599         if (reg & OPT3001_CONFIGURATION_CT)
 600                 opt->int_time = 800000;
 601         else
 602                 opt->int_time = 100000;
 603
 604         /* Ensure device is in shutdown initially */
 605         opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
 606
 607         /* Configure for latched window-style comparison operation */
 608         reg |= OPT3001_CONFIGURATION_L;
 609         reg &= ~OPT3001_CONFIGURATION_POL;
 610         reg &= ~OPT3001_CONFIGURATION_ME;
 611         reg &= ~OPT3001_CONFIGURATION_FC_MASK;
 612
 613         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 614                         reg);
 615         if (ret < 0) {
 616                 dev_err(opt->dev, "failed to write register %02x\n",
 617                                 OPT3001_CONFIGURATION);
 618                 return ret;
 619         }
 620
 621         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_LOW_LIMIT);
 622         if (ret < 0) {
 623                 dev_err(opt->dev, "failed to read register %02x\n",
 624                                 OPT3001_LOW_LIMIT);
 625                 return ret;
 626         }
 627
 628         opt->low_thresh_mantissa = OPT3001_REG_MANTISSA(ret);
 629         opt->low_thresh_exp = OPT3001_REG_EXPONENT(ret);
 630
 631         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_HIGH_LIMIT);
 632         if (ret < 0) {
 633                 dev_err(opt->dev, "failed to read register %02x\n",
 634                                 OPT3001_HIGH_LIMIT);
 635                 return ret;
 636         }
 637
 638         opt->high_thresh_mantissa = OPT3001_REG_MANTISSA(ret);
 639         opt->high_thresh_exp = OPT3001_REG_EXPONENT(ret);
 640
 641         return 0;
 642 }
 643
 644 static irqreturn_t opt3001_irq(int irq, void *_iio)
 645 {
 646         struct iio_dev *iio = _iio;
 647         struct opt3001 *opt = iio_priv(iio);
 648         int ret;
 649
 650         if (!opt->ok_to_ignore_lock)
 651                 mutex_lock(&opt->lock);
 652
 653         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 654         if (ret < 0) {
 655                 dev_err(opt->dev, "failed to read register %02x\n",
 656                                 OPT3001_CONFIGURATION);
 657                 goto out;
 658         }
 659
 660         if ((ret & OPT3001_CONFIGURATION_M_MASK) ==
 661                         OPT3001_CONFIGURATION_M_CONTINUOUS) {
 662                 if (ret & OPT3001_CONFIGURATION_FH)
 663                         iio_push_event(iio,
 664                                         IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
 665                                                         IIO_EV_TYPE_THRESH,
 666                                                         IIO_EV_DIR_RISING),
 667                                         iio_get_time_ns());
 668                 if (ret & OPT3001_CONFIGURATION_FL)
 669                         iio_push_event(iio,
 670                                         IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
 671                                                         IIO_EV_TYPE_THRESH,
 672                                                         IIO_EV_DIR_FALLING),
 673                                         iio_get_time_ns());
 674         } else if (ret & OPT3001_CONFIGURATION_CRF) {
 675                 ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_RESULT);
 676                 if (ret < 0) {
 677                         dev_err(opt->dev, "failed to read register %02x\n",
 678                                         OPT3001_RESULT);
 679                         goto out;
 680                 }
 681                 opt->result = ret;
 682                 opt->result_ready = true;
 683                 wake_up(&opt->result_ready_queue);
 684         }
 685
 686 out:
 687         if (!opt->ok_to_ignore_lock)
 688                 mutex_unlock(&opt->lock);
 689
 690         return IRQ_HANDLED;
 691 }
 692
 693 static int opt3001_probe(struct i2c_client *client,
 694                 const struct i2c_device_id *id)
 695 {
 696         struct device *dev = &client->dev;
 697
 698         struct iio_dev *iio;
 699         struct opt3001 *opt;
 700         int irq = client->irq;
 701         int ret;
 702
 703         iio = devm_iio_device_alloc(dev, sizeof(*opt));
 704         if (!iio)
 705                 return -ENOMEM;
 706
 707         opt = iio_priv(iio);
 708         opt->client = client;
 709         opt->dev = dev;
 710
 711         mutex_init(&opt->lock);
 712         init_waitqueue_head(&opt->result_ready_queue);
 713         i2c_set_clientdata(client, iio);
 714
 715         ret = opt3001_read_id(opt);
 716         if (ret)
 717                 return ret;
 718
 719         ret = opt3001_configure(opt);
 720         if (ret)
 721                 return ret;
 722
 723         iio->name = client->name;
 724         iio->channels = opt3001_channels;
 725         iio->num_channels = ARRAY_SIZE(opt3001_channels);
 726         iio->dev.parent = dev;
 727         iio->modes = INDIO_DIRECT_MODE;
 728         iio->info = &opt3001_info;
 729
 730         ret = devm_iio_device_register(dev, iio);
 731         if (ret) {
 732                 dev_err(dev, "failed to register IIO device\n");
 733                 return ret;
 734         }
 735
 736         ret = request_threaded_irq(irq, NULL, opt3001_irq,
 737                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 738                         "opt3001", iio);
 739         if (ret) {
 740                 dev_err(dev, "failed to request IRQ #%d\n", irq);
 741                 return ret;
 742         }
 743
 744         return 0;
 745 }
 746
 747 static int opt3001_remove(struct i2c_client *client)
 748 {
 749         struct iio_dev *iio = i2c_get_clientdata(client);
 750         struct opt3001 *opt = iio_priv(iio);
 751         int ret;
 752         u16 reg;
 753
 754         free_irq(client->irq, iio);
 755
 756         ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
 757         if (ret < 0) {
 758                 dev_err(opt->dev, "failed to read register %02x\n",
 759                                 OPT3001_CONFIGURATION);
 760                 return ret;
 761         }
 762
 763         reg = ret;
 764         opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
 765
 766         ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
 767                         reg);
 768         if (ret < 0) {
 769                 dev_err(opt->dev, "failed to write register %02x\n",
 770                                 OPT3001_CONFIGURATION);
 771                 return ret;
 772         }
 773
 774         return 0;
 775 }
 776
 777 static const struct i2c_device_id opt3001_id[] = {
 778         { "opt3001", 0 },
 779         { } /* Terminating Entry */
 780 };
 781 MODULE_DEVICE_TABLE(i2c, opt3001_id);
 782
 783 static const struct of_device_id opt3001_of_match[] = {
 784         { .compatible = "ti,opt3001" },
 785         { }
 786 };
 787
 788 static struct i2c_driver opt3001_driver = {
 789         .probe = opt3001_probe,
 790         .remove = opt3001_remove,
 791         .id_table = opt3001_id,
 792
 793         .driver = {
 794                 .name = "opt3001",
 795                 .of_match_table = of_match_ptr(opt3001_of_match),
 796         },
 797 };
 798
 799 module_i2c_driver(opt3001_driver);
 800
 801 MODULE_LICENSE("GPL v2");
 802 MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");
 803 MODULE_DESCRIPTION("Texas Instruments OPT3001 Light Sensor Driver");