drivers/iio/light/tcs3472.c

   1 /*
   2  * tcs3472.c - Support for TAOS TCS3472 color light-to-digital converter
   3  *
   4  * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
   5  *
   6  * This file is subject to the terms and conditions of version 2 of
   7  * the GNU General Public License.  See the file COPYING in the main
   8  * directory of this archive for more details.
   9  *
  10  * Color light sensor with 16-bit channels for red, green, blue, clear);
  11  * 7-bit I2C slave address 0x39 (TCS34721, TCS34723) or 0x29 (TCS34725,
  12  * TCS34727)
  13  *
  14  * Datasheet: http://ams.com/eng/content/download/319364/1117183/file/TCS3472_Datasheet_EN_v2.pdf
  15  *
  16  * TODO: wait time
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/i2c.h>
  21 #include <linux/delay.h>
  22 #include <linux/pm.h>
  23
  24 #include <linux/iio/iio.h>
  25 #include <linux/iio/sysfs.h>
  26 #include <linux/iio/events.h>
  27 #include <linux/iio/trigger_consumer.h>
  28 #include <linux/iio/buffer.h>
  29 #include <linux/iio/triggered_buffer.h>
  30
  31 #define TCS3472_DRV_NAME "tcs3472"
  32
  33 #define TCS3472_COMMAND BIT(7)
  34 #define TCS3472_AUTO_INCR BIT(5)
  35 #define TCS3472_SPECIAL_FUNC (BIT(5) | BIT(6))
  36
  37 #define TCS3472_INTR_CLEAR (TCS3472_COMMAND | TCS3472_SPECIAL_FUNC | 0x06)
  38
  39 #define TCS3472_ENABLE (TCS3472_COMMAND | 0x00)
  40 #define TCS3472_ATIME (TCS3472_COMMAND | 0x01)
  41 #define TCS3472_WTIME (TCS3472_COMMAND | 0x03)
  42 #define TCS3472_AILT (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x04)
  43 #define TCS3472_AIHT (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x06)
  44 #define TCS3472_PERS (TCS3472_COMMAND | 0x0c)
  45 #define TCS3472_CONFIG (TCS3472_COMMAND | 0x0d)
  46 #define TCS3472_CONTROL (TCS3472_COMMAND | 0x0f)
  47 #define TCS3472_ID (TCS3472_COMMAND | 0x12)
  48 #define TCS3472_STATUS (TCS3472_COMMAND | 0x13)
  49 #define TCS3472_CDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x14)
  50 #define TCS3472_RDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x16)
  51 #define TCS3472_GDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x18)
  52 #define TCS3472_BDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x1a)
  53
  54 #define TCS3472_STATUS_AINT BIT(4)
  55 #define TCS3472_STATUS_AVALID BIT(0)
  56 #define TCS3472_ENABLE_AIEN BIT(4)
  57 #define TCS3472_ENABLE_AEN BIT(1)
  58 #define TCS3472_ENABLE_PON BIT(0)
  59 #define TCS3472_CONTROL_AGAIN_MASK (BIT(0) | BIT(1))
  60
  61 struct tcs3472_data {
  62         struct i2c_client *client;
  63         struct mutex lock;
  64         u16 low_thresh;
  65         u16 high_thresh;
  66         u8 enable;
  67         u8 control;
  68         u8 atime;
  69         u8 apers;
  70         u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */
  71 };
  72
  73 static const struct iio_event_spec tcs3472_events[] = {
  74         {
  75                 .type = IIO_EV_TYPE_THRESH,
  76                 .dir = IIO_EV_DIR_RISING,
  77                 .mask_separate = BIT(IIO_EV_INFO_VALUE),
  78         }, {
  79                 .type = IIO_EV_TYPE_THRESH,
  80                 .dir = IIO_EV_DIR_FALLING,
  81                 .mask_separate = BIT(IIO_EV_INFO_VALUE),
  82         }, {
  83                 .type = IIO_EV_TYPE_THRESH,
  84                 .dir = IIO_EV_DIR_EITHER,
  85                 .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
  86                                  BIT(IIO_EV_INFO_PERIOD),
  87         },
  88 };
  89
  90 #define TCS3472_CHANNEL(_color, _si, _addr) { \
  91         .type = IIO_INTENSITY, \
  92         .modified = 1, \
  93         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  94         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBSCALE) | \
  95                 BIT(IIO_CHAN_INFO_INT_TIME), \
  96         .channel2 = IIO_MOD_LIGHT_##_color, \
  97         .address = _addr, \
  98         .scan_index = _si, \
  99         .scan_type = { \
 100                 .sign = 'u', \
 101                 .realbits = 16, \
 102                 .storagebits = 16, \
 103                 .endianness = IIO_CPU, \
 104         }, \
 105         .event_spec = _si ? NULL : tcs3472_events, \
 106         .num_event_specs = _si ? 0 : ARRAY_SIZE(tcs3472_events), \
 107 }
 108
 109 static const int tcs3472_agains[] = { 1, 4, 16, 60 };
 110
 111 static const struct iio_chan_spec tcs3472_channels[] = {
 112         TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA),
 113         TCS3472_CHANNEL(RED, 1, TCS3472_RDATA),
 114         TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA),
 115         TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA),
 116         IIO_CHAN_SOFT_TIMESTAMP(4),
 117 };
 118
 119 static int tcs3472_req_data(struct tcs3472_data *data)
 120 {
 121         int tries = 50;
 122         int ret;
 123
 124         while (tries--) {
 125                 ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
 126                 if (ret < 0)
 127                         return ret;
 128                 if (ret & TCS3472_STATUS_AVALID)
 129                         break;
 130                 msleep(20);
 131         }
 132
 133         if (tries < 0) {
 134                 dev_err(&data->client->dev, "data not ready\n");
 135                 return -EIO;
 136         }
 137
 138         return 0;
 139 }
 140
 141 static int tcs3472_read_raw(struct iio_dev *indio_dev,
 142                            struct iio_chan_spec const *chan,
 143                            int *val, int *val2, long mask)
 144 {
 145         struct tcs3472_data *data = iio_priv(indio_dev);
 146         int ret;
 147
 148         switch (mask) {
 149         case IIO_CHAN_INFO_RAW:
 150                 ret = iio_device_claim_direct_mode(indio_dev);
 151                 if (ret)
 152                         return ret;
 153                 ret = tcs3472_req_data(data);
 154                 if (ret < 0) {
 155                         iio_device_release_direct_mode(indio_dev);
 156                         return ret;
 157                 }
 158                 ret = i2c_smbus_read_word_data(data->client, chan->address);
 159                 iio_device_release_direct_mode(indio_dev);
 160                 if (ret < 0)
 161                         return ret;
 162                 *val = ret;
 163                 return IIO_VAL_INT;
 164         case IIO_CHAN_INFO_CALIBSCALE:
 165                 *val = tcs3472_agains[data->control &
 166                         TCS3472_CONTROL_AGAIN_MASK];
 167                 return IIO_VAL_INT;
 168         case IIO_CHAN_INFO_INT_TIME:
 169                 *val = 0;
 170                 *val2 = (256 - data->atime) * 2400;
 171                 return IIO_VAL_INT_PLUS_MICRO;
 172         }
 173         return -EINVAL;
 174 }
 175
 176 static int tcs3472_write_raw(struct iio_dev *indio_dev,
 177                                struct iio_chan_spec const *chan,
 178                                int val, int val2, long mask)
 179 {
 180         struct tcs3472_data *data = iio_priv(indio_dev);
 181         int i;
 182
 183         switch (mask) {
 184         case IIO_CHAN_INFO_CALIBSCALE:
 185                 if (val2 != 0)
 186                         return -EINVAL;
 187                 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
 188                         if (val == tcs3472_agains[i]) {
 189                                 data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
 190                                 data->control |= i;
 191                                 return i2c_smbus_write_byte_data(
 192                                         data->client, TCS3472_CONTROL,
 193                                         data->control);
 194                         }
 195                 }
 196                 return -EINVAL;
 197         case IIO_CHAN_INFO_INT_TIME:
 198                 if (val != 0)
 199                         return -EINVAL;
 200                 for (i = 0; i < 256; i++) {
 201                         if (val2 == (256 - i) * 2400) {
 202                                 data->atime = i;
 203                                 return i2c_smbus_write_byte_data(
 204                                         data->client, TCS3472_ATIME,
 205                                         data->atime);
 206                         }
 207
 208                 }
 209                 return -EINVAL;
 210         }
 211         return -EINVAL;
 212 }
 213
 214 /*
 215  * Translation from APERS field value to the number of consecutive out-of-range
 216  * clear channel values before an interrupt is generated
 217  */
 218 static const int tcs3472_intr_pers[] = {
 219         0, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60
 220 };
 221
 222 static int tcs3472_read_event(struct iio_dev *indio_dev,
 223         const struct iio_chan_spec *chan, enum iio_event_type type,
 224         enum iio_event_direction dir, enum iio_event_info info, int *val,
 225         int *val2)
 226 {
 227         struct tcs3472_data *data = iio_priv(indio_dev);
 228         int ret;
 229         unsigned int period;
 230
 231         mutex_lock(&data->lock);
 232
 233         switch (info) {
 234         case IIO_EV_INFO_VALUE:
 235                 *val = (dir == IIO_EV_DIR_RISING) ?
 236                         data->high_thresh : data->low_thresh;
 237                 ret = IIO_VAL_INT;
 238                 break;
 239         case IIO_EV_INFO_PERIOD:
 240                 period = (256 - data->atime) * 2400 *
 241                         tcs3472_intr_pers[data->apers];
 242                 *val = period / USEC_PER_SEC;
 243                 *val2 = period % USEC_PER_SEC;
 244                 ret = IIO_VAL_INT_PLUS_MICRO;
 245                 break;
 246         default:
 247                 ret = -EINVAL;
 248                 break;
 249         }
 250
 251         mutex_unlock(&data->lock);
 252
 253         return ret;
 254 }
 255
 256 static int tcs3472_write_event(struct iio_dev *indio_dev,
 257         const struct iio_chan_spec *chan, enum iio_event_type type,
 258         enum iio_event_direction dir, enum iio_event_info info, int val,
 259         int val2)
 260 {
 261         struct tcs3472_data *data = iio_priv(indio_dev);
 262         int ret;
 263         u8 command;
 264         int period;
 265         int i;
 266
 267         mutex_lock(&data->lock);
 268         switch (info) {
 269         case IIO_EV_INFO_VALUE:
 270                 switch (dir) {
 271                 case IIO_EV_DIR_RISING:
 272                         command = TCS3472_AIHT;
 273                         break;
 274                 case IIO_EV_DIR_FALLING:
 275                         command = TCS3472_AILT;
 276                         break;
 277                 default:
 278                         ret = -EINVAL;
 279                         goto error;
 280                 }
 281                 ret = i2c_smbus_write_word_data(data->client, command, val);
 282                 if (ret)
 283                         goto error;
 284
 285                 if (dir == IIO_EV_DIR_RISING)
 286                         data->high_thresh = val;
 287                 else
 288                         data->low_thresh = val;
 289                 break;
 290         case IIO_EV_INFO_PERIOD:
 291                 period = val * USEC_PER_SEC + val2;
 292                 for (i = 1; i < ARRAY_SIZE(tcs3472_intr_pers) - 1; i++) {
 293                         if (period <= (256 - data->atime) * 2400 *
 294                                         tcs3472_intr_pers[i])
 295                                 break;
 296                 }
 297                 ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS, i);
 298                 if (ret)
 299                         goto error;
 300
 301                 data->apers = i;
 302                 break;
 303         default:
 304                 ret = -EINVAL;
 305                 break;
 306         }
 307 error:
 308         mutex_unlock(&data->lock);
 309
 310         return ret;
 311 }
 312
 313 static int tcs3472_read_event_config(struct iio_dev *indio_dev,
 314         const struct iio_chan_spec *chan, enum iio_event_type type,
 315         enum iio_event_direction dir)
 316 {
 317         struct tcs3472_data *data = iio_priv(indio_dev);
 318         int ret;
 319
 320         mutex_lock(&data->lock);
 321         ret = !!(data->enable & TCS3472_ENABLE_AIEN);
 322         mutex_unlock(&data->lock);
 323
 324         return ret;
 325 }
 326
 327 static int tcs3472_write_event_config(struct iio_dev *indio_dev,
 328         const struct iio_chan_spec *chan, enum iio_event_type type,
 329         enum iio_event_direction dir, int state)
 330 {
 331         struct tcs3472_data *data = iio_priv(indio_dev);
 332         int ret = 0;
 333         u8 enable_old;
 334
 335         mutex_lock(&data->lock);
 336
 337         enable_old = data->enable;
 338
 339         if (state)
 340                 data->enable |= TCS3472_ENABLE_AIEN;
 341         else
 342                 data->enable &= ~TCS3472_ENABLE_AIEN;
 343
 344         if (enable_old != data->enable) {
 345                 ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 346                                                 data->enable);
 347                 if (ret)
 348                         data->enable = enable_old;
 349         }
 350         mutex_unlock(&data->lock);
 351
 352         return ret;
 353 }
 354
 355 static irqreturn_t tcs3472_event_handler(int irq, void *priv)
 356 {
 357         struct iio_dev *indio_dev = priv;
 358         struct tcs3472_data *data = iio_priv(indio_dev);
 359         int ret;
 360
 361         ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
 362         if (ret >= 0 && (ret & TCS3472_STATUS_AINT)) {
 363                 iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
 364                                                 IIO_EV_TYPE_THRESH,
 365                                                 IIO_EV_DIR_EITHER),
 366                                 iio_get_time_ns(indio_dev));
 367
 368                 i2c_smbus_read_byte_data(data->client, TCS3472_INTR_CLEAR);
 369         }
 370
 371         return IRQ_HANDLED;
 372 }
 373
 374 static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
 375 {
 376         struct iio_poll_func *pf = p;
 377         struct iio_dev *indio_dev = pf->indio_dev;
 378         struct tcs3472_data *data = iio_priv(indio_dev);
 379         int i, j = 0;
 380
 381         int ret = tcs3472_req_data(data);
 382         if (ret < 0)
 383                 goto done;
 384
 385         for_each_set_bit(i, indio_dev->active_scan_mask,
 386                 indio_dev->masklength) {
 387                 ret = i2c_smbus_read_word_data(data->client,
 388                         TCS3472_CDATA + 2*i);
 389                 if (ret < 0)
 390                         goto done;
 391
 392                 data->buffer[j++] = ret;
 393         }
 394
 395         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 396                 iio_get_time_ns(indio_dev));
 397
 398 done:
 399         iio_trigger_notify_done(indio_dev->trig);
 400
 401         return IRQ_HANDLED;
 402 }
 403
 404 static ssize_t tcs3472_show_int_time_available(struct device *dev,
 405                                         struct device_attribute *attr,
 406                                         char *buf)
 407 {
 408         size_t len = 0;
 409         int i;
 410
 411         for (i = 1; i <= 256; i++)
 412                 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
 413                         2400 * i);
 414
 415         /* replace trailing space by newline */
 416         buf[len - 1] = '\n';
 417
 418         return len;
 419 }
 420
 421 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
 422 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
 423
 424 static struct attribute *tcs3472_attributes[] = {
 425         &iio_const_attr_calibscale_available.dev_attr.attr,
 426         &iio_dev_attr_integration_time_available.dev_attr.attr,
 427         NULL
 428 };
 429
 430 static const struct attribute_group tcs3472_attribute_group = {
 431         .attrs = tcs3472_attributes,
 432 };
 433
 434 static const struct iio_info tcs3472_info = {
 435         .read_raw = tcs3472_read_raw,
 436         .write_raw = tcs3472_write_raw,
 437         .read_event_value = tcs3472_read_event,
 438         .write_event_value = tcs3472_write_event,
 439         .read_event_config = tcs3472_read_event_config,
 440         .write_event_config = tcs3472_write_event_config,
 441         .attrs = &tcs3472_attribute_group,
 442 };
 443
 444 static int tcs3472_probe(struct i2c_client *client,
 445                            const struct i2c_device_id *id)
 446 {
 447         struct tcs3472_data *data;
 448         struct iio_dev *indio_dev;
 449         int ret;
 450
 451         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 452         if (indio_dev == NULL)
 453                 return -ENOMEM;
 454
 455         data = iio_priv(indio_dev);
 456         i2c_set_clientdata(client, indio_dev);
 457         data->client = client;
 458         mutex_init(&data->lock);
 459
 460         indio_dev->dev.parent = &client->dev;
 461         indio_dev->info = &tcs3472_info;
 462         indio_dev->name = TCS3472_DRV_NAME;
 463         indio_dev->channels = tcs3472_channels;
 464         indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
 465         indio_dev->modes = INDIO_DIRECT_MODE;
 466
 467         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
 468         if (ret < 0)
 469                 return ret;
 470
 471         if (ret == 0x44)
 472                 dev_info(&client->dev, "TCS34721/34725 found\n");
 473         else if (ret == 0x4d)
 474                 dev_info(&client->dev, "TCS34723/34727 found\n");
 475         else
 476                 return -ENODEV;
 477
 478         ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
 479         if (ret < 0)
 480                 return ret;
 481         data->control = ret;
 482
 483         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
 484         if (ret < 0)
 485                 return ret;
 486         data->atime = ret;
 487
 488         ret = i2c_smbus_read_word_data(data->client, TCS3472_AILT);
 489         if (ret < 0)
 490                 return ret;
 491         data->low_thresh = ret;
 492
 493         ret = i2c_smbus_read_word_data(data->client, TCS3472_AIHT);
 494         if (ret < 0)
 495                 return ret;
 496         data->high_thresh = ret;
 497
 498         data->apers = 1;
 499         ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS,
 500                                         data->apers);
 501         if (ret < 0)
 502                 return ret;
 503
 504         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
 505         if (ret < 0)
 506                 return ret;
 507
 508         /* enable device */
 509         data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
 510         data->enable &= ~TCS3472_ENABLE_AIEN;
 511         ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 512                 data->enable);
 513         if (ret < 0)
 514                 return ret;
 515
 516         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 517                 tcs3472_trigger_handler, NULL);
 518         if (ret < 0)
 519                 return ret;
 520
 521         if (client->irq) {
 522                 ret = request_threaded_irq(client->irq, NULL,
 523                                            tcs3472_event_handler,
 524                                            IRQF_TRIGGER_FALLING | IRQF_SHARED |
 525                                            IRQF_ONESHOT,
 526                                            client->name, indio_dev);
 527                 if (ret)
 528                         goto buffer_cleanup;
 529         }
 530
 531         ret = iio_device_register(indio_dev);
 532         if (ret < 0)
 533                 goto free_irq;
 534
 535         return 0;
 536
 537 free_irq:
 538         free_irq(client->irq, indio_dev);
 539 buffer_cleanup:
 540         iio_triggered_buffer_cleanup(indio_dev);
 541         return ret;
 542 }
 543
 544 static int tcs3472_powerdown(struct tcs3472_data *data)
 545 {
 546         int ret;
 547         u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
 548
 549         mutex_lock(&data->lock);
 550
 551         ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 552                 data->enable & ~enable_mask);
 553         if (!ret)
 554                 data->enable &= ~enable_mask;
 555
 556         mutex_unlock(&data->lock);
 557
 558         return ret;
 559 }
 560
 561 static int tcs3472_remove(struct i2c_client *client)
 562 {
 563         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 564
 565         iio_device_unregister(indio_dev);
 566         free_irq(client->irq, indio_dev);
 567         iio_triggered_buffer_cleanup(indio_dev);
 568         tcs3472_powerdown(iio_priv(indio_dev));
 569
 570         return 0;
 571 }
 572
 573 #ifdef CONFIG_PM_SLEEP
 574 static int tcs3472_suspend(struct device *dev)
 575 {
 576         struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
 577                 to_i2c_client(dev)));
 578         return tcs3472_powerdown(data);
 579 }
 580
 581 static int tcs3472_resume(struct device *dev)
 582 {
 583         struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
 584                 to_i2c_client(dev)));
 585         int ret;
 586         u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
 587
 588         mutex_lock(&data->lock);
 589
 590         ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 591                 data->enable | enable_mask);
 592         if (!ret)
 593                 data->enable |= enable_mask;
 594
 595         mutex_unlock(&data->lock);
 596
 597         return ret;
 598 }
 599 #endif
 600
 601 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
 602
 603 static const struct i2c_device_id tcs3472_id[] = {
 604         { "tcs3472", 0 },
 605         { }
 606 };
 607 MODULE_DEVICE_TABLE(i2c, tcs3472_id);
 608
 609 static struct i2c_driver tcs3472_driver = {
 610         .driver = {
 611                 .name   = TCS3472_DRV_NAME,
 612                 .pm     = &tcs3472_pm_ops,
 613         },
 614         .probe          = tcs3472_probe,
 615         .remove         = tcs3472_remove,
 616         .id_table       = tcs3472_id,
 617 };
 618 module_i2c_driver(tcs3472_driver);
 619
 620 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 621 MODULE_DESCRIPTION("TCS3472 color light sensors driver");
 622 MODULE_LICENSE("GPL");