drivers/iio/light/tcs3414.c

   1 /*
   2  * tcs3414.c - Support for TAOS TCS3414 digital color sensor
   3  *
   4  * Copyright (c) 2014 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  * Digital color sensor with 16-bit channels for red, green, blue, clear);
  11  * 7-bit I2C slave address 0x39 (TCS3414) or 0x29, 0x49, 0x59 (TCS3413,
  12  * TCS3415, TCS3416, resp.)
  13  *
  14  * TODO: sync, interrupt support, thresholds, prescaler
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/i2c.h>
  19 #include <linux/delay.h>
  20 #include <linux/pm.h>
  21
  22 #include <linux/iio/iio.h>
  23 #include <linux/iio/sysfs.h>
  24 #include <linux/iio/trigger_consumer.h>
  25 #include <linux/iio/buffer.h>
  26 #include <linux/iio/triggered_buffer.h>
  27
  28 #define TCS3414_DRV_NAME "tcs3414"
  29
  30 #define TCS3414_COMMAND BIT(7)
  31 #define TCS3414_COMMAND_WORD (TCS3414_COMMAND | BIT(5))
  32
  33 #define TCS3414_CONTROL (TCS3414_COMMAND | 0x00)
  34 #define TCS3414_TIMING (TCS3414_COMMAND | 0x01)
  35 #define TCS3414_ID (TCS3414_COMMAND | 0x04)
  36 #define TCS3414_GAIN (TCS3414_COMMAND | 0x07)
  37 #define TCS3414_DATA_GREEN (TCS3414_COMMAND_WORD | 0x10)
  38 #define TCS3414_DATA_RED (TCS3414_COMMAND_WORD | 0x12)
  39 #define TCS3414_DATA_BLUE (TCS3414_COMMAND_WORD | 0x14)
  40 #define TCS3414_DATA_CLEAR (TCS3414_COMMAND_WORD | 0x16)
  41
  42 #define TCS3414_CONTROL_ADC_VALID BIT(4)
  43 #define TCS3414_CONTROL_ADC_EN BIT(1)
  44 #define TCS3414_CONTROL_POWER BIT(0)
  45
  46 #define TCS3414_INTEG_MASK GENMASK(1, 0)
  47 #define TCS3414_INTEG_12MS 0x0
  48 #define TCS3414_INTEG_100MS 0x1
  49 #define TCS3414_INTEG_400MS 0x2
  50
  51 #define TCS3414_GAIN_MASK GENMASK(5, 4)
  52 #define TCS3414_GAIN_SHIFT 4
  53
  54 struct tcs3414_data {
  55         struct i2c_client *client;
  56         u8 control;
  57         u8 gain;
  58         u8 timing;
  59         /* Ensure timestamp is naturally aligned */
  60         struct {
  61                 u16 chans[4];
  62                 s64 timestamp __aligned(8);
  63         } scan;
  64 };
  65
  66 #define TCS3414_CHANNEL(_color, _si, _addr) { \
  67         .type = IIO_INTENSITY, \
  68         .modified = 1, \
  69         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  70         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
  71                 BIT(IIO_CHAN_INFO_INT_TIME), \
  72         .channel2 = IIO_MOD_LIGHT_##_color, \
  73         .address = _addr, \
  74         .scan_index = _si, \
  75         .scan_type = { \
  76                 .sign = 'u', \
  77                 .realbits = 16, \
  78                 .storagebits = 16, \
  79                 .endianness = IIO_CPU, \
  80         }, \
  81 }
  82
  83 /* scale factors: 1/gain */
  84 static const int tcs3414_scales[][2] = {
  85         {1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
  86 };
  87
  88 /* integration time in ms */
  89 static const int tcs3414_times[] = { 12, 100, 400 };
  90
  91 static const struct iio_chan_spec tcs3414_channels[] = {
  92         TCS3414_CHANNEL(GREEN, 0, TCS3414_DATA_GREEN),
  93         TCS3414_CHANNEL(RED, 1, TCS3414_DATA_RED),
  94         TCS3414_CHANNEL(BLUE, 2, TCS3414_DATA_BLUE),
  95         TCS3414_CHANNEL(CLEAR, 3, TCS3414_DATA_CLEAR),
  96         IIO_CHAN_SOFT_TIMESTAMP(4),
  97 };
  98
  99 static int tcs3414_req_data(struct tcs3414_data *data)
 100 {
 101         int tries = 25;
 102         int ret;
 103
 104         ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 105                 data->control | TCS3414_CONTROL_ADC_EN);
 106         if (ret < 0)
 107                 return ret;
 108
 109         while (tries--) {
 110                 ret = i2c_smbus_read_byte_data(data->client, TCS3414_CONTROL);
 111                 if (ret < 0)
 112                         return ret;
 113                 if (ret & TCS3414_CONTROL_ADC_VALID)
 114                         break;
 115                 msleep(20);
 116         }
 117
 118         ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 119                 data->control);
 120         if (ret < 0)
 121                 return ret;
 122
 123         if (tries < 0) {
 124                 dev_err(&data->client->dev, "data not ready\n");
 125                 return -EIO;
 126         }
 127
 128         return 0;
 129 }
 130
 131 static int tcs3414_read_raw(struct iio_dev *indio_dev,
 132                            struct iio_chan_spec const *chan,
 133                            int *val, int *val2, long mask)
 134 {
 135         struct tcs3414_data *data = iio_priv(indio_dev);
 136         int i, ret;
 137
 138         switch (mask) {
 139         case IIO_CHAN_INFO_RAW:
 140                 ret = iio_device_claim_direct_mode(indio_dev);
 141                 if (ret)
 142                         return ret;
 143                 ret = tcs3414_req_data(data);
 144                 if (ret < 0) {
 145                         iio_device_release_direct_mode(indio_dev);
 146                         return ret;
 147                 }
 148                 ret = i2c_smbus_read_word_data(data->client, chan->address);
 149                 iio_device_release_direct_mode(indio_dev);
 150                 if (ret < 0)
 151                         return ret;
 152                 *val = ret;
 153                 return IIO_VAL_INT;
 154         case IIO_CHAN_INFO_SCALE:
 155                 i = (data->gain & TCS3414_GAIN_MASK) >> TCS3414_GAIN_SHIFT;
 156                 *val = tcs3414_scales[i][0];
 157                 *val2 = tcs3414_scales[i][1];
 158                 return IIO_VAL_INT_PLUS_MICRO;
 159         case IIO_CHAN_INFO_INT_TIME:
 160                 *val = 0;
 161                 *val2 = tcs3414_times[data->timing & TCS3414_INTEG_MASK] * 1000;
 162                 return IIO_VAL_INT_PLUS_MICRO;
 163         }
 164         return -EINVAL;
 165 }
 166
 167 static int tcs3414_write_raw(struct iio_dev *indio_dev,
 168                                struct iio_chan_spec const *chan,
 169                                int val, int val2, long mask)
 170 {
 171         struct tcs3414_data *data = iio_priv(indio_dev);
 172         int i;
 173
 174         switch (mask) {
 175         case IIO_CHAN_INFO_SCALE:
 176                 for (i = 0; i < ARRAY_SIZE(tcs3414_scales); i++) {
 177                         if (val == tcs3414_scales[i][0] &&
 178                                 val2 == tcs3414_scales[i][1]) {
 179                                 data->gain &= ~TCS3414_GAIN_MASK;
 180                                 data->gain |= i << TCS3414_GAIN_SHIFT;
 181                                 return i2c_smbus_write_byte_data(
 182                                         data->client, TCS3414_GAIN,
 183                                         data->gain);
 184                         }
 185                 }
 186                 return -EINVAL;
 187         case IIO_CHAN_INFO_INT_TIME:
 188                 if (val != 0)
 189                         return -EINVAL;
 190                 for (i = 0; i < ARRAY_SIZE(tcs3414_times); i++) {
 191                         if (val2 == tcs3414_times[i] * 1000) {
 192                                 data->timing &= ~TCS3414_INTEG_MASK;
 193                                 data->timing |= i;
 194                                 return i2c_smbus_write_byte_data(
 195                                         data->client, TCS3414_TIMING,
 196                                         data->timing);
 197                         }
 198                 }
 199                 return -EINVAL;
 200         default:
 201                 return -EINVAL;
 202         }
 203 }
 204
 205 static irqreturn_t tcs3414_trigger_handler(int irq, void *p)
 206 {
 207         struct iio_poll_func *pf = p;
 208         struct iio_dev *indio_dev = pf->indio_dev;
 209         struct tcs3414_data *data = iio_priv(indio_dev);
 210         int i, j = 0;
 211
 212         for_each_set_bit(i, indio_dev->active_scan_mask,
 213                 indio_dev->masklength) {
 214                 int ret = i2c_smbus_read_word_data(data->client,
 215                         TCS3414_DATA_GREEN + 2*i);
 216                 if (ret < 0)
 217                         goto done;
 218
 219                 data->scan.chans[j++] = ret;
 220         }
 221
 222         iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 223                 iio_get_time_ns(indio_dev));
 224
 225 done:
 226         iio_trigger_notify_done(indio_dev->trig);
 227
 228         return IRQ_HANDLED;
 229 }
 230
 231 static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
 232 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
 233
 234 static struct attribute *tcs3414_attributes[] = {
 235         &iio_const_attr_scale_available.dev_attr.attr,
 236         &iio_const_attr_integration_time_available.dev_attr.attr,
 237         NULL
 238 };
 239
 240 static const struct attribute_group tcs3414_attribute_group = {
 241         .attrs = tcs3414_attributes,
 242 };
 243
 244 static const struct iio_info tcs3414_info = {
 245         .read_raw = tcs3414_read_raw,
 246         .write_raw = tcs3414_write_raw,
 247         .attrs = &tcs3414_attribute_group,
 248         .driver_module = THIS_MODULE,
 249 };
 250
 251 static int tcs3414_buffer_preenable(struct iio_dev *indio_dev)
 252 {
 253         struct tcs3414_data *data = iio_priv(indio_dev);
 254
 255         data->control |= TCS3414_CONTROL_ADC_EN;
 256         return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 257                 data->control);
 258 }
 259
 260 static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
 261 {
 262         struct tcs3414_data *data = iio_priv(indio_dev);
 263         int ret;
 264
 265         ret = iio_triggered_buffer_predisable(indio_dev);
 266         if (ret < 0)
 267                 return ret;
 268
 269         data->control &= ~TCS3414_CONTROL_ADC_EN;
 270         return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 271                 data->control);
 272 }
 273
 274 static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
 275         .preenable = tcs3414_buffer_preenable,
 276         .postenable = &iio_triggered_buffer_postenable,
 277         .predisable = tcs3414_buffer_predisable,
 278 };
 279
 280 static int tcs3414_probe(struct i2c_client *client,
 281                            const struct i2c_device_id *id)
 282 {
 283         struct tcs3414_data *data;
 284         struct iio_dev *indio_dev;
 285         int ret;
 286
 287         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 288         if (indio_dev == NULL)
 289                 return -ENOMEM;
 290
 291         data = iio_priv(indio_dev);
 292         i2c_set_clientdata(client, indio_dev);
 293         data->client = client;
 294
 295         indio_dev->dev.parent = &client->dev;
 296         indio_dev->info = &tcs3414_info;
 297         indio_dev->name = TCS3414_DRV_NAME;
 298         indio_dev->channels = tcs3414_channels;
 299         indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
 300         indio_dev->modes = INDIO_DIRECT_MODE;
 301
 302         ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
 303         if (ret < 0)
 304                 return ret;
 305
 306         switch (ret & 0xf0) {
 307         case 0x00:
 308                 dev_info(&client->dev, "TCS3404 found\n");
 309                 break;
 310         case 0x10:
 311                 dev_info(&client->dev, "TCS3413/14/15/16 found\n");
 312                 break;
 313         default:
 314                 return -ENODEV;
 315         }
 316
 317         data->control = TCS3414_CONTROL_POWER;
 318         ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 319                 data->control);
 320         if (ret < 0)
 321                 return ret;
 322
 323         data->timing = TCS3414_INTEG_12MS; /* free running */
 324         ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
 325                 data->timing);
 326         if (ret < 0)
 327                 return ret;
 328
 329         ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
 330         if (ret < 0)
 331                 return ret;
 332         data->gain = ret;
 333
 334         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 335                 tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
 336         if (ret < 0)
 337                 return ret;
 338
 339         ret = iio_device_register(indio_dev);
 340         if (ret < 0)
 341                 goto buffer_cleanup;
 342
 343         return 0;
 344
 345 buffer_cleanup:
 346         iio_triggered_buffer_cleanup(indio_dev);
 347         return ret;
 348 }
 349
 350 static int tcs3414_powerdown(struct tcs3414_data *data)
 351 {
 352         return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 353                 data->control & ~(TCS3414_CONTROL_POWER |
 354                 TCS3414_CONTROL_ADC_EN));
 355 }
 356
 357 static int tcs3414_remove(struct i2c_client *client)
 358 {
 359         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 360
 361         iio_device_unregister(indio_dev);
 362         iio_triggered_buffer_cleanup(indio_dev);
 363         tcs3414_powerdown(iio_priv(indio_dev));
 364
 365         return 0;
 366 }
 367
 368 #ifdef CONFIG_PM_SLEEP
 369 static int tcs3414_suspend(struct device *dev)
 370 {
 371         struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
 372                 to_i2c_client(dev)));
 373         return tcs3414_powerdown(data);
 374 }
 375
 376 static int tcs3414_resume(struct device *dev)
 377 {
 378         struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
 379                 to_i2c_client(dev)));
 380         return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 381                 data->control);
 382 }
 383 #endif
 384
 385 static SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend, tcs3414_resume);
 386
 387 static const struct i2c_device_id tcs3414_id[] = {
 388         { "tcs3414", 0 },
 389         { }
 390 };
 391 MODULE_DEVICE_TABLE(i2c, tcs3414_id);
 392
 393 static struct i2c_driver tcs3414_driver = {
 394         .driver = {
 395                 .name   = TCS3414_DRV_NAME,
 396                 .pm     = &tcs3414_pm_ops,
 397         },
 398         .probe          = tcs3414_probe,
 399         .remove         = tcs3414_remove,
 400         .id_table       = tcs3414_id,
 401 };
 402 module_i2c_driver(tcs3414_driver);
 403
 404 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 405 MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
 406 MODULE_LICENSE("GPL");