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