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