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  * TODO: interrupt support, thresholds, wait time
  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 TCS3472_DRV_NAME "tcs3472"
  29
  30 #define TCS3472_COMMAND BIT(7)
  31 #define TCS3472_AUTO_INCR BIT(5)
  32
  33 #define TCS3472_ENABLE (TCS3472_COMMAND | 0x00)
  34 #define TCS3472_ATIME (TCS3472_COMMAND | 0x01)
  35 #define TCS3472_WTIME (TCS3472_COMMAND | 0x03)
  36 #define TCS3472_AILT (TCS3472_COMMAND | 0x04)
  37 #define TCS3472_AIHT (TCS3472_COMMAND | 0x06)
  38 #define TCS3472_PERS (TCS3472_COMMAND | 0x0c)
  39 #define TCS3472_CONFIG (TCS3472_COMMAND | 0x0d)
  40 #define TCS3472_CONTROL (TCS3472_COMMAND | 0x0f)
  41 #define TCS3472_ID (TCS3472_COMMAND | 0x12)
  42 #define TCS3472_STATUS (TCS3472_COMMAND | 0x13)
  43 #define TCS3472_CDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x14)
  44 #define TCS3472_RDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x16)
  45 #define TCS3472_GDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x18)
  46 #define TCS3472_BDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x1a)
  47
  48 #define TCS3472_STATUS_AVALID BIT(0)
  49 #define TCS3472_ENABLE_AEN BIT(1)
  50 #define TCS3472_ENABLE_PON BIT(0)
  51 #define TCS3472_CONTROL_AGAIN_MASK (BIT(0) | BIT(1))
  52
  53 struct tcs3472_data {
  54         struct i2c_client *client;
  55         u8 enable;
  56         u8 control;
  57         u8 atime;
  58         u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */
  59 };
  60
  61 #define TCS3472_CHANNEL(_color, _si, _addr) { \
  62         .type = IIO_INTENSITY, \
  63         .modified = 1, \
  64         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  65         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBSCALE) | \
  66                 BIT(IIO_CHAN_INFO_INT_TIME), \
  67         .channel2 = IIO_MOD_LIGHT_##_color, \
  68         .address = _addr, \
  69         .scan_index = _si, \
  70         .scan_type = { \
  71                 .sign = 'u', \
  72                 .realbits = 16, \
  73                 .storagebits = 16, \
  74                 .endianness = IIO_CPU, \
  75         }, \
  76 }
  77
  78 static const int tcs3472_agains[] = { 1, 4, 16, 60 };
  79
  80 static const struct iio_chan_spec tcs3472_channels[] = {
  81         TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA),
  82         TCS3472_CHANNEL(RED, 1, TCS3472_RDATA),
  83         TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA),
  84         TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA),
  85         IIO_CHAN_SOFT_TIMESTAMP(4),
  86 };
  87
  88 static int tcs3472_req_data(struct tcs3472_data *data)
  89 {
  90         int tries = 50;
  91         int ret;
  92
  93         while (tries--) {
  94                 ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
  95                 if (ret < 0)
  96                         return ret;
  97                 if (ret & TCS3472_STATUS_AVALID)
  98                         break;
  99                 msleep(20);
 100         }
 101
 102         if (tries < 0) {
 103                 dev_err(&data->client->dev, "data not ready\n");
 104                 return -EIO;
 105         }
 106
 107         return 0;
 108 }
 109
 110 static int tcs3472_read_raw(struct iio_dev *indio_dev,
 111                            struct iio_chan_spec const *chan,
 112                            int *val, int *val2, long mask)
 113 {
 114         struct tcs3472_data *data = iio_priv(indio_dev);
 115         int ret;
 116
 117         switch (mask) {
 118         case IIO_CHAN_INFO_RAW:
 119                 ret = iio_device_claim_direct_mode(indio_dev);
 120                 if (ret)
 121                         return ret;
 122                 ret = tcs3472_req_data(data);
 123                 if (ret < 0) {
 124                         iio_device_release_direct_mode(indio_dev);
 125                         return ret;
 126                 }
 127                 ret = i2c_smbus_read_word_data(data->client, chan->address);
 128                 iio_device_release_direct_mode(indio_dev);
 129                 if (ret < 0)
 130                         return ret;
 131                 *val = ret;
 132                 return IIO_VAL_INT;
 133         case IIO_CHAN_INFO_CALIBSCALE:
 134                 *val = tcs3472_agains[data->control &
 135                         TCS3472_CONTROL_AGAIN_MASK];
 136                 return IIO_VAL_INT;
 137         case IIO_CHAN_INFO_INT_TIME:
 138                 *val = 0;
 139                 *val2 = (256 - data->atime) * 2400;
 140                 return IIO_VAL_INT_PLUS_MICRO;
 141         }
 142         return -EINVAL;
 143 }
 144
 145 static int tcs3472_write_raw(struct iio_dev *indio_dev,
 146                                struct iio_chan_spec const *chan,
 147                                int val, int val2, long mask)
 148 {
 149         struct tcs3472_data *data = iio_priv(indio_dev);
 150         int i;
 151
 152         switch (mask) {
 153         case IIO_CHAN_INFO_CALIBSCALE:
 154                 if (val2 != 0)
 155                         return -EINVAL;
 156                 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
 157                         if (val == tcs3472_agains[i]) {
 158                                 data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
 159                                 data->control |= i;
 160                                 return i2c_smbus_write_byte_data(
 161                                         data->client, TCS3472_CONTROL,
 162                                         data->control);
 163                         }
 164                 }
 165                 return -EINVAL;
 166         case IIO_CHAN_INFO_INT_TIME:
 167                 if (val != 0)
 168                         return -EINVAL;
 169                 for (i = 0; i < 256; i++) {
 170                         if (val2 == (256 - i) * 2400) {
 171                                 data->atime = i;
 172                                 return i2c_smbus_write_word_data(
 173                                         data->client, TCS3472_ATIME,
 174                                         data->atime);
 175                         }
 176
 177                 }
 178                 return -EINVAL;
 179         }
 180         return -EINVAL;
 181 }
 182
 183 static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
 184 {
 185         struct iio_poll_func *pf = p;
 186         struct iio_dev *indio_dev = pf->indio_dev;
 187         struct tcs3472_data *data = iio_priv(indio_dev);
 188         int i, j = 0;
 189
 190         int ret = tcs3472_req_data(data);
 191         if (ret < 0)
 192                 goto done;
 193
 194         for_each_set_bit(i, indio_dev->active_scan_mask,
 195                 indio_dev->masklength) {
 196                 ret = i2c_smbus_read_word_data(data->client,
 197                         TCS3472_CDATA + 2*i);
 198                 if (ret < 0)
 199                         goto done;
 200
 201                 data->buffer[j++] = ret;
 202         }
 203
 204         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 205                 iio_get_time_ns(indio_dev));
 206
 207 done:
 208         iio_trigger_notify_done(indio_dev->trig);
 209
 210         return IRQ_HANDLED;
 211 }
 212
 213 static ssize_t tcs3472_show_int_time_available(struct device *dev,
 214                                         struct device_attribute *attr,
 215                                         char *buf)
 216 {
 217         size_t len = 0;
 218         int i;
 219
 220         for (i = 1; i <= 256; i++)
 221                 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
 222                         2400 * i);
 223
 224         /* replace trailing space by newline */
 225         buf[len - 1] = '\n';
 226
 227         return len;
 228 }
 229
 230 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
 231 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
 232
 233 static struct attribute *tcs3472_attributes[] = {
 234         &iio_const_attr_calibscale_available.dev_attr.attr,
 235         &iio_dev_attr_integration_time_available.dev_attr.attr,
 236         NULL
 237 };
 238
 239 static const struct attribute_group tcs3472_attribute_group = {
 240         .attrs = tcs3472_attributes,
 241 };
 242
 243 static const struct iio_info tcs3472_info = {
 244         .read_raw = tcs3472_read_raw,
 245         .write_raw = tcs3472_write_raw,
 246         .attrs = &tcs3472_attribute_group,
 247         .driver_module = THIS_MODULE,
 248 };
 249
 250 static int tcs3472_probe(struct i2c_client *client,
 251                            const struct i2c_device_id *id)
 252 {
 253         struct tcs3472_data *data;
 254         struct iio_dev *indio_dev;
 255         int ret;
 256
 257         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 258         if (indio_dev == NULL)
 259                 return -ENOMEM;
 260
 261         data = iio_priv(indio_dev);
 262         i2c_set_clientdata(client, indio_dev);
 263         data->client = client;
 264
 265         indio_dev->dev.parent = &client->dev;
 266         indio_dev->info = &tcs3472_info;
 267         indio_dev->name = TCS3472_DRV_NAME;
 268         indio_dev->channels = tcs3472_channels;
 269         indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
 270         indio_dev->modes = INDIO_DIRECT_MODE;
 271
 272         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
 273         if (ret < 0)
 274                 return ret;
 275
 276         if (ret == 0x44)
 277                 dev_info(&client->dev, "TCS34721/34725 found\n");
 278         else if (ret == 0x4d)
 279                 dev_info(&client->dev, "TCS34723/34727 found\n");
 280         else
 281                 return -ENODEV;
 282
 283         ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
 284         if (ret < 0)
 285                 return ret;
 286         data->control = ret;
 287
 288         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
 289         if (ret < 0)
 290                 return ret;
 291         data->atime = ret;
 292
 293         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
 294         if (ret < 0)
 295                 return ret;
 296
 297         /* enable device */
 298         data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
 299         ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 300                 data->enable);
 301         if (ret < 0)
 302                 return ret;
 303
 304         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 305                 tcs3472_trigger_handler, NULL);
 306         if (ret < 0)
 307                 return ret;
 308
 309         ret = iio_device_register(indio_dev);
 310         if (ret < 0)
 311                 goto buffer_cleanup;
 312
 313         return 0;
 314
 315 buffer_cleanup:
 316         iio_triggered_buffer_cleanup(indio_dev);
 317         return ret;
 318 }
 319
 320 static int tcs3472_powerdown(struct tcs3472_data *data)
 321 {
 322         return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 323                 data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
 324 }
 325
 326 static int tcs3472_remove(struct i2c_client *client)
 327 {
 328         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 329
 330         iio_device_unregister(indio_dev);
 331         iio_triggered_buffer_cleanup(indio_dev);
 332         tcs3472_powerdown(iio_priv(indio_dev));
 333
 334         return 0;
 335 }
 336
 337 #ifdef CONFIG_PM_SLEEP
 338 static int tcs3472_suspend(struct device *dev)
 339 {
 340         struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
 341                 to_i2c_client(dev)));
 342         return tcs3472_powerdown(data);
 343 }
 344
 345 static int tcs3472_resume(struct device *dev)
 346 {
 347         struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
 348                 to_i2c_client(dev)));
 349         return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 350                 data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
 351 }
 352 #endif
 353
 354 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
 355
 356 static const struct i2c_device_id tcs3472_id[] = {
 357         { "tcs3472", 0 },
 358         { }
 359 };
 360 MODULE_DEVICE_TABLE(i2c, tcs3472_id);
 361
 362 static struct i2c_driver tcs3472_driver = {
 363         .driver = {
 364                 .name   = TCS3472_DRV_NAME,
 365                 .pm     = &tcs3472_pm_ops,
 366         },
 367         .probe          = tcs3472_probe,
 368         .remove         = tcs3472_remove,
 369         .id_table       = tcs3472_id,
 370 };
 371 module_i2c_driver(tcs3472_driver);
 372
 373 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 374 MODULE_DESCRIPTION("TCS3472 color light sensors driver");
 375 MODULE_LICENSE("GPL");