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 = tcs3472_req_data(data);
 120                 if (ret < 0)
 121                         return ret;
 122                 ret = i2c_smbus_read_word_data(data->client, chan->address);
 123                 if (ret < 0)
 124                         return ret;
 125                 *val = ret;
 126                 return IIO_VAL_INT;
 127         case IIO_CHAN_INFO_CALIBSCALE:
 128                 *val = tcs3472_agains[data->control &
 129                         TCS3472_CONTROL_AGAIN_MASK];
 130                 return IIO_VAL_INT;
 131         case IIO_CHAN_INFO_INT_TIME:
 132                 *val = 0;
 133                 *val2 = (256 - data->atime) * 2400;
 134                 return IIO_VAL_INT_PLUS_MICRO;
 135         }
 136         return -EINVAL;
 137 }
 138
 139 static int tcs3472_write_raw(struct iio_dev *indio_dev,
 140                                struct iio_chan_spec const *chan,
 141                                int val, int val2, long mask)
 142 {
 143         struct tcs3472_data *data = iio_priv(indio_dev);
 144         int i;
 145
 146         switch (mask) {
 147         case IIO_CHAN_INFO_CALIBSCALE:
 148                 if (val2 != 0)
 149                         return -EINVAL;
 150                 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
 151                         if (val == tcs3472_agains[i]) {
 152                                 data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
 153                                 data->control |= i;
 154                                 return i2c_smbus_write_byte_data(
 155                                         data->client, TCS3472_CONTROL,
 156                                         data->control);
 157                         }
 158                 }
 159                 return -EINVAL;
 160         case IIO_CHAN_INFO_INT_TIME:
 161                 if (val != 0)
 162                         return -EINVAL;
 163                 for (i = 0; i < 256; i++) {
 164                         if (val2 == (256 - i) * 2400) {
 165                                 data->atime = i;
 166                                 return i2c_smbus_write_word_data(
 167                                         data->client, TCS3472_ATIME,
 168                                         data->atime);
 169                         }
 170
 171                 }
 172                 return -EINVAL;
 173         }
 174         return -EINVAL;
 175 }
 176
 177 static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
 178 {
 179         struct iio_poll_func *pf = p;
 180         struct iio_dev *indio_dev = pf->indio_dev;
 181         struct tcs3472_data *data = iio_priv(indio_dev);
 182         int len = 0;
 183         int i, j = 0;
 184
 185         int ret = tcs3472_req_data(data);
 186         if (ret < 0)
 187                 goto done;
 188
 189         for_each_set_bit(i, indio_dev->active_scan_mask,
 190                 indio_dev->masklength) {
 191                 ret = i2c_smbus_read_word_data(data->client,
 192                         TCS3472_CDATA + 2*i);
 193                 if (ret < 0)
 194                         goto done;
 195
 196                 data->buffer[j++] = ret;
 197                 len += 2;
 198         }
 199
 200         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 201                 iio_get_time_ns());
 202
 203 done:
 204         iio_trigger_notify_done(indio_dev->trig);
 205
 206         return IRQ_HANDLED;
 207 }
 208
 209 static ssize_t tcs3472_show_int_time_available(struct device *dev,
 210                                         struct device_attribute *attr,
 211                                         char *buf)
 212 {
 213         size_t len = 0;
 214         int i;
 215
 216         for (i = 1; i <= 256; i++)
 217                 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
 218                         2400 * i);
 219
 220         /* replace trailing space by newline */
 221         buf[len - 1] = '\n';
 222
 223         return len;
 224 }
 225
 226 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
 227 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
 228
 229 static struct attribute *tcs3472_attributes[] = {
 230         &iio_const_attr_calibscale_available.dev_attr.attr,
 231         &iio_dev_attr_integration_time_available.dev_attr.attr,
 232         NULL
 233 };
 234
 235 static const struct attribute_group tcs3472_attribute_group = {
 236         .attrs = tcs3472_attributes,
 237 };
 238
 239 static const struct iio_info tcs3472_info = {
 240         .read_raw = tcs3472_read_raw,
 241         .write_raw = tcs3472_write_raw,
 242         .attrs = &tcs3472_attribute_group,
 243         .driver_module = THIS_MODULE,
 244 };
 245
 246 static int tcs3472_probe(struct i2c_client *client,
 247                            const struct i2c_device_id *id)
 248 {
 249         struct tcs3472_data *data;
 250         struct iio_dev *indio_dev;
 251         int ret;
 252
 253         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 254         if (indio_dev == NULL)
 255                 return -ENOMEM;
 256
 257         data = iio_priv(indio_dev);
 258         i2c_set_clientdata(client, indio_dev);
 259         data->client = client;
 260
 261         indio_dev->dev.parent = &client->dev;
 262         indio_dev->info = &tcs3472_info;
 263         indio_dev->name = TCS3472_DRV_NAME;
 264         indio_dev->channels = tcs3472_channels;
 265         indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
 266         indio_dev->modes = INDIO_DIRECT_MODE;
 267
 268         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
 269         if (ret < 0)
 270                 return ret;
 271
 272         if (ret == 0x44)
 273                 dev_info(&client->dev, "TCS34721/34725 found\n");
 274         else if (ret == 0x4d)
 275                 dev_info(&client->dev, "TCS34723/34727 found\n");
 276         else
 277                 return -ENODEV;
 278
 279         ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
 280         if (ret < 0)
 281                 return ret;
 282         data->control = ret;
 283
 284         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
 285         if (ret < 0)
 286                 return ret;
 287         data->atime = ret;
 288
 289         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
 290         if (ret < 0)
 291                 return ret;
 292
 293         /* enable device */
 294         data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
 295         ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 296                 data->enable);
 297         if (ret < 0)
 298                 return ret;
 299
 300         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 301                 tcs3472_trigger_handler, NULL);
 302         if (ret < 0)
 303                 return ret;
 304
 305         ret = iio_device_register(indio_dev);
 306         if (ret < 0)
 307                 goto buffer_cleanup;
 308
 309         return 0;
 310
 311 buffer_cleanup:
 312         iio_triggered_buffer_cleanup(indio_dev);
 313         return ret;
 314 }
 315
 316 static int tcs3472_powerdown(struct tcs3472_data *data)
 317 {
 318         return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 319                 data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
 320 }
 321
 322 static int tcs3472_remove(struct i2c_client *client)
 323 {
 324         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 325
 326         iio_device_unregister(indio_dev);
 327         iio_triggered_buffer_cleanup(indio_dev);
 328         tcs3472_powerdown(iio_priv(indio_dev));
 329
 330         return 0;
 331 }
 332
 333 #ifdef CONFIG_PM_SLEEP
 334 static int tcs3472_suspend(struct device *dev)
 335 {
 336         struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
 337                 to_i2c_client(dev)));
 338         return tcs3472_powerdown(data);
 339 }
 340
 341 static int tcs3472_resume(struct device *dev)
 342 {
 343         struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
 344                 to_i2c_client(dev)));
 345         return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 346                 data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
 347 }
 348 #endif
 349
 350 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
 351
 352 static const struct i2c_device_id tcs3472_id[] = {
 353         { "tcs3472", 0 },
 354         { }
 355 };
 356 MODULE_DEVICE_TABLE(i2c, tcs3472_id);
 357
 358 static struct i2c_driver tcs3472_driver = {
 359         .driver = {
 360                 .name   = TCS3472_DRV_NAME,
 361                 .pm     = &tcs3472_pm_ops,
 362                 .owner  = THIS_MODULE,
 363         },
 364         .probe          = tcs3472_probe,
 365         .remove         = tcs3472_remove,
 366         .id_table       = tcs3472_id,
 367 };
 368 module_i2c_driver(tcs3472_driver);
 369
 370 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 371 MODULE_DESCRIPTION("TCS3472 color light sensors driver");
 372 MODULE_LICENSE("GPL");