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