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