kernel/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         struct mutex lock;
  56         u8 enable;
  57         u8 control;
  58         u8 atime;
  59         u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */
  60 };
  61
  62 #define TCS3472_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_CALIBSCALE) | \
  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 static const int tcs3472_agains[] = { 1, 4, 16, 60 };
  80
  81 static const struct iio_chan_spec tcs3472_channels[] = {
  82         TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA),
  83         TCS3472_CHANNEL(RED, 1, TCS3472_RDATA),
  84         TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA),
  85         TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA),
  86         IIO_CHAN_SOFT_TIMESTAMP(4),
  87 };
  88
  89 static int tcs3472_req_data(struct tcs3472_data *data)
  90 {
  91         int tries = 50;
  92         int ret;
  93
  94         while (tries--) {
  95                 ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
  96                 if (ret < 0)
  97                         return ret;
  98                 if (ret & TCS3472_STATUS_AVALID)
  99                         break;
 100                 msleep(20);
 101         }
 102
 103         if (tries < 0) {
 104                 dev_err(&data->client->dev, "data not ready\n");
 105                 return -EIO;
 106         }
 107
 108         return 0;
 109 }
 110
 111 static int tcs3472_read_raw(struct iio_dev *indio_dev,
 112                            struct iio_chan_spec const *chan,
 113                            int *val, int *val2, long mask)
 114 {
 115         struct tcs3472_data *data = iio_priv(indio_dev);
 116         int ret;
 117
 118         switch (mask) {
 119         case IIO_CHAN_INFO_RAW:
 120                 if (iio_buffer_enabled(indio_dev))
 121                         return -EBUSY;
 122
 123                 mutex_lock(&data->lock);
 124                 ret = tcs3472_req_data(data);
 125                 if (ret < 0) {
 126                         mutex_unlock(&data->lock);
 127                         return ret;
 128                 }
 129                 ret = i2c_smbus_read_word_data(data->client, chan->address);
 130                 mutex_unlock(&data->lock);
 131                 if (ret < 0)
 132                         return ret;
 133                 *val = ret;
 134                 return IIO_VAL_INT;
 135         case IIO_CHAN_INFO_CALIBSCALE:
 136                 *val = tcs3472_agains[data->control &
 137                         TCS3472_CONTROL_AGAIN_MASK];
 138                 return IIO_VAL_INT;
 139         case IIO_CHAN_INFO_INT_TIME:
 140                 *val = 0;
 141                 *val2 = (256 - data->atime) * 2400;
 142                 return IIO_VAL_INT_PLUS_MICRO;
 143         }
 144         return -EINVAL;
 145 }
 146
 147 static int tcs3472_write_raw(struct iio_dev *indio_dev,
 148                                struct iio_chan_spec const *chan,
 149                                int val, int val2, long mask)
 150 {
 151         struct tcs3472_data *data = iio_priv(indio_dev);
 152         int i;
 153
 154         switch (mask) {
 155         case IIO_CHAN_INFO_CALIBSCALE:
 156                 if (val2 != 0)
 157                         return -EINVAL;
 158                 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
 159                         if (val == tcs3472_agains[i]) {
 160                                 data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
 161                                 data->control |= i;
 162                                 return i2c_smbus_write_byte_data(
 163                                         data->client, TCS3472_CONTROL,
 164                                         data->control);
 165                         }
 166                 }
 167                 return -EINVAL;
 168         case IIO_CHAN_INFO_INT_TIME:
 169                 if (val != 0)
 170                         return -EINVAL;
 171                 for (i = 0; i < 256; i++) {
 172                         if (val2 == (256 - i) * 2400) {
 173                                 data->atime = i;
 174                                 return i2c_smbus_write_word_data(
 175                                         data->client, TCS3472_ATIME,
 176                                         data->atime);
 177                         }
 178
 179                 }
 180                 return -EINVAL;
 181         }
 182         return -EINVAL;
 183 }
 184
 185 static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
 186 {
 187         struct iio_poll_func *pf = p;
 188         struct iio_dev *indio_dev = pf->indio_dev;
 189         struct tcs3472_data *data = iio_priv(indio_dev);
 190         int i, j = 0;
 191
 192         int ret = tcs3472_req_data(data);
 193         if (ret < 0)
 194                 goto done;
 195
 196         for_each_set_bit(i, indio_dev->active_scan_mask,
 197                 indio_dev->masklength) {
 198                 ret = i2c_smbus_read_word_data(data->client,
 199                         TCS3472_CDATA + 2*i);
 200                 if (ret < 0)
 201                         goto done;
 202
 203                 data->buffer[j++] = ret;
 204         }
 205
 206         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 207                 iio_get_time_ns());
 208
 209 done:
 210         iio_trigger_notify_done(indio_dev->trig);
 211
 212         return IRQ_HANDLED;
 213 }
 214
 215 static ssize_t tcs3472_show_int_time_available(struct device *dev,
 216                                         struct device_attribute *attr,
 217                                         char *buf)
 218 {
 219         size_t len = 0;
 220         int i;
 221
 222         for (i = 1; i <= 256; i++)
 223                 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
 224                         2400 * i);
 225
 226         /* replace trailing space by newline */
 227         buf[len - 1] = '\n';
 228
 229         return len;
 230 }
 231
 232 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
 233 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
 234
 235 static struct attribute *tcs3472_attributes[] = {
 236         &iio_const_attr_calibscale_available.dev_attr.attr,
 237         &iio_dev_attr_integration_time_available.dev_attr.attr,
 238         NULL
 239 };
 240
 241 static const struct attribute_group tcs3472_attribute_group = {
 242         .attrs = tcs3472_attributes,
 243 };
 244
 245 static const struct iio_info tcs3472_info = {
 246         .read_raw = tcs3472_read_raw,
 247         .write_raw = tcs3472_write_raw,
 248         .attrs = &tcs3472_attribute_group,
 249         .driver_module = THIS_MODULE,
 250 };
 251
 252 static int tcs3472_probe(struct i2c_client *client,
 253                            const struct i2c_device_id *id)
 254 {
 255         struct tcs3472_data *data;
 256         struct iio_dev *indio_dev;
 257         int ret;
 258
 259         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 260         if (indio_dev == NULL)
 261                 return -ENOMEM;
 262
 263         data = iio_priv(indio_dev);
 264         i2c_set_clientdata(client, indio_dev);
 265         data->client = client;
 266         mutex_init(&data->lock);
 267
 268         indio_dev->dev.parent = &client->dev;
 269         indio_dev->info = &tcs3472_info;
 270         indio_dev->name = TCS3472_DRV_NAME;
 271         indio_dev->channels = tcs3472_channels;
 272         indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
 273         indio_dev->modes = INDIO_DIRECT_MODE;
 274
 275         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
 276         if (ret < 0)
 277                 return ret;
 278
 279         if (ret == 0x44)
 280                 dev_info(&client->dev, "TCS34721/34725 found\n");
 281         else if (ret == 0x4d)
 282                 dev_info(&client->dev, "TCS34723/34727 found\n");
 283         else
 284                 return -ENODEV;
 285
 286         ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
 287         if (ret < 0)
 288                 return ret;
 289         data->control = ret;
 290
 291         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
 292         if (ret < 0)
 293                 return ret;
 294         data->atime = ret;
 295
 296         ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
 297         if (ret < 0)
 298                 return ret;
 299
 300         /* enable device */
 301         data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
 302         ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 303                 data->enable);
 304         if (ret < 0)
 305                 return ret;
 306
 307         ret = iio_triggered_buffer_setup(indio_dev, NULL,
 308                 tcs3472_trigger_handler, NULL);
 309         if (ret < 0)
 310                 return ret;
 311
 312         ret = iio_device_register(indio_dev);
 313         if (ret < 0)
 314                 goto buffer_cleanup;
 315
 316         return 0;
 317
 318 buffer_cleanup:
 319         iio_triggered_buffer_cleanup(indio_dev);
 320         return ret;
 321 }
 322
 323 static int tcs3472_powerdown(struct tcs3472_data *data)
 324 {
 325         return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 326                 data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
 327 }
 328
 329 static int tcs3472_remove(struct i2c_client *client)
 330 {
 331         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 332
 333         iio_device_unregister(indio_dev);
 334         iio_triggered_buffer_cleanup(indio_dev);
 335         tcs3472_powerdown(iio_priv(indio_dev));
 336
 337         return 0;
 338 }
 339
 340 #ifdef CONFIG_PM_SLEEP
 341 static int tcs3472_suspend(struct device *dev)
 342 {
 343         struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
 344                 to_i2c_client(dev)));
 345         return tcs3472_powerdown(data);
 346 }
 347
 348 static int tcs3472_resume(struct device *dev)
 349 {
 350         struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
 351                 to_i2c_client(dev)));
 352         return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
 353                 data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
 354 }
 355 #endif
 356
 357 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
 358
 359 static const struct i2c_device_id tcs3472_id[] = {
 360         { "tcs3472", 0 },
 361         { }
 362 };
 363 MODULE_DEVICE_TABLE(i2c, tcs3472_id);
 364
 365 static struct i2c_driver tcs3472_driver = {
 366         .driver = {
 367                 .name   = TCS3472_DRV_NAME,
 368                 .pm     = &tcs3472_pm_ops,
 369                 .owner  = THIS_MODULE,
 370         },
 371         .probe          = tcs3472_probe,
 372         .remove         = tcs3472_remove,
 373         .id_table       = tcs3472_id,
 374 };
 375 module_i2c_driver(tcs3472_driver);
 376
 377 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 378 MODULE_DESCRIPTION("TCS3472 color light sensors driver");
 379 MODULE_LICENSE("GPL");