drivers/iio/light/tcs3414.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * tcs3414.c - Support for TAOS TCS3414 digital color sensor
   4  *
   5  * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
   6  *
   7  * Digital color sensor with 16-bit channels for red, green, blue, clear);
   8  * 7-bit I2C slave address 0x39 (TCS3414) or 0x29, 0x49, 0x59 (TCS3413,
   9  * TCS3415, TCS3416, resp.)
  10  *
  11  * TODO: sync, interrupt support, thresholds, prescaler
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/i2c.h>
  16 #include <linux/delay.h>
  17 #include <linux/pm.h>
  18
  19 #include <linux/iio/iio.h>
  20 #include <linux/iio/sysfs.h>
  21 #include <linux/iio/trigger_consumer.h>
  22 #include <linux/iio/buffer.h>
  23 #include <linux/iio/triggered_buffer.h>
  24
  25 #define TCS3414_DRV_NAME "tcs3414"
  26
  27 #define TCS3414_COMMAND BIT(7)
  28 #define TCS3414_COMMAND_WORD (TCS3414_COMMAND | BIT(5))
  29
  30 #define TCS3414_CONTROL (TCS3414_COMMAND | 0x00)
  31 #define TCS3414_TIMING (TCS3414_COMMAND | 0x01)
  32 #define TCS3414_ID (TCS3414_COMMAND | 0x04)
  33 #define TCS3414_GAIN (TCS3414_COMMAND | 0x07)
  34 #define TCS3414_DATA_GREEN (TCS3414_COMMAND_WORD | 0x10)
  35 #define TCS3414_DATA_RED (TCS3414_COMMAND_WORD | 0x12)
  36 #define TCS3414_DATA_BLUE (TCS3414_COMMAND_WORD | 0x14)
  37 #define TCS3414_DATA_CLEAR (TCS3414_COMMAND_WORD | 0x16)
  38
  39 #define TCS3414_CONTROL_ADC_VALID BIT(4)
  40 #define TCS3414_CONTROL_ADC_EN BIT(1)
  41 #define TCS3414_CONTROL_POWER BIT(0)
  42
  43 #define TCS3414_INTEG_MASK GENMASK(1, 0)
  44 #define TCS3414_INTEG_12MS 0x0
  45 #define TCS3414_INTEG_100MS 0x1
  46 #define TCS3414_INTEG_400MS 0x2
  47
  48 #define TCS3414_GAIN_MASK GENMASK(5, 4)
  49 #define TCS3414_GAIN_SHIFT 4
  50
  51 struct tcs3414_data {
  52         struct i2c_client *client;
  53         u8 control;
  54         u8 gain;
  55         u8 timing;
  56         /* Ensure timestamp is naturally aligned */
  57         struct {
  58                 u16 chans[4];
  59                 s64 timestamp __aligned(8);
  60         } scan;
  61 };
  62
  63 #define TCS3414_CHANNEL(_color, _si, _addr) { \
  64         .type = IIO_INTENSITY, \
  65         .modified = 1, \
  66         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  67         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
  68                 BIT(IIO_CHAN_INFO_INT_TIME), \
  69         .channel2 = IIO_MOD_LIGHT_##_color, \
  70         .address = _addr, \
  71         .scan_index = _si, \
  72         .scan_type = { \
  73                 .sign = 'u', \
  74                 .realbits = 16, \
  75                 .storagebits = 16, \
  76                 .endianness = IIO_CPU, \
  77         }, \
  78 }
  79
  80 /* scale factors: 1/gain */
  81 static const int tcs3414_scales[][2] = {
  82         {1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
  83 };
  84
  85 /* integration time in ms */
  86 static const int tcs3414_times[] = { 12, 100, 400 };
  87
  88 static const struct iio_chan_spec tcs3414_channels[] = {
  89         TCS3414_CHANNEL(GREEN, 0, TCS3414_DATA_GREEN),
  90         TCS3414_CHANNEL(RED, 1, TCS3414_DATA_RED),
  91         TCS3414_CHANNEL(BLUE, 2, TCS3414_DATA_BLUE),
  92         TCS3414_CHANNEL(CLEAR, 3, TCS3414_DATA_CLEAR),
  93         IIO_CHAN_SOFT_TIMESTAMP(4),
  94 };
  95
  96 static int tcs3414_req_data(struct tcs3414_data *data)
  97 {
  98         int tries = 25;
  99         int ret;
 100
 101         ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 102                 data->control | TCS3414_CONTROL_ADC_EN);
 103         if (ret < 0)
 104                 return ret;
 105
 106         while (tries--) {
 107                 ret = i2c_smbus_read_byte_data(data->client, TCS3414_CONTROL);
 108                 if (ret < 0)
 109                         return ret;
 110                 if (ret & TCS3414_CONTROL_ADC_VALID)
 111                         break;
 112                 msleep(20);
 113         }
 114
 115         ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 116                 data->control);
 117         if (ret < 0)
 118                 return ret;
 119
 120         if (tries < 0) {
 121                 dev_err(&data->client->dev, "data not ready\n");
 122                 return -EIO;
 123         }
 124
 125         return 0;
 126 }
 127
 128 static int tcs3414_read_raw(struct iio_dev *indio_dev,
 129                            struct iio_chan_spec const *chan,
 130                            int *val, int *val2, long mask)
 131 {
 132         struct tcs3414_data *data = iio_priv(indio_dev);
 133         int i, ret;
 134
 135         switch (mask) {
 136         case IIO_CHAN_INFO_RAW:
 137                 ret = iio_device_claim_direct_mode(indio_dev);
 138                 if (ret)
 139                         return ret;
 140                 ret = tcs3414_req_data(data);
 141                 if (ret < 0) {
 142                         iio_device_release_direct_mode(indio_dev);
 143                         return ret;
 144                 }
 145                 ret = i2c_smbus_read_word_data(data->client, chan->address);
 146                 iio_device_release_direct_mode(indio_dev);
 147                 if (ret < 0)
 148                         return ret;
 149                 *val = ret;
 150                 return IIO_VAL_INT;
 151         case IIO_CHAN_INFO_SCALE:
 152                 i = (data->gain & TCS3414_GAIN_MASK) >> TCS3414_GAIN_SHIFT;
 153                 *val = tcs3414_scales[i][0];
 154                 *val2 = tcs3414_scales[i][1];
 155                 return IIO_VAL_INT_PLUS_MICRO;
 156         case IIO_CHAN_INFO_INT_TIME:
 157                 *val = 0;
 158                 *val2 = tcs3414_times[data->timing & TCS3414_INTEG_MASK] * 1000;
 159                 return IIO_VAL_INT_PLUS_MICRO;
 160         }
 161         return -EINVAL;
 162 }
 163
 164 static int tcs3414_write_raw(struct iio_dev *indio_dev,
 165                                struct iio_chan_spec const *chan,
 166                                int val, int val2, long mask)
 167 {
 168         struct tcs3414_data *data = iio_priv(indio_dev);
 169         int i;
 170
 171         switch (mask) {
 172         case IIO_CHAN_INFO_SCALE:
 173                 for (i = 0; i < ARRAY_SIZE(tcs3414_scales); i++) {
 174                         if (val == tcs3414_scales[i][0] &&
 175                                 val2 == tcs3414_scales[i][1]) {
 176                                 data->gain &= ~TCS3414_GAIN_MASK;
 177                                 data->gain |= i << TCS3414_GAIN_SHIFT;
 178                                 return i2c_smbus_write_byte_data(
 179                                         data->client, TCS3414_GAIN,
 180                                         data->gain);
 181                         }
 182                 }
 183                 return -EINVAL;
 184         case IIO_CHAN_INFO_INT_TIME:
 185                 if (val != 0)
 186                         return -EINVAL;
 187                 for (i = 0; i < ARRAY_SIZE(tcs3414_times); i++) {
 188                         if (val2 == tcs3414_times[i] * 1000) {
 189                                 data->timing &= ~TCS3414_INTEG_MASK;
 190                                 data->timing |= i;
 191                                 return i2c_smbus_write_byte_data(
 192                                         data->client, TCS3414_TIMING,
 193                                         data->timing);
 194                         }
 195                 }
 196                 return -EINVAL;
 197         default:
 198                 return -EINVAL;
 199         }
 200 }
 201
 202 static irqreturn_t tcs3414_trigger_handler(int irq, void *p)
 203 {
 204         struct iio_poll_func *pf = p;
 205         struct iio_dev *indio_dev = pf->indio_dev;
 206         struct tcs3414_data *data = iio_priv(indio_dev);
 207         int i, j = 0;
 208
 209         iio_for_each_active_channel(indio_dev, i) {
 210                 int ret = i2c_smbus_read_word_data(data->client,
 211                         TCS3414_DATA_GREEN + 2*i);
 212                 if (ret < 0)
 213                         goto done;
 214
 215                 data->scan.chans[j++] = ret;
 216         }
 217
 218         iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 219                 iio_get_time_ns(indio_dev));
 220
 221 done:
 222         iio_trigger_notify_done(indio_dev->trig);
 223
 224         return IRQ_HANDLED;
 225 }
 226
 227 static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
 228 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
 229
 230 static struct attribute *tcs3414_attributes[] = {
 231         &iio_const_attr_scale_available.dev_attr.attr,
 232         &iio_const_attr_integration_time_available.dev_attr.attr,
 233         NULL
 234 };
 235
 236 static const struct attribute_group tcs3414_attribute_group = {
 237         .attrs = tcs3414_attributes,
 238 };
 239
 240 static const struct iio_info tcs3414_info = {
 241         .read_raw = tcs3414_read_raw,
 242         .write_raw = tcs3414_write_raw,
 243         .attrs = &tcs3414_attribute_group,
 244 };
 245
 246 static int tcs3414_buffer_postenable(struct iio_dev *indio_dev)
 247 {
 248         struct tcs3414_data *data = iio_priv(indio_dev);
 249
 250         data->control |= TCS3414_CONTROL_ADC_EN;
 251         return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 252                 data->control);
 253 }
 254
 255 static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
 256 {
 257         struct tcs3414_data *data = iio_priv(indio_dev);
 258
 259         data->control &= ~TCS3414_CONTROL_ADC_EN;
 260         return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 261                 data->control);
 262 }
 263
 264 static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
 265         .postenable = tcs3414_buffer_postenable,
 266         .predisable = tcs3414_buffer_predisable,
 267 };
 268
 269 static int tcs3414_powerdown(struct tcs3414_data *data)
 270 {
 271         return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 272                 data->control & ~(TCS3414_CONTROL_POWER |
 273                 TCS3414_CONTROL_ADC_EN));
 274 }
 275
 276 static void tcs3414_powerdown_cleanup(void *data)
 277 {
 278         tcs3414_powerdown(data);
 279 }
 280
 281 static int tcs3414_probe(struct i2c_client *client)
 282 {
 283         struct tcs3414_data *data;
 284         struct iio_dev *indio_dev;
 285         int ret;
 286
 287         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 288         if (indio_dev == NULL)
 289                 return -ENOMEM;
 290
 291         data = iio_priv(indio_dev);
 292         i2c_set_clientdata(client, indio_dev);
 293         data->client = client;
 294
 295         indio_dev->info = &tcs3414_info;
 296         indio_dev->name = TCS3414_DRV_NAME;
 297         indio_dev->channels = tcs3414_channels;
 298         indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
 299         indio_dev->modes = INDIO_DIRECT_MODE;
 300
 301         ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
 302         if (ret < 0)
 303                 return ret;
 304
 305         switch (ret & 0xf0) {
 306         case 0x00:
 307                 dev_info(&client->dev, "TCS3404 found\n");
 308                 break;
 309         case 0x10:
 310                 dev_info(&client->dev, "TCS3413/14/15/16 found\n");
 311                 break;
 312         default:
 313                 return -ENODEV;
 314         }
 315
 316         data->control = TCS3414_CONTROL_POWER;
 317         ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 318                 data->control);
 319         if (ret < 0)
 320                 return ret;
 321
 322         ret = devm_add_action_or_reset(&client->dev, tcs3414_powerdown_cleanup,
 323                                        data);
 324         if (ret < 0)
 325                 return ret;
 326
 327         data->timing = TCS3414_INTEG_12MS; /* free running */
 328         ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
 329                 data->timing);
 330         if (ret < 0)
 331                 return ret;
 332
 333         ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
 334         if (ret < 0)
 335                 return ret;
 336         data->gain = ret;
 337
 338         ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
 339                 tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
 340         if (ret < 0)
 341                 return ret;
 342
 343         return devm_iio_device_register(&client->dev, indio_dev);
 344 }
 345
 346 static int tcs3414_suspend(struct device *dev)
 347 {
 348         struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
 349                 to_i2c_client(dev)));
 350         return tcs3414_powerdown(data);
 351 }
 352
 353 static int tcs3414_resume(struct device *dev)
 354 {
 355         struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
 356                 to_i2c_client(dev)));
 357         return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 358                 data->control);
 359 }
 360
 361 static DEFINE_SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend,
 362                                 tcs3414_resume);
 363
 364 static const struct i2c_device_id tcs3414_id[] = {
 365         { "tcs3414" },
 366         { }
 367 };
 368 MODULE_DEVICE_TABLE(i2c, tcs3414_id);
 369
 370 static struct i2c_driver tcs3414_driver = {
 371         .driver = {
 372                 .name   = TCS3414_DRV_NAME,
 373                 .pm     = pm_sleep_ptr(&tcs3414_pm_ops),
 374         },
 375         .probe          = tcs3414_probe,
 376         .id_table       = tcs3414_id,
 377 };
 378 module_i2c_driver(tcs3414_driver);
 379
 380 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 381 MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
 382 MODULE_LICENSE("GPL");