linux/drivers/iio/light/tcs3414.c
<<
>>
Prefs
   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
  51struct 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 */
  81static const int tcs3414_scales[][2] = {
  82        {1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
  83};
  84
  85/* integration time in ms */
  86static const int tcs3414_times[] = { 12, 100, 400 };
  87
  88static 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
  96static 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
 128static 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
 164static 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
 202static 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        for_each_set_bit(i, indio_dev->active_scan_mask,
 210                indio_dev->masklength) {
 211                int ret = i2c_smbus_read_word_data(data->client,
 212                        TCS3414_DATA_GREEN + 2*i);
 213                if (ret < 0)
 214                        goto done;
 215
 216                data->scan.chans[j++] = ret;
 217        }
 218
 219        iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 220                iio_get_time_ns(indio_dev));
 221
 222done:
 223        iio_trigger_notify_done(indio_dev->trig);
 224
 225        return IRQ_HANDLED;
 226}
 227
 228static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
 229static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
 230
 231static struct attribute *tcs3414_attributes[] = {
 232        &iio_const_attr_scale_available.dev_attr.attr,
 233        &iio_const_attr_integration_time_available.dev_attr.attr,
 234        NULL
 235};
 236
 237static const struct attribute_group tcs3414_attribute_group = {
 238        .attrs = tcs3414_attributes,
 239};
 240
 241static const struct iio_info tcs3414_info = {
 242        .read_raw = tcs3414_read_raw,
 243        .write_raw = tcs3414_write_raw,
 244        .attrs = &tcs3414_attribute_group,
 245};
 246
 247static int tcs3414_buffer_postenable(struct iio_dev *indio_dev)
 248{
 249        struct tcs3414_data *data = iio_priv(indio_dev);
 250
 251        data->control |= TCS3414_CONTROL_ADC_EN;
 252        return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 253                data->control);
 254}
 255
 256static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
 257{
 258        struct tcs3414_data *data = iio_priv(indio_dev);
 259
 260        data->control &= ~TCS3414_CONTROL_ADC_EN;
 261        return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 262                data->control);
 263}
 264
 265static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
 266        .postenable = tcs3414_buffer_postenable,
 267        .predisable = tcs3414_buffer_predisable,
 268};
 269
 270static int tcs3414_powerdown(struct tcs3414_data *data)
 271{
 272        return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 273                data->control & ~(TCS3414_CONTROL_POWER |
 274                TCS3414_CONTROL_ADC_EN));
 275}
 276
 277static void tcs3414_powerdown_cleanup(void *data)
 278{
 279        tcs3414_powerdown(data);
 280}
 281
 282static int tcs3414_probe(struct i2c_client *client,
 283                           const struct i2c_device_id *id)
 284{
 285        struct tcs3414_data *data;
 286        struct iio_dev *indio_dev;
 287        int ret;
 288
 289        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 290        if (indio_dev == NULL)
 291                return -ENOMEM;
 292
 293        data = iio_priv(indio_dev);
 294        i2c_set_clientdata(client, indio_dev);
 295        data->client = client;
 296
 297        indio_dev->info = &tcs3414_info;
 298        indio_dev->name = TCS3414_DRV_NAME;
 299        indio_dev->channels = tcs3414_channels;
 300        indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
 301        indio_dev->modes = INDIO_DIRECT_MODE;
 302
 303        ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
 304        if (ret < 0)
 305                return ret;
 306
 307        switch (ret & 0xf0) {
 308        case 0x00:
 309                dev_info(&client->dev, "TCS3404 found\n");
 310                break;
 311        case 0x10:
 312                dev_info(&client->dev, "TCS3413/14/15/16 found\n");
 313                break;
 314        default:
 315                return -ENODEV;
 316        }
 317
 318        data->control = TCS3414_CONTROL_POWER;
 319        ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 320                data->control);
 321        if (ret < 0)
 322                return ret;
 323
 324        ret = devm_add_action_or_reset(&client->dev, tcs3414_powerdown_cleanup,
 325                                       data);
 326        if (ret < 0)
 327                return ret;
 328
 329        data->timing = TCS3414_INTEG_12MS; /* free running */
 330        ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
 331                data->timing);
 332        if (ret < 0)
 333                return ret;
 334
 335        ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
 336        if (ret < 0)
 337                return ret;
 338        data->gain = ret;
 339
 340        ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
 341                tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
 342        if (ret < 0)
 343                return ret;
 344
 345        return devm_iio_device_register(&client->dev, indio_dev);
 346}
 347
 348#ifdef CONFIG_PM_SLEEP
 349static int tcs3414_suspend(struct device *dev)
 350{
 351        struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
 352                to_i2c_client(dev)));
 353        return tcs3414_powerdown(data);
 354}
 355
 356static int tcs3414_resume(struct device *dev)
 357{
 358        struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
 359                to_i2c_client(dev)));
 360        return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
 361                data->control);
 362}
 363#endif
 364
 365static SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend, tcs3414_resume);
 366
 367static const struct i2c_device_id tcs3414_id[] = {
 368        { "tcs3414", 0 },
 369        { }
 370};
 371MODULE_DEVICE_TABLE(i2c, tcs3414_id);
 372
 373static struct i2c_driver tcs3414_driver = {
 374        .driver = {
 375                .name   = TCS3414_DRV_NAME,
 376                .pm     = &tcs3414_pm_ops,
 377        },
 378        .probe          = tcs3414_probe,
 379        .id_table       = tcs3414_id,
 380};
 381module_i2c_driver(tcs3414_driver);
 382
 383MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
 384MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
 385MODULE_LICENSE("GPL");
 386