iio/light/tcs3414.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * tcs3414.c - Support for TAOS TCS3414 digital color sensor
0004  *
0005  * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
0006  *
0007  * Digital color sensor with 16-bit channels for red, green, blue, clear);
0008  * 7-bit I2C slave address 0x39 (TCS3414) or 0x29, 0x49, 0x59 (TCS3413,
0009  * TCS3415, TCS3416, resp.)
0010  *
0011  * TODO: sync, interrupt support, thresholds, prescaler
0012  */
0013
0014 #include <linux/module.h>
0015 #include <linux/i2c.h>
0016 #include <linux/delay.h>
0017 #include <linux/pm.h>
0018
0019 #include <linux/iio/iio.h>
0020 #include <linux/iio/sysfs.h>
0021 #include <linux/iio/trigger_consumer.h>
0022 #include <linux/iio/buffer.h>
0023 #include <linux/iio/triggered_buffer.h>
0024
0025 #define TCS3414_DRV_NAME "tcs3414"
0026
0027 #define TCS3414_COMMAND BIT(7)
0028 #define TCS3414_COMMAND_WORD (TCS3414_COMMAND | BIT(5))
0029
0030 #define TCS3414_CONTROL (TCS3414_COMMAND | 0x00)
0031 #define TCS3414_TIMING (TCS3414_COMMAND | 0x01)
0032 #define TCS3414_ID (TCS3414_COMMAND | 0x04)
0033 #define TCS3414_GAIN (TCS3414_COMMAND | 0x07)
0034 #define TCS3414_DATA_GREEN (TCS3414_COMMAND_WORD | 0x10)
0035 #define TCS3414_DATA_RED (TCS3414_COMMAND_WORD | 0x12)
0036 #define TCS3414_DATA_BLUE (TCS3414_COMMAND_WORD | 0x14)
0037 #define TCS3414_DATA_CLEAR (TCS3414_COMMAND_WORD | 0x16)
0038
0039 #define TCS3414_CONTROL_ADC_VALID BIT(4)
0040 #define TCS3414_CONTROL_ADC_EN BIT(1)
0041 #define TCS3414_CONTROL_POWER BIT(0)
0042
0043 #define TCS3414_INTEG_MASK GENMASK(1, 0)
0044 #define TCS3414_INTEG_12MS 0x0
0045 #define TCS3414_INTEG_100MS 0x1
0046 #define TCS3414_INTEG_400MS 0x2
0047
0048 #define TCS3414_GAIN_MASK GENMASK(5, 4)
0049 #define TCS3414_GAIN_SHIFT 4
0050
0051 struct tcs3414_data {
0052     struct i2c_client *client;
0053     u8 control;
0054     u8 gain;
0055     u8 timing;
0056     /* Ensure timestamp is naturally aligned */
0057     struct {
0058         u16 chans[4];
0059         s64 timestamp __aligned(8);
0060     } scan;
0061 };
0062
0063 #define TCS3414_CHANNEL(_color, _si, _addr) { \
0064     .type = IIO_INTENSITY, \
0065     .modified = 1, \
0066     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
0067     .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
0068         BIT(IIO_CHAN_INFO_INT_TIME), \
0069     .channel2 = IIO_MOD_LIGHT_##_color, \
0070     .address = _addr, \
0071     .scan_index = _si, \
0072     .scan_type = { \
0073         .sign = 'u', \
0074         .realbits = 16, \
0075         .storagebits = 16, \
0076         .endianness = IIO_CPU, \
0077     }, \
0078 }
0079
0080 /* scale factors: 1/gain */
0081 static const int tcs3414_scales[][2] = {
0082     {1, 0}, {0, 250000}, {0, 62500}, {0, 15625}
0083 };
0084
0085 /* integration time in ms */
0086 static const int tcs3414_times[] = { 12, 100, 400 };
0087
0088 static const struct iio_chan_spec tcs3414_channels[] = {
0089     TCS3414_CHANNEL(GREEN, 0, TCS3414_DATA_GREEN),
0090     TCS3414_CHANNEL(RED, 1, TCS3414_DATA_RED),
0091     TCS3414_CHANNEL(BLUE, 2, TCS3414_DATA_BLUE),
0092     TCS3414_CHANNEL(CLEAR, 3, TCS3414_DATA_CLEAR),
0093     IIO_CHAN_SOFT_TIMESTAMP(4),
0094 };
0095
0096 static int tcs3414_req_data(struct tcs3414_data *data)
0097 {
0098     int tries = 25;
0099     int ret;
0100
0101     ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
0102         data->control | TCS3414_CONTROL_ADC_EN);
0103     if (ret < 0)
0104         return ret;
0105
0106     while (tries--) {
0107         ret = i2c_smbus_read_byte_data(data->client, TCS3414_CONTROL);
0108         if (ret < 0)
0109             return ret;
0110         if (ret & TCS3414_CONTROL_ADC_VALID)
0111             break;
0112         msleep(20);
0113     }
0114
0115     ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
0116         data->control);
0117     if (ret < 0)
0118         return ret;
0119
0120     if (tries < 0) {
0121         dev_err(&data->client->dev, "data not ready\n");
0122         return -EIO;
0123     }
0124
0125     return 0;
0126 }
0127
0128 static int tcs3414_read_raw(struct iio_dev *indio_dev,
0129                struct iio_chan_spec const *chan,
0130                int *val, int *val2, long mask)
0131 {
0132     struct tcs3414_data *data = iio_priv(indio_dev);
0133     int i, ret;
0134
0135     switch (mask) {
0136     case IIO_CHAN_INFO_RAW:
0137         ret = iio_device_claim_direct_mode(indio_dev);
0138         if (ret)
0139             return ret;
0140         ret = tcs3414_req_data(data);
0141         if (ret < 0) {
0142             iio_device_release_direct_mode(indio_dev);
0143             return ret;
0144         }
0145         ret = i2c_smbus_read_word_data(data->client, chan->address);
0146         iio_device_release_direct_mode(indio_dev);
0147         if (ret < 0)
0148             return ret;
0149         *val = ret;
0150         return IIO_VAL_INT;
0151     case IIO_CHAN_INFO_SCALE:
0152         i = (data->gain & TCS3414_GAIN_MASK) >> TCS3414_GAIN_SHIFT;
0153         *val = tcs3414_scales[i][0];
0154         *val2 = tcs3414_scales[i][1];
0155         return IIO_VAL_INT_PLUS_MICRO;
0156     case IIO_CHAN_INFO_INT_TIME:
0157         *val = 0;
0158         *val2 = tcs3414_times[data->timing & TCS3414_INTEG_MASK] * 1000;
0159         return IIO_VAL_INT_PLUS_MICRO;
0160     }
0161     return -EINVAL;
0162 }
0163
0164 static int tcs3414_write_raw(struct iio_dev *indio_dev,
0165                    struct iio_chan_spec const *chan,
0166                    int val, int val2, long mask)
0167 {
0168     struct tcs3414_data *data = iio_priv(indio_dev);
0169     int i;
0170
0171     switch (mask) {
0172     case IIO_CHAN_INFO_SCALE:
0173         for (i = 0; i < ARRAY_SIZE(tcs3414_scales); i++) {
0174             if (val == tcs3414_scales[i][0] &&
0175                 val2 == tcs3414_scales[i][1]) {
0176                 data->gain &= ~TCS3414_GAIN_MASK;
0177                 data->gain |= i << TCS3414_GAIN_SHIFT;
0178                 return i2c_smbus_write_byte_data(
0179                     data->client, TCS3414_GAIN,
0180                     data->gain);
0181             }
0182         }
0183         return -EINVAL;
0184     case IIO_CHAN_INFO_INT_TIME:
0185         if (val != 0)
0186             return -EINVAL;
0187         for (i = 0; i < ARRAY_SIZE(tcs3414_times); i++) {
0188             if (val2 == tcs3414_times[i] * 1000) {
0189                 data->timing &= ~TCS3414_INTEG_MASK;
0190                 data->timing |= i;
0191                 return i2c_smbus_write_byte_data(
0192                     data->client, TCS3414_TIMING,
0193                     data->timing);
0194             }
0195         }
0196         return -EINVAL;
0197     default:
0198         return -EINVAL;
0199     }
0200 }
0201
0202 static irqreturn_t tcs3414_trigger_handler(int irq, void *p)
0203 {
0204     struct iio_poll_func *pf = p;
0205     struct iio_dev *indio_dev = pf->indio_dev;
0206     struct tcs3414_data *data = iio_priv(indio_dev);
0207     int i, j = 0;
0208
0209     for_each_set_bit(i, indio_dev->active_scan_mask,
0210         indio_dev->masklength) {
0211         int ret = i2c_smbus_read_word_data(data->client,
0212             TCS3414_DATA_GREEN + 2*i);
0213         if (ret < 0)
0214             goto done;
0215
0216         data->scan.chans[j++] = ret;
0217     }
0218
0219     iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
0220         iio_get_time_ns(indio_dev));
0221
0222 done:
0223     iio_trigger_notify_done(indio_dev->trig);
0224
0225     return IRQ_HANDLED;
0226 }
0227
0228 static IIO_CONST_ATTR(scale_available, "1 0.25 0.0625 0.015625");
0229 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.012 0.1 0.4");
0230
0231 static struct attribute *tcs3414_attributes[] = {
0232     &iio_const_attr_scale_available.dev_attr.attr,
0233     &iio_const_attr_integration_time_available.dev_attr.attr,
0234     NULL
0235 };
0236
0237 static const struct attribute_group tcs3414_attribute_group = {
0238     .attrs = tcs3414_attributes,
0239 };
0240
0241 static const struct iio_info tcs3414_info = {
0242     .read_raw = tcs3414_read_raw,
0243     .write_raw = tcs3414_write_raw,
0244     .attrs = &tcs3414_attribute_group,
0245 };
0246
0247 static int tcs3414_buffer_postenable(struct iio_dev *indio_dev)
0248 {
0249     struct tcs3414_data *data = iio_priv(indio_dev);
0250
0251     data->control |= TCS3414_CONTROL_ADC_EN;
0252     return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
0253         data->control);
0254 }
0255
0256 static int tcs3414_buffer_predisable(struct iio_dev *indio_dev)
0257 {
0258     struct tcs3414_data *data = iio_priv(indio_dev);
0259
0260     data->control &= ~TCS3414_CONTROL_ADC_EN;
0261     return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
0262         data->control);
0263 }
0264
0265 static const struct iio_buffer_setup_ops tcs3414_buffer_setup_ops = {
0266     .postenable = tcs3414_buffer_postenable,
0267     .predisable = tcs3414_buffer_predisable,
0268 };
0269
0270 static int tcs3414_powerdown(struct tcs3414_data *data)
0271 {
0272     return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
0273         data->control & ~(TCS3414_CONTROL_POWER |
0274         TCS3414_CONTROL_ADC_EN));
0275 }
0276
0277 static void tcs3414_powerdown_cleanup(void *data)
0278 {
0279     tcs3414_powerdown(data);
0280 }
0281
0282 static int tcs3414_probe(struct i2c_client *client,
0283                const struct i2c_device_id *id)
0284 {
0285     struct tcs3414_data *data;
0286     struct iio_dev *indio_dev;
0287     int ret;
0288
0289     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
0290     if (indio_dev == NULL)
0291         return -ENOMEM;
0292
0293     data = iio_priv(indio_dev);
0294     i2c_set_clientdata(client, indio_dev);
0295     data->client = client;
0296
0297     indio_dev->info = &tcs3414_info;
0298     indio_dev->name = TCS3414_DRV_NAME;
0299     indio_dev->channels = tcs3414_channels;
0300     indio_dev->num_channels = ARRAY_SIZE(tcs3414_channels);
0301     indio_dev->modes = INDIO_DIRECT_MODE;
0302
0303     ret = i2c_smbus_read_byte_data(data->client, TCS3414_ID);
0304     if (ret < 0)
0305         return ret;
0306
0307     switch (ret & 0xf0) {
0308     case 0x00:
0309         dev_info(&client->dev, "TCS3404 found\n");
0310         break;
0311     case 0x10:
0312         dev_info(&client->dev, "TCS3413/14/15/16 found\n");
0313         break;
0314     default:
0315         return -ENODEV;
0316     }
0317
0318     data->control = TCS3414_CONTROL_POWER;
0319     ret = i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
0320         data->control);
0321     if (ret < 0)
0322         return ret;
0323
0324     ret = devm_add_action_or_reset(&client->dev, tcs3414_powerdown_cleanup,
0325                        data);
0326     if (ret < 0)
0327         return ret;
0328
0329     data->timing = TCS3414_INTEG_12MS; /* free running */
0330     ret = i2c_smbus_write_byte_data(data->client, TCS3414_TIMING,
0331         data->timing);
0332     if (ret < 0)
0333         return ret;
0334
0335     ret = i2c_smbus_read_byte_data(data->client, TCS3414_GAIN);
0336     if (ret < 0)
0337         return ret;
0338     data->gain = ret;
0339
0340     ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
0341         tcs3414_trigger_handler, &tcs3414_buffer_setup_ops);
0342     if (ret < 0)
0343         return ret;
0344
0345     return devm_iio_device_register(&client->dev, indio_dev);
0346 }
0347
0348 static int tcs3414_suspend(struct device *dev)
0349 {
0350     struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
0351         to_i2c_client(dev)));
0352     return tcs3414_powerdown(data);
0353 }
0354
0355 static int tcs3414_resume(struct device *dev)
0356 {
0357     struct tcs3414_data *data = iio_priv(i2c_get_clientdata(
0358         to_i2c_client(dev)));
0359     return i2c_smbus_write_byte_data(data->client, TCS3414_CONTROL,
0360         data->control);
0361 }
0362
0363 static DEFINE_SIMPLE_DEV_PM_OPS(tcs3414_pm_ops, tcs3414_suspend,
0364                 tcs3414_resume);
0365
0366 static const struct i2c_device_id tcs3414_id[] = {
0367     { "tcs3414", 0 },
0368     { }
0369 };
0370 MODULE_DEVICE_TABLE(i2c, tcs3414_id);
0371
0372 static struct i2c_driver tcs3414_driver = {
0373     .driver = {
0374         .name   = TCS3414_DRV_NAME,
0375         .pm = pm_sleep_ptr(&tcs3414_pm_ops),
0376     },
0377     .probe      = tcs3414_probe,
0378     .id_table   = tcs3414_id,
0379 };
0380 module_i2c_driver(tcs3414_driver);
0381
0382 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
0383 MODULE_DESCRIPTION("TCS3414 digital color sensors driver");
0384 MODULE_LICENSE("GPL");