- 根目录:
- drivers
- iio
- light
- tcs3472.c
/*
* tcs3472.c - Support for TAOS TCS3472 color light-to-digital converter
*
* Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
*
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
*
* Color light sensor with 16-bit channels for red, green, blue, clear);
* 7-bit I2C slave address 0x39 (TCS34721, TCS34723) or 0x29 (TCS34725,
* TCS34727)
*
* TODO: interrupt support, thresholds, wait time
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#define TCS3472_DRV_NAME "tcs3472"
#define TCS3472_COMMAND BIT(7)
#define TCS3472_AUTO_INCR BIT(5)
#define TCS3472_ENABLE (TCS3472_COMMAND | 0x00)
#define TCS3472_ATIME (TCS3472_COMMAND | 0x01)
#define TCS3472_WTIME (TCS3472_COMMAND | 0x03)
#define TCS3472_AILT (TCS3472_COMMAND | 0x04)
#define TCS3472_AIHT (TCS3472_COMMAND | 0x06)
#define TCS3472_PERS (TCS3472_COMMAND | 0x0c)
#define TCS3472_CONFIG (TCS3472_COMMAND | 0x0d)
#define TCS3472_CONTROL (TCS3472_COMMAND | 0x0f)
#define TCS3472_ID (TCS3472_COMMAND | 0x12)
#define TCS3472_STATUS (TCS3472_COMMAND | 0x13)
#define TCS3472_CDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x14)
#define TCS3472_RDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x16)
#define TCS3472_GDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x18)
#define TCS3472_BDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x1a)
#define TCS3472_STATUS_AVALID BIT(0)
#define TCS3472_ENABLE_AEN BIT(1)
#define TCS3472_ENABLE_PON BIT(0)
#define TCS3472_CONTROL_AGAIN_MASK (BIT(0) | BIT(1))
struct tcs3472_data {
struct i2c_client *client;
struct mutex lock;
u8 enable;
u8 control;
u8 atime;
u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */
};
#define TCS3472_CHANNEL(_color, _si, _addr) { \
.type = IIO_INTENSITY, \
.modified = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBSCALE) | \
BIT(IIO_CHAN_INFO_INT_TIME), \
.channel2 = IIO_MOD_LIGHT_##_color, \
.address = _addr, \
.scan_index = _si, \
.scan_type = { \
.sign = 'u', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_CPU, \
}, \
}
static const int tcs3472_agains[] = { 1, 4, 16, 60 };
static const struct iio_chan_spec tcs3472_channels[] = {
TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA),
TCS3472_CHANNEL(RED, 1, TCS3472_RDATA),
TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA),
TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA),
IIO_CHAN_SOFT_TIMESTAMP(4),
};
static int tcs3472_req_data(struct tcs3472_data *data)
{
int tries = 50;
int ret;
while (tries--) {
ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
if (ret < 0)
return ret;
if (ret & TCS3472_STATUS_AVALID)
break;
msleep(20);
}
if (tries < 0) {
dev_err(&data->client->dev, "data not ready\n");
return -EIO;
}
return 0;
}
static int tcs3472_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct tcs3472_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
mutex_lock(&data->lock);
ret = tcs3472_req_data(data);
if (ret < 0) {
mutex_unlock(&data->lock);
return ret;
}
ret = i2c_smbus_read_word_data(data->client, chan->address);
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBSCALE:
*val = tcs3472_agains[data->control &
TCS3472_CONTROL_AGAIN_MASK];
return IIO_VAL_INT;
case IIO_CHAN_INFO_INT_TIME:
*val = 0;
*val2 = (256 - data->atime) * 2400;
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static int tcs3472_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct tcs3472_data *data = iio_priv(indio_dev);
int i;
switch (mask) {
case IIO_CHAN_INFO_CALIBSCALE:
if (val2 != 0)
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
if (val == tcs3472_agains[i]) {
data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
data->control |= i;
return i2c_smbus_write_byte_data(
data->client, TCS3472_CONTROL,
data->control);
}
}
return -EINVAL;
case IIO_CHAN_INFO_INT_TIME:
if (val != 0)
return -EINVAL;
for (i = 0; i < 256; i++) {
if (val2 == (256 - i) * 2400) {
data->atime = i;
return i2c_smbus_write_word_data(
data->client, TCS3472_ATIME,
data->atime);
}
}
return -EINVAL;
}
return -EINVAL;
}
static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct tcs3472_data *data = iio_priv(indio_dev);
int i, j = 0;
int ret = tcs3472_req_data(data);
if (ret < 0)
goto done;
for_each_set_bit(i, indio_dev->active_scan_mask,
indio_dev->masklength) {
ret = i2c_smbus_read_word_data(data->client,
TCS3472_CDATA + 2*i);
if (ret < 0)
goto done;
data->buffer[j++] = ret;
}
iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
iio_get_time_ns());
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static ssize_t tcs3472_show_int_time_available(struct device *dev,
struct device_attribute *attr,
char *buf)
{
size_t len = 0;
int i;
for (i = 1; i <= 256; i++)
len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
2400 * i);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
static struct attribute *tcs3472_attributes[] = {
&iio_const_attr_calibscale_available.dev_attr.attr,
&iio_dev_attr_integration_time_available.dev_attr.attr,
NULL
};
static const struct attribute_group tcs3472_attribute_group = {
.attrs = tcs3472_attributes,
};
static const struct iio_info tcs3472_info = {
.read_raw = tcs3472_read_raw,
.write_raw = tcs3472_write_raw,
.attrs = &tcs3472_attribute_group,
.driver_module = THIS_MODULE,
};
static int tcs3472_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct tcs3472_data *data;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (indio_dev == NULL)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
mutex_init(&data->lock);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &tcs3472_info;
indio_dev->name = TCS3472_DRV_NAME;
indio_dev->channels = tcs3472_channels;
indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
if (ret < 0)
return ret;
if (ret == 0x44)
dev_info(&client->dev, "TCS34721/34725 found\n");
else if (ret == 0x4d)
dev_info(&client->dev, "TCS34723/34727 found\n");
else
return -ENODEV;
ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
if (ret < 0)
return ret;
data->control = ret;
ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
if (ret < 0)
return ret;
data->atime = ret;
ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
if (ret < 0)
return ret;
/* enable device */
data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
data->enable);
if (ret < 0)
return ret;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
tcs3472_trigger_handler, NULL);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0)
goto buffer_cleanup;
return 0;
buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
return ret;
}
static int tcs3472_powerdown(struct tcs3472_data *data)
{
return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
}
static int tcs3472_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
tcs3472_powerdown(iio_priv(indio_dev));
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int tcs3472_suspend(struct device *dev)
{
struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return tcs3472_powerdown(data);
}
static int tcs3472_resume(struct device *dev)
{
struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));
}
#endif
static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
static const struct i2c_device_id tcs3472_id[] = {
{ "tcs3472", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tcs3472_id);
static struct i2c_driver tcs3472_driver = {
.driver = {
.name = TCS3472_DRV_NAME,
.pm = &tcs3472_pm_ops,
.owner = THIS_MODULE,
},
.probe = tcs3472_probe,
.remove = tcs3472_remove,
.id_table = tcs3472_id,
};
module_i2c_driver(tcs3472_driver);
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("TCS3472 color light sensors driver");
MODULE_LICENSE("GPL");