Re: [PATCH v2] iio: Add tcs3472 color light sensor driver

[Jonathan Cameron <jic23@kernel.org>]

On 09/14/13 20:38, Peter Meerwald wrote:
> chip has four 16-bit channels for red, green, blue, clear color
> intensity; driver supports the TCS3x7x family of devices and was
> tested with a TCS34725 chip; further information here:
> http://www.ams.com/eng/Products/Light-Sensors/Color-Sensor/TCS34725
> 
> v2 (thanks to Jonathan Cameron):
> * drop dynamic buffer allocation, buffer is in tcs3472_data
> * limit sysfs output to PAGE_SIZE
> * check val2 == 0 when writing CALIBSCALE
> 
> Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
> Cc: Jon Brenner <jon.brenner@ams.com>
Applied to the togreg branch of iio.git

Thanks

Jonathan
> ---
>  drivers/iio/light/Kconfig   |  10 ++
>  drivers/iio/light/Makefile  |   1 +
>  drivers/iio/light/tcs3472.c | 369 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 380 insertions(+)
>  create mode 100644 drivers/iio/light/tcs3472.c
> 
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 488fff7..e73a1ab 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -55,6 +55,16 @@ config SENSORS_LM3533
>  	  changes. The ALS-control output values can be set per zone for the
>  	  three current output channels.
>  
> +config TCS3472
> +	tristate "TAOS TCS3472 color light-to-digital converter"
> +	depends on I2C
> +	help
> +	 If you say yes here you get support for the TAOS TCS3472
> +	 family of color light-to-digital converters with IR filter.
> +
> +	 This driver can also be built as a module.  If so, the module
> +	 will be called tcs3472.
> +
>  config SENSORS_TSL2563
>  	tristate "TAOS TSL2560, TSL2561, TSL2562 and TSL2563 ambient light sensors"
>  	depends on I2C
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index cd6f3cf..fb31140 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -8,5 +8,6 @@ obj-$(CONFIG_APDS9300)		+= apds9300.o
>  obj-$(CONFIG_HID_SENSOR_ALS)	+= hid-sensor-als.o
>  obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
>  obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o
> +obj-$(CONFIG_TCS3472)		+= tcs3472.o
>  obj-$(CONFIG_TSL4531)		+= tsl4531.o
>  obj-$(CONFIG_VCNL4000)		+= vcnl4000.o
> diff --git a/drivers/iio/light/tcs3472.c b/drivers/iio/light/tcs3472.c
> new file mode 100644
> index 0000000..95510bd
> --- /dev/null
> +++ b/drivers/iio/light/tcs3472.c
> @@ -0,0 +1,369 @@
> +/*
> + * 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;
> +	u8 enable;
> +	u8 control;
> +	u8 atime;
> +	u16 buffer[4];
> +};
> +
> +/* 4 16-bit channels + timestamp = 16 bytes */
> +#define TSL3472_BUFFER_SIZE 16
> +
> +#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 = IIO_ST('u', 16, 16, 0), \
> +}
> +
> +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:
> +		ret = tcs3472_req_data(data);
> +		if (ret < 0)
> +			return ret;
> +		ret = i2c_smbus_read_word_data(data->client, chan->address);
> +		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 len = 0;
> +	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;
> +		len += 2;
> +	}
> +
> +	if (indio_dev->scan_timestamp)
> +		*(s64 *)((u8 *)data->buffer + ALIGN(len, sizeof(s64)))
> +			= iio_get_time_ns();
> +	iio_push_to_buffers(indio_dev, (u8 *)data->buffer);
> +
> +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;
> +
> +	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)
> +{
> +	return tcs3472_powerdown(iio_priv(dev_to_iio_dev(dev)));
> +}
> +
> +static int tcs3472_resume(struct device *dev)
> +{
> +	struct tcs3472_data *data = iio_priv(dev_to_iio_dev(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");
>