Re: [PATCH v3] iio: light: Add support for Capella CM3323 color sensor

[Jonathan Cameron <jic23@kernel.org>]

On 14/03/15 19:11, Daniel Baluta wrote:
> Minimal implementation providing raw light intensity
> and integration time attribute.
> 
> Userspace applications can use GREEN channel for raw
> illuminance readings following this table:
> 
> Integration Time | G Sensitivity
> ================================
> 40 ms            | 0.18
> 80 ms            | 0.09
> 160 ms           | 0.045
> 320 ms           | 0.0225
> 640 ms           | 0.01125
> 1280 ms          | 0.005625
> 
> Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Applied to the togreg branch of iio.git - initially pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan
> ---
> Changes since v2:
>  * use iio_device_register instead of devm_* variant, in order
>    to better control call order at remove
>  * introduce cm3323_disable and call it in error path for cm3323_probe
> 
> Changes since v1:
>  * fixed nits after Peter's review - https://lkml.org/lkml/2015/1/22/196
>  * removed IIO_LIGHT channel since illuminance can be computed
>    in userspace based on GREEN channel
> 
>  drivers/iio/light/Kconfig  |   10 ++
>  drivers/iio/light/Makefile |    1 +
>  drivers/iio/light/cm3323.c |  286 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 297 insertions(+)
>  create mode 100644 drivers/iio/light/cm3323.c
> 
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index ae68c64..cd937d9 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -59,6 +59,16 @@ config CM3232
>  	 To compile this driver as a module, choose M here:
>  	 the module will be called cm3232.
>  
> +config CM3323
> +	depends on I2C
> +	tristate "Capella CM3323 color light sensor"
> +	help
> +	 Say Y here if you want to build a driver for Capela CM3323
> +	 color sensor.
> +
> +	 To compile this driver as a module, choose M here: the module will
> +	 be called cm3323.
> +
>  config CM36651
>  	depends on I2C
>  	tristate "CM36651 driver"
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index b12a516..ad7c30f 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_AL3320A)		+= al3320a.o
>  obj-$(CONFIG_APDS9300)		+= apds9300.o
>  obj-$(CONFIG_CM32181)		+= cm32181.o
>  obj-$(CONFIG_CM3232)		+= cm3232.o
> +obj-$(CONFIG_CM3323)		+= cm3323.o
>  obj-$(CONFIG_CM36651)		+= cm36651.o
>  obj-$(CONFIG_GP2AP020A00F)	+= gp2ap020a00f.o
>  obj-$(CONFIG_HID_SENSOR_ALS)	+= hid-sensor-als.o
> diff --git a/drivers/iio/light/cm3323.c b/drivers/iio/light/cm3323.c
> new file mode 100644
> index 0000000..869033e
> --- /dev/null
> +++ b/drivers/iio/light/cm3323.c
> @@ -0,0 +1,286 @@
> +/*
> + * CM3323 - Capella Color Light Sensor
> + *
> + * Copyright (c) 2015, Intel Corporation.
> + *
> + * 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.
> + *
> + * IIO driver for CM3323 (7-bit I2C slave address 0x10)
> + *
> + * TODO: calibscale to correct the lens factor
> + */
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/mutex.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#define CM3323_DRV_NAME "cm3323"
> +
> +#define CM3323_CMD_CONF		0x00
> +#define CM3323_CMD_RED_DATA	0x08
> +#define CM3323_CMD_GREEN_DATA	0x09
> +#define CM3323_CMD_BLUE_DATA	0x0A
> +#define CM3323_CMD_CLEAR_DATA	0x0B
> +
> +#define CM3323_CONF_SD_BIT	BIT(0) /* sensor disable */
> +#define CM3323_CONF_AF_BIT	BIT(1) /* auto/manual force mode */
> +#define CM3323_CONF_IT_MASK	(BIT(4) | BIT(5) | BIT(6))
> +#define CM3323_CONF_IT_SHIFT	4
> +
> +#define CM3323_INT_TIME_AVAILABLE "0.04 0.08 0.16 0.32 0.64 1.28"
> +
> +static const struct {
> +	int val;
> +	int val2;
> +} cm3323_int_time[] = {
> +	{0, 40000},  /* 40 ms */
> +	{0, 80000},  /* 80 ms */
> +	{0, 160000}, /* 160 ms */
> +	{0, 320000}, /* 320 ms */
> +	{0, 640000}, /* 640 ms */
> +	{1, 280000}, /* 1280 ms */
> +};
> +
> +struct cm3323_data {
> +	struct i2c_client *client;
> +	u16 reg_conf;
> +	struct mutex mutex;
> +};
> +
> +#define CM3323_COLOR_CHANNEL(_color, _addr) { \
> +	.type = IIO_INTENSITY, \
> +	.modified = 1, \
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> +	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), \
> +	.channel2 = IIO_MOD_LIGHT_##_color, \
> +	.address = _addr, \
> +}
> +
> +static const struct iio_chan_spec cm3323_channels[] = {
> +	CM3323_COLOR_CHANNEL(RED, CM3323_CMD_RED_DATA),
> +	CM3323_COLOR_CHANNEL(GREEN, CM3323_CMD_GREEN_DATA),
> +	CM3323_COLOR_CHANNEL(BLUE, CM3323_CMD_BLUE_DATA),
> +	CM3323_COLOR_CHANNEL(CLEAR, CM3323_CMD_CLEAR_DATA),
> +};
> +
> +static IIO_CONST_ATTR_INT_TIME_AVAIL(CM3323_INT_TIME_AVAILABLE);
> +
> +static struct attribute *cm3323_attributes[] = {
> +	&iio_const_attr_integration_time_available.dev_attr.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group cm3323_attribute_group = {
> +	.attrs = cm3323_attributes,
> +};
> +
> +static int cm3323_init(struct iio_dev *indio_dev)
> +{
> +	int ret;
> +	struct cm3323_data *data = iio_priv(indio_dev);
> +
> +	ret = i2c_smbus_read_word_data(data->client, CM3323_CMD_CONF);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "Error reading reg_conf\n");
> +		return ret;
> +	}
> +
> +	/* enable sensor and set auto force mode */
> +	ret &= ~(CM3323_CONF_SD_BIT | CM3323_CONF_AF_BIT);
> +
> +	ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF, ret);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "Error writing reg_conf\n");
> +		return ret;
> +	}
> +
> +	data->reg_conf = ret;
> +
> +	return 0;
> +}
> +
> +static void cm3323_disable(struct iio_dev *indio_dev)
> +{
> +	int ret;
> +	struct cm3323_data *data = iio_priv(indio_dev);
> +
> +	ret = i2c_smbus_write_word_data(data->client, CM3323_CMD_CONF,
> +					CM3323_CONF_SD_BIT);
> +	if (ret < 0)
> +		dev_err(&data->client->dev, "Error writing reg_conf\n");
> +}
> +
> +static int cm3323_set_it_bits(struct cm3323_data *data, int val, int val2)
> +{
> +	int i, ret;
> +	u16 reg_conf;
> +
> +	for (i = 0; i < ARRAY_SIZE(cm3323_int_time); i++) {
> +		if (val == cm3323_int_time[i].val &&
> +		    val2 == cm3323_int_time[i].val2) {
> +			reg_conf = data->reg_conf;
> +			reg_conf |= i << CM3323_CONF_IT_SHIFT;
> +
> +			ret = i2c_smbus_write_word_data(data->client,
> +							CM3323_CMD_CONF,
> +							reg_conf);
> +			if (ret < 0)
> +				return ret;
> +
> +			data->reg_conf = reg_conf;
> +			return 0;
> +		}
> +	}
> +	return -EINVAL;
> +}
> +
> +static int cm3323_get_it_bits(struct cm3323_data *data)
> +{
> +	int bits;
> +
> +	bits = (data->reg_conf & CM3323_CONF_IT_MASK) >>
> +		CM3323_CONF_IT_SHIFT;
> +
> +	if (bits >= ARRAY_SIZE(cm3323_int_time))
> +		return -EINVAL;
> +	return bits;
> +}
> +
> +static int cm3323_read_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan, int *val,
> +			   int *val2, long mask)
> +{
> +	int i, ret;
> +	struct cm3323_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&data->mutex);
> +		ret = i2c_smbus_read_word_data(data->client, chan->address);
> +		if (ret < 0) {
> +			mutex_unlock(&data->mutex);
> +			return ret;
> +		}
> +		*val = ret;
> +		mutex_unlock(&data->mutex);
> +
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_INT_TIME:
> +		mutex_lock(&data->mutex);
> +		i = cm3323_get_it_bits(data);
> +		if (i < 0) {
> +			mutex_unlock(&data->mutex);
> +			return -EINVAL;
> +		}
> +
> +		*val = cm3323_int_time[i].val;
> +		*val2 = cm3323_int_time[i].val2;
> +		mutex_unlock(&data->mutex);
> +
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int cm3323_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan, int val,
> +			    int val2, long mask)
> +{
> +	struct cm3323_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_INT_TIME:
> +		mutex_lock(&data->mutex);
> +		ret = cm3323_set_it_bits(data, val, val2);
> +		mutex_unlock(&data->mutex);
> +
> +		return ret;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct iio_info cm3323_info = {
> +	.driver_module	= THIS_MODULE,
> +	.read_raw	= cm3323_read_raw,
> +	.write_raw	= cm3323_write_raw,
> +	.attrs		= &cm3323_attribute_group,
> +};
> +
> +static int cm3323_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct cm3323_data *data;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	i2c_set_clientdata(client, indio_dev);
> +	data->client = client;
> +
> +	mutex_init(&data->mutex);
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->info = &cm3323_info;
> +	indio_dev->name = CM3323_DRV_NAME;
> +	indio_dev->channels = cm3323_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(cm3323_channels);
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	ret = cm3323_init(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "cm3323 chip init failed\n");
> +		return ret;
> +	}
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "failed to register iio dev\n");
> +		goto err_init;
> +	}
> +	return 0;
> +err_init:
> +	cm3323_disable(indio_dev);
> +	return ret;
> +}
> +
> +static int cm3323_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +	cm3323_disable(indio_dev);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id cm3323_id[] = {
> +	{"cm3323", 0},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, cm3323_id);
> +
> +static struct i2c_driver cm3323_driver = {
> +	.driver = {
> +		.name = CM3323_DRV_NAME,
> +	},
> +	.probe		= cm3323_probe,
> +	.remove		= cm3323_remove,
> +	.id_table	= cm3323_id,
> +};
> +
> +module_i2c_driver(cm3323_driver);
> +
> +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
> +MODULE_DESCRIPTION("Capella CM3323 Color Light Sensor driver");
> +MODULE_LICENSE("GPL v2");
>