Re: [PATCH v2] light sensor: Add a calibscale file to the isl29018 light sensor driver.

[Rhyland Klein <rklein@nvidia.com>]

On Tue, 2011-06-28 at 16:46 -0700, Bryan Freed wrote:
> Defaulting to 1, this gives a way to amplify the lux value before being
> reduced by the programmed adc_bit shift.
> Only support whole numbers right now.  When this driver is converted to the new
> IIO_CHAN framework, it will be easy to support the framework's pseudo float.
> 
> Add illuminance0_calibscale documentation to sysfs-bus-iio-light.
> 
> Signed-off-by: Bryan Freed <bfreed@chromium.org>
> ---
>  .../staging/iio/Documentation/sysfs-bus-iio-light  |    8 ++++
>  drivers/staging/iio/light/isl29018.c               |   35 +++++++++++++++++++-
>  2 files changed, 42 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-light b/drivers/staging/iio/Documentation/sysfs-bus-iio-light
> index 21d2774..edbf470 100644
> --- a/drivers/staging/iio/Documentation/sysfs-bus-iio-light
> +++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-light
> @@ -75,3 +75,11 @@ KernelVersion:	2.6.37
>  Contact:	linux-iio@vger.kernel.org
>  Description:
>  		This property gets/sets the sensors ADC analog integration time.
> +
> +What:		/sys/bus/iio/devices/device[n]/illuminance0_calibscale
> +KernelVersion:	2.6.37
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		Hardware or software applied calibration scale factor assumed
> +		to account for attenuation due to industrial design (glass
> +		filters or aperture holes).
> diff --git a/drivers/staging/iio/light/isl29018.c b/drivers/staging/iio/light/isl29018.c
> index 4794ffd..cd88311 100644
> --- a/drivers/staging/iio/light/isl29018.c
> +++ b/drivers/staging/iio/light/isl29018.c
> @@ -57,6 +57,7 @@ struct isl29018_chip {
>  	struct iio_dev		*indio_dev;
>  	struct i2c_client	*client;
>  	struct mutex		lock;
> +	unsigned int		lux_scale;
>  	unsigned int		range;
>  	unsigned int		adc_bit;
>  	int			prox_scheme;
> @@ -166,7 +167,7 @@ static int isl29018_read_lux(struct i2c_client *client, int *lux)
>  	if (lux_data < 0)
>  		return lux_data;
>  
> -	*lux = (lux_data * chip->range) >> chip->adc_bit;
> +	*lux = (lux_data * chip->range * chip->lux_scale) >> chip->adc_bit;
>  
>  	return 0;
>  }
> @@ -264,6 +265,34 @@ static ssize_t get_sensor_data(struct device *dev, char *buf, int mode)
>  }
>  
>  /* Sysfs interface */
> +/* lux_scale */
> +static ssize_t show_lux_scale(struct device *dev,
> +			struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +
> +	return sprintf(buf, "%d\n", chip->lux_scale);
> +}
> +
> +static ssize_t store_lux_scale(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct isl29018_chip *chip = indio_dev->dev_data;
> +	unsigned long lval;
> +
> +	lval = simple_strtoul(buf, NULL, 10);
> +	if (lval == 0)
> +		return -EINVAL;
> +
> +	mutex_lock(&chip->lock);
> +	chip->lux_scale = lval;
> +	mutex_unlock(&chip->lock);
> +
> +	return count;
> +}
> +
>  /* range */
>  static ssize_t show_range(struct device *dev,
>  			struct device_attribute *attr, char *buf)
> @@ -412,6 +441,8 @@ static IIO_DEVICE_ATTR(proximity_on_chip_ambient_infrared_supression,
>  					show_prox_infrared_supression,
>  					store_prox_infrared_supression, 0);
>  static IIO_DEVICE_ATTR(illuminance0_input, S_IRUGO, show_lux, NULL, 0);
> +static IIO_DEVICE_ATTR(illuminance0_calibscale, S_IRUGO | S_IWUSR,
> +					show_lux_scale, store_lux_scale, 0);
>  static IIO_DEVICE_ATTR(intensity_infrared_raw, S_IRUGO, show_ir, NULL, 0);
>  static IIO_DEVICE_ATTR(proximity_raw, S_IRUGO, show_proxim_ir, NULL, 0);
>  
> @@ -424,6 +455,7 @@ static struct attribute *isl29018_attributes[] = {
>  	ISL29018_CONST_ATTR(adc_resolution_available),
>  	ISL29018_DEV_ATTR(proximity_on_chip_ambient_infrared_supression),
>  	ISL29018_DEV_ATTR(illuminance0_input),
> +	ISL29018_DEV_ATTR(illuminance0_calibscale),
>  	ISL29018_DEV_ATTR(intensity_infrared_raw),
>  	ISL29018_DEV_ATTR(proximity_raw),
>  	NULL
> @@ -478,6 +510,7 @@ static int __devinit isl29018_probe(struct i2c_client *client,
>  
>  	mutex_init(&chip->lock);
>  
> +	chip->lux_scale = 1;
>  	chip->range = 1000;
>  	chip->adc_bit = 16;
>  

Seems fine with me.

Acked-by: Rhyland Klein <rklein@nvidia.com>