Re: [PATCH v3] iio: temperature: mlx90632: Interface to change object ambient temperature

[Jonathan Cameron <jic23@kernel.org>]

On Sun,  6 Sep 2020 23:02:31 +0200
Crt Mori <cmo@melexis.com> wrote:

> Since object temperature might be different than the sensor temperature
> the infrared sensors should provide an interface to inject ambient
> temperature. This was in past done via write to ambient temperature
> interface (in_temp_ambient_raw), but I think most people did not know
> about it. This solution introduces a new iio type of the CALIBAMBIENT
> which is hopefully more descriptive and more explicit about the purpose
> and capabilities of the sensors.
> 
> Signed-off-by: Crt Mori <cmo@melexis.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Applied to the togreg branch of iio.git and pushed out as testing for
all the normal reasons involving autobuilders etc.

Thanks,

Jonathan

> ---
>  Documentation/ABI/testing/sysfs-bus-iio | 8 ++++++++
>  drivers/iio/industrialio-core.c         | 1 +
>  drivers/iio/temperature/mlx90632.c      | 9 +++++++--
>  include/linux/iio/types.h               | 1 +
>  4 files changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
> index 5c62bfb0f3f5..084436a315e2 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio
> +++ b/Documentation/ABI/testing/sysfs-bus-iio
> @@ -1740,3 +1740,11 @@ KernelVersion:	5.5
>  Contact:	linux-iio@vger.kernel.org
>  Description:
>  		One of the following thermocouple types: B, E, J, K, N, R, S, T.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_temp_object_calibambient
> +What:		/sys/bus/iio/devices/iio:deviceX/in_tempX_object_calibambient
> +KernelVersion:	5.9
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		Calibrated ambient temperature for object temperature
> +		calculation in milli degrees Celsius.
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 606d5e61c575..941011502f4d 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -165,6 +165,7 @@ static const char * const iio_chan_info_postfix[] = {
>  	[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
>  	[IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
>  	[IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
> +	[IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient",
>  };
>  
>  #if defined(CONFIG_DEBUG_FS)
> diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
> index 94bca2b2866a..048cafa04455 100644
> --- a/drivers/iio/temperature/mlx90632.c
> +++ b/drivers/iio/temperature/mlx90632.c
> @@ -761,7 +761,9 @@ static int mlx90632_read_raw(struct iio_dev *indio_dev,
>  			*val2 = data->emissivity * 1000;
>  		}
>  		return IIO_VAL_INT_PLUS_MICRO;
> -
> +	case IIO_CHAN_INFO_CALIBAMBIENT:
> +		*val = data->object_ambient_temperature;
> +		return IIO_VAL_INT;
>  	default:
>  		return -EINVAL;
>  	}
> @@ -781,6 +783,9 @@ static int mlx90632_write_raw(struct iio_dev *indio_dev,
>  			return -EINVAL;
>  		data->emissivity = val * 1000 + val2 / 1000;
>  		return 0;
> +	case IIO_CHAN_INFO_CALIBAMBIENT:
> +		data->object_ambient_temperature = val;
> +		return 0;
>  	default:
>  		return -EINVAL;
>  	}
> @@ -798,7 +803,7 @@ static const struct iio_chan_spec mlx90632_channels[] = {
>  		.modified = 1,
>  		.channel2 = IIO_MOD_TEMP_OBJECT,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> -			BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
> +			BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) | BIT(IIO_CHAN_INFO_CALIBAMBIENT),
>  	},
>  };
>  
> diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
> index e6fd3645963c..1e3ed6f55bca 100644
> --- a/include/linux/iio/types.h
> +++ b/include/linux/iio/types.h
> @@ -59,6 +59,7 @@ enum iio_chan_info_enum {
>  	IIO_CHAN_INFO_CALIBEMISSIVITY,
>  	IIO_CHAN_INFO_OVERSAMPLING_RATIO,
>  	IIO_CHAN_INFO_THERMOCOUPLE_TYPE,
> +	IIO_CHAN_INFO_CALIBAMBIENT,
>  };
>  
>  #endif /* _IIO_TYPES_H_ */