iio: core: Introduce IIO_CHAN_INFO_CALIBEMISSIVITY

Contact-less IR temperature sensors measure the temperature of an object
by using its thermal radiation.  Surfaces with different emissivity
ratios emit different amounts of energy at the same temperature.

IIO_CHAN_INFO_CALIBEMISSIVITY allows the user to inform the sensor of the
emissivity of the object in front of it, in order to effectively measure
its temperature.

A device providing such setting is Melexis's MLX90614:
http://melexis.com/Assets/IR-sensor-thermometer-MLX90614-Datasheet-5152.aspx.

Signed-off-by: Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>
Cc: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Vianney le Clément de Saint-Marcq 2015-03-30 10:34:58 +02:00 committed by Jonathan Cameron
parent a25691c1f9
commit c8a8585431
3 changed files with 13 additions and 0 deletions

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@ -1364,3 +1364,14 @@ Description:
hwfifo_watermak_min but not equal to any of the values in this
list, the driver will chose an appropriate value for the
hardware fifo watermark level.
What: /sys/bus/iio/devices/iio:deviceX/in_temp_calibemissivity
What: /sys/bus/iio/devices/iio:deviceX/in_tempX_calibemissivity
What: /sys/bus/iio/devices/iio:deviceX/in_temp_object_calibemissivity
What: /sys/bus/iio/devices/iio:deviceX/in_tempX_object_calibemissivity
KernelVersion: 4.1
Contact: linux-iio@vger.kernel.org
Description:
The emissivity ratio of the surface in the field of view of the
contactless temperature sensor. Emissivity varies from 0 to 1,
with 1 being the emissivity of a black body.

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@ -128,6 +128,7 @@ static const char * const iio_chan_info_postfix[] = {
[IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
[IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
[IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
[IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
};
/**

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@ -43,6 +43,7 @@ enum iio_chan_info_enum {
IIO_CHAN_INFO_CALIBWEIGHT,
IIO_CHAN_INFO_DEBOUNCE_COUNT,
IIO_CHAN_INFO_DEBOUNCE_TIME,
IIO_CHAN_INFO_CALIBEMISSIVITY,
};
enum iio_shared_by {