Commit d6fa1406 authored by Roan van Dijk's avatar Roan van Dijk Committed by Jonathan Cameron
Browse files

iio: documentation: Document scd4x calibration use 



Add entries from Documentation/ABI/testing/sysfs-bus-iio-scd30
to Documentation/ABI/testing/sysfs-bus-iio. The attributes of the scd4x
and scd30 are common.

Remove Documentation/ABI/testing/sysfs-bus-iio-scd30.

Signed-off-by: default avatarRoan van Dijk <roan@protonic.nl>
Link: https://lore.kernel.org/r/20211008101706.755942-5-roan@protonic.nl


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 49d22b69

Documentation/ABI/testing/sysfs-bus-iio

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Original line number Diff line number Diff line
@@ -1958,3 +1958,44 @@ Description: 
		Specify the percent for light sensor relative to the channel

		absolute value that a data field should change before an event

		is generated. Units are a percentage of the prior reading.



What:		/sys/bus/iio/devices/iio:deviceX/calibration_auto_enable

Date:		June 2020

KernelVersion:	5.8

Contact:	linux-iio@vger.kernel.org

Description:

		Some sensors have the ability to apply auto calibration at

		runtime. For example, it may be necessary to compensate for

		contaminant build-up in a measurement chamber or optical

		element deterioration that would otherwise lead to sensor drift.



		Writing 1 or 0 to this attribute will respectively activate or

		deactivate this auto calibration function.



		Upon reading, the current status is returned.



What:		/sys/bus/iio/devices/iio:deviceX/calibration_forced_value

Date:		June 2020

KernelVersion:	5.8

Contact:	linux-iio@vger.kernel.org

Description:

		Some sensors have the ability to apply a manual calibration using

		a known measurement value, perhaps obtained from an external

		reference device.



		Writing a value to this function will force such a calibration

		change. For the scd30 the value should be from the range

		[400 1 2000].



		Note for the scd30 that a valid value may only be obtained once

		it is has been written. Until then any read back of this value

		should be ignored. As for the scd4x an error will be returned

		immediately if the manual calibration has failed.



What:		/sys/bus/iio/devices/iio:deviceX/calibration_forced_value_available

KernelVersion:  5.15

Contact:        linux-iio@vger.kernel.org

Description:

		Available range for the forced calibration value, expressed as:



		- a range specified as "[min step max]"

Documentation/ABI/testing/sysfs-bus-iio-scd30

deleted100644 → 0
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Original line number Diff line number Diff line 
What:		/sys/bus/iio/devices/iio:deviceX/calibration_auto_enable

Date:		June 2020

KernelVersion:	5.8

Contact:	linux-iio@vger.kernel.org

Description:

		Contaminants build-up in the measurement chamber or optical

		elements deterioration leads to sensor drift.



		One can compensate for sensor drift by using automatic self

		calibration procedure (asc).



		Writing 1 or 0 to this attribute will respectively activate or

		deactivate asc.



		Upon reading current asc status is returned.



What:		/sys/bus/iio/devices/iio:deviceX/calibration_forced_value

Date:		June 2020

KernelVersion:	5.8

Contact:	linux-iio@vger.kernel.org

Description:

		Contaminants build-up in the measurement chamber or optical

		elements deterioration leads to sensor drift.



		One can compensate for sensor drift by using forced

		recalibration (frc). This is useful in case there's known

		co2 reference available nearby the sensor.



		Picking value from the range [400 1 2000] and writing it to the

		sensor will set frc.



		Upon reading current frc value is returned. Note that after

		power cycling default value (i.e 400) is returned even though

		internally sensor had recalibrated itself.