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: Roan van Dijk <roan@protonic.nl>
Link: https://lore.kernel.org/r/20211008101706.755942-5-roan@protonic.nl
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index f19ff76a3b5498efadd21c4830ae972a06818902..c551301b33f1790a19bcda87594e6dc35915bfb3 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -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]"

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-scd30 b/Documentation/ABI/testing/sysfs-bus-iio-scd30
deleted file mode 100644 (file)
index b9712f3..0000000
--- a/Documentation/ABI/testing/sysfs-bus-iio-scd30
+++ /dev/null
@@ -1,34 +0,0 @@
-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.