Re: [PATCH 4/6] Documentation: ABI: testing: scd30: document iio attributes

From: Peter Meerwald-Stadler
Date: Wed Apr 22 2020 - 12:40:20 EST


On Wed, 22 Apr 2020, Tomasz Duszynski wrote:

> Add documentation for sensor specific iio attributes.

minor comments below

> Signed-off-by: Tomasz Duszynski <tomasz.duszynski@xxxxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-bus-iio-scd30 | 97 +++++++++++++++++++
> 1 file changed, 97 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-scd30
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-scd30 b/Documentation/ABI/testing/sysfs-bus-iio-scd30
> new file mode 100644
> index 000000000000..0431a718447d
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-scd30
> @@ -0,0 +1,97 @@
> +What: /sys/bus/iio/devices/iio:deviceX/pressure_comp
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + Given that sensor's CO2 measurement chamber has fixed volume
> + pressure changes will affect concentration readings. Writing
> + current ambient pressure here will allow senor to make necessary

sensor

> + adjustments. Upon reading previously set value is returned.
> + Units are millibars.

unit for pressure in IIO is kilopascal (e.g.
/sys/bus/iio/devices/iio:deviceX/in_pressure_raw)

> +
> +What: /sys/bus/iio/devices/iio:deviceX/pressure_comp_available
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + The range of available values in millibars represented as the
> + minimum value, the step and the maximum value, all enclosed in
> + square brackets.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/meas_interval
> +Date: January 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + Amount of time between subsequent measurements. Writing this
> + attribute will change measurement interval. Upon reading
> + current measurement interval is returned. Units are seconds.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/meas_interval_available
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + The range of available values in seconds represented as the
> + minimum value, the step and the maximum value, all enclosed in
> + square brackets.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/asc
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + Writing 1 or 0 to this attribute will respectively activate or
> + deactivate automatic self calibration procedure. Upon reading 1

deactivate automatic self calibration (asc) procedure

> + is returned if asc is ongoing, 0 otherwise.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/frc
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + Forced recalibration is used to compensate for sensor drifts
> + when a reference value of CO2 concentration in close proximity
> + to the sensor is available. Writing attribute will set frc
> + value. Upon reading current frc is returned. Units are
> + millibars.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/frc_available
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + The range of available values in millibars represented as the
> + minimum value, the step and the maximum value, all enclosed in
> + square brackets.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/temp_offset
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + Sensor readings may be affected by ambient temperature.
> + Writing temperature offset will compensate for unwanted changes.
> + Note that written offset gets multiplied by a factor of 100
> + by a sensor internally.
> +
> + For example, writing 10 here will correspond to 0.1 degree
> + Celsius.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/temp_offset_available
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + The range of available values in degrees Celsius represented as
> + the minimum value, the step and the maximum value, all enclosed
> + in square brackets.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/reset
> +Date: April 2020
> +KernelVersion: 5.8
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + Software reset mechanism forces sensor into the same state
> + as after powering up without the need for removing power supply.
> + Writing any value will reset sensor.
>

--

Peter Meerwald-Stadler
Mobile: +43 664 24 44 418