Re: [PATCH v3 1/2] dt-bindings: thermal: generic-adc: Add optional io-channel-cells property
From: Svyatoslav Ryhel
Date: Wed Mar 05 2025 - 05:05:50 EST
ср, 5 бер. 2025 р. о 12:00 Lukasz Luba <lukasz.luba@xxxxxxx> пише:
>
>
>
> On 3/3/25 12:21, Svyatoslav Ryhel wrote:
> > This implements a mechanism to derive temperature values from an existing ADC IIO
> > channel, effectively creating a temperature IIO channel. This approach avoids adding
> > a new sensor and its associated conversion table, while providing IIO-based temperature
> > data for devices that may not utilize hwmon.
> >
> > Signed-off-by: Svyatoslav Ryhel <clamor95@xxxxxxxxx>
> > ---
> > .../devicetree/bindings/thermal/generic-adc-thermal.yaml | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/thermal/generic-adc-thermal.yaml b/Documentation/devicetree/bindings/thermal/generic-adc-thermal.yaml
> > index 12e6418dc24d..4bc2cff0593c 100644
> > --- a/Documentation/devicetree/bindings/thermal/generic-adc-thermal.yaml
> > +++ b/Documentation/devicetree/bindings/thermal/generic-adc-thermal.yaml
> > @@ -30,6 +30,9 @@ properties:
> > io-channel-names:
> > const: sensor-channel
> >
> > + '#io-channel-cells':
> > + const: 1
> > +
> > temperature-lookup-table:
> > description: |
> > Lookup table to map the relation between ADC value and temperature.
> > @@ -60,6 +63,7 @@ examples:
> > #thermal-sensor-cells = <0>;
> > io-channels = <&ads1015 1>;
> > io-channel-names = "sensor-channel";
> > + #io-channel-cells = <1>;
> > temperature-lookup-table = <
> > (-40000) 2578
> > (-39000) 2577
>
> Do we really need this change in the DT?
> Won't the code in the thermal driver that registers a new iio device
> would just be enough?
>
> I agree with Rob that it looks odd.
Building tree will complain on missing cells property if you try to
bind it. It is not in required category anyway.