Re: [PATCH v3 1/2] dt-bindings: iio: temperature: add support for MCP998X

From: Victor.Duicu
Date: Mon Jun 23 2025 - 09:08:13 EST


On Fri, 2025-06-13 at 15:40 +0100, Conor Dooley wrote:
> On Fri, Jun 13, 2025 at 04:02:06PM +0300,
> victor.duicu@xxxxxxxxxxxxx wrote:
> > From: Victor Duicu <victor.duicu@xxxxxxxxxxxxx>
> >

Hi Conor,

> > This is the devicetree schema for Microchip MCP998X/33 and
> > MCP998XD/33D Automotive Temperature Monitor Family.
> >
> > Signed-off-by: Victor Duicu <victor.duicu@xxxxxxxxxxxxx>
> > ---
> >  .../iio/temperature/microchip,mcp9982.yaml    | 211
> > ++++++++++++++++++
> >  1 file changed, 211 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/iio/temperature/microchip,mcp9982
> > .yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/iio/temperature/microchip,mcp99
> > 82.yaml
> > b/Documentation/devicetree/bindings/iio/temperature/microchip,mcp99
> > 82.yaml
> > new file mode 100644
> > index 000000000000..ec939d463612
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/iio/temperature/microchip,mcp99
> > 82.yaml
> > @@ -0,0 +1,211 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> >
> > +
> > +  microchip,resistance-comp-ch1-2-enable:
> > +    description:
> > +      Enable resistance error correction(REC) for external
> > channels 1 and 2.
> > +      The chip internal hardware counterbalances the parasitic
> > resistance in
> > +      series with the external diodes. The compensation can be
> > activated or
> > +      disabled in hardware for both channels 1 and 2 at the same
> > time.
> > +    type: boolean
>
> On the previous version I objected to this wording for the property,
> where it is being used as an enable, and instead said that it should
> indicate the presence of the parasitic resistance. Did I miss some
> sort
> of new justification for it still talking about being an enable?
>

My apologies, I forgot to modify the name of the variable.
I will change the variables to something like:

microchip,parasitic-res-on-channel1-2:
description:
Indicates that the chip and the diodes/transistors are sufficiently far
apart that a parasitic resistance is added to the wires, which can
affect the measurements. Due to the anti-parallel diode connections,
channels 1 and 2 are affected together.

>
> > +  microchip,resistance-comp-ch3-4-enable:
> > +    description:
> > +      Enable resistance error correction(REC) for external
> > channels 3 and 4.
> > +      The chip internal hardware counterbalances the parasitic
> > resistance in
> > +      series with the external diodes. The compensation can be
> > activated or
> > +      disabled in hardware for both channels 3 and 4 at the same
> > time.
> > +    type: boolean
>
With Kind Regards,
Victor Duicu

> Cheers,
> Conor.