Re: [PATCH v3 1/7] dt-bindings: pincfg-node: Add input-voltage-microvolt property

[Conor Dooley]

On Thu, Mar 12, 2026 at 05:42:31PM +0000, Conor Dooley wrote:
> On Thu, Mar 12, 2026 at 07:30:34PM +0800, Yu-Chun Lin wrote:
> > From: Tzuyi Chang <tychang@xxxxxxxxxxx>
> > 
> > Add a generic pin configuration property "input-voltage-microvolt" to
> > support hardware designs where the input logic threshold is decoupled
> > from the power supply voltage.
> > 
> > This property allows the pinctrl driver to configure the correct internal
> > reference voltage for pins that need to accept input signals at a different
> > voltage level than their power supply. For example, a pin powered by 3.3V
> > may need to accept 1.8V logic signals.
> > 
> > This defines the reference for VIH (Input High Voltage) and VIL (Input Low
> > Voltage) thresholds, enabling proper signal detection across different
> > voltage domains.
> > 
> > Signed-off-by: Tzuyi Chang <tychang@xxxxxxxxxxx>
> > Co-developed-by: Yu-Chun Lin <eleanor.lin@xxxxxxxxxxx>
> > Signed-off-by: Yu-Chun Lin <eleanor.lin@xxxxxxxxxxx>
> > ---
> > Changes in v3:
> > - Rebased onto the devel branch of the pinctrl tree.
> > - Improved commit message and description.
> > ---
> >  Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml
> > index fe936ab09104..fd49a0d53bf0 100644
> > --- a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml
> > +++ b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml
> > @@ -162,6 +162,11 @@ properties:
> >        this affects the expected delay in ps before latching a value to
> >        an output pin.
> >  
> > +  input-voltage-microvolt:
> > +    description: Specifies the input voltage level of the pin in microvolts.
> > +      This defines the reference for  VIH (Input High Voltage) and VIL
> > +      (Input Low Voltage) thresholds for proper signal detection.
> 
> Should this be added here:
>   - if:
>       required:
>         - input-disable
>     then:
>       properties:
>         input-enable: false
> 
> and made mutually exclusive with input-disable?

Also looking at v1, should this be something like
"input-threshold-voltage-microvolt"? "input-voltage-microvolt" doesn't
seem specific enough to the described use case.

> 
> > +
> >  allOf:
> >    - if:
> >        required:
> > -- 
> > 2.34.1
> >

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