Re: [PATCH 1/3] dt-bindings: i3c: renesas,i3c: Document analog noise filter control

[Frank Li <Frank.li@oss.nxp.com>]

On Tue, Oct 20, 2026 at 10:36:26AM +0100, Diogo Ivo wrote:
> The analog noise filter for the input terminals (I3C_SDA, I3C_SCL) of
> the Renesas I3C controller is controlled through the SYS_I3C_CFG
> register of the system controller. Document the
> renesas,analog-noise-filter property, which references the system
> controller together with the offset of the SYS_I3C_CFG register and
> the state of the filter: 1 enables the filter and 0 bypasses it.
>
> The property is optional: device trees not providing it keep the
> filter at its reset value.
>
> Signed-off-by: Diogo Ivo <diogo.ivo.sx@renesas.com>
> ---
>  .../devicetree/bindings/i3c/renesas,i3c.yaml          | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/i3c/renesas,i3c.yaml b/Documentation/devicetree/bindings/i3c/renesas,i3c.yaml
> index 08fcea89a015..381807844351 100644
> --- a/Documentation/devicetree/bindings/i3c/renesas,i3c.yaml
> +++ b/Documentation/devicetree/bindings/i3c/renesas,i3c.yaml
> @@ -96,6 +96,25 @@ properties:
>        - const: presetn
>        - const: tresetn
>
> +  renesas,analog-noise-filter:
> +    $ref: /schemas/types.yaml#/definitions/phandle-array

I don't like this syscon property, look like it is one kind pad propterty.
Is it possible model as pinctrl?

Frank

> +    description:
> +      Analog noise filter for the I3C input signals (I3C_SDA, I3C_SCL),
> +      controlled through the SYS_I3C_CFG register of the system
> +      controller (SYSC). Three entries specifying the system controller,
> +      the offset of the SYS_I3C_CFG register and the state of the filter.
> +      If not present, the filter keeps its reset state.
> +    items:
> +      - items:
> +          - description: phandle to the system controller node
> +          - description: offset of the SYS_I3C_CFG register within the SYSC
> +          - enum: [0, 1]
> +            description: |
> +              state of the analog noise filter:
> +               - 1: enable the filter, performing noise reduction on the
> +                 I3C_SDA and I3C_SCL input signals
> +               - 0: bypass the filter
> +
>  required:
>    - compatible
>    - reg
>
> --
> 2.56.0
>