[PATCH v3] dt-bindings: pinctrl: Convert Amlogic Meson pinctrl binding

[Martin Blumenstingl]

Hi Heiner,

On Wed, Feb 1, 2023 at 11:13 PM Heiner Kallweit <hkallweit1 at gmail.com> wrote:
[...]
> >> +      - items:
> >> +          - const: amlogic,meson8m2-aobus-pinctrl
> >> +          - const: amlogic,meson8-aobus-pinctrl
> >> +      - items:
> >> +          - const: amlogic,meson8m2-cbus-pinctrl
> >> +          - const: amlogic,meson8-cbus-pinctrl
> >
> > Again, can't have both with and without the fallback allowed.
> >
> Hi Martin,
>
> meson8m2 is the only chip version having a fallback for the
> pinctrl compatible. Is this fallback really needed?
> Looking at the driver it seems that both compatibles
> are handled identically.
Back in the day we decided to duplicate the Meson8 driver code just to
add four new pin functions that are added by the Meson8m2 SoC
generation:
"eth_rxd2", "eth_rxd3", "eth_txd2", "eth_txd3"

The compatible string was defined with a similar approach: since
Meson8m2 just adds a few bits to the Meson8 pin controller it's
backwards compatible.

If the fallback has to be removed then I'm okay with that but I would
like to understand it first.
So far I thought that Rob basically asked to remove the following two
compatible strings from the enum (as they're listed separately with
their fallbacks):
- amlogic,meson8m2-cbus-pinctrl
- amlogic,meson8m2-aobus-pinctrl


Best regards,
Martin