Re: [PATCH v4 2/3] dt-bindings: serial: amlogic,meson-uart: Add compatible string for T7

[Neil Armstrong]

On 22/06/2023 11:26, Conor Dooley wrote:
> Hey Lucas,
>
> On Thu, Jun 22, 2023 at 09:40:44AM +0100, Lucas Tanure wrote:
> > Amlogic T7 SoCs uses the same UART controller as S4 SoCs and G12A.
> > There is no need for an extra compatible line in the driver, but
> > add T7 compatible line for documentation.
> >
> > Co-developed-by: Conor Dooley <conor@xxxxxxxxxx>
>
> You can delete this, I don't need a Co-developed-by tag for review
> feedback.
>
> > Signed-off-by: Lucas Tanure <tanure@xxxxxxxxx>
> > ---
> >   .../devicetree/bindings/serial/amlogic,meson-uart.yaml      | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml b/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> > index 01ec45b3b406..4ca4673169aa 100644
> > --- a/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> > +++ b/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> > @@ -46,6 +46,12 @@ properties:
> >             - amlogic,meson8b-uart
> >             - amlogic,meson-gx-uart
> >             - amlogic,meson-s4-uart
> > +      - description: Everything-Else power domain UART controller on G12A compatible SoCs
>
> s/Everything-Else/Always-on/


"Everything-Else" was the amlogic naming for the non-always-on power domain, but it seems
it's no more something used on new SoCs like the T7 family.

Anyway, the description is wrong, and it's a mess because we used "amlogic,meson-ao-uart"
for uarts on the Always-On domain, but here it's described as Everything-Else...

Lucas, is there AO_uarts on T7 ? if not drop this amlogic,meson-ao-uart for the T7 UARTs.

But if there's no more AO uart controller, you'll need to change drivers/tty/serial/meson_uart.c
and add a OF_EARLYCON_DECLARE() for amlogic,meson-t7-uart.

But still, why don't you use the amlogic,meson-s4-uart as fallback instead ?

+      - description: UART controller on T7 compatible SoCs
+        items:
+          - const: amlogic,meson-t7-uart
+          - const: amlogic,meson-s4-uart

and update meson_uart.c if there's no AO uarts anymore....

Neil

> Otherwise,
> Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>
> Perhaps it can be fixed on application, I don't know how the amlogic
> maintainers operate.
>
> Cheers,
> Conor.
>
> > +        items:
> > +          - enum:
> > +              - amlogic,meson-t7-uart
> > +          - const: amlogic,meson-g12a-uart
> > +          - const: amlogic,meson-ao-uart
> >         - description: Everything-Else power domain UART controller on G12A SoCs
> >           items:
> >             - const: amlogic,meson-g12a-uart
> > --
> > 2.41.0