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From:   Lucas Tanure <tanure@linux.com>
Date:   Thu, 22 Jun 2023 08:36:49 +0100
Message-ID: <CAJX_Q+3+bdXd-NrsQymXerpWZuj3zb8CKHcZRNM_iLSZcp2Mfg@mail.gmail.com>
Subject: Re: [PATCH v3 2/3] dt-bindings: serial: amlogic,meson-uart: Add
 compatible string for T7
To:     Conor Dooley <conor.dooley@microchip.com>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Conor Dooley <conor@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>, Nick <nick@khadas.com>,
        Artem <art@khadas.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org
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On Thu, Jun 22, 2023 at 8:12 AM Conor Dooley <conor.dooley@microchip.com> wrote:
>
> On Thu, Jun 22, 2023 at 07:43:31AM +0100, Lucas Tanure wrote:
> > On Thu, Jun 22, 2023 at 7:05 AM Krzysztof Kozlowski
> > <krzysztof.kozlowski@linaro.org> wrote:
> > > On 22/06/2023 07:32, Lucas Tanure wrote:
> > > > On Wed, Jun 21, 2023 at 7:12 PM Conor Dooley <conor@kernel.org> wrote:
> > > >> On Wed, Jun 21, 2023 at 03:53:04PM +0200, Krzysztof Kozlowski wrote:
> > > >>> On 21/06/2023 15:32, 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.
> > > >>>>
> > > >>>> Signed-off-by: Lucas Tanure <tanure@linux.com>
> > > >>>> ---
> > > >>>>  .../devicetree/bindings/serial/amlogic,meson-uart.yaml          | 2 ++
> > > >>>>  1 file changed, 2 insertions(+)
> > > >>>>
> > > >>>> diff --git a/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml b/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> > > >>>> index 01ec45b3b406..860ab58d87b0 100644
> > > >>>> --- a/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> > > >>>> +++ b/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> > > >>>> @@ -33,6 +33,7 @@ properties:
> > > >>>>                - amlogic,meson8b-uart
> > > >>>>                - amlogic,meson-gx-uart
> > > >>>>                - amlogic,meson-s4-uart
> > > >>>> +              - amlogic,meson-t7-uart
> > > >>>>            - const: amlogic,meson-ao-uart
> > > >>>>        - description: Always-on power domain UART controller on G12A SoCs
> > > >>>>          items:
> > > >>>> @@ -46,6 +47,7 @@ properties:
> > > >>>>            - amlogic,meson8b-uart
> > > >>>>            - amlogic,meson-gx-uart
> > > >>>>            - amlogic,meson-s4-uart
> > > >>>> +          - amlogic,meson-t7-uart
> > > >>>
> > > >>> It does not look like you tested the DTS against bindings. Please run
> > > >>> `make dtbs_check` (see
> > > >>> Documentation/devicetree/bindings/writing-schema.rst or
> > > >>> https://www.linaro.org/blog/tips-and-tricks-for-validating-devicetree-sources-with-the-devicetree-schema/
> > > >>> for instructions).
> > > >>
> > > >> Check back on the previous version, I should've posted an untested
> > > >> version of what you need to add.
> > > > I saw that, but adding a S4 doesn't make sense to me. And you didn't
> > > > show the entire change, so I can't understand what you want there.
> > >
> > > For sure you need something which does not trigger errors. If you claim
> > > adding S4 as fallback does not make sense, then why did you use it?
> > > Sending a code which is clearly incorrect does not make sense.
> > >
> > Sorry, I think we are talking about different things. It does not make
> > sense to me to add an S4 line in the documentation when it is already
> > there. So I could not understand or make sense of the patch Conor sent
> > in reply to my V2.
>
> That is just how it works. You need to spell out exactly which
> combinations are permitted. The current entry for s4 says that s4 is
> only permitted in isolation.
> Since you are adding "amlogic,meson-t7-uart", "amlogic,meson-s4-uart"
> you need to explicitly allow that combination. You'll notice if you look
> at the file that the gx uart appears more than once.
>
> Given the g12a was the most recently added compatible, it might make
> sense to follow the pattern that it had set, given the thing your
> original patch copied the match data from was the g12a. That change to
> the dt-binding would look like:
> diff --git a/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml b/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> index 01ec45b3b406..eae11e87b88a 100644
> --- a/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> +++ b/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
> @@ -50,6 +50,13 @@ properties:
>          items:
>            - const: amlogic,meson-g12a-uart
>            - const: amlogic,meson-gx-uart
> +      - description:
> +          Everything-Else power domain UART controller on G12A compatible SoCs
> +        items:
> +          - enum:
> +              - amlogic,meson-t7-uart
> +          - const: amlogic,meson-g12a-uart
> +          - const: amlogic,meson-gx-uart
>
>    reg:
>      maxItems: 1
>
> /I/ don't really care whether you do that, or do the s4 version of it,
> but following the most recent pattern might make more sense. When I
> suggested s4, it was because I only looked at the driver patch rather
> than the code itself.
>
> > Krzysztof, I will check again with dtbs_check and re-send.
>
> Cheers,
> Conor.
I am struggling to understand this. Everything I try fails the check.