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Reply-To: tanure@linux.com
From:   Lucas Tanure <tanure@linux.com>
Date:   Thu, 22 Jun 2023 09:26:02 +0100
Message-ID: <CAJX_Q+2Fc5sdp-0kHp99UEo_oiqTeO-LA95+Ak+aW0HMqDgtPw@mail.gmail.com>
Subject: Re: [PATCH v3 2/3] dt-bindings: serial: amlogic,meson-uart: Add
 compatible string for T7
To:     neil.armstrong@linaro.org
Cc:     Conor Dooley <conor.dooley@microchip.com>,
        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>,
        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 9:13 AM Neil Armstrong
<neil.armstrong@linaro.org> wrote:
>
> On 22/06/2023 09:36, Lucas Tanure wrote:
> > 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.
>
> I just applied Conor's change on top of v6.4-rc1 and ran:
> make dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml
>
> and the check was successful.
>
> Neil
>
>
I am sending v4 in a few minutes