From:   Alexander Stein <alexander.stein@ew.tq-group.com>
To:     dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Liu Ying <victor.liu@nxp.com>
Cc:     marex@denx.de, stefan@agner.ch, airlied@gmail.com, daniel@ffwll.ch,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de,
        festevam@gmail.com, linux-imx@nxp.com,
        krzysztof.kozlowski@linaro.org, LW@karo-electronics.de
Subject: Re: [PATCH v3 1/6] dt-bindings: lcdif: Add i.MX93 LCDIF support
Date:   Wed, 15 Feb 2023 09:44:51 +0100
Message-ID: <2703596.mvXUDI8C0e@steina-w>
Organization: TQ-Systems GmbH
In-Reply-To: <41bc30ac7af4b0ce3ff608b604fb6ea762428680.camel@nxp.com>
References: <20230213085612.1026538-1-victor.liu@nxp.com> <2551514.Lt9SDvczpP@steina-w> <41bc30ac7af4b0ce3ff608b604fb6ea762428680.camel@nxp.com>
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Hi Liu,

Am Mittwoch, 15. Februar 2023, 08:49:56 CET schrieb Liu Ying:
> On Wed, 2023-02-15 at 08:26 +0100, Alexander Stein wrote:
> > Hi Liu,
>=20
> Hi Alexander,
>=20
> > thanks for the update.
>=20
> Thanks for the review.
>=20
> > Am Montag, 13. Februar 2023, 09:56:07 CET schrieb Liu Ying:
> > > There is one LCDIF embedded in i.MX93 SoC to connect with
> > > MIPI DSI controller through LCDIF cross line pattern(controlled
> > > by mediamix blk-ctrl) or connect with LVDS display bridge(LDB)
> > > directly or connect with a parallel display through parallel
> > > display format(also controlled by mediamix blk-ctrl).  i.MX93
> > > LCDIF IP is essentially the same to i.MX8MP LCDIF IP.  Add device
> > > tree binding for i.MX93 LCDIF.
> > >=20
> > > Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> > > Reviewed-by: Marek Vasut <marex@denx.de>
> > > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > > ---
> > > v2->v3:
> > > * No change.
> > >=20
> > > v1->v2:
> > > * Add Krzysztof's A-b and Marek's R-b tags on patch 1/6.
> > >=20
> > >  Documentation/devicetree/bindings/display/fsl,lcdif.yaml | 7
> > >=20
> > > ++++++-
> > >=20
> > >  1 file changed, 6 insertions(+), 1 deletion(-)
> > >=20
> > > diff --git
> > > a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
> > > b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml index
> > > 75b4efd70ba8..fc11ab5fc465 100644
> > > --- a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
> > > +++ b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
> > >=20
> > > @@ -21,6 +21,7 @@ properties:
> > >            - fsl,imx28-lcdif
> > >            - fsl,imx6sx-lcdif
> > >            - fsl,imx8mp-lcdif
> > >=20
> > > +          - fsl,imx93-lcdif
> > >=20
> > >        - items:
> > >            - enum:
> > >                - fsl,imx6sl-lcdif
> > >=20
> > > @@ -88,7 +89,9 @@ allOf:
> > >        properties:
> > >          compatible:
> > >            contains:
> > > -            const: fsl,imx8mp-lcdif
> > > +            enum:
> > > +              - fsl,imx8mp-lcdif
> > > +              - fsl,imx93-lcdif
> > >=20
> > >      then:
> > >        properties:
> > >          clocks:
> > > @@ -107,6 +110,7 @@ allOf:
> > >                enum:
> > >                  - fsl,imx6sx-lcdif
> > >                  - fsl,imx8mp-lcdif
> > >=20
> > > +                - fsl,imx93-lcdif
> > >=20
> > >      then:
> > >        properties:
> > >          clocks:
> > > @@ -123,6 +127,7 @@ allOf:
> > >                - fsl,imx8mm-lcdif
> > >                - fsl,imx8mn-lcdif
> > >                - fsl,imx8mp-lcdif
> > >=20
> > > +              - fsl,imx93-lcdif
> > >=20
> > >      then:
> > >        required:
> > >          - power-domains
> >=20
> > I would have expected that fsl,imx93-lcdif supports up to 3 endpoints
> > (MIPI
> > DSI, LVDS, and parallel) in a 'ports' subnode. But this binding only
> > supports
> > a single 'port' sub-node. Also an example for this case might be very
> > helpful.
>=20
> The port node allows multiple endpoints(See graph.yaml[1]).  It's
> enough to use the existing port node instead of using ports node.

Ah, I wasn't aware of that possibility for OF graph. Yep, agreed then it's=
=20
enough.

> For i.MX93 LCDIF, the port node will be something like this:
> --------------------8<--------------------------
> port {
>         #address-cells =3D <1>;
>         #size-cells =3D <0>;
>=20
>         lcdif_to_pdfc: endpoint@0 {
>                 reg =3D <0>;
>         };
>=20
>         lcdif_to_ldb: endpoint@1 {
>                 reg =3D <1>;
>         };
>=20
>         lcdif_to_cross_line_pattern: endpoint@2 {
>                 reg =3D <2>;
>         };
> };
> --------------------8<--------------------------
>=20
> Looks like it's not necessary to add a specifc example for i.MX93
> LCDIF.

=46ine by me.
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>

> [1]
> https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/gr=
aph
> .yaml#L48
>=20
> Regards,
> Liu Ying

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