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From:   Rob Herring <robh@kernel.org>
Date:   Mon, 30 Aug 2021 10:05:19 -0500
Message-ID: <CAL_JsqJ_cProt35pdd2MjoHsSKtd+0n1Dwq6ooV+CJH5sfOFWg@mail.gmail.com>
Subject: Re: [PATCH v7 3/5] dt-binding: mt8183: Add Mediatek MDP3 dt-bindings
To:     moudy ho <moudy.ho@mediatek.com>
Cc:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Jernej Skrabec <jernej.skrabec@siol.net>,
        Maoguang Meng <maoguang.meng@mediatek.com>,
        daoyuan huang <daoyuan.huang@mediatek.com>,
        Ping-Hsun Wu <ping-hsun.wu@mediatek.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Rob Landley <rob@landley.net>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        devicetree@vger.kernel.org,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Tomasz Figa <tfiga@chromium.org>,
        Nicolas Boichat <drinkcat@chromium.org>,
        Alexandre Courbot <acourbot@chromium.org>,
        Pi-Hsun Shih <pihsun@chromium.org>, menghui.lin@mediatek.com,
        Sj Huang <sj.huang@mediatek.com>, ben.lok@mediatek.com,
        randy.wu@mediatek.com,
        srv_heupstream <srv_heupstream@mediatek.com>,
        Hsin-Yi Wang <hsinyi@google.com>
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On Mon, Aug 30, 2021 at 2:58 AM moudy ho <moudy.ho@mediatek.com> wrote:
>
> On Tue, 2021-08-24 at 13:02 -0500, Rob Herring wrote:
> > On Tue, Aug 24, 2021 at 06:00:25PM +0800, Moudy Ho wrote:
> > > This patch adds DT binding document for Media Data Path 3 (MDP3)
> > > a unit in multimedia system used for scaling and color format
> > > convert.
> > >
> > > Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
> > > ---
> > >  .../bindings/media/mediatek,mdp3-ccorr.yaml   |  57 +++++
> > >  .../bindings/media/mediatek,mdp3-rdma.yaml    | 207
> > > ++++++++++++++++++
> > >  .../bindings/media/mediatek,mdp3-rsz.yaml     |  65 ++++++
> > >  .../bindings/media/mediatek,mdp3-wdma.yaml    |  71 ++++++
> > >  .../bindings/media/mediatek,mdp3-wrot.yaml    |  71 ++++++
> > >  5 files changed, 471 insertions(+)
> > >  create mode 100644
> > > Documentation/devicetree/bindings/media/mediatek,mdp3-ccorr.yaml
> > >  create mode 100644
> > > Documentation/devicetree/bindings/media/mediatek,mdp3-rdma.yaml
> > >  create mode 100644
> > > Documentation/devicetree/bindings/media/mediatek,mdp3-rsz.yaml
> > >  create mode 100644
> > > Documentation/devicetree/bindings/media/mediatek,mdp3-wdma.yaml
> > >  create mode 100644
> > > Documentation/devicetree/bindings/media/mediatek,mdp3-wrot.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/media/mediatek,mdp3-
> > > ccorr.yaml b/Documentation/devicetree/bindings/media/mediatek,mdp3-
> > > ccorr.yaml
> > > new file mode 100644
> > > index 000000000000..59fd68b46022
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/media/mediatek,mdp3-
> > > ccorr.yaml
> > > @@ -0,0 +1,57 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id:
> > > https://urldefense.com/v3/__http://devicetree.org/schemas/media/mediatek,mdp3-ccorr.yaml*__;Iw!!CTRNKA9wMg0ARbw!1C0ChLqzi7Zq8D2d4_S4IqCEei4GXdgy3_VCQg8MdsJP7n8TlxbGyajipusfH8hi$
> > >
> > > +$schema:
> > > https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!1C0ChLqzi7Zq8D2d4_S4IqCEei4GXdgy3_VCQg8MdsJP7n8TlxbGyajipi-OInix$
> > >
> > > +
> > > +title: Mediatek Media Data Path 3 CCORR Device Tree Bindings
> > > +
> > > +maintainers:
> > > +  - Daoyuan Huang <daoyuan.huang@mediatek.com>
> > > +  - Moudy Ho <moudy.ho@mediatek.com>
> > > +
> > > +description: |
> > > +  One of Media Data Path 3 (MDP3) components used to do color
> > > correction with 3X3 matrix.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    items:
> > > +      - enum:
> > > +        - mediatek,mt8183-mdp3-ccorr
> > > +
> > > +  mediatek,mdp3-id:
> > > +    $ref: /schemas/types.yaml#/definitions/uint32
> > > +    maxItems: 1
> > > +    description: |
> > > +      HW index to distinguish same functionality modules.
> >
> > If we wanted h/w indexes in DT, we'd have a standard property. Why
> > do
> > you need this?
> >
> I'm sorry not quite sure what HW indexes means (something like
> aliases?)

It means whatever you said in your description.

And no, I'm not suggesting you use aliases.

> It was originally used to mark multiple identical modules in the MDP
> data path algorithm, so that appropriate paths can be dynamically
> dispatched.

If they are identical, then why do you need to distinguish them in DT?
If there's some difference you need to know about such as connections
to other blocks, then describe that. Another common example is needing
to know what bits/registers to access in a syscon phandle. For that,
make the register offset or bits be args to the phandle property.

Rob