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Message-ID: <8f3dba943170361211d9bb4c8bf1be12bbfdec20.camel@mediatek.com>
Subject: Re: [PATCH v2] dt-bindings: arm: mediatek: mmsys: change compatible
 for MT8195
From:   Bo-Chen Chen <rex-bc.chen@mediatek.com>
To:     Matthias Brugger <matthias.bgg@gmail.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "krzysztof.kozlowski+dt@linaro.org" 
        <krzysztof.kozlowski+dt@linaro.org>
CC:     Jason-JH Lin =?UTF-8?Q?=28=E6=9E=97=E7=9D=BF=E7=A5=A5=29?= 
        <Jason-JH.Lin@mediatek.com>,
        Nancy Lin =?UTF-8?Q?=28=E6=9E=97=E6=AC=A3=E8=9E=A2=29?= 
        <Nancy.Lin@mediatek.com>,
        "CK Hu =?UTF-8?Q?=28=E8=83=A1=E4=BF=8A=E5=85=89=29?=" 
        <ck.hu@mediatek.com>,
        "chunkuang.hu@kernel.org" <chunkuang.hu@kernel.org>,
        "angelogioacchino.delregno@collabora.com" 
        <angelogioacchino.delregno@collabora.com>,
        "hsinyi@google.com" <hsinyi@google.com>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-mediatek@lists.infradead.org" 
        <linux-mediatek@lists.infradead.org>,
        Project_Global_Chrome_Upstream_Group 
        <Project_Global_Chrome_Upstream_Group@mediatek.com>
Date:   Fri, 26 Aug 2022 10:07:56 +0800
In-Reply-To: <3ed3d73a-1671-708e-7c42-498cca6aaf1d@gmail.com>
References: <20220825091448.14008-1-rex-bc.chen@mediatek.com>
         <3ed3d73a-1671-708e-7c42-498cca6aaf1d@gmail.com>
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On Thu, 2022-08-25 at 22:57 +0800, Matthias Brugger wrote:
> 
> On 25/08/2022 11:14, Bo-Chen Chen wrote:
> > From: "Jason-JH.Lin" <jason-jh.lin@mediatek.com>
> > 
> > For previous MediaTek SoCs, such as MT8173, there are 2 display HW
> > pipelines binding to 1 mmsys with the same power domain, the same
> > clock driver and the same mediatek-drm driver.
> > 
> > For MT8195, VDOSYS0 and VDOSYS1 are 2 display HW pipelines binding
> > to
> > 2 different power domains, different clock drivers and different
> > mediatek-drm drivers.
> > 
> > Moreover, Hardware pipeline of VDOSYS0 has these components: COLOR,
> > CCORR, AAL, GAMMA, DITHER. They are related to the PQ (Picture
> > Quality)
> > and they makes VDOSYS0 supports PQ function while they are not
> > including in VDOSYS1.
> > 
> > Hardware pipeline of VDOSYS1 has the component ETHDR (HDR related
> > component). It makes VDOSYS1 supports the HDR function while it's
> > not
> > including in VDOSYS0.
> > 
> > To summarize0:
> > Only VDOSYS0 can support PQ adjustment.
> > Only VDOSYS1 can support HDR adjustment.
> > 
> > Therefore, we need to separate these two different mmsys hardwares
> > to
> > 2 different compatibles for MT8195.
> > 
> > Fixes: 81c5a41d10b9 ("dt-bindings: arm: mediatek: mmsys: add mt8195
> > SoC binding")
> > Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> > Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
> > ---
> > Changes for v2:
> > 1. Add hardware difference for VDOSYS0 and VDOSYS1 in commit
> > message.
> > ---
> >   .../devicetree/bindings/arm/mediatek/mediatek,mmsys.yaml       |
> > 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yam
> > l
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yam
> > l
> > index 6ad023eec193..bfbdd30d2092 100644
> > ---
> > a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yam
> > l
> > +++
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yam
> > l
> > @@ -31,7 +31,8 @@ properties:
> >                 - mediatek,mt8183-mmsys
> >                 - mediatek,mt8186-mmsys
> >                 - mediatek,mt8192-mmsys
> > -              - mediatek,mt8195-mmsys
> > +              - mediatek,mt8195-vdosys0
> 
> Thanks for you patch. As I mentioned on v1, I propose to set 
> mediatek,mt8195-mmsys as fallback for mediatek,mt8195-vdosys0 to not
> break 
> backwards compatibility.
> 
> Apart from that, the binding change will need some changes to support
> the new 
> binding. Please provide these together with this patch.
> 
> Regards,
> Matthias
> 

Hello Matthias,

Thanks for your comments.
The purpose of this patch is to confirm we can separate mt8195 mmsys
into two compatibles. I think this modification is accepted.

After this, I think Jason-JH will push another series with this binding
patch. In Jason-JH's series, we will modify mmsys driver based on this.
And I think we don't need to keep "mediatek,mt8195-mmsys" if we also
modify mmsys drivers in the same series.

Is it ok that postpones to pick this patch until we finish review
follow-up series?

BRs,
Bo-Chen
> > +              - mediatek,mt8195-vdosys >                 -
> > mediatek,mt8365-mmsys
> >             - const: syscon
> >         - items: