Re: [PATCH v1 1/5] dt-bindings: arm: mediatek: mmsys: add mt8195 SoC binding

[Jason-JH Lin <jason-jh.lin@mediatek.com>]

On Fri, 2021-07-23 at 13:13 +0200, Enric Balletbo Serra wrote:
> Hi Jason,
> 
> Thank you for your patch.
> 
> Missatge de jason-jh.lin <jason-jh.lin@mediatek.com> del dia dj., 22
> de jul. 2021 a les 11:26:
> > 
> > There are 2 display hardware path in mt8195, namely vdosys0 and
> > vdosys1, so add their definition in mtk-mmsys documentation.
> > 
> 
> Just having 2 display hardware paths is not a reason to have two
> compatibles, isn't the IP block the same? Why do you need to
> introduce
> the two compatibles?
> 
> Thanks,
>   Enric
> 

Hi Enric,

Thanks for reviewing my patch.

The reason for using two compatibles is that vdosys0 and vdosys1 are
different IP blocks.

Because mmsys provides clock control, other display function blocks may
use them as clock provider.

E.g.
1. mmsys with compatible="mediatek,mt8195-vdosys0"
[v4,1/6] arm64: dts: mt8195: add display node for vdosys0

https://patchwork.kernel.org/project/linux-mediatek/patch/20210723090233.24007-2-jason-jh.lin@mediatek.com/

ovl0: disp_ovl@1c000000 {
	...
	clocks = <&vdosys0 CLK_VDO0_DISP_OVL0>;
	...
};

2. mmsys with compatible="mediatek,mt8195-vdosys1"
[v2,06/14] arm64: dts: mt8195: add display node for vdosys1

https://patchwork.kernel.org/project/linux-mediatek/patch/20210722094551.15255-7-nancy.lin@mediatek.com/

vdo1_rdma0: vdo1_rdma@1c104000 {
	...
	clocks = <&vdosys1 CLK_VDO1_MDP_RDMA0>;
	...
};

Regards,
Jason-JH.Lin

> > Signed-off-by: jason-jh.lin <jason-jh.lin@mediatek.com>
> > ---
> > this patch is base on [1][2]
> > 
> > [1] dt-bindings: arm: mediatek: mmsys: convert to YAML format
> > - 
> > https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20210519161847.3747352-1-fparent@baylibre.com/__;!!CTRNKA9wMg0ARbw!ycgPEK4yBDojiiZJC2E9mGwvxJbaLqhyUxzJIq0ckEP-JVteBcjFdc6ixkNbmknH8f2P$
> >  
> > [2] dt-bindings: arm: mediatek: mmsys: add MT8365 SoC binding
> > - 
> > https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20210519161847.3747352-2-fparent@baylibre.com/__;!!CTRNKA9wMg0ARbw!ycgPEK4yBDojiiZJC2E9mGwvxJbaLqhyUxzJIq0ckEP-JVteBcjFdc6ixkNbmju2GBrD$
> >  
> > ---
> >  .../devicetree/bindings/arm/mediatek/mediatek,mmsys.yaml        |
> > 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yam
> > l
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yam
> > l
> > index 2d4ff0ce387b..0789a9614f12 100644
> > ---
> > a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yam
> > l
> > +++
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yam
> > l
> > @@ -30,6 +30,8 @@ properties:
> >                - mediatek,mt8173-mmsys
> >                - mediatek,mt8183-mmsys
> >                - mediatek,mt8365-mmsys
> > +              - mediatek,mt8195-vdosys0
> > +              - mediatek,mt8195-vdosys1
> >            - const: syscon
> >        - items:
> >            - const: mediatek,mt7623-mmsys
> > --
> > 2.18.0
> > 
--