Hi Jason,

Missatge de Jason-JH Lin [off-list ref] del dia dl., 26
de jul. 2021 a les 9:02:

On Fri, 2021-07-23 at 13:13 +0200, Enric Balletbo Serra wrote:

quoted

Hi Jason,

Thank you for your patch.

Missatge de jason-jh.lin [off-list ref] del dia dj., 22
de jul. 2021 a les 11:26:

quoted

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.

With that there are different IP blocks, what do you mean? Do you mean
that there are two completely different blocks with completely
different functionalities?

Or that there is the same IP block twice? I mean, of course, the
registers are different but has exactly the same functionality.

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>;
        ...
};

Note that I am talking without knowing the hardware in detail, but I
am wondering why I can't have something like this, where every mmsys
is a clock and reset controller provider.

vdosys0: syscon@14000000 {
          compatible = "mediatek,mt8195-mmsys", "syscon";
          reg = <0 0x14000000 0 0x1000>;
          #clock-cells = <1>;
          #reset-cells = <1>;
};

vdosys1: syscon@15000000 {
          compatible = "mediatek,mt8195-mmsys", "syscon";
          reg = <0 0x15000000 0 0x1000>;
          #clock-cells = <1>;
          #reset-cells = <1>;
};

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

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

What are the differences between vdosys0 and vdosys1 from a hardware
point of view?

Cheers,
  Enric

Regards,
Jason-JH.Lin

quoted

quoted

Signed-off-by: jason-jh.lin <redacted>
---
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

--

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