Re: [PATCH v2 1/2] dt-bindings: memory-controllers: mtk-smi: Add support for mt8189

["Zhengnan Chen (陈征南)" <Zhengnan.Chen@mediatek.com>]

On Thu, 2025-10-30 at 11:43 -0500, Rob Herring wrote:
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> 
> On Mon, Oct 27, 2025 at 08:14:27PM +0800, Zhengnan Chen wrote:
> > Add binding description for mt8189.
> > 
> > The clocks number of mt8189 smi-sub common has a bit difference.
> > Its clock count is 2, while mt8195 has 3. Therefore, the minimum
> > number of clocks is changed to 2, with the third one being
> > optional.
> > 
> > About what smi-sub-common is, please check the below diagram,
> > we add it in mediatek,smi-common.yaml file.
> > 
> > Signed-off-by: Zhengnan Chen <zhengnan.chen@mediatek.com>
> > ---
> > Hi Angelo,
> > We add a diagram in the smi-common yaml, We are not sure if you
> > agree
> > with this. thus I remove your R-b.
> > 
> > Thanks.
> > ---
> > ---
> >  .../mediatek,smi-common.yaml                  | 25
> > +++++++++++++++++--
> >  .../memory-controllers/mediatek,smi-larb.yaml |  3 +++
> >  2 files changed, 26 insertions(+), 2 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/memory-
> > controllers/mediatek,smi-common.yaml
> > b/Documentation/devicetree/bindings/memory-
> > controllers/mediatek,smi-common.yaml
> > index 0762e0ff66ef..454d11a83973 100644
> > --- a/Documentation/devicetree/bindings/memory-
> > controllers/mediatek,smi-common.yaml
> > +++ b/Documentation/devicetree/bindings/memory-
> > controllers/mediatek,smi-common.yaml
> > @@ -25,6 +25,21 @@ description: |
> >    SMI generation 1 to transform the smi clock into emi clock
> > domain, but that is
> >    not needed for SMI generation 2.
> > 
> > +  The smi-common connects with smi-larb and IOMMU. The maximum
> > inputs number of
> > +  a smi-common is 8. In SMI generation 2, the engines number may
> > be over 8.
> > +  In this case, we use a smi-sub-common to merge some larbs.
> > +  The block diagram something is like:
> > +
> > +                          IOMMU
> > +                           | |
> > +                       smi-common
> > +              ---------------------------
> > +               |          |           ...
> > +              larb0   sub-common      ...  <-max number is 8
> > +                   ----------------
> > +                    |     |    ...
> > +                  larb1 larbX  ...  <-max number is 8
> > +
> >  properties:
> >    compatible:
> >      oneOf:
> > @@ -40,6 +55,8 @@ properties:
> >            - mediatek,mt8186-smi-common
> >            - mediatek,mt8188-smi-common-vdo
> >            - mediatek,mt8188-smi-common-vpp
> > +          - mediatek,mt8189-smi-common
> > +          - mediatek,mt8189-smi-sub-common
> >            - mediatek,mt8192-smi-common
> >            - mediatek,mt8195-smi-common-vdo
> >            - mediatek,mt8195-smi-common-vpp
> > @@ -108,19 +125,23 @@ allOf:
> >          compatible:
> >            contains:
> >              enum:
> > +              - mediatek,mt8189-smi-sub-common
> >                - mediatek,mt8195-smi-sub-common
> >      then:
> >        required:
> >          - mediatek,smi
> >        properties:
> >          clocks:
> > -          minItems: 3
> > +          minItems: 2
> 
> So now 2 clocks is valid for mt8195?
> 
  No, the mt8195 still requires 3 clock cycles.
  This approach can accommodate ICs that require 2 or 3 clocks
  simultaneously.

> >            maxItems: 3
> >          clock-names:
> > +          minItems: 2
> > +          maxItems: 3
> >            items:
> >              - const: apb
> >              - const: smi
> > -            - const: gals0
> > +          additionalItems:
> > +            const: gals0
> >      else:
> >        properties:
> >          mediatek,smi: false
> > diff --git a/Documentation/devicetree/bindings/memory-
> > controllers/mediatek,smi-larb.yaml
> > b/Documentation/devicetree/bindings/memory-
> > controllers/mediatek,smi-larb.yaml
> > index 2e7fac4b5094..9a5dafd7c07e 100644
> > --- a/Documentation/devicetree/bindings/memory-
> > controllers/mediatek,smi-larb.yaml
> > +++ b/Documentation/devicetree/bindings/memory-
> > controllers/mediatek,smi-larb.yaml
> > @@ -27,6 +27,7 @@ properties:
> >            - mediatek,mt8183-smi-larb
> >            - mediatek,mt8186-smi-larb
> >            - mediatek,mt8188-smi-larb
> > +          - mediatek,mt8189-smi-larb
> >            - mediatek,mt8192-smi-larb
> >            - mediatek,mt8195-smi-larb
> > 
> > @@ -85,6 +86,7 @@ allOf:
> >              - mediatek,mt8183-smi-larb
> >              - mediatek,mt8186-smi-larb
> >              - mediatek,mt8188-smi-larb
> > +            - mediatek,mt8189-smi-larb
> >              - mediatek,mt8195-smi-larb
> > 
> >      then:
> > @@ -119,6 +121,7 @@ allOf:
> >                - mediatek,mt6779-smi-larb
> >                - mediatek,mt8186-smi-larb
> >                - mediatek,mt8188-smi-larb
> > +              - mediatek,mt8189-smi-larb
> >                - mediatek,mt8192-smi-larb
> >                - mediatek,mt8195-smi-larb
> > 
> > --
> > 2.46.0
> >