[PATCH v2 3/4] dt-bindings: ufs: mediatek,ufs: add MT8195 compatible and update clock nodes

Rob Herring robh at kernel.org
Tue Jul 22 21:50:09 PDT 2025


On Tue, Jul 22, 2025 at 11:39:54AM +0200, AngeloGioacchino Del Regno wrote:
> Il 22/07/25 10:57, Macpaul Lin ha scritto:
> > Add MT8195 UFSHCI compatible string.
> > Relax the schema to allow between one to eight clocks/clock-names
> > entries for all MediaTek UFS nodes. Legacy platforms may only need
> > a few clocks, whereas newer devices such as the MT8195 require
> > additional clock-gating domains. For MT8195 specifically, enforce
> > exactly eight clocks and clock-names entries to satisfy its hardware
> > requirements.
> > 
> > Signed-off-by: Macpaul Lin <macpaul.lin at mediatek.com>
> > ---
> >   .../devicetree/bindings/ufs/mediatek,ufs.yaml | 42 ++++++++++++++++---
> >   1 file changed, 36 insertions(+), 6 deletions(-)
> > 
> > Changes for v2:
> >   - Remove duplicate minItems and maxItems as suggested in the review.
> >   - Add a description of how the MT8195 hardware differs from earlier
> >     platforms.
> > 
> > diff --git a/Documentation/devicetree/bindings/ufs/mediatek,ufs.yaml b/Documentation/devicetree/bindings/ufs/mediatek,ufs.yaml
> > index 20f341d25ebc..1dec54fb00f3 100644
> > --- a/Documentation/devicetree/bindings/ufs/mediatek,ufs.yaml
> > +++ b/Documentation/devicetree/bindings/ufs/mediatek,ufs.yaml
> > @@ -9,21 +9,20 @@ title: Mediatek Universal Flash Storage (UFS) Controller
> >   maintainers:
> >     - Stanley Chu <stanley.chu at mediatek.com>
> > -allOf:
> > -  - $ref: ufs-common.yaml
> > -
> >   properties:
> >     compatible:
> >       enum:
> >         - mediatek,mt8183-ufshci
> >         - mediatek,mt8192-ufshci
> > +      - mediatek,mt8195-ufshci
> >     clocks:
> > -    maxItems: 1
> > +    minItems: 1
> > +    maxItems: 8
> >     clock-names:
> > -    items:
> > -      - const: ufs
> > +    minItems: 1
> > +    maxItems: 8
> >     phys:
> >       maxItems: 1
> > @@ -47,6 +46,37 @@ required:
> >   unevaluatedProperties: false
> > +allOf:
> > +  - $ref: ufs-common.yaml
> > +
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - mediatek,mt8195-ufshci
> > +    then:
> > +      properties:
> > +        clocks:
> > +          minItems: 8
> > +        clock-names:
> > +          items:
> > +            - const: ufs
> > +            - const: ufs_aes
> > +            - const: ufs_tick
> > +            - const: unipro_sysclk
> > +            - const: unipro_tick
> > +            - const: unipro_mp_bclk
> 
> The unipro mp_bclk really is the ufs-sap clock; besides, the standard has clocks
> for both TX and RX symbols - and also MT8195 (and also MT6991, MT8196, and others)
> UFS controller do have both TX and RX symbol clocks.
> 
> Besides, you're also missing the crypto clocks for UFS, which brings the count to
> 12 total clocks for MT8195.
> 
> Please, look at my old submission, which actually fixes the compatibles other than
> adding the right clocks for all UFS controllers in MediaTek platforms.
> 
> https://lore.kernel.org/all/20240612074309.50278-1-angelogioacchino.delregno@collabora.com/
> 
> I want to take the occasion to remind everyone that my fixes were discarded because
> the MediaTek UFS driver maintainer wants to keep the low quality of the driver in
> favor of easier downstream porting - which is *not* in any way adhering to quality
> standards that the Linux community deserves.

Sounds like we need a new maintainer then. They clearly don't understand 
that downstream doesn't exist.

Rob



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