Re: [PATCH 2/7] dt-bindings: phy: mediatek,tphy: add property to set pre-emphasis

[Chunfeng Yun]

On Tue, 2022-08-23 at 13:24 +0300, Krzysztof Kozlowski wrote:
> On 22/08/2022 10:07, Chunfeng Yun wrote:
> > On Fri, 2022-08-19 at 15:15 +0300, Krzysztof Kozlowski wrote:
> > > On 19/08/2022 12:13, Chunfeng Yun wrote:
> > > > Add a property to set usb2 phy's pre-emphasis.
> > > > 
> > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > > > ---
> > > >  Documentation/devicetree/bindings/phy/mediatek,tphy.yaml | 7
> > > > +++++++
> > > >  1 file changed, 7 insertions(+)
> > > > 
> > > > diff --git
> > > > a/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
> > > > b/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
> > > > index 848edfb1f677..aee2f3027371 100644
> > > > --- a/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
> > > > +++ b/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
> > > > @@ -219,6 +219,13 @@ patternProperties:
> > > >          minimum: 1
> > > >          maximum: 15
> > > >  
> > > > +      mediatek,pre-emphasis:
> > > > +        description:
> > > > +          The selection of pre-emphasis (U2 phy)
> > > > +        $ref: /schemas/types.yaml#/definitions/uint32
> > > > +        minimum: 1
> > > > +        maximum: 3
> > > 
> > > Instead of hard-coding register values in bindings, you should
> > > rather
> > > describe here feature/effect. If it is in units, use unit
> > > suffixes.
> > > If
> > > it is some choice, usually string enum is appropriate.
> > 
> > How about changing description as bellow:
> > 
> > "The level of pre-emphasis, increases one level, boosts the
> > relative
> > amplitudes of signal's higher frequencies components about 4.16%
> > (U2
> > phy)"
> > 
> 
> Still the question is what is the unit. 4.16%?
No unit, it's a level value, like an index of array.

> 
> Best regards,
> Krzysztof