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Message-ID: <816ecf6287533137b750c8bde9de5830e4229c56.camel@mediatek.com>
Subject: Re: [PATCH 2/7] dt-bindings: phy: mediatek,tphy: add property to
 set pre-emphasis
From:   Chunfeng Yun <chunfeng.yun@mediatek.com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Vinod Koul <vkoul@kernel.org>, Rob Herring <robh+dt@kernel.org>
CC:     Kishon Vijay Abraham I <kishon@ti.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>,
        <linux-phy@lists.infradead.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        Eddie Hung <eddie.hung@mediatek.com>
Date:   Mon, 22 Aug 2022 15:07:35 +0800
In-Reply-To: <438da392-f419-ad76-7e91-aa4aab36e12c@linaro.org>
References: <20220819091344.2274-1-chunfeng.yun@mediatek.com>
         <20220819091344.2274-2-chunfeng.yun@mediatek.com>
         <438da392-f419-ad76-7e91-aa4aab36e12c@linaro.org>
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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@mediatek.com>
> > ---
> >  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)"

Thanks

> 
> Best regards,
> Krzysztof