On 29/08/2022 05:37, Chunfeng Yun wrote: > On Fri, 2022-08-26 at 09:36 +0300, Krzysztof Kozlowski wrote: >> On 26/08/2022 08:36, Chunfeng Yun wrote: >>> 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. >>> >> >> So a value from register/device programming? > Yes >> Rather a regular units >> should be used if that's possible. If not, this should be clearly >> described here, not some magical number which you encode into DTS... > Ok, I'll add more descriptions. Better use logical value, e.g. https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml#L38 Best regards, Krzysztof
