On 31/08/2022 06:00, Chunfeng Yun wrote: > On Tue, 2022-08-30 at 13:08 +0300, Krzysztof Kozlowski wrote: >> 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.ya >>>>>>>>> ml | >>>>>>>>> 7 >>>>>>>>> +++++++ >>>>>>>>> 1 file changed, 7 insertions(+) >>>>>>>>> >>>>>>>>> diff --git >>>>>>>>> a/Documentation/devicetree/bindings/phy/mediatek,tphy.y >>>>>>>>> aml >>>>>>>>> b/Documentation/devicetree/bindings/phy/mediatek,tphy.y >>>>>>>>> aml >>>>>>>>> index 848edfb1f677..aee2f3027371 100644 >>>>>>>>> --- >>>>>>>>> a/Documentation/devicetree/bindings/phy/mediatek,tphy.y >>>>>>>>> aml >>>>>>>>> +++ >>>>>>>>> b/Documentation/devicetree/bindings/phy/mediatek,tphy.y >>>>>>>>> aml >>>>>>>>> @@ -219,6 +219,13 @@ patternProperties: >>>>>>>>> minimum: 1 >>>>>>>>> maximum: 15 >>>>>>>>> >>>>>>>>> + mediatek,pre-emphasis: >>>>>>>>> + description: >>>>>>>>> + The selection of pre-emphasis (U2 phy) >>>>>>>>> + $ref: /schemas/types.yaml#/definitions/uint32 >>>>>>>>> + minimum: 1 >>>>>>>>> + maximum: 3 >>>>>>>> >>>>>>>> Instead of hard-coding register values in bindings, you >>>>>>>> should >>>>>>>> rather >>>>>>>> describe here feature/effect. If it is in units, use unit >>>>>>>> suffixes. >>>>>>>> If >>>>>>>> it is some choice, usually string enum is appropriate. >>>>>>> >>>>>>> How about changing description as bellow: >>>>>>> >>>>>>> "The level of pre-emphasis, increases one level, boosts the >>>>>>> relative >>>>>>> amplitudes of signal's higher frequencies components about >>>>>>> 4.16% >>>>>>> (U2 >>>>>>> phy)" >>>>>>> >>>>>> >>>>>> Still the question is what is the unit. 4.16%? >>>>> >>>>> No unit, it's a level value, like an index of array. >>>>> >>>> >>>> So a value from register/device programming? >>> >>> Yes >>>> Rather a regular units >>>> should be used if that's possible. If not, this should be clearly >>>> described here, not some magical number which you encode into >>>> DTS... >>> >>> Ok, I'll add more descriptions. >> >> Better use logical value, e.g. >> > https://urldefense.com/v3/__https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml*L38__;Iw!!CTRNKA9wMg0ARbw!1e-h0R_uwcaHKfKC9qYfaRWYeuWRq1sLCGy3yupNmkFyuW5s1nmRotL7Y0vFG9ETLLTA$ >> > Optional unit may be -percent or -bp, but the value 4.16% * X > (X=1,2,3...)is not an exact value, they are variable in a range and > dependent more factors. > So I think use level value is simple enough. Then again explain exactly what are the levels. How you wrote it last time, -bp would do the trick. Best regards, Krzysztof
