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? 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... Best regards, Krzysztof
