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

On Tue, 2022-08-23 at 13:24 +0300, Krzysztof Kozlowski wrote:

On 22/08/2022 10:07, Chunfeng Yun wrote:

quoted

On Fri, 2022-08-19 at 15:15 +0300, Krzysztof Kozlowski wrote:

quoted

On 19/08/2022 12:13, Chunfeng Yun wrote:

quoted

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)"

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