In accordance with the driver comments the PIPE3 de-emphasis can be tuned to be either -6dB, -2.5dB or disabled. Let's add the de-emphasis property constraints so the DT schema would make sure the controller DT node is equipped with correct value. Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Rob Herring <robh@xxxxxxxxxx> --- Changelog v2: - Grammar fix: "s/tunned/tuned" - Grammar fix: remove redundant "or" conjunction. --- Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml index 4f68c5cd7a45..64579aed404f 100644 --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml @@ -153,6 +153,10 @@ properties: The value driven to the PHY is controlled by the LTSSM during USB3 Compliance mode. $ref: /schemas/types.yaml#/definitions/uint8 + enum: + - 0 # -6dB de-emphasis + - 1 # -3.5dB de-emphasis + - 2 # No de-emphasis snps,dis_u3_susphy_quirk: description: When set core will disable USB3 suspend phy -- 2.28.0