[v3 1/3] dt-bindings: phy: qcom,usb-snps-femto-v2: Add phy override params bindings

Pavan Kondeti quic_pkondeti at quicinc.com
Sun May 8 19:52:58 PDT 2022


Hi Krishna,

On Sun, May 08, 2022 at 05:42:25PM +0530, Krishna Kurapati wrote:
> From: Sandeep Maheswaram <quic_c_sanm at quicinc.com>
> 
> Add device tree bindings for SNPS phy tuning parameters.
> 
> Signed-off-by: Sandeep Maheswaram <quic_c_sanm at quicinc.com>
> Signed-off-by: Krishna Kurapati <quic_kriskura at quicinc.com>
> ---
>  .../bindings/phy/qcom,usb-snps-femto-v2.yaml       | 87 ++++++++++++++++++++++
>  1 file changed, 87 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/phy/qcom,usb-snps-femto-v2.yaml b/Documentation/devicetree/bindings/phy/qcom,usb-snps-femto-v2.yaml
> index 1ce251d..6c2ecdd 100644
> --- a/Documentation/devicetree/bindings/phy/qcom,usb-snps-femto-v2.yaml
> +++ b/Documentation/devicetree/bindings/phy/qcom,usb-snps-femto-v2.yaml
> @@ -53,6 +53,93 @@ properties:
>    vdda33-supply:
>      description: phandle to the regulator 3.3V supply node.
>  

<snip>

> +
> +  qcom,hs-rise-fall-time-bps:
> +    $ref: /schemas/types.yaml#/definitions/int32
> +    description:
> +      This adjusts the rise/fall times of the high-speed waveform.
> +      The values defined are in multiples of basis points (1bp = 0.01%).
> +      The hardware accepts only discrete values. The value closest to the
> +      provided input will be chosen as the override value for this param.
> +
> +  qcom,hs-crossover-voltage:
> +    $ref: /schemas/types.yaml#/definitions/int32
> +    description:
> +      This adjusts the voltage at which the DP<#> and DM<#>
> +      signals cross while transmitting in HS mode.
> +      The values defined are in milli volts. The hardware accepts only
> +      discrete values. The value closest to the provided input will be
> +      chosen as the override value for this param.
> +
> +  qcom,hs-output-impedance:
> +    $ref: /schemas/types.yaml#/definitions/int32
> +    description:
> +      In some applications, there can be significant series resistance
> +      on the D+ and D- paths between the transceiver and cable. This adjusts
> +      the driver source impedance to compensate for added series
> +      resistance on the USB. The values defined are in milliohms.

%s/milliohms/mill ohms

> +      The hardware accepts only discrete values. The value closest to the
> +      provided input will be chosen as the override value for this param.
> +

What are the units for HS crossover voltage and output impedence? can you add
units as a suffix like other parameters?

Thanks,
Pavan



More information about the linux-phy mailing list