Re: [v4 1/3] dt-bindings: phy: qcom,usb-snps-femto-v2: Add phy override params bindings

[Krishna Kurapati PSSNV]

On 5/11/2022 11:49 PM, Krzysztof Kozlowski wrote:
> On 11/05/2022 17:26, Krishna Kurapati wrote:
> > From: Sandeep Maheswaram <quic_c_sanm@xxxxxxxxxxx>
> >
> > Add device tree bindings for SNPS phy tuning parameters.
> >
> > Signed-off-by: Sandeep Maheswaram <quic_c_sanm@xxxxxxxxxxx>
> > Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
> > ---
> >   .../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..70efffe 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.
> >   
> > +  qcom,hs-disconnect-bps:
> > +    $ref: /schemas/types.yaml#/definitions/int32
> > +    description:
> > +      This adjusts the voltage level for the threshold used to
> > +      detect a disconnect event at the host. Possible values are.
> > +      The values defined are in multiples of basis points (1bp = 0.01%).
> This means there is some minimum and maximum (100%)?
>
> > +      The hardware accepts only discrete values. The value closest to the
> > +      provided input will be chosen as the override value for this param.
> > +
> > +  qcom,squelch-detector-bps:
> > +    $ref: /schemas/types.yaml#/definitions/int32
> > +    description:
> > +      This adjusts the voltage level for the threshold used to
> > +      detect valid high-speed data.
> > +      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-amplitude-bps:
> > +    $ref: /schemas/types.yaml#/definitions/int32
> > +    description:
> > +      This adjusts the high-speed DC level voltage.
> > +      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,pre-emphasis-duration-bps:
> > +    $ref: /schemas/types.yaml#/definitions/int32
> > +    description:
> > +      This signal controls the duration for which the
> > +      HS pre-emphasis current is sourced onto DP<#> or DM<#>.
> > +      The HS Transmitter pre-emphasis duration is defined in terms of
> > +      unit amounts. One unit of pre-emphasis duration is approximately
> > +      650 ps and is defined as 1X pre-emphasis duration.
> > +      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,pre-emphasis-amplitude-bps:
> > +    $ref: /schemas/types.yaml#/definitions/int32
> > +    description:
> > +      This signal controls the amount of current sourced to
> > +      DP<#> and DM<#> after a J-to-K or K-to-J transition.
> > +      The HS Transmitter pre-emphasis current is defined in terms of unit
> > +      amounts. One unit amount is approximately 2 mA and is defined as
> > +      1X pre-emphasis current.
> > +      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-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-mv:
> > +    $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-mohm:
> > +    $ref: /schemas/types.yaml#/definitions/int32
> Here and in other places, please use standard units. See
> dtschema/schemas/property-units.yaml in dtschema repo.
>
>
> Best regards,
> Krzysztof

Hi Krzystof, thanks for the input.

I see there are microvolt and microohm units present in 
schemas/property-units.yaml

Would it be possible to add bps (basis point) to the list of standard 
units if it makes sense to use it ?

Regards,

Krishna,