Re: [PATCH v8 1/3] dt-bindings: phy: qcom,usb-snps-femto-v2: Add phy override params bindings

[Krishna Kurapati PSSNV]

On 6/8/2022 3:06 PM, Krzysztof Kozlowski wrote:
> On 01/06/2022 08:56, 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>
> > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> > ---
> >   .../bindings/phy/qcom,usb-snps-femto-v2.yaml       | 96 ++++++++++++++++++++++
> >   1 file changed, 96 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..daeeb04 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 +53,102 @@ properties:
> >     vdda33-supply:
> >       description: phandle to the regulator 3.3V supply node.
> >   
> > +  qcom,hs-disconnect-bp:
> > +    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%).
> > +      The hardware accepts only discrete values. The value closest to the
> > +      provided input will be chosen as the override value for this param.
> > +    minimum: -272
> > +    maximum: 2156
> > +
> > +  qcom,squelch-detector-bp:
> > +    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.
> > +    minimum: -2090
> > +    maximum: 1590
> > +
> > +  qcom,hs-amplitude-bp:
> > +    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.
> > +    minimum: -660
> > +    maximum: 2670
> > +
> > +  qcom,pre-emphasis-duration-bp:
> > +    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.
> > +    minimum: 10000
> > +    maximum: 20000
> > +
> > +  qcom,pre-emphasis-amplitude-bp:
> > +    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.
> > +    minimum: 10000
> > +    maximum: 40000
> > +
> > +  qcom,hs-rise-fall-time-bp:
> > +    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.
> > +    minimum: -4100
> > +    maximum: 5430
> > +
> > +  qcom,hs-crossover-voltage-microvolt:
> > +    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.
> It's not accurate anymore - it's microvolt. I propose to skip this one
> sentence, because unit is obvious from the type.

Hi Krzysztof,

Sure, will omit this line in the next series.

> > +    maximum: 28000
> > +
> > +  qcom,hs-output-impedance-micro-ohms:
> > +    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 milli ohms.
> The same. Other places might need similar change.
>
> Best regards,
> Krzysztof

Sure, Will make sure to remove the basis points sentence from other 
params as well as bp has been added to dtschema and is self-explanatory.


Thanks,

Krishna,