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

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Krishna Kurapati <quic_kriskura@quicinc.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Rob Herring <robh+dt@kernel.org>, Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Stephen Boyd <swboyd@chromium.org>,
	Doug Anderson <dianders@chromium.org>,
	Matthias Kaehlcke <mka@chromium.org>,
	Wesley Cheng <quic_wcheng@quicinc.com>,
	Vinod Koul <vkoul@kernel.org>
Cc: devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-phy@lists.infradead.org, quic_pkondeti@quicinc.com,
	quic_ppratap@quicinc.com, quic_vpulyala@quicinc.com,
	Sandeep Maheswaram <quic_c_sanm@quicinc.com>
Subject: Re: [v4 1/3] dt-bindings: phy: qcom,usb-snps-femto-v2: Add phy override params bindings
Date: Wed, 11 May 2022 20:19:46 +0200	[thread overview]
Message-ID: <d296720d-ccbe-27f0-8ba1-9653af25dd52@linaro.org> (raw)
In-Reply-To: <1652282793-5580-2-git-send-email-quic_kriskura@quicinc.com>

On 11/05/2022 17:26, Krishna Kurapati wrote:
> From: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> 
> Add device tree bindings for SNPS phy tuning parameters.
> 
> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> Signed-off-by: Krishna Kurapati <quic_kriskura@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..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