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From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Tue, 5 Mar 2024 21:03:36 +0200
Message-ID: <CAA8EJpph+R2oJjABvNQYwp=pZLxQPzzs41Hhw4feOdQ3eU-6UA@mail.gmail.com>
Subject: Re: [RFC 1/3] dt-bindings: usb: qcom,dwc3: Add support for multiple power-domains
To: Sriram Dash <quic_sriramd@quicinc.com>
Cc: andersson@kernel.org, konrad.dybcio@linaro.org, vkoul@kernel.org, 
	kishon@kernel.org, robh@kernel.org, krzysztof.kozlowski+dt@linaro.org, 
	conor+dt@kernel.org, gregkh@linuxfoundation.org, quic_wcheng@quicinc.com, 
	Thinh.Nguyen@synopsys.com, p.zabel@pengutronix.de, 
	linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org, 
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, 
	linux-usb@vger.kernel.org, quic_psodagud@quicinc.com, quic_nkela@quicinc.com, 
	manivannan.sadhasivam@linaro.org, ulf.hansson@linaro.org, 
	sudeep.holla@arm.com, quic_shazhuss@quicinc.com
Content-Type: text/plain; charset="UTF-8"

On Tue, 5 Mar 2024 at 18:58, Sriram Dash <quic_sriramd@quicinc.com> wrote:
>
> Some target systems allow multiple resources to be managed by firmware.
> On these targets, tasks related to clocks, regulators, resets, and
> interconnects can be delegated to the firmware, while the remaining
> responsibilities are handled by Linux.
>
> To support the management of partial resources in Linux and leave the rest
> to firmware, multiple power domains are introduced. Each power domain can
> manage one or more resources, depending on the specific use case.
>
> These power domains handle SCMI calls to the firmware, enabling the
> activation and deactivation of firmware-managed resources.
>
> Signed-off-by: Sriram Dash <quic_sriramd@quicinc.com>
> ---
>  .../phy/qcom,sc8280xp-qmp-usb3-uni-phy.yaml        | 74 ++++++++++++++++------
>  .../bindings/phy/qcom,usb-snps-femto-v2.yaml       | 49 ++++++++++++--
>  .../devicetree/bindings/usb/qcom,dwc3.yaml         | 37 ++++++++++-
>  3 files changed, 130 insertions(+), 30 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb3-uni-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb3-uni-phy.yaml
> index 1e2d4dd..53b9ba9 100644
> --- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb3-uni-phy.yaml
> +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb3-uni-phy.yaml
> @@ -44,7 +44,32 @@ properties:
>      maxItems: 5
>
>    power-domains:
> -    maxItems: 1
> +    description: specifies a phandle to PM domain provider node
> +    minItems: 1
> +    maxItems: 2
> +
> +  power-domain-names:
> +    description:
> +      A list of power domain name strings sorted in the same order as the
> +      power-domains property.
> +
> +      For platforms where some resource are firmware managed, the name
> +      corresponding to the index of an SCMI domain provider can be
> +      "usb_core" or "usb_transfer".
> +    items:
> +      - const: usb_core
> +      - const: usb_transfer
> +
> +  qmp,fw-managed:
> +    description:
> +      Some targets allow multiple resources to be managed by firmware.
> +      On these targets, tasks related to clocks, regulators, resets, and
> +      interconnects can be delegated to the firmware, while the remaining
> +      responsibilities are handled by Linux.
> +
> +      Decide if the target resources will be managed by firmware or High level
> +      OS.
> +    type: boolean
>
>    resets:
>      maxItems: 2
> @@ -70,14 +95,6 @@ properties:
>  required:
>    - compatible
>    - reg
> -  - clocks
> -  - clock-names
> -  - resets
> -  - reset-names
> -  - vdda-phy-supply
> -  - vdda-pll-supply
> -  - "#clock-cells"
> -  - clock-output-names
>    - "#phy-cells"
>
>  allOf:
> @@ -86,6 +103,33 @@ allOf:
>          compatible:
>            contains:
>              enum:
> +              - qcom,sa8775p-qmp-usb3-uni-phy
> +              - qcom,sc8280xp-qmp-usb3-uni-phy
> +              - qcom,x1e80100-qmp-usb3-uni-phy
> +    then:
> +      required:
> +        - power-domains
> +
> +  - if:
> +      not:
> +        required:
> +          - qmp,fw-managed
> +    then:
> +      required:
> +        - clocks
> +        - clock-names
> +        - resets
> +        - reset-names
> +        - vdda-phy-supply
> +        - vdda-pll-supply
> +        - clock-output-names
> +        - "#clock-cells"
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
>                - qcom,ipq6018-qmp-usb3-phy
>                - qcom,ipq8074-qmp-usb3-phy
>                - qcom,ipq9574-qmp-usb3-phy
> @@ -144,18 +188,6 @@ allOf:
>              - const: com_aux
>              - const: pipe
>
> -  - if:
> -      properties:
> -        compatible:
> -          contains:
> -            enum:
> -              - qcom,sa8775p-qmp-usb3-uni-phy
> -              - qcom,sc8280xp-qmp-usb3-uni-phy
> -              - qcom,x1e80100-qmp-usb3-uni-phy
> -    then:
> -      required:
> -        - power-domains
> -
>  additionalProperties: false
>
>  examples:
> 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 0f200e3..ad2f08f 100644
> --- a/Documentation/devicetree/bindings/phy/qcom,usb-snps-femto-v2.yaml
> +++ b/Documentation/devicetree/bindings/phy/qcom,usb-snps-femto-v2.yaml
> @@ -49,6 +49,34 @@ properties:
>      items:
>        - const: ref
>
> +  power-domains:
> +    description: specifies a phandle to PM domain provider node
> +    minItems: 1
> +    maxItems: 2
> +
> +  power-domain-names:
> +    description:
> +      A list of power domain name strings sorted in the same order as the
> +      power-domains property.
> +
> +      For platforms where some resource are firmware managed, the name
> +      corresponding to the index of an SCMI domain provider can be
> +      "usb_core" or "usb_transfer".
> +    items:
> +      - const: usb_core
> +      - const: usb_transfer
> +
> +  hsphy,fw-managed:
> +    description:
> +      Some targets allow multiple resources to be managed by firmware.
> +      On these targets, tasks related to clocks, regulators, resets, and
> +      interconnects can be delegated to the firmware, while the remaining
> +      responsibilities are handled by Linux.
> +
> +      Decide if the target resources will be managed by firmware or High level
> +      OS.
> +    type: boolean
> +
>    resets:
>      items:
>        - description: PHY core reset
> @@ -154,12 +182,21 @@ required:
>    - compatible
>    - reg
>    - "#phy-cells"
> -  - clocks
> -  - clock-names
> -  - resets
> -  - vdda-pll-supply
> -  - vdda18-supply
> -  - vdda33-supply
> +
> +
> +allOf:
> +  - if:
> +      not:
> +        required:
> +          - hsphy,fw-managed
> +    then:
> +      required:
> +        - clocks
> +        - clock-names
> +        - resets
> +        - vdda-pll-supply
> +        - vdda18-supply
> +        - vdda33-supply
>
>  additionalProperties: false
>
> diff --git a/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml b/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml
> index 63d150b..5bf3a29 100644
> --- a/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml
> +++ b/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml
> @@ -64,7 +64,31 @@ properties:
>
>    power-domains:
>      description: specifies a phandle to PM domain provider node
> -    maxItems: 1
> +    minItems: 1
> +    maxItems: 2
> +
> +  power-domain-names:
> +    description:
> +      A list of power domain name strings sorted in the same order as the
> +      power-domains property.
> +
> +      For platforms where some resource are firmware managed, the name
> +      corresponding to the index of an SCMI domain provider can be
> +      "usb_core" or "usb_transfer".
> +    items:
> +      - const: usb_core
> +      - const: usb_transfer
> +
> +  qcom,fw-managed:
> +    description:
> +      Some targets allow multiple resources to be managed by firmware.
> +      On these targets, tasks related to clocks, regulators, resets, and
> +      interconnects can be delegated to the firmware, while the remaining
> +      responsibilities are handled by Linux.
> +
> +      Decide if the target resources will be managed by firmware or High level
> +      OS.
> +    type: boolean

I think this is an overkill. You know that SA8775 is going to use
SCMI-based clocks / PD management. Thus I'd suggest adding new
bindings file targeting qcom,sa8775-dwc3. Also you can drop the
qcom,fw-managed property at all, let the driver decide basing on the
compat string.


>
>    required-opps:
>      maxItems: 1
> @@ -148,13 +172,20 @@ required:
>    - "#address-cells"
>    - "#size-cells"
>    - ranges
> -  - clocks
> -  - clock-names
>    - interrupts
>    - interrupt-names
>
>  allOf:
>    - if:
> +      not:
> +        required:
> +          - qcom,fw-managed
> +    then:
> +      required:
> +        - clocks
> +        - clock-names
> +
> +  - if:
>        properties:
>          compatible:
>            contains:
> --
> 2.7.4
>
>


--
With best wishes
Dmitry