Received-SPF: pass (google.com: domain of linux-kernel+bounces-94196-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Message-ID: <4f1e4e66-e728-472e-92f4-17c295548a14@quicinc.com>
Date: Wed, 6 Mar 2024 21:21:37 +0530
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [RFC 1/3] dt-bindings: usb: qcom,dwc3: Add support for multiple
 power-domains
Content-Language: en-US
To: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
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>
References: <1709657858-8563-1-git-send-email-quic_sriramd@quicinc.com>
 <1709657858-8563-2-git-send-email-quic_sriramd@quicinc.com>
 <CAA8EJpph+R2oJjABvNQYwp=pZLxQPzzs41Hhw4feOdQ3eU-6UA@mail.gmail.com>
From: Sriram Dash <quic_sriramd@quicinc.com>
In-Reply-To: <CAA8EJpph+R2oJjABvNQYwp=pZLxQPzzs41Hhw4feOdQ3eU-6UA@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit

On 3/6/2024 12:33 AM, Dmitry Baryshkov wrote:
> 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.
> 
> 

Thank you for the suggestion Dmitry. I will include
new compat string for SA8775 which will decide whether
to use scmi based clock/ PD.

>>
>>     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