linux-kernel - Re: [PATCH v2 1/3] dt-bindings: power: Introduce 'assigned-performance-states' property

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Message-ID: <4245f8c0-bafb-3c80-ff4b-8db4855f1432@codeaurora.org>
Date:   Fri, 18 Jun 2021 11:31:58 +0530
From:   Rajendra Nayak <rnayak@...eaurora.org>
To:     Ulf Hansson <ulf.hansson@...aro.org>
Cc:     Rob Herring <robh+dt@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        DTML <devicetree@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        Stephen Boyd <swboyd@...omium.org>,
        Roja Rani Yarubandi <rojay@...eaurora.org>
Subject: Re: [PATCH v2 1/3] dt-bindings: power: Introduce
 'assigned-performance-states' property


On 6/15/2021 8:35 PM, Ulf Hansson wrote:
> On Thu, 27 May 2021 at 08:13, Rajendra Nayak <rnayak@...eaurora.org> wrote:
>>
>> While most devices within power-domains which support performance states,
>> scale the performance state dynamically, some devices might want to
>> set a static/default performance state while the device is active.
>> These devices typically would also run off a fixed clock and not support
>> dynamically scaling the device's performance, also known as DVFS techniques.
>> Add a property 'assigned-performance-states' which client devices can
>> use to set this default performance state on their power-domains.
>>
>> Signed-off-by: Rajendra Nayak <rnayak@...eaurora.org>
> 
> Rajendra, I think this is ready to be re-spinned on top of the latest
> changes for genpd that Rafael recently queued [1].

Thanks Ulf, yes, I plan to re-spin these based on the recent discussions,
re-using the existing required-opps bindings soon.
  
> If you would prefer me to do it, then please let me know. Otherwise I
> will be awaiting a new version from you.
> 
> Kind regards
> Uffe
> 
> [1]
> https://lore.kernel.org/linux-pm/CAJZ5v0i0FD-F7tN=AJNEY5HVVTCNuciLT4hCqdoS5bgF5WdmaA@mail.gmail.com/
> 
>> ---
>>   .../devicetree/bindings/power/power-domain.yaml    | 50 ++++++++++++++++++++++
>>   1 file changed, 50 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/power/power-domain.yaml b/Documentation/devicetree/bindings/power/power-domain.yaml
>> index aed51e9..88cebf2 100644
>> --- a/Documentation/devicetree/bindings/power/power-domain.yaml
>> +++ b/Documentation/devicetree/bindings/power/power-domain.yaml
>> @@ -66,6 +66,19 @@ properties:
>>         by the given provider should be subdomains of the domain specified
>>         by this binding.
>>
>> +  assigned-performance-states:
>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>> +    description:
>> +       Some devices might need to configure their power domains in a default
>> +       performance state while the device is active. These devices typically
>> +       would also run off a fixed clock and not support dynamically scaling the
>> +       device's performance, also known as DVFS techniques. The list of performance
>> +       state values should correspond to the list of power domains specified as part
>> +       of the power-domains property. Each cell corresponds to one power-domain.
>> +       A value of 0 can be used for power-domains with no performance state
>> +       requirement. In case the power-domains have OPP tables associated, the values
>> +       here would typically match with one of the entries in the OPP table.
>> +
>>   required:
>>     - "#power-domain-cells"
>>
>> @@ -131,3 +144,40 @@ examples:
>>               min-residency-us = <7000>;
>>           };
>>       };
>> +
>> +  - |
>> +    parent4: power-controller@...40000 {
>> +        compatible = "foo,power-controller";
>> +        reg = <0x12340000 0x1000>;
>> +        #power-domain-cells = <0>;
>> +    };
>> +
>> +    parent5: power-controller@...10000 {
>> +        compatible = "foo,power-controller";
>> +        reg = <0x43210000 0x1000>;
>> +        #power-domain-cells = <0>;
>> +        operating-points-v2 = <&power_opp_table>;
>> +
>> +        power_opp_table: opp-table {
>> +            compatible = "operating-points-v2";
>> +
>> +            power_opp_low: opp1 {
>> +                opp-level = <16>;
>> +            };
>> +
>> +            rpmpd_opp_ret: opp2 {
>> +                opp-level = <64>;
>> +            };
>> +
>> +            rpmpd_opp_svs: opp3 {
>> +                opp-level = <256>;
>> +            };
>> +        };
>> +    };
>> +
>> +    child4: consumer@...41000 {
>> +        compatible = "foo,consumer";
>> +        reg = <0x12341000 0x1000>;
>> +        power-domains = <&parent4>, <&parent5>;
>> +        assigned-performance-states = <0>, <256>;
>> +    };
>> --
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
>> of Code Aurora Forum, hosted by The Linux Foundation
>>

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation