linux-kernel - Re: [PATCH 2/3] dt-bindings: opp: opp-v2-kryo-cpu: add opp-microvolt nvmem based

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Message-ID: <c5888e27-18e7-24da-f177-4651fc875269@linaro.org>
Date:   Sun, 22 Jan 2023 15:17:54 +0100
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Christian Marangi <ansuelsmth@...il.com>
Cc:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Ilia Lin <ilia.lin@...nel.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Nishanth Menon <nm@...com>, Stephen Boyd <sboyd@...nel.org>,
        Yassine Oudjana <y.oudjana@...tonmail.com>,
        linux-arm-msm@...r.kernel.org, linux-pm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] dt-bindings: opp: opp-v2-kryo-cpu: add opp-microvolt
 nvmem based

On 22/01/2023 15:15, Christian Marangi wrote:
> On Sun, Jan 22, 2023 at 03:00:22PM +0100, Krzysztof Kozlowski wrote:
>> On 21/01/2023 01:01, Christian Marangi wrote:
>>> The operating-points-v2-kryo-cpu driver supports defining multiple
>>> opp-microvolt based on the blown efuses in the soc. It consist of 3
>>> values that are parsed: speedbin, psv and version. They are all
>>> appended to the opp-microvolt name and selected by the nvmem driver and
>>> loaded dynamically at runtime.
>>>
>>> Example:
>>>
>>> opp-microvolt-speed0-pvs0-v0 = <1050000 997500 1102500>;
>>> opp-microvolt-speed0-pvs1-v0 = <975000 926250 1023750>;
>>> opp-microvolt-speed0-pvs2-v0 = <925000 878750 971250>;
>>> opp-microvolt-speed0-pvs3-v0 = <850000 807500 892500>;
>>>
>>> Add support for this and reject these special binding if we don't have a
>>> nvmem-cell to read data from.
>>>
>>> Signed-off-by: Christian Marangi <ansuelsmth@...il.com>
>>> ---
>>>  .../devicetree/bindings/opp/opp-v2-kryo-cpu.yaml | 16 ++++++++++++++++
>>>  1 file changed, 16 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/opp/opp-v2-kryo-cpu.yaml b/Documentation/devicetree/bindings/opp/opp-v2-kryo-cpu.yaml
>>> index b4947b326773..cea932339faf 100644
>>> --- a/Documentation/devicetree/bindings/opp/opp-v2-kryo-cpu.yaml
>>> +++ b/Documentation/devicetree/bindings/opp/opp-v2-kryo-cpu.yaml
>>> @@ -61,6 +61,17 @@ patternProperties:
>>>  
>>>        required-opps: true
>>>  
>>> +    patternProperties:
>>> +      '^opp-microvolt-speed[0-9]-pvs[0-9]-v[0-9]$':
>>
>> This does not end with correct unit suffix. Should be
>> opp-speed-.....-microvolt
>>
> 
> I think I didn't understand this?
> 
> From opp-v2-base and from what we are using downstream, the named
> opp-micrvolt works correctly.
> 
> (speed[0-9]-pvs[0-9]-v[0-9] is the entire name of the named
> opp-microvolt- binding)
> 
> This is the reference I always used for the pattern. [1]
> Here the pattern used by the driver. [2]
> 
> [1] https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/opp/opp-v2-base.yaml#L209
> [2] https://elixir.bootlin.com/linux/latest/source/drivers/cpufreq/qcom-cpufreq-nvmem.c#L238

Are you documenting existing property or adding new? Commit msg suggests
you add new property, so what do you reference here? How is it related?

> 
>>> +        description: |
>>> +          Assign a microvolt value to the opp hz based on the efuses value from
>>> +          speedbin, pvs and vers
>>
>> Where is the DTS change?
> 
> You mean an additional example that use this additional binding? This
> may be difficult to add since the current example in this schema is a
> root one and I can't put multiple root example.

No, I mean, you DTS using it. We do not want empty (unused) bindings...

Best regards,
Krzysztof