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

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Date:   Sun, 22 Jan 2023 15:35:48 +0100
From:   Christian Marangi <ansuelsmth@...il.com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
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 Sun, Jan 22, 2023 at 03:31:14PM +0100, Krzysztof Kozlowski wrote:
> On 22/01/2023 15:21, Christian Marangi wrote:
> > On Sun, Jan 22, 2023 at 03:17:54PM +0100, Krzysztof Kozlowski wrote:
> >> 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?
> >>
> > 
> > It should have been added from the start when the schema was submitted
> > but I get what you mean with the other question.
> > 
> >>>
> >>>>> +        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...
> >>
> > 
> > Ok, will drop this and make it part of the ipq8064 opp series that will use
> > this binding.
> 
> You can also link the DTS changes, it's also fine.
> 

There are some required changes to do on the driver so the opp series
still have to be submitted so I guess dropping this is the only way
currently. But it's not a problem the real important patch in the series
is the first one.

-- 
	Ansuel