Re: [PATCH 3/3] ARM: tegra: Pass multiple versions in opp-supported-hw property

[Dmitry Osipenko]

31.08.2020 11:41, Viresh Kumar пишет:
> On 31-08-20, 10:54, Dmitry Osipenko wrote:
>> 31.08.2020 07:39, Viresh Kumar пишет:
>> ...
>>>>> Dmitry, I think there is further scope of simplifying stuff here by
>>>>> using the opp-microvolt-<name> property and corresponding
>>>>> dev_pm_opp_set_prop_name() call.
>>>
>>> Any inputs on this Dmitry ?
>>
>> Could you please give an example?
> 
> There are many users of it in the kernel. grep for "opp-microvolt-" in
> the DT files and you will see.
> 
> The use of this property is to specific multiple microvolt properties
> to the same frequency without a need to create separate nodes for them
> all. The right microvolt property will be selected based on the call
> made to dev_pm_opp_set_prop_name(), search for that too in kernel.
> 

It's not clear to me how it could be applicable to the Tegra CPU OPP
because Tegra depends on a combination of SPEEDO + PROCESS versions.

It's not like all voltages are the same for all OPPs that have the same
PROCESS ID, otherwise it indeed would be nice to have
"opp-microvolt-process0", but unfortunately this variant is not suitable
for Tegra because some freqs have different voltages using the same
PROCESS ID and the same applies to the SPEEDO ID.