Messages in this thread | | | Date | Tue, 20 Aug 2019 08:31:14 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH v2 0/9] Exynos Adaptive Supply Voltage support |
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On 19-08-19, 15:39, Sylwester Nawrocki wrote: > Unfortunately not, the patch set as I see it is another way of updating > an OPP after it was parsed from DT. OPP remove/add could work equally > well in our use case.
Adding OPPs dynamically has limitations, you can't set many values which are otherwise possible with DT. And removing/adding is not the right thing to do technically.
> The problem is that we have the information on how to translate the > common OPP voltage to a voltage specific to given silicon encoded jointly > in the ASV tables and the CHIPID registers (efuse/OTP memory). > Additionally, algorithm of selecting ASV data (OPP voltage) based on > the "key" data from registers is not generic, it is usually different > per each SoC type. > > I tried to identify some patterns in those tables in order to simplify > possible DT binding, but that was not really successful. I ended up just > keeping whole tables.
Sorry but I am unable to understand the difficulty you are facing now. So what I suggest is something like this.
- Use DT to get a frequency and voltage for each frequency. - At runtime, based on SoC, registers, efuses, etc, update the voltage of the OPPs. - This algo can be different for each SoC, no one is stopping you from doing that.
Am I missing something ?
-- viresh
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