Re: [PATCH v3 00/28] ARM: qcom: apq8064: support CPU frequency scaling

Dmitry Baryshkov
2023-07-07T10:59:45Z

On Fri, 7 Jul 2023 at 12:34, Linus Walleij <linus.walleij@linaro.org> wrote:
>
> On Sun, Jul 2, 2023 at 7:43 PM Dmitry Baryshkov
> <dmitry.baryshkov@linaro.org> wrote:
>
> > Implement CPUFreq support for one of the oldest supported Qualcomm
> > platforms, APQ8064. Each core has independent power and frequency
> > control. Additionally the L2 cache is scaled to follow the CPU
> > frequencies (failure to do so results in strange semi-random crashes).
> >
> > Core voltage is controlled through the SAW2 devices, one for each core.
> > The L2 has two regulators, vdd-mem and vdd-dig.
> >
> > Dependencies: [1].
> >
> > [1] https://lore.kernel.org/linux-arm-msm/20230702134320.98831-1-dmitry.baryshkov@linaro.org/
>
> Just because it looks so cool, I applied this patches and the prerequisite
> to master and booted the result on the APQ8060 DragonBoard, and
> it still works.
> Tested-by: Linus Walleij <linus.walleij@linaro.org>
> (Mostly for the DTS refactoring, which is what affects APQ8060)
>
> I guess the APQ8064 cpufreq and APQ8060 isn't actually far
> apart, so it should be possible to fix APQ8060 as well, but we
> can take that another day. I always wanted to fix the SAW2
> regulators.

APQ8060 (as well as MSM8260 / MSM8660) were a previous generation of
the cores, Scorpion vs Krait. So far it requires two items to work:
SCPLL, the core pll driver, and the fixed AVS setting (which might
also be required for MSM8960). Let me take a glance in the next couple
of days.

--
With best wishes
Dmitry