Quoting Geert Uytterhoeven (2021-03-26 05:00:53)
> Hi Mike, Stephen,
>
> This patch series improves the accuracy of the CPU clock rate on R-Car
> Gen3 SoCs, and adds support for CPU boost modes (marked "turbo-mode" in
> the operating points table in DT).
> As usual, it is preceded by a few small cleanups.
>
> The easiest way to test this is by enabling
> CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE, and writing the requested clock
> rate to /sys/devices/system/cpu/cpufreq/policy$n/scaling_setspeed
> (n=0 for the first cluster, n=2 or 4 for the second cluster).
> Note that you need to do
>
> echo 1 > /sys/devices/system/cpu/cpufreq/boost
>
> before you can enable boost modes.
>
> The PLL rates and CPU clock rates and voltages can be monitored in
> /sys/kernel/debug/{clk/{z,z2,.pll[024]}/clk_rate,reg*/dvfs/cpu*/*uV}.
> The DVFS voltage measured by the on-board max9611 can be monitored
> remotely using iio-monitor.
>
> This series has been tested on Salvator-(X)S (with R-Car H3 ES1.0, H3
> ES2.0, M3-W, and M3-N) and Ebisu-4D (R-Car E3).
>
> As boost modes may be unstable without increasing the CPU core voltage,
> this series depends on "[PATCH 0/2] arm64: dts: renesas: Add cpu-supply
> properties for DVFS"[1]. Hence I think it is better to postpone this to
> v5.14.
>
> Thanks for your comments!
>
Acked-by: Stephen Boyd <sboyd@xxxxxxxxxx>
