Re: [RFC/RFT v3 14/14] arm64: dts: meson-g12b-odroid-n2: enable DVFS

From: Martin Blumenstingl
Date: Tue Jul 02 2019 - 20:39:49 EST


On Mon, Jul 1, 2019 at 11:13 AM Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote:
>
> Enable DVFS for the Odroid-N2 by setting the clock, OPP and supply
> for each cores of each CPU clusters.
>
> The first cluster uses the "VDDCPU_B" power supply, and the second
> cluster uses the "VDDCPU_A" power supply.
>
> Each power supply can achieve 0.73V to 1.01V using 2 distinct PWM
> outputs clocked at 800KHz with an inverse duty-cycle.
>
> DVFS has been tested by running the arm64 cpuburn at [1] and cycling
> between all the possible cpufreq translations of each cluster and
> checking the final frequency using the clock-measurer, script at [2].
>
> [1] https://github.com/ssvb/cpuburn-arm/blob/master/cpuburn-a53.S
> [2] https://gist.github.com/superna9999/d4de964dbc0f84b7d527e1df2ddea25f
>
> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>

[...]
> + vddcpu_b: regulator-vddcpu-b {
> + /*
> + * Silergy SY8120B1ABC Regulator.
> + */
interesting that they use different regulator ICs for CPU A and CPU B
the public schematics confirm your comments