Re: [PATCH v2] ARM: dts: sun8i-h3: add sy8106a to orange pi plus

From: Maxime Ripard
Date: Mon Oct 01 2018 - 14:42:25 EST


On Sat, Sep 29, 2018 at 03:18:30PM +0200, jorik@xxxxxxxxxxxxxx wrote:
> From: Jorik Jonker <jorik@xxxxxxxxxxxxxx>
>
> The Orange Pi Plus board lacks voltage scaling capabilities in its
> current form. This results in random freezes during boot when cpufreq is
> enabled, probably due to wrong voltages.
>
> This patch (more or less copy/paste from 06139c) does the following
> things on this board:
> - enable r_i2c
> - add sy8106a to the r_i2c bus
> - have the sy8106a regulate VDD of cpu
>
> Since the Orange Pi Plus has the same PMU setup as the Orange Pi PC, I
> simply took min/max/fixed/ramp from the latter DTS. In that file the
> origin of the values are described by the following comment:
>
> "The datasheet uses 1.1V as the minimum value of VDD-CPUX,
> however both the Armbian DVFS table and the official one
> have operating points with voltage under 1.1V, and both
> DVFS table are known to work properly at the lowest
> operating point.
> Use 1.0V as the minimum voltage instead."
>
> I have tested this on patch two Orange Pi Plus boards, by running a
> kernel with this patch and do intermettent runs of cpuburn while
> monitoring voltage, frequency and temperature. The board runs stable
> across its operatiing points while showing a reasonable (< 40C)
> temperature. My Orange Pi PC, when put to the same test, yields similar
> stable results.
>
> Signed-off-by: Jorik Jonker <jorik@xxxxxxxxxxxxxx>

Queued for 4.21, thanks!
Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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