[PATCH v8 2/2] arm64: dts: rockchip: Add ALIENTEK QuarkPi-CA2

[Bob Hui]

Hi Shawn,

Thanks for the review.

The 3.3 V rail of the M.2 E-key socket (VCC3V3_PCIE) is not a PMIC output:
it is generated by its own buck on the M.2/WiFi sheet (U36, SY8089AAC),
fed from the board input rail, and its EN pin is tied high through R246
(10k), with the 100 nF capacitor on that pin (C477) not populated. There
is no GPIO for it, so Linux cannot gate the rail.

That is why it carries always-on/boot-on - to state that the rail is not
switchable. Boards where the M.2 3.3 V rail has an enable GPIO, like
rk3568-rock-3a, omit them; for a fixed rail this pair is the usual
description, as in rk3566-soquartz-model-a.dts.

If you would rather the rail was not described at all, I can drop the node
and the vpcie3v3-supply reference; the hardware is the same either way.

Thanks,
Bob