avoid syscon fallback class for getting regmap

[Frank Wunderlich]

Hi,

i'm working on OF_UPSTREAM for mediatek boards and noticed missing syscon-fallback on some (mt7988) devicetree nodes.

i know that u-boot uses this fallback to get the regmap shared across drivers, but only initializing once with the syscon_uclass.

i tried adding the syscon-fallback to linux device tree and got pointed [1] back to uboot to solve the issue there...

are there any ways to avoid syscon in device tree and get the regmap of different node?

i guess i could use [2], but then it is possible to aquire same regmap multiple times which may result in issues (e.g. race-conditions).
I also want to avoid creating multiple drivers doing the exactily same thing like syscon.

one easy (but maybe unwanted way) is to add all compatibles for affected syscons to the syscon driver...but then it is no more generic (baed on compatibles then vendor-specific).

regards Frank

[1] https://lkml.org/lkml/2024/7/10/669
[2] https://elixir.bootlin.com/u-boot/latest/source/drivers/core/regmap.c#L242