avoid syscon fallback class for getting regmap

[Simon Glass]

Hi Frank,

On Wed, 10 Jul 2024 at 14:43, Frank Wunderlich <frank-w at public-files.de> wrote:
>
> 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).

One option is to create a new driver in a new file and have its ops
use the syscon ops. See for example
arch/arm/mach-rockchip/rk3399/syscon_rk3399.c

Regards,
Simon