Re: [PATCH 0/6] arm64: ti: Use syscon for the Control Module

[Tomi Valkeinen]

Hi Andrew,

On 29/05/2026 01:59, Andrew Davis wrote:
> On 5/28/26 7:53 AM, Tomi Valkeinen wrote:
> > I have been trying to get BeagleY-AI display support to upstream:
> >
> > 20260513-beagley-ai-display-v2-0-9e9bcefde6bc@xxxxxxxxxxxxxxxx
> >
> > One difficulty has been the handling of the Control Module region, as
> > we need access to a single in that region, surrounded by registers for
> > other subsystems. In my series I made the related node a syscon, thus
> > allowing versatile access to the registers:
> >
> > https://lore.kernel.org/all/20260513-beagley-ai-display- 
> > v2-14-9e9bcefde6bc@xxxxxxxxxxxxxxxx/
> >
> > However, that's not a correct way to handle it. I realized we already
> > have ti,j721e-system-controller.yaml binding for older SoCs, which has
> > syscon but it's not used for the newer TI SoCs. This series takes the
> > same binding into use for the newer SoCs.
>
> We moved away from this system-controller thing because it was always
> a hack to allow us to poke into random control registers from nodes
> throughout the DT. This was a mess and also caused issues with multiple
> mappings to the same registers (some sub nodes inside the control space
> also make their own mappings). If you need access to registers then make
> a node with those registers in the `reg` property.

Like in this patch (dss_dpi0_clk_ctrl)?

https://lore.kernel.org/all/20260420-beagley-ai-display-v1-14-f628543dfd14%40ideasonboard.com/

My understanding is that that's NACKed, as we end up adding new syscon 
compats and syscon nodes for (possibly many) single register blocks.

 Tomi