Re: [PATCH 00/37] arm64: Add initial device trees for Apple M2 Pro/Max/Ultra devices

[Janne Grunau <j@jannau.net>]

On Fri, Aug 29, 2025 at 12:11:40AM +0800, Nick Chan wrote:
> 
> Janne Grunau 於 2025/8/28 晚上10:01 寫道:
> > This series adds device trees for Apple's M2 Pro, Max and Ultra based
> > devices. The M2 Pro (t6020), M2 Max (t6021) and M2 Ultra (t6022) SoCs
> > follow design of the t600x family so copy the structure of SoC *.dtsi
> > files.
> [...]
> > After discussion with the devicetree maintainers we agreed to not extend
> > lists with the generic compatibles anymore [1]. Instead either the first
> > compatible SoC or t8103 is used as fallback compatible supported by the
> > drivers. t8103 is used as default since most drivers and bindings were
> > initially written for M1 based devices.
> >
> > The series adds those fallback compatibles to drivers where necessary,
> > annotates the SoC lists for generic compatibles as "do not extend" and
> > adds t6020 per-SoC compatibles.
> 
> The series is inconsistent about the use of generic fallback compatibles.
> 
> "apple,aic2", "apple,s5l-fpwm", "apple,asc-mailbox-v4" is still used.

Those are less generic than say "apple,spi". For "apple,aic2" especially
it's clear which SoCs use it and the set is closed (ignoring iphone SoCs
which very likely will never run linux). For the interrupt controller
the fallout of not using the "apple,aic2" is larger since even m1n1
expect that. irq driver is special in so far as it requires more than
adding a compatible.
I think "apple,s5l-fpwm" and "apple,asc-mailbox-v4" are specific enough
and describe simple hardware so the will not cause issues unlike the
complex firmware based "apple,nvme-ans2".

Janne