Re: [PATCH 14/16] arm64: dts: axis: Add initial device tree support

[Krzysztof Kozlowski <krzk@kernel.org>]

On 10/07/2025 09:48, Arnd Bergmann wrote:
> On Thu, Jul 10, 2025, at 02:20, ksk4725@coasia.com wrote:
>> From: sungminpark <smn1196@coasia.com>
>>
>> Add initial device tree support for Axis ARTPEC-8 SoC and Grizzly board.
>> This SoC contains four cores of cortex-a53 CPUs and other various
>> peripheral IPs.
> 
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index fa1e04e87d1d..371005f3f41a 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -2320,6 +2320,20 @@ F:	drivers/crypto/axis
>>  F:	drivers/mmc/host/usdhi6rol0.c
>>  F:	drivers/pinctrl/pinctrl-artpec*
>>
>> +ARM/ARTPEC ARM64 MACHINE SUPPORT
>> +M:	Jesper Nilsson <jesper.nilsson@axis.com>
>> +M:	Ravi Patel <ravi.patel@samsung.com>
>> +M:	SeonGu Kang <ksk4725@coasia.com>
>> +M:	SungMin Park <smn1196@coasia.com>
>> +L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
>> +L:	linux-samsung-soc@vger.kernel.org
>> +L:	linux-arm-kernel@axis.com
>> +S:	Maintained
>> +F:	Documentation/devicetree/bindings/clock/axis,artpec*-clock.yaml
>> +F:	arch/arm64/boot/dts/axis/
>> +F:	drivers/clk/samsung/clk-artpec*.c
>> +F:	include/dt-bindings/clock/axis,artpec*-clk.h
> 
> I'm trying to understand the SoC family tree here. I see that
> you have an entry for ARTPEC SoCs above it, which currently
> covers artpec6 (Cortex-A9, apparently not Samsung based).
> 
> Is the reason for having two entries here that artpec6/7 and
> artpec8/9 are two separate SoC families, or is this just because
> they are using 32-bit and 64-bit cores, respectively?

These should be entirely different families. Artpec6 was not done by
Samsung and this one - Artpec 8 - is basically Samsung SoC, just like
they did designs for Tesla and Google GS101.

I don't know about Artpec 9.

All this should be explained in DTS or bindings commit msg, btw.

> 
>>
>> +config ARCH_ARTPEC
>> +	bool "Axis Communications ARTPEC SoC Family"
>> +	help
>> +	   This enables support for the ARMv8 based ARTPEC SoC Family.
>> +
>> +config ARCH_ARTPEC8
>> +	bool "Axis ARTPEC-8 SoC Platform"
>> +	depends on ARCH_ARTPEC
>> +	depends on ARCH_EXYNOS
>> +	select ARM_GIC
>> +	help
>> +	  This enables support for the Axis ARTPEC-8 SoC.
>> +
> 
> I would prefer to be less fine-grained here, especially as
> it seems that ARTPEC9 is again quite similar to ARTPEC8, as
> far as I can guess from public information.
> 
> Could you fold both entries into a single ARCH_ARTPEC?

So far ARCH_ARTPEC = ARCH_ARTPEC8, so obviously it can be folded. I
don't know if Artpec 9 will ever be upstreamed. This Artpec 8 is like 4
or 5 year effort - they sent first patches some years ago, but DTS was
not ready. Therefore I think we should not assume there will be Artpec 9
yet. If it comes, we can always split things.


Best regards,
Krzysztof