Re: [PATCH v2 3/8] dt-bindings: mips: realtek: Add rtl930x-soc compatible

[Krzysztof Kozlowski <krzk@kernel.org>]

On 26/06/2024 23:01, Chris Packham wrote:
>>>>> +              - realtek,rtl9302c
>>>> Why board has the name of SoC?
>>> What I have is actually a reference board with the name
>>> RTL9302C_2xRTL8224_2XGE. If found that a bit incomprehensible so I
>>> (over) shortened it. Technically it would be something like
>>> cameo,rtl9302c-2x-rtl8224-2xge which I can include in the next round.
>> Looks fine to me.
>>
>>>>> +          - const: realtek,rtl9302-soc
>>>> Drop the -soc suffix. The rtl9302 is the soc.
>>> On that. I hope to eventually add "realtek,rtl9302-switch" for the DSA
>>> switch block in the same chip. So keeping the -soc suffix was
>>> intentional to try to disambiguate things. I can drop the -soc if the
>>> consensus is that there is no need to disambiguate the two.
>> Thanks for explanation, kind of depends on what exactly is this. Most of
>> SoCs comprise of several items. The entire chip is the soc, e.g.
>> "qcom,foo1234". It might have MAC/Ethernet/whatever inside, controllable
>> by the SoC (Linux, bootloader, TF, hypervisor, other VM guest) and that
>> part is "qcom,foo1234-ethernet". Regardless whether Linux OS actually
>> controls it or not.
>>
>> The question is whether DSA switch is part of the SoC or not.
> 
> The RTL9302C is a single package but I'd assume internally it has 
> multiple dies.
> 
>  From the block diagram in the datasheet they do have a portion they 
> call the "SoC" which has the CPU and peripherals like UARTs, GPIOs, SPI 
> etc. That is separate from the switch block which has a bunch of MACs, 
> SERDES and various network switch tables. So based on that 
> "realtek,rtl9302-soc" and "realtek,rtl9302-switch" as two separate 
> things make sense to me.
> 

OK, -soc and -switch are fine with me.

> I'm still trying to figure out a bit more of the details. The block 
> diagram looks a lot like you'd expect to see with a traditional DSA 
> switch where you have a SoC Ethernet NIC/MAC connected to one port of a 
> switch. But getting into the datasheet it looks like what they call the 
> NIC is actually just the DMA portion of the switch as the registers are 
> all in that second block. As is the MDIO interface. I'm considering that 
> maybe the DSA model isn't right for this and I should be looking at 
> switchdev instead.



Best regards,
Krzysztof