Re: [PATCH v4 1/3] ASoC: dt-bindings: support imx95's CM7 core

[Laurentiu Mihalcea <laurentiumihalcea111@gmail.com>]

On 2/12/2025 2:38 PM, Mark Brown wrote:
> On Wed, Feb 12, 2025 at 12:11:49PM +0200, Daniel Baluta wrote:
>> On Wed, Feb 12, 2025 at 11:38 AM Marco Felsch <m.felsch@pengutronix.de> wrote:
>>> On 25-02-11, Laurentiu Mihalcea wrote:
>>>> +    const: fsl,imx95-cm7-sof
>>> Albeit Krzysztof already add his Reviewed-by, can I ask why we need to
>>> add the -sof suffix instead of -audio or so? SOF is a software project
>>> but you can clearly run different software on the audio-copro as well.
>> Sure you can run a different software project on the audio DSP but
>> you will need a way to distinguish between the different projects.
>> There might be different mailbox, memory configurations. So you will  need
>> to invent another suffix specific to the new project.
>> We can make  const: fsl,imx95-cm7-audio as the one used with SOF
>> and think about a different name later for when another project will
>> want to use the DSP.
> I think the point here was that the DT should stay the same even if the
> DSP firwmare changes, just as how changing the main OS shouldn't affect
> the DT.

It's rather unfortunate but based on the experience from the 8 series
(imx8qm, imx8qxp, imx8mp), the programming model can differ quite
a bit (e.g: remoteproc vs SOF) even if the core is the same (i.e: DSP core).

The different programming models also required different DT configurations
(e.g: dif. mboxes as Daniel mentioned, some extra properties (i.e: reg-names), etc...)

The "-sof" suffix was chosen here instead of the more generic "-audio" (or whatever else
alternative) because the DT configuration is specific to SOF's programming model. Other
audio applications running on the same core may have dif. configurations (e.g: use
DTCM/ITCM for memory instead of DDR, dif. mbox count, etc...). I suppose this kind of thing
is bound to happen to some degree since the DT node doesn't just describe the CM7 core
(but, rather, it also encompasses information on the memory, mboxes, etc. used)
but perhaps I'm wrong?