On Wed, Nov 06, 2024 at 01:03:08PM +0100, Matthias Schiffer wrote:

On Tue, 2024-11-05 at 18:55 +0000, Conor Dooley wrote:

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On Tue, Nov 05, 2024 at 11:40:20AM +0100, Matthias Schiffer wrote:

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On Mon, 2024-11-04 at 18:47 +0000, Conor Dooley wrote:

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On Mon, Nov 04, 2024 at 10:47:25AM +0100, Matthias Schiffer wrote:

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The TQMa62xx is a SoM family with a pluggable connector. The MBa62xx is
the matching reference/starterkit carrier board.

Why all the wildcards? Why isn't there a compatible per device in the
family?

Because all variants use the same Device Tree. There is also only one compatible and one (main) DTSI
for the AM62 SoC family, which our Device Trees are based on.

So what varies between the members of the family?

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For the compatible string we've chosen the TQMa6254 as the representative for the TQMa62xx family.

And all the boards in the family are the exact same?

There is a single TQMa62xx PCB, which has some AM62 family SoC installed (AM6254 in the case of the
TQMa6254, but all AM62 are possible). TQMa62xx is also the name used for marketing when not talking
about a specific SoC variant:
https://www.tq-group.com/en/products/tq-embedded/arm-architecture/tqma62xx/

Some SoM variants with different RAM/eMMC/SPI-NOR/... do exist, but they don't have separate device
trees (firmware may patch some variant information into the DTB however, like the correct RAM size).

Choosing one representative for the family including the SoC variant number, but not distinguishing
minor variants matches the level of detail used for our other SOMs already supported by mainline
Linux (like the TQMa64xxL and various i.MX-based platforms).

I don't like any of this wildcard stuff at all, who is to say that the
next soc you put on your SoM won't be an am62a7, which has a specific
compatible in the kernel? Your fallback then would be ti,am62a7 not
ti,am625. Probably someone will say "that's the am62a family not the
am62 family" - but that exact thing is why I hate all of this
wildcarding. It's barely any more effort to have a tqm6231 and a tqm6254
compatible than what you're doing with wildcard but it is unambiguous.