On Tue, 19 Mar 2024 at 14:03, Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx> wrote: > > On 19/03/2024 15:05, Naushir Patuck wrote: > > On Tue, 19 Mar 2024 at 13:02, Krzysztof Kozlowski > > <krzysztof.kozlowski@xxxxxxxxxx> wrote: > >> > >> On 19/03/2024 13:57, Naushir Patuck wrote: > >>>>>> > >>>>>> See writing bindings. Compatibles should be SoC specific. In some cases > >>>>>> generic fallbacks make sense, in some note. But don't just choose > >>>>>> "generic fallback" because you want. Provide rationale. > >>>>> > >>>>> If the compatible is SoC specific, I suppose "raspberrypi,rp1-cfe" > >>>>> would be the correct string. > >>>> > >>>> Sure, but then please think what if rp1 is on Rpi6, called exactly the > >>>> same (rp1), with some minor differences? Could it be? > >>> > >>> Yes, this is definitely possible. In such cases, I would expect the > >>> hardware to have a version register that would be queried by the > >>> driver to adjust for minor differences, and the compatible string > >>> remains the same. Does that seem reasonable? > >> > >> The "would expect" is concerning. The register(s) must be there already, > >> with proper value. > >> > > > > A version register already exists in the current hardware, so we will > > update it to identify future hardware revisions. > > But that's a version register for the FE block, not for the whole > module, right? Are you suggesting that you'll make sure the FE version > will be changed every time anything in the bigger CFE block is changed, > and thus the FE version would also reflect the whole CFE version? Yes, we will update the FE versioning when either CSI2 / FE blocks are updated. > > Can there be versions without the FE block, with just the CSI-2 parts? There is no version register just in the CSI2 block in isolation, so this is not possible. > > Also, I'm still wondering about the RP1 part there in the compatible > string. Is it necessary? The CFE is located in the RP1 co-processor, but > is that relevant? > > Is there a versioning for the whole RP1 chip? Maybe it's going to the > wrong direction if we use the board/SoC for this compatible name, as > it's actually the RP1 where the CFE is located in, not the SoC. > I don't really know the conversion required to answer this one. Logically CFE is on RP1, so it makes sense to me to have "rp1" in the string, but I will follow the judgment of the maintainers. Regards, Naush
