On Mon, 8 Jul 2024 14:23:44 +0200 Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote: > Hi Krzysztof, > > krzk@xxxxxxxxxx wrote on Mon, 8 Jul 2024 09:33:04 +0200: > > > On 08/07/2024 08:30, Miquel Raynal wrote: > > > Hi Conor, > > > > > >>>>> +properties: > > >>>>> + compatible: > > >>>>> + oneOf: > > >>>>> + - items: > > >>>>> + - enum: > > >>>>> + - sophgo,cv1800b-saradc > > >>>>> + - const: sophgo,cv18xx-saradc > > >>>> > > >>>> I don't think the fallback here makes sense. If there's other devices > > >>>> with a compatible programming model added later, we can fall back to the > > >>>> cv1800b. > > > > > > I'm sorry but isn't this slightly disagreeing with the "writing > > > bindings" doc pointed in v1? It says, > > > > > > * DO use fallback compatibles when devices are the same as or a subset > > > of prior implementations. > > > > > > I believe we fall in the "devices are the same" category, so I would > > > have myself wrote a similar binding here with a compatible matching > > > them all, plus a hardware-implementation-specific compatible as well; > > > just in case. > > > > Fallback from one model to another. There is no "another" model here, > > but wildcard. There is no such device as cv18xx, right? > > No there is not. But I don't think there is a "base" model either. > Just multiple SoCs named cv18<something> with apparently the same ADC. > > So actually I guess the discussion here is about the wildcard > compatible. It feels strange to me to have no generic compatible either > with a wildcard or with a "base" implementation (because there is > probably none). So I guess the solution here is to just list a single > specific compatible in the end. It comes from long experience of silicon vendors not being consistent with part naming. Far too often we've had a nice generic wild card entry and along comes the vendor with a new part in the middle of that range that is completely incompatible. Then we end up with people assuming the wildcard means it will work and a bunch of bug reports. Hence no wild cards, just define first supported part as your 'base' and go from there. It's even more fun when a vendor driver papers over the differences and so it 'works', but the upstream one doesn't. In extreme case because a different driver entirely is required. So basically we don't trust silicon vendors :) Speaking as someone who works for one - I think that's entirely reasonable!! Jonathan > > Thanks, > Miquèl > >
