Quite a few reference platforms (including Wolfson ones, which is why I'm particularly interested) use replaceable modules to allow configuration changes. Since we can often identify the configuration at runtime we should ideally do that but currently there's no infrastructure to help with that, generally this seems to be done in arch code for the machine but this doesn't scale when even the CPU might change and isn't terribly device tree compatible either. For reference the code for current Wolfson plugin modules is in arch/arm/mach-s3c64xx/mach-crag6410-module.c. The most obvious current fit here is the MFD subsystem but it feels like we need some slightly different infastructure to what MFD currently provides. MFD is really set up to handle platform devices with a core and linear ranges of resources fanning out from that core since they're really oriented around chips. In contrast these boards are more about remapping random collections of potentially unrelated resources and instantiating devices on all sorts of buses and share more with board files. I'm just starting to put some stuff together for this so I was wondering if anyone had been thinking about this and had any bright ideas for how to handle it, and also if people think that MFD is a good fit for this or if we should split the silicon MFDs from these PCBs.
Attachment:
signature.asc
Description: Digital signature
