I am late to the discussion, is there any specific reason to maintain a
separate platform file (c_can_pci.c).

Because it depends on pci and ifdef is bad.

I think 90% of the code is copied from c_can_paltform.c, code
changes will be less if you merge to existing c_can platform driver.

Yes, but then we need to ifdef around, which merges two bad files
into a single but worse file.

But since the only current user of c_can is the platform device, why
not merging the platform with the core and having pci just register a
platform device?  The only problem I see is that we need cooperation,
because neither me nor federico have a c_can equipped board besides
the pci one.

thanks
/alessandro