Re: Could I (ab)use bus (struct bus_type) for virtual Broadcom bus?

George Kashperko
2011-04-15T18:39:59Z

> >> Arnd: I found you saying:
> >> > I believe the one thing we really want from this driver is the bus
> >> > scan code, which is not present in the amba bus implementation,
> >> I explained how it works, I believe scanning (EPROM in this case) it
> >> Broadcom specific, not really AMBA standard. How do you see it?
> >>
> > It might not Broadcom specific as EPROM core seems to be CoreLink one
> > core and maybe is arm-developed. But it isn't documented publicly and we
> > don't know yet if it is obligatory for all amba (or at least axi)
> > interconnects or not.
>
> Maybe EPROM is not Broadcom specific, but I suspect the content we
> deal with in bcmai/axi is Broadcom specific. I didn't see any notes of
> manuf/id/rev/class we deal with. So I guess everything *we* (out
> driver) read from EPROM is Bcm specific.
>

Played around amba registers on bcm4716. For all amba cores present
(under all I mean broadcom ip core agents, oob router core, erom core,
and other I-dont-know-what-for cores present at 0x18100000). All those
feature AMBA_CID (0xb105f00d) as PrimeCell ID, and slightly different
PrimeCell PeripheralIDs:
* vendor 0xBB, part_number 0x368 for broadcom cores' agents;
* vendor 0xBB, part_number 0x367 for OOB router core (don't ask me wth
is this please);
* vendor 0xBB, part_number 0x366 for EROM core;

ARM vendor id is 0x41. Might 0xBB is Broadcom vendor id but I've found
no evidence for that with google.

Have nice day,
George