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

George Kashperko
2011-04-15T19:53:38Z

> W dniu 15 kwietnia 2011 20:36 użytkownik George Kashperko
> <george@znau.edu.ua> napisał:
> >> >> 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.
>
> Yeah, as I suspected, everything except Broadcom specific cores
> matches AMBA standards quite nicely. Still, I don't see anything in it
> we could use for driver.
>
> Let's wait for Russell and Arnd to comment.
>

Btw, googling for PL366, PL367, PL368 gives nothing relevant except one
reference to "NIC-301 Interconnect Device Management (PL368)" which is
restricted to arm partners. Think it have something to do with that
magic "DMP - Device Management Plugin" Broadcom guys mentioned earlier.
Might those 0xBB/0x368 cores are produced with that "plugin".

Have nice day,
George