> W dniu 15 kwietnia 2011 20:36 uÅytkownik George Kashperko > <george@xxxxxxxxxxx> napisaÅ: > >> >> 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. Summarising the differences and similarities in broadcom core management for ssb and amba I think on another possibility on making bus-related things. SSB-attached cores were OCP-compliant ones. This resulted in OCP device identification with 16-bit vendor id, 12-bit core id with all IDs starting with 0x800. 4-bit revision code. Also seems this implied status/control registers. AMBA-attached broadcom cores seems to follow this reusing their OCP-compliant cores on axi. So, we could start with introducing virtual "ocp" bus (which could be of some use for other vendors utilising ocp model) with additional library/module for broadcom-specific extensions (accounting for buscommon/buscore/etc.). On other hand just broadcom-specific bus looks like good alternative too but here I just fail to decide on relevant naming. Have nice day, George -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
