On Feb 1, 2007, at 11:48 AM, Russell McGuire wrote: > This might be the wrong forum to discuss HW routing, but I am not > sure of > many HW guys that would understand blob setups. I know I still don't. > > I read through the booting-without-of-tree.txt and it doesn't > explain this > other than the interrupt routing needs to be present. Perhaps some > of the > maintainers of the 83xx platforms can explain how this blob is > developed? > I assume their board work with the submitted mp38360emds.dts files, > as an > example. > > Let me see if I can simplify this, I had this schematic reviewed by > Pericom > <a PCI bridge MFG> and they recommended these IDSEL lines. And I > know the > card detection works great, in U-boot. > > My external PCI bridge is the only thing routed directly to the > 8360 Host > bridge. The PCI Host bridge in my system is connected on IDSEL- > >AD25,0x19 > Perhaps I shouldn't use any interrupt routing for this, as there is > no true > /INTA line tied directly to the bridge? > > My Three PCI slots are routed as follows: > > Bus 0, Bridge Chip, IDSEL = AD25
Huh, this is only describes one slot/connection. If you have 3 slots, they'd have 3 unique IDSELs > Other side of the Host bridge, all are routed to INTA directly to the > CPU. > Bus 1, Slot 1, IDSEL = AD20 <card would be ID'd as 1.04 (Bus.Dev)> > Bus 1, Slot 2, IDSEL = AD24 <card would be ID'd as 1.08 (Bus.Dev)> > Bus 2, Slot 1, IDSEL = AD20 <card would be ID'd as 2.04 (Bus.Dev)> > > That being said: > /* IDSEL 0x19 AD25*/ > c800 0 0 1 700 14 8 so the way you read this: <PCI DEV specifier> <INT A-D> <HOST IRQ specifier> Do break it down further: <PCI DEV specifier>: [(bus << 16) | (idsel << 11)] 0 0 <INT A-D>: INTA - 1 INTB - 2 INTC - 3 INTD - 4 <HOST IRQ specifier> (on 83xx): [linux,phandle for interrupt controller] [IRQ #] [sense] > I see in the c800 directly corresponds to the 83xx manual for PCI > CONFIG > address mapping for AD25. > > I think the '1' is mapped to /INTA, which is the only PCI INT > available in > the 8360E. INTA..INTD is more about the device, not host. > I understand the 700 in this case is the address of the [EMAIL PROTECTED] > > That leaves 5 fields/questions. > 1) What do the first two '0's after c800 mean? There always 0 0, since the int masks them away (they normally describe the address the device is at) > 2) What does the '14' map to? 0x14 is the external IRQ # its wired to. > 3) What does the '8' map to? Sense of IRQ, should always be level for PCI. > 4) Why would some boards map multiple interrupts to a single IDSEL, > like the > mpc8360emds.dts file? Is this to handle extra bridges that might be > plugged > in at a later time? This is to handle the fact that a PCI add on card put into a slot might use multiple interrupts (INTA, INTB), so it lists multiple entries to cover the 4 PCI defined interrupts. > If I understand the mapping correctly then I think I can hard code > in the > interrupts for the PCI slots. > > So I don't drive everybody nuts, is there actual documentation on > this. I > would be happy to stop spamming this list... :-) There is, but its scattered in places. Its good to ask these questions so the answers will get archived and other people can figure it out as well. - k _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
