RE: 8360E - PCI / DTC Blob Setup

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Fri, 2007-02-02 at 05:36 -0800, Russell McGuire wrote:
> Well I am getting smarter on this:
> 
> I have read through the PCI Bridge Specs and found another issue that might
> have been causing a problem with the IDSEL lines. Unless you are interested
> I'll forgo that explanation and just go with fact that I have changed the
> IDSEL mappings to be legal when they are issued from the 83xx.
> 
> I have changed the IDSELs to be as follows, does this look correct?
> I agree with placing the NODE for the bridge into the dts file to be
> correct. Except I get stuck immediately at trying to come up with an
> address. I.e. the PCI host has a PCI@8500, which makes sense. But the Bridge
> chip doesn't have a mapped address to place in the file. I did read the PCI
> OF node spec <dated 1996> it hints that PCI-PCI bridges are essentially the
> same domain and may not need translation.

The unit address of a PCI device is it's bus/idsel/function, the
PCI-2-PCI bridge is no exception.  Thus it doesn't need to have an
assigned-address property, only "reg", which on PCI, doesn't contain
-assigned- addresses, but purely a description of the BARs. In fact, you
only really need the "reg" property for the config space itself which is
enough to give you a valid unit-address (@xxxx) for your bridge and to
make the PCI parsing code in linux happy.

Ben.