RE: 8360E - PCI / DTC Blob Setup
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2007-02-05 01:45:58
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.