ppc4xx_pci: disable PCI (PnP) via fdt

ppc4xx_pci: disable PCI (PnP) via fdt

[Matthias Fuchs]

Hi,

is it possible to disable PCI PnP via the device tree on a 4xx system?

I am working with a 440EPx board that can be system CPU (with PCI hostbridge)
or a PCI adapter board. In the latter setup I want to disable PCI PnP, 
preferred by manipulating the fdt by U-Boot. The PCI mode is 
detected by U-Boot through a GPIO signal. I do not want to remove the 
complete /plb/pci... path of the device tree for adapter mode , because I do 
not want the PCI bus to be totally invisible. lspci and friends should still 
show devices on the local PCI bus.

The 4xx PCIE fdt handling handles a 'status' and 'device_type' property.
These properties behave not the way I need and also they are only
available for PCIE. 

With arch/ppc kernels I did this by returning '1' from 
ppc_md.pci_exclude_device when PCI PnP should not be done.
Even though I could do it the same way with arch/powerpc, I hope
that there is a fdt-way.

Any ideas?

BTW, isn't it a good idea to handle the 'status' and 'device_type' property 
for PCI in the same way as for PCIE?

Matthias