tree 9a743c7b356f5ceba15b3008588126fdced94fb8
parent 11123346bfba8e65631957c6c25ed1a6ca1b4ffe
author David Gibson <david@gibson.dropbear.id.au> 1181710379 +1000
committer Paul Mackerras <paulus@samba.org> 1181824216 +1000

[POWERPC] Derive ebc ranges property from EBC registers

In the device tree for Ebony, the 'ranges' property in the node for
the EBC bridge shows the mappings from the chip select / address lines
actually used for the EBC peripherals into the address space of the
OPB.  At present, these mappings are hardcoded in ebony.dts for the
mappings set up by the OpenBIOS firmware when it configures the EBC
bridge.

This replaces the hardcoded mappings with code in the zImage to
read the EBC configuration registers and create an appropriate ranges
property based on them.  This should make the zImage and kernel more
robust to changes in firmware configuration.  In particular, some of
the Ebony's DIP switches can change the effective address of the Flash
and other peripherals in OPB space.  With this patch, the kernel will
be able to cope with at least some of the possible variations.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>