[PATCH 15/16] Add device tree for Ebony

[Yoder Stuart-B08248]

> >> Hmm.  There are two "soc" devices here, one nested under the
> >> first??
> >>
> >> I'm assuming these are two levels of busses the opb bus is attached
> >> to the plb bus.  Is the "soc" device_type the right way to
> >> do this?
> >
> > Right, OPB hangs off of PLB in this case.  I dunno if "soc" is the 
> > right
> > device type for them though.
> 
> I would use device_type "plb" (or "plb4") and "opb" I think.
> Similar to how PCI and ISA etc. busses are represented.

I think we should avoid making up new device_types unlesss it
really is necessary.

Is it really necessary to distinguish between devices on
the PLB or OPB?

As I undestand it the "soc" device type is a logical container
for a group of devices in an SOC, not necessarily a group
of devices on the same bus.  Could we simply list all those
devices under an "soc" node at the same level.

If for some reason the bus hierarchy distinction _is_ required,
my suggestion would be to create new generic device type for
representing an internal bus.   The "device_type" is supposed
to be somewhat general-- "network", "serial", etc.

We could create something like "soc-bus" or "internal-bus" with
a compatible field that identifies the type of bus.

The general philosophy is a general device_type prooperty and
a specific compatible property.

Stuart Yoder