Re: [PATCH] of: support an enumerated-bus compatible value

On 07/02/2012 03:44 PM, Segher Boessenkool wrote:

quoted

But don't get too hung up on regulators; there are plenty of other
devices that can exist in DT that aren't memory-mapped; GPIO-keys,
aggregate sound complexes, perhaps WiFi/rfkill nodes, etc. All are
affected by the same DT representation issue.

So what is the issue?  You have some node (the "bus node") under which
you have the "regulator@0", "frobnicator@1" etc. nodes.  You refer to
these device nodes by phandle always, you cannot programmatically
control those devices (otherwise, they should be child node of a *real*
bus node).  The bus node does not represent any device at all, and no
device driver can ever do anything with it; it should not have a
"compatible" property either.

Without the "bus" node having a compatible property, nothing will
recurse into it to instantiate the devices that the child nodes
represent; the fact that they're reference by phandle doesn't
instantiate the device, just references it.