clock bindings

[Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

I've started looking at the DT clock bindings in more depth. To what 
level should the clock tree be defined in the DT? Should it be a 
one-to-one correlation of current struct clk nodes to node in DT where 
each node is a single input and output? Or only define a single (or few) 
node with the inputs (oscillators) and many outputs for SOC's clock 
controller (i.e. MX51 CCM).

If the DT itself does not have a hierarchical construction of nodes that 
matches the clock tree hierarchy, then creating the hierarchy at 
run-time will be a challenge and not be very efficient. It would require 
1 pass for each clock node type to create all the nodes, and then 
another pass to setup the hierarchy.

Rob