Re: GPIO - marking individual pins (not) available in device tree

No, no, no, no, no.  Making complex multi-level representations of
nested things for gpios is just insanity. 

You know, I don't find this "argument" particularly compelling.  But it 
certainly is strongly worded.

 Just use the same encoded
format as we already use for gpio descriptors in 'gpios' properties
(which is gpio controller specific, with length defined by
#gpio-cells).

http://en.wikipedia.org/wiki/Proof_by_assertion