On 07/30/2013 02:48 PM, Nishanth Menon wrote:

On 07/30/2013 01:34 PM, Stephen Warren wrote:

quoted

On 07/30/2013 12:00 PM, Sudeep KarkadaNagesha wrote:

quoted

From: Sudeep KarkadaNagesha <redacted>

If more than one similar devices share the same OPPs, currently we
need to replicate the OPP entries in all the nodes.

Few drivers like cpufreq depend on physical cpu0 node to specify the
OPPs and only that node is referred irrespective of the logical cpu
accessing it. Alternatively to support cpuhotplug path, few drivers
parse all the cpu nodes for OPPs. Instead we can specify the phandle
of the node with which the current node shares the operating points.

This patch adds support to specify the phandle in the operating points
of any device node, where the node specified by the phandle holds the
actual OPPs.

quoted

diff --git a/Documentation/devicetree/bindings/power/opp.txt

b/Documentation/devicetree/bindings/power/opp.txt

quoted

+Optional properties:
+- operating-points-phandle: phandle to the device node with which this

That's a funny name. Bikeshedding a bit, how about
shared-operating-points?

I haven't thought at all about whether this change conceptually makes
sense.

They may not really be shared- we could have phandle list even.

Well, they are shared, or you wouldn't have one node pointing at another
node and hence sharing the same property...

one
might have optional OPP sets for a chip family that one may  - I was
about to suggest something similar to pinctrl

operating-points-names = "default", "performance", "cheapboard-config" ;)
operating-points-0 = <&...>
operating-points-1 = <&...>
operating-points-2 = <&...>

There is an assertion that DT should only represent the absolute max
limits for things like this, and not policy-oriented data such as
different performance profiles. I don't expect you'll see anything like
the above in DT, since it's more policy than HW description.