On Wed, Apr 20, 2016 at 12:31:22PM +0100, Will Deacon wrote:

On Mon, Apr 18, 2016 at 01:04:53PM -0700, Tai Tri Nguyen wrote:

quoted

quoted

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+Required properties for MCB subnode:
+- compatible         : Shall be "apm,xgene-pmu-mcb".
+- reg                        : First resource shall be the MCB PMU resource.
+- index                      : Instance number of the MCB PMU.
+
+Required properties for MC subnode:
+- compatible         : Shall be "apm,xgene-pmu-mc".
+- reg                        : First resource shall be the MC PMU resource.
+- index                      : Instance number of the MC PMU.

Don't use indexes. You probably need phandles to the nodes these are
related to.

How many variations of child nodes do you expect to have? 2, 10, 50? You
might want to just collapse all this down to a single node and put this
information in the driver if it is fixed for each SoC and there's only a
handful.

For each kind of PMU, for example memory controller PMU, I expect to
have the number of instances up to 8.
They are actually all independent PMU nodes and have their own CSR memory bases.
The indexes are used for exposing the devices to perf user only. It
doesn't have an impact on the programming model.
Mark also had the same concern.

Regardless, I'll need an ack from Rob or Mark before I can merge this.

I still have a concern with this. Needing an index to expose to the user 
is generally not a valid reason. That's OS specific and therefore 
doesn't belong in DT.

Rob