[patch] initial perf_event support for Raspberry-Pi

On 12/31/2013 02:54 PM, Vince Weaver wrote:

The following patch enables performance counter support on Raspberry-Pi.

We have this working on the 2708 based rasp-pi kernels by manually putting
the device registration in the platform files.

This change does things properly in a device tree.  The boot messages look 
proper, but my rasp-pi hangs somewhere in USB enabling when running a 
stock 3.13-rc6 kernel so I have been unable to fully test this change.

I also understand that the rasp-pi 1176 pmu support is missing the 
overflow interrupt.  I'm not sure if that's true of all 2835 
implementations.  If not, then this patch will need to be changed a bit.

I've applied this to bcm2835's for-3.15/dt branch, with minor fixes.