ARM: bcm2835: perf_event support for Raspberry-Pi

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.

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
[swarren, fixed DT node sort order]
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>

diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi
index b021c96d3ba18225660185b037b5a5e1d65f68d5..beb8659813b28d90c257f55c2c931ab9dd1ce14e 100644 (file)
--- a/arch/arm/boot/dts/bcm2835.dtsi
+++ b/arch/arm/boot/dts/bcm2835.dtsi
@@ -113,6 +113,10 @@
                        reg = <0x7e980000 0x10000>;
                        interrupts = <1 9>;
                };
+
+               arm-pmu {
+                       compatible = "arm,arm1176-pmu";
+               };
        };
 
        clocks {