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authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2012-07-13 12:06:26 +0100
committerJon Medhurst <tixy@linaro.org>2013-04-29 09:43:22 +0100
commitd24bfc093eb0482b390a7098839574b80c79fe4f (patch)
tree3c2ebd226bfdeff272c177c023079c5739af76c8 /arch/arm/mach-vexpress/Makefile
parentbb7cfd97181f3f536c50360eb6d8a405d6a664b3 (diff)
downloadvexpress-lsk-d24bfc093eb0482b390a7098839574b80c79fe4f.tar.gz
ARM: vexpress: add TC2 CPU idle PM
TC2 test-chip integrates power management circuitry and firmware that allows to remove voltage from both (A7 and A15) clusters when they are idle or more generically when the system is forced into shutdown mode. All CPUs in a cluster share the same voltage source so they cannot be shutdown independently. In order to take advantage of TC2 power management capabilities this patch implements a multi-cluster aware CPU idle implementation. It is based on coupled C-state concept provided by this code: http://lists.infradead.org/pipermail/linux-arm-kernel/2012-April/097084.html CPUs that are part of the same cluster are coupled using the mask provided by the MPIDR at boot. Once all CPUs hit the coupled barrier the primary CPU in the cluster (the one with MPIDR[7:0] == 0) waits for secondaries to clean their L1 and enter wfi. Then it cleans all cache levels, exits cluster coherency and starts the procedure to shutdown the respective cluster. All wake-up IRQ sources are enabled by default. Deep shutdown states for clusters are not enabled by default. To enabled them: A15 cluster echo 0 > /sys/kernel/debug/idle_debug/enable_idle A7 cluster echo 1 > /sys/kernel/debug/idle_debug/enable_idle Tested thoroughly using lookbusy to modulate system load and trigger idle states entry/exit.
Diffstat (limited to 'arch/arm/mach-vexpress/Makefile')
-rw-r--r--arch/arm/mach-vexpress/Makefile1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile
index 80b64971fbd..03d9029dbd6 100644
--- a/arch/arm/mach-vexpress/Makefile
+++ b/arch/arm/mach-vexpress/Makefile
@@ -8,3 +8,4 @@ obj-y := v2m.o reset.o
obj-$(CONFIG_ARCH_VEXPRESS_CA9X4) += ct-ca9x4.o
obj-$(CONFIG_SMP) += platsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
+obj-$(CONFIG_ARCH_VEXPRESS_TC2_PM) += cpuidle-tc2.o hotplug-asm.o tc2-sleep.o