ARM: mvebu: update Armada XP DT for dynamic frequency scaling
In order to support dynamic frequency scaling:
* the cpuclk Device Tree node needs to be updated to describe a
second set of registers describing the PMU DFS registers.
* the clock-latency property of the CPUs must be filled, otherwise
the ondemand and conservative cpufreq governors refuse to work. The
latency is high because the cost of a frequency transition is quite
high on those CPUs.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1404920715-19834-5-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/arch/arm/boot/dts/armada-xp-mv78260.dtsi b/arch/arm/boot/dts/armada-xp-mv78260.dtsi
index 3396b25..480e237 100644
--- a/arch/arm/boot/dts/armada-xp-mv78260.dtsi
+++ b/arch/arm/boot/dts/armada-xp-mv78260.dtsi
@@ -36,6 +36,7 @@
compatible = "marvell,sheeva-v7";
reg = <0>;
clocks = <&cpuclk 0>;
+ clock-latency = <1000000>;
};
cpu@1 {
@@ -43,6 +44,7 @@
compatible = "marvell,sheeva-v7";
reg = <1>;
clocks = <&cpuclk 1>;
+ clock-latency = <1000000>;
};
};