[PATCHv3 4/7] ARM: mvebu: update Armada XP DT for dynamic frequency scaling

Thomas Petazzoni
2014-07-09T15:45:24Z

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>
---
arch/arm/boot/dts/armada-xp-mv78230.dtsi | 2 ++
arch/arm/boot/dts/armada-xp-mv78260.dtsi | 2 ++
arch/arm/boot/dts/armada-xp-mv78460.dtsi | 4 ++++
arch/arm/boot/dts/armada-xp.dtsi | 2 +-
4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/armada-xp-mv78230.dtsi b/arch/arm/boot/dts/armada-xp-mv78230.dtsi
index 1257ff1..2592e1c 100644
--- a/arch/arm/boot/dts/armada-xp-mv78230.dtsi
+++ b/arch/arm/boot/dts/armada-xp-mv78230.dtsi
@@ -34,6 +34,7 @@
compatible = "marvell,sheeva-v7";
reg = <0>;
clocks = <&cpuclk 0>;
+ clock-latency = <1000000>;
};

cpu@1 {
@@ -41,6 +42,7 @@
compatible = "marvell,sheeva-v7";
reg = <1>;
clocks = <&cpuclk 1>;
+ clock-latency = <1000000>;
};
};

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>;
};
};

diff --git a/arch/arm/boot/dts/armada-xp-mv78460.dtsi b/arch/arm/boot/dts/armada-xp-mv78460.dtsi
index 6da84bf..2c7b1fe 100644
--- a/arch/arm/boot/dts/armada-xp-mv78460.dtsi
+++ b/arch/arm/boot/dts/armada-xp-mv78460.dtsi
@@ -37,6 +37,7 @@
compatible = "marvell,sheeva-v7";
reg = <0>;
clocks = <&cpuclk 0>;
+ clock-latency = <1000000>;
};

cpu@1 {
@@ -44,6 +45,7 @@
compatible = "marvell,sheeva-v7";
reg = <1>;
clocks = <&cpuclk 1>;
+ clock-latency = <1000000>;
};

cpu@2 {
@@ -51,6 +53,7 @@
compatible = "marvell,sheeva-v7";
reg = <2>;
clocks = <&cpuclk 2>;
+ clock-latency = <1000000>;
};

cpu@3 {
@@ -58,6 +61,7 @@
compatible = "marvell,sheeva-v7";
reg = <3>;
clocks = <&cpuclk 3>;
+ clock-latency = <1000000>;
};
};

diff --git a/arch/arm/boot/dts/armada-xp.dtsi b/arch/arm/boot/dts/armada-xp.dtsi
index 5902e83..bff9f6c 100644
--- a/arch/arm/boot/dts/armada-xp.dtsi
+++ b/arch/arm/boot/dts/armada-xp.dtsi
@@ -99,7 +99,7 @@
cpuclk: clock-complex@18700 {
#clock-cells = <1>;
compatible = "marvell,armada-xp-cpu-clock";
- reg = <0x18700 0xA0>;
+ reg = <0x18700 0xA0>, <0x1c054 0x10>;
clocks = <&coreclk 1>;
};

--
2.0.0