[4.4-rc][PATCH v2] ARM: dts: am4372: fix clock source for arm twd and global timers

[Grygorii Strashko]

ARM TWD and Global timer are clocked by PERIPHCLK which is MPU_CLK/2.
But now they are clocked by dpll_mpu_m2_ck == MPU_CLK and, as result.
Timekeeping core misbehaves. For example, execution of command
"sleep 5" will take 10 sec instead of 5.

Hence, fix it by adding mpu_periphclk ("fixed-factor-clock") and use
it for clocking ARM TWD and Global timer (same way as on OMAP4).

Cc: Tony Lindgren <tony at atomide.com>
Cc: Felipe Balbi <balbi at ti.com>
Cc: Tero Kristo <t-kristo at ti.com>
Fixes:commit 8cbd4c2f6a99 ("arm: boot: dts: am4372: add ARM timers and SCU nodes")
Signed-off-by: Grygorii Strashko <grygorii.strashko at ti.com>
---
Changes in v2:
 - fix: mpu_periphclk should be clocked from dpll_mpu_m2_ck instead of
   dpll_mpu_ck.
link on v1:
 http://www.spinics.net/lists/arm-kernel/msg463898.html

 arch/arm/boot/dts/am4372.dtsi        | 4 ++--
 arch/arm/boot/dts/am43xx-clocks.dtsi | 8 ++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/am4372.dtsi b/arch/arm/boot/dts/am4372.dtsi
index d83ff9c..de8791a 100644
--- a/arch/arm/boot/dts/am4372.dtsi
+++ b/arch/arm/boot/dts/am4372.dtsi
@@ -74,7 +74,7 @@
 		reg = <0x48240200 0x100>;
 		interrupts = <GIC_PPI 11 IRQ_TYPE_LEVEL_HIGH>;
 		interrupt-parent = <&gic>;
-		clocks = <&dpll_mpu_m2_ck>;
+		clocks = <&mpu_periphclk>;
 	};
 
 	local_timer: timer at 48240600 {
@@ -82,7 +82,7 @@
 		reg = <0x48240600 0x100>;
 		interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_HIGH>;
 		interrupt-parent = <&gic>;
-		clocks = <&dpll_mpu_m2_ck>;
+		clocks = <&mpu_periphclk>;
 	};
 
 	l2-cache-controller at 48242000 {
diff --git a/arch/arm/boot/dts/am43xx-clocks.dtsi b/arch/arm/boot/dts/am43xx-clocks.dtsi
index cc88728..a38af2b 100644
--- a/arch/arm/boot/dts/am43xx-clocks.dtsi
+++ b/arch/arm/boot/dts/am43xx-clocks.dtsi
@@ -259,6 +259,14 @@
 		ti,invert-autoidle-bit;
 	};
 
+	mpu_periphclk: mpu_periphclk {
+		#clock-cells = <0>;
+		compatible = "fixed-factor-clock";
+		clocks = <&dpll_mpu_m2_ck>;
+		clock-mult = <1>;
+		clock-div = <2>;
+	};
+
 	dpll_ddr_ck: dpll_ddr_ck {
 		#clock-cells = <0>;
 		compatible = "ti,am3-dpll-clock";
-- 
2.6.3