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* [4.4-rc][PATCH v2] ARM: dts: am4372: fix clock source for arm twd and global timers
@ 2015-11-30 15:56 ` Grygorii Strashko
  0 siblings, 0 replies; 12+ messages in thread
From: Grygorii Strashko @ 2015-11-30 15:56 UTC (permalink / raw)
  To: tony-4v6yS6AI5VpBDgjK7y7TUQ, t-kristo-l0cyMroinI0
  Cc: nsekhar-l0cyMroinI0, linux-omap-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	devicetree-u79uwXL29TY76Z2rM5mHXA, Grygorii Strashko,
	Felipe Balbi

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-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
Cc: Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>
Cc: Tero Kristo <t-kristo-l0cyMroinI0@public.gmane.org>
Fixes:commit 8cbd4c2f6a99 ("arm: boot: dts: am4372: add ARM timers and SCU nodes")
Signed-off-by: Grygorii Strashko <grygorii.strashko-l0cyMroinI0@public.gmane.org>
---
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@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@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

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^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2015-12-10  0:47 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-11-30 15:56 [4.4-rc][PATCH v2] ARM: dts: am4372: fix clock source for arm twd and global timers Grygorii Strashko
2015-11-30 15:56 ` Grygorii Strashko
     [not found] ` <1448898998-32749-1-git-send-email-grygorii.strashko-l0cyMroinI0@public.gmane.org>
2015-12-03 16:35   ` Tony Lindgren
2015-12-03 16:35     ` Tony Lindgren
     [not found]     ` <20151203163551.GQ23396-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
2015-12-03 18:04       ` Grygorii Strashko
2015-12-03 18:04         ` Grygorii Strashko
     [not found]         ` <5660843E.3000801-l0cyMroinI0@public.gmane.org>
2015-12-08 17:41           ` Grygorii Strashko
2015-12-08 17:41             ` Grygorii Strashko
2015-12-08 18:03   ` Felipe Balbi
2015-12-08 18:03     ` Felipe Balbi
     [not found]     ` <87wpsolsvo.fsf-HgARHv6XitJaoMGHk7MhZQC/G2K4zDHf@public.gmane.org>
2015-12-10  0:47       ` Tony Lindgren
2015-12-10  0:47         ` Tony Lindgren

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