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* [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808
@ 2014-09-11  4:30 ` Doug Anderson
  0 siblings, 0 replies; 7+ messages in thread
From: Doug Anderson @ 2014-09-11  4:30 UTC (permalink / raw)
  To: Heiko Stuebner
  Cc: Chris Zhong, Addy Ke, linux-arm-kernel, linux-rockchip,
	Doug Anderson, robh+dt, pawel.moll, mark.rutland, ijc+devicetree,
	galak, linux, devicetree, linux-kernel

We should be able to talk to the PMIC at 400kHz.  No need to talk at
the slow 100kHz.

As measured by ftrace (with a bunch of extra patches, since cpufreq
for rk808 hasn't landed yet):
  before this change: cpu0_set_target() => ~500us
  after this change:  cpu0_set_target() => ~300us

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
 arch/arm/boot/dts/rk3288-evb-rk808.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/rk3288-evb-rk808.dts b/arch/arm/boot/dts/rk3288-evb-rk808.dts
index 36db177..ff522f8 100644
--- a/arch/arm/boot/dts/rk3288-evb-rk808.dts
+++ b/arch/arm/boot/dts/rk3288-evb-rk808.dts
@@ -18,6 +18,7 @@
 };
 
 &i2c0 {
+	clock-frequency = <400000>;
 	status = "okay";
 
 	rk808: pmic@1b {
-- 
2.1.0.rc2.206.gedb03e5


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2014-09-11  9:23 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-09-11  4:30 [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808 Doug Anderson
2014-09-11  4:30 ` Doug Anderson
2014-09-11  9:17 ` Addy
2014-09-11  9:17   ` Addy
2014-09-11  9:17   ` Addy
2014-09-11  9:23 ` Heiko Stübner
2014-09-11  9:23   ` Heiko Stübner

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