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From: Doug Anderson <dianders@chromium.org>
To: Heiko Stuebner <heiko@sntech.de>
Cc: Chris Zhong <zyw@rock-chips.com>,
	Addy Ke <addy.ke@rock-chips.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org,
	Doug Anderson <dianders@chromium.org>,
	robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com,
	ijc+devicetree@hellion.org.uk, galak@codeaurora.org,
	linux@arm.linux.org.uk, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808
Date: Wed, 10 Sep 2014 21:30:15 -0700	[thread overview]
Message-ID: <1410409815-22200-1-git-send-email-dianders@chromium.org> (raw)

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


WARNING: multiple messages have this Message-ID (diff)
From: dianders@chromium.org (Doug Anderson)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808
Date: Wed, 10 Sep 2014 21:30:15 -0700	[thread overview]
Message-ID: <1410409815-22200-1-git-send-email-dianders@chromium.org> (raw)

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 at 1b {
-- 
2.1.0.rc2.206.gedb03e5

             reply	other threads:[~2014-09-11  4:30 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-11  4:30 Doug Anderson [this message]
2014-09-11  4:30 ` [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808 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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