From: Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>,
Fabio Estevam
<fabio.estevam-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
Shawn Guo <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Subject: [PATCH] ARM: mxs: Slow down the I2C clock speed
Date: Tue, 2 Apr 2013 01:29:29 +0200 [thread overview]
Message-ID: <1364858969-17745-1-git-send-email-marex@denx.de> (raw)
Slow down the I2C clock speed on M28 and SPS1 as it turns out the
I2C block in i.MX28 can not operate stable enough with the bus
running at 400kHz. Note that the driver used by Freescale runs
the bus at 250kHz when 400kHz speed is selected, but the mainline
Linux kernel runs the bus at actual 400kHz and that's where it is
occasionally unstable. Play safe and run the bus at 100kHz.
Signed-off-by: Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
Cc: Fabio Estevam <fabio.estevam-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
Cc: Shawn Guo <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
arch/arm/boot/dts/imx28-m28evk.dts | 1 -
arch/arm/boot/dts/imx28-sps1.dts | 1 -
2 files changed, 2 deletions(-)
diff --git a/arch/arm/boot/dts/imx28-m28evk.dts b/arch/arm/boot/dts/imx28-m28evk.dts
index 5f0ba99..5aa44e0 100644
--- a/arch/arm/boot/dts/imx28-m28evk.dts
+++ b/arch/arm/boot/dts/imx28-m28evk.dts
@@ -177,7 +177,6 @@
i2c0: i2c@80058000 {
pinctrl-names = "default";
pinctrl-0 = <&i2c0_pins_a>;
- clock-frequency = <400000>;
status = "okay";
sgtl5000: codec@0a {
diff --git a/arch/arm/boot/dts/imx28-sps1.dts b/arch/arm/boot/dts/imx28-sps1.dts
index e6cde8a..6c6a544 100644
--- a/arch/arm/boot/dts/imx28-sps1.dts
+++ b/arch/arm/boot/dts/imx28-sps1.dts
@@ -70,7 +70,6 @@
i2c0: i2c@80058000 {
pinctrl-names = "default";
pinctrl-0 = <&i2c0_pins_a>;
- clock-frequency = <400000>;
status = "okay";
rtc: rtc@51 {
--
1.7.10.4
next reply other threads:[~2013-04-01 23:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-01 23:29 Marek Vasut [this message]
[not found] ` <1364858969-17745-1-git-send-email-marex-ynQEQJNshbs@public.gmane.org>
2013-04-02 11:28 ` [PATCH] ARM: mxs: Slow down the I2C clock speed Shawn Guo
[not found] ` <20130402112850.GD24039-rvtDTF3kK1ictlrPMvKcciBecyulp+rMXqFh9Ls21Oc@public.gmane.org>
2013-04-02 19:11 ` Marek Vasut
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