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From: Daniel Drake <drake@endlessm.com>
To: kgene.kim@samsung.com
Cc: linux-samsung-soc@vger.kernel.org, liquid.acid@gmx.net,
	m.szyprowski@samsung.com, linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] ARM: dts: ODROID i2c improvements
Date: Wed, 16 Jul 2014 09:50:06 +0100	[thread overview]
Message-ID: <1405500606-5752-2-git-send-email-drake@endlessm.com> (raw)
In-Reply-To: <1405500606-5752-1-git-send-email-drake@endlessm.com>

Increase max i2c bus frequency beyond the default for faster
data transfers. According to the manual, these faster speeds are
only available when the board is wired up the right way. In this case,
the vendor kernel has run at this speed for a long time.

sda-delay is needed for talking to RTC on PMIC, otherwise the i2c
controller never sees an ACK. Strangely the other PMIC i2c slave (the
main one) works fine even without this delay. I Chose value 100 to
match the vendor kernel.

Signed-off-by: Daniel Drake <drake@endlessm.com>
---
 arch/arm/boot/dts/exynos4412-odroid-common.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi
index cb6f55f..adadaf9 100644
--- a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi
+++ b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi
@@ -134,6 +134,8 @@
 	i2c@13860000 {
 		pinctrl-0 = <&i2c0_bus>;
 		pinctrl-names = "default";
+		samsung,i2c-sda-delay = <100>;
+		samsung,i2c-max-bus-freq = <400000>;
 		status = "okay";
 
 		usb3503: usb3503@08 {
-- 
1.9.1

  reply	other threads:[~2014-07-16  8:50 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-16  8:50 [PATCH 1/2] ARM: dts: Enable PMIC interrupts on ODROID Daniel Drake
2014-07-16  8:50 ` Daniel Drake [this message]
2014-07-16 12:34   ` [PATCH 2/2] ARM: dts: ODROID i2c improvements Tomasz Figa
2014-08-12 13:11   ` Tomeu Vizoso
2014-07-16 12:34 ` [PATCH 1/2] ARM: dts: Enable PMIC interrupts on ODROID Tomasz Figa
2014-08-12 13:06 ` Tomeu Vizoso
2014-08-18 16:43   ` Kukjin Kim
2014-08-19  9:57     ` Bartlomiej Zolnierkiewicz
2014-08-19 10:15       ` Javier Martinez Canillas
2014-08-19 20:18         ` Olof Johansson
2014-08-22 10:39           ` Kukjin Kim
2014-08-24 18:32             ` Olof Johansson

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