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Message-Id: <20191022041152.3663-3-biwen.li@nxp.com>
Date: Tue, 22 Oct 2019 12:11:52 +0800
From: Biwen Li <biwen.li@....com>
To: peda@...ntia.se, leoyang.li@....com, robh+dt@...nel.org,
mark.rutland@....com
Cc: linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org,
devicetree@...r.kernel.org, Biwen Li <biwen.li@....com>
Subject: [v5,3/3] arm64: dts: fsl-ls208xa-rdb: fix an errata E-00013
Specify a channel zero in idle state to
avoid enterring tri-stated state for PCA9547.
About E-00013:
- Description: I2C1 and I2C3 buses
are missing pull-up.
- Impact: When the PCA954x device is tri-stated, the I2C bus
will float. This makes the I2C bus and its associated
downstream devices inaccessible.
- Hardware fix: Populate resistors R189 and R190 for I2C1
and resistors R228 and R229 for I2C3.
- Software fix: Remove the tri-state option from the PCA954x
driver(PCA954x always on enable status, specify a
channel zero in dts to fix the errata E-00013).
Signed-off-by: Biwen Li <biwen.li@....com>
---
Change in v5:
- specify a channel zero when pca9547 in idle state.
arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
index 6fd7f63085c9..412f1bc0db5f 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
@@ -49,6 +49,7 @@
reg = <0x75>;
#address-cells = <1>;
#size-cells = <0>;
+ idle-state = <0>;
i2c@1 {
#address-cells = <1>;
#size-cells = <0>;
--
2.17.1
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