diff mbox series

[5/6] arm64: dts: ls208xa-rdb: fix errata E-00013

Message ID 20220317190109.3742-5-leoyang.li@nxp.com (mailing list archive)
State New, archived
Headers show
Series [1/6] arm64: dts: ls2080a-qds: add mdio mux nodes from on-board FPGA | expand

Commit Message

Leo Li March 17, 2022, 7:01 p.m. UTC
From: Biwen Li <biwen.li@nxp.com>

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@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
---
 arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi | 2 ++
 1 file changed, 2 insertions(+)

Comments

Shawn Guo April 10, 2022, 1:25 a.m. UTC | #1
On Thu, Mar 17, 2022 at 02:01:08PM -0500, Li Yang wrote:
> From: Biwen Li <biwen.li@nxp.com>
> 
> Specify a channel zero in idle state to
> avoid enterring tri-stated state for PCA9547.

Please check Documentation/process/submitting-patches.rst for commit log
wrapping requirement.

> About E-00013:
> 	- Description: I2C1 and I2C3 buses

Use space instead of tab for bullet indent.

Shawn

> 	  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@nxp.com>
> Signed-off-by: Li Yang <leoyang.li@nxp.com>
> ---
>  arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
> index 4b71c4fcb35f..a752f06a2e74 100644
> --- a/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
> +++ b/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
> @@ -49,6 +49,8 @@ pca9547@75 {
>  		reg = <0x75>;
>  		#address-cells = <1>;
>  		#size-cells = <0>;
> +		idle-state = <0>;
> +
>  		i2c@1 {
>  			#address-cells = <1>;
>  			#size-cells = <0>;
> -- 
> 2.25.1
>
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
index 4b71c4fcb35f..a752f06a2e74 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls208xa-rdb.dtsi
@@ -49,6 +49,8 @@  pca9547@75 {
 		reg = <0x75>;
 		#address-cells = <1>;
 		#size-cells = <0>;
+		idle-state = <0>;
+
 		i2c@1 {
 			#address-cells = <1>;
 			#size-cells = <0>;