| Message ID | 20191022041152.3663-3-biwen.li@nxp.com |
|---|---|
| State | Superseded |
| Delegated to: | Peter Rosin |
| Headers | show |
| Series | [v5,1/3] dt-bindings: i2c: support property idle-state | expand |
Hi! This patch needs an ack from the arm64 dts maintainers. I cannot sneak it in "behind their backs". So, it will have to wait. Sorry for not noticing earlier. Cheers, Peter On 2019-10-22 06:11, Biwen Li wrote: > 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> > --- > 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>; >
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>;
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> --- 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(+)