diff options
| author | Jeffrey Hugo <jeffrey.l.hugo@gmail.com> | 2019-10-21 09:19:21 -0700 |
|---|---|---|
| committer | Bjorn Andersson <bjorn.andersson@linaro.org> | 2019-12-17 21:26:58 -0800 |
| commit | 8529728f25d620d82c118bd683fcd7bcf2b18ac5 (patch) | |
| tree | bf7f9a489a5e57d5f4c6ea80fb8e752e18861603 | |
| parent | 39523c56b668f71b3f23adc624a0e16315e0c47f (diff) | |
arm64: dts: qcom: msm8998: Fixup uart3 gpio config for bluetooth
It turns out that the wcn3990 can float the gpio lines during bootup, etc
which will result in the uart core thinking there is incoming data. This
results in the bluetooth stack getting garbage. By applying a bias to
match what wcn3990 would drive, the issue is corrected.
Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Link: https://lore.kernel.org/r/20191021161921.31825-1-jeffrey.l.hugo@gmail.com
[bjorn: Moved board specific pinctrl states to the end]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
| -rw-r--r-- | arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi | 23 | ||||
| -rw-r--r-- | arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi | 23 | ||||
| -rw-r--r-- | arch/arm64/boot/dts/qcom/msm8998-pins.dtsi | 25 |
3 files changed, 67 insertions, 4 deletions
diff --git a/arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi b/arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi index 0f84fa0894a4..b3cf263f4a00 100644 --- a/arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi +++ b/arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi @@ -301,3 +301,26 @@ vdd-1.3-rfa-supply = <&vreg_l17a_1p3>; vdd-3.3-ch0-supply = <&vreg_l25a_3p3>; }; + +/* PINCTRL - board-specific pinctrl */ +&blsp1_uart3_on { + rx { + /delete-property/ bias-disable; + /* + * Configure a pull-up on 45 (RX). This is needed to + * avoid garbage data when the TX pin of the Bluetooth + * module is in tri-state (module powered off or not + * driving the signal yet). + */ + bias-pull-up; + }; + + cts { + /delete-property/ bias-disable; + /* + * Configure a pull-down on 47 (CTS) to match the pull + * of the Bluetooth module. + */ + bias-pull-down; + }; +}; diff --git a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi index 1220756fb5b3..6835fbd9636e 100644 --- a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi +++ b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi @@ -373,3 +373,26 @@ vdd-1.3-rfa-supply = <&vreg_l17a_1p3>; vdd-3.3-ch0-supply = <&vreg_l25a_3p3>; }; + +/* PINCTRL - board-specific pinctrl */ +&blsp1_uart3_on { + rx { + /delete-property/ bias-disable; + /* + * Configure a pull-up on 45 (RX). This is needed to + * avoid garbage data when the TX pin of the Bluetooth + * module is in tri-state (module powered off or not + * driving the signal yet). + */ + bias-pull-up; + }; + + cts { + /delete-property/ bias-disable; + /* + * Configure a pull-down on 47 (CTS) to match the pull + * of the Bluetooth module. + */ + bias-pull-down; + }; +}; diff --git a/arch/arm64/boot/dts/qcom/msm8998-pins.dtsi b/arch/arm64/boot/dts/qcom/msm8998-pins.dtsi index e32d3ab395ea..7c222cbf19d9 100644 --- a/arch/arm64/boot/dts/qcom/msm8998-pins.dtsi +++ b/arch/arm64/boot/dts/qcom/msm8998-pins.dtsi @@ -77,13 +77,30 @@ }; blsp1_uart3_on: blsp1_uart3_on { - mux { - pins = "gpio45", "gpio46", "gpio47", "gpio48"; + tx { + pins = "gpio45"; function = "blsp_uart3_a"; + drive-strength = <2>; + bias-disable; }; - config { - pins = "gpio45", "gpio46", "gpio47", "gpio48"; + rx { + pins = "gpio46"; + function = "blsp_uart3_a"; + drive-strength = <2>; + bias-disable; + }; + + cts { + pins = "gpio47"; + function = "blsp_uart3_a"; + drive-strength = <2>; + bias-disable; + }; + + rfr { + pins = "gpio48"; + function = "blsp_uart3_a"; drive-strength = <2>; bias-disable; }; |