Messages in this thread Patch in this message | | | Date | Sun, 20 Oct 2019 19:11:23 -0700 | From | Bjorn Andersson <> | Subject | Re: [PATCH] arm64: dts: qcom: msm8998: Fixup uart3 gpio config for bluetooth |
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On Sat 19 Oct 15:12 PDT 2019, Jeffrey Hugo wrote:
> 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> > --- > .../boot/dts/qcom/msm8998-clamshell.dtsi | 31 +++++++++++++++++++ > arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi | 31 +++++++++++++++++++ > 2 files changed, 62 insertions(+) > > diff --git a/arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi b/arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi > index ab24d415acc0..7e02cb6c8e07 100644 > --- a/arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi > +++ b/arch/arm64/boot/dts/qcom/msm8998-clamshell.dtsi > @@ -74,6 +74,37 @@ > }; > }; > > +&blsp1_uart3_on { > + /delete-node/ config;
So it would make much more sense then to split &blsp1_uart3_on in sections defining its pins, than the "logical" config and mux split.
Please send a patch that changes msm8998-pins.dtsi to be:
blsp_uart3_on: blsp1-uart3-on { ctx { };
rts { };
rx [ };
tx { }; };
There's no need for the "pinconf" part and for pinctrl states with a single pin/group we can simply omit the subnode (as this is now possible).
Apart from that, I think this looks good!
Regards, Bjorn
> + > + pinconf-cts { > + /* > + * Configure a pull-down on 47 (CTS) to match the pull > + * of the Bluetooth module. > + */ > + pins = "gpio47"; > + bias-pull-down; > + }; > + > + pinconf-rts-tx { > + /* We'll drive 48 (RFR) and 45 (TX), so no pull */ > + pins = "gpio45", "gpio48"; > + drive-strength = <2>; > + bias-disable; > + }; > + > + pinconf-rx { > + /* > + * 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). > + */ > + pins = "gpio45"; > + bias-pull-up; > + }; > +}; > + > &dsi0 { > status = "okay"; > > diff --git a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi > index 1a1836ed1052..17f51af5e999 100644 > --- a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi > +++ b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi > @@ -37,6 +37,37 @@ > }; > }; > > +&blsp1_uart3_on { > + /delete-node/ config; > + > + pinconf-cts { > + /* > + * Configure a pull-down on 47 (CTS) to match the pull > + * of the Bluetooth module. > + */ > + pins = "gpio47"; > + bias-pull-down; > + }; > + > + pinconf-rts-tx { > + /* We'll drive 48 (RFR) and 45 (TX), so no pull */ > + pins = "gpio45", "gpio48"; > + drive-strength = <2>; > + bias-disable; > + }; > + > + pinconf-rx { > + /* > + * 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). > + */ > + pins = "gpio45"; > + bias-pull-up; > + }; > +}; > + > &blsp2_uart1 { > status = "okay"; > }; > -- > 2.17.1 >
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