Messages in this thread | | | Date | Thu, 17 Jan 2019 13:55:59 -0800 | From | Bjorn Andersson <> | Subject | Re: [PATCH] arm64: dts: qcom: sdm845-mtp: Add WCN3990 BT node |
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On Thu 17 Jan 11:28 PST 2019, Matthias Kaehlcke wrote:
> On Wed, Jan 16, 2019 at 08:40:06PM -0800, Bjorn Andersson wrote: [..] > > +&qup_uart6_default { > > + pinmux { > > + pins = "gpio45", "gpio46", "gpio47", "gpio48"; > > + function = "qup6"; > > + }; > > + > > + ctsrx { > > + pins = "gpio45", "gpio48"; > > + drive-strength = <2>; > > CTS and RX are input signals, no need to configure drive strength in > this case IIUC. >
Right, didn't think that far when I hacked this up.
> > + bias-no-pull; > > On another SDM845 based device we observe garbage on RX at > initialization time, unless we enable a pull-up. > > > + }; > > + > > + rts { > > + pins = "gpio46"; > > + drive-strength = <2>; > > + bias-pull-down; > > + }; > > On our device we don't configure a pull on the lines driven by the > AP. I think a pull-down on RTS should be fine though since it matches > the pull (during reset) on CTS of the BT module. > > > + tx { > > + pins = "gpio47"; > > + drive-strength = <2>; > > + bias-pull-up; > > + }; > > +}; > > Similar to RTS, the pull matches the one on RXD of the BT module. > > For reference, this is what we currently use on our device: > > https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1391888/3/arch/arm64/boot/dts/qcom/sdm845-cheza.dtsi >
Thanks, I will update the patch.
Regards, Bjorn
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