Messages in this thread | | | Date | Fri, 10 Mar 2023 08:09:59 +0100 | From | Johan Hovold <> | Subject | Re: [PATCH v5 4/4] arm64: dts: qcom: thinkpad-x13s: Add bluetooth |
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On Thu, Mar 09, 2023 at 02:07:58PM -0600, Steev Klimaszewski wrote: > On Thu, Mar 9, 2023 at 11:24 AM Johan Hovold <johan@kernel.org> wrote: > > On Wed, Feb 08, 2023 at 08:09:16PM -0600, Steev Klimaszewski wrote:
> > > + uart2_state: uart2-state { > > > > Rename this one too: > > > > uart2_default: uart2-default-state > > > > > + cts-pins { > > > + pins = "gpio122"; > > > > This should be gpio121 (gpio122 is rts). > > > > You are right that it should be... however... if I actually set it to > be 121.... bluetooth doesn't actually come up/work?
I'm running with this fixed locally and it's working here.
Not muxing the cts-pin should break flow control (e.g. the host will send data regardless of if the device signals that it's ready to receive it).
> > > + function = "qup2"; > > > + bias-disable; > > > > Don't we need a pull-down on this one to avoid a floating input when the > > module is powered down? > > Maybe? I don't have access to the schematics or anything so I was > going with the best guess based on what worked by poking and prodding. > Will try this.
There are no external resistors and most of the Qualcomm boards with these Bluetooth modules appear to enable the internal pull-down on cts.
But there are also two boards that recently switched to bias-bus-hold:
3d0e375bae55 ("arm64: dts: qcom: sc7280-qcard: Configure CTS pin to bias-bus-hold for bluetooth")
to avoid leakage. Perhaps that's what we want here too.
Johan
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