Re: [PATCH] arm64: dts: qcom: lemans-evk: Enable Bluetooth support

From: Konrad Dybcio

Date: Mon Nov 10 2025 - 06:50:39 EST


On 11/10/25 6:57 AM, Wei Deng wrote:
> There's a WCN6855 WiFi/Bluetooth module on an M.2 card. To make
> Bluetooth work, we need to define the necessary device tree nodes,
> including UART configuration and power supplies.
>
> Since there is no standard M.2 binding in the device tree at present,
> the PMU is described using dedicated PMU nodes to represent the
> internal regulators required by the module.
>
> The 3.3V supply for the module is assumed to come directly from the
> main board supply, which is 12V. To model this in the device tree, we
> add a fixed 12V regulator node as the DC-IN source and connect it to
> the 3.3V regulator node.
>
> Signed-off-by: Wei Deng <wei.deng@xxxxxxxxxxxxxxxx>
> ---

[...]

> &apps_rsc {
> @@ -627,6 +708,22 @@ &qupv3_id_2 {
> status = "okay";
> };
>
> +&qup_uart17_cts {
> + bias-disable;
> +};
> +
> +&qup_uart17_rts {
> + bias-pull-down;
> +};
> +
> +&qup_uart17_tx {
> + bias-pull-up;
> +};
> +
> +&qup_uart17_rx {
> + bias-pull-down;
> +};

This is notably different than all other platforms' bluetooth pin
settings - for example pulling down RX sounds odd, since UART signal
is supposed to be high at idle

see hamoa.dtsi : qup_uart14_default as an example

Konrad