Re: [PATCH v2 4/4] arm64: dts: qcom: sm7225-fairphone-fp4: Add Bluetooth

["Luca Weiss" <luca.weiss@fairphone.com>]

On Tue Mar 10, 2026 at 7:02 PM CET, Conor Dooley wrote:
> On Fri, May 12, 2023 at 03:58:26PM +0200, Luca Weiss wrote:
>
>> +&qup_uart1_cts {
>> +	/*
>> +	 * Configure a bias-bus-hold on CTS to lower power
>> +	 * usage when Bluetooth is turned off. Bus hold will
>> +	 * maintain a low power state regardless of whether
>> +	 * the Bluetooth module drives the pin in either
>> +	 * direction or leaves the pin fully unpowered.
>> +	 */
>> +	bias-bus-hold;
>> +};
>> +
>> +&qup_uart1_rts {
>> +	/* We'll drive RTS, so no pull */
>> +	drive-strength = <2>;
>> +	bias-disable;
>> +};
>> +
>> +&qup_uart1_rx {
>> +	/*
>> +	 * Configure a pull-up on 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;
>> +};
>> +
>> +&qup_uart1_tx {
>> +	/* We'll drive TX, so no pull */
>> +	drive-strength = <2>;
>> +	bias-disable;
>> +};
>
> I recently made some changes to pincfg-node.yaml to detect if there's
> conflicting properties used, and these got detected. Should these not
> do what has been done on the msm8998-xiaomi-sagit, and delete the
> inherited bias-foo from the dtsi?
> &blsp1_i2c5_sleep {
> 	/delete-property/ bias-pull-up;
> 	bias-disable;
> };

Yes, you're completely right.

In the final dtb qup-uart1-{cts,rts,rx,tx}-default-state contain two
bias-* properties, this must be wrong.

Thanks for pointing this out, I'll prepare a patch soon!

Regards
Luca