Re: [PATCH 4/5] arm64: dts: qcom: milos-fairphone-fp6: Enable Bluetooth

[Konrad Dybcio]

On 3/13/26 3:00 PM, Luca Weiss wrote:
> On Fri Mar 13, 2026 at 11:40 AM CET, Luca Weiss wrote:
>> On Wed Jan 21, 2026 at 12:52 PM CET, Konrad Dybcio wrote:
>>> On 1/16/26 3:50 PM, Luca Weiss wrote:
>>>> Add the nodes to describe the WCN6755 chip with its PMU and Bluetooth
>>>> parts.
>>>>
>>>> Thanks to Alexander Koskovich for helping with the bringup, adding
>>>> 'clocks' to the PMU node to make Bluetooth work.
>>>>
>>>> Signed-off-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx>
>>>> ---
>>>>  arch/arm64/boot/dts/qcom/milos-fairphone-fp6.dts | 174 +++++++++++++++++++++++
>>>>  1 file changed, 174 insertions(+)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/qcom/milos-fairphone-fp6.dts b/arch/arm64/boot/dts/qcom/milos-fairphone-fp6.dts
>>>> index 52895dd9e4fa..cbe1507b0aaa 100644
>>>> --- a/arch/arm64/boot/dts/qcom/milos-fairphone-fp6.dts
>>>> +++ b/arch/arm64/boot/dts/qcom/milos-fairphone-fp6.dts
> 
> <snip>
> 
>>>> +	bluetooth_enable_default: bluetooth-enable-default-state {
>>>> +		pins = "gpio53";
>>>> +		function = "gpio";
>>>> +		output-low;
>>>> +		bias-disable;
>>>> +	};
>>>
>>> Not sure if we need to drive that pin.. perhaps a pull-down would
>>> suffice?
>>
>> I'll give it a shot, this pinctrl is coming from downstream but perhaps
>> the downstream btpower.c driver is differing in behavior to the upstream
>> PMU driver.
> 
> Seems to work, but honestly I'm not sure what the actual effects of this
> change are?

output-low actually actively drives the pin low, while bias-pull-down
connects it to an internal pull-down circuit, which is weaker, but also
saves power (because the pin isn't actually driven)

Konrad