Re: [PATCH 4/6] arm64: dts: qcom: kaanapali-mtp: Enable bluetooth and Wifi

Dmitry Baryshkov
2026-04-01T11:08:19Z

On Wed, Apr 01, 2026 at 06:39:19PM +0800, Zijun Hu wrote:
> On 3/30/2026 7:53 PM, Dmitry Baryshkov wrote:
> >>> - Is the pin defined in the schema?
> >> schema define property 'swctrl-gpios' with description
> >> "GPIO line indicating the state of the clock supply to the BT module"
> >>
> >>> - Is the pin wired in the hardware?
> >> pin SW_CTRL is wired in hardware.
> > Granted your three answers, it can and should be described in the DT.
> >
> >> i have below confusions about 'swctrl-gpios' of 'qcom,wcn7850-pmu'
> >> which WCN7850 pin is 'swctrl-gpios' mean for ?
> >> Why to introduce 'swctrl-gpios' ?
> >> what problem does it solve ?
> >> how to solve the problem ?
> > Please descibe the hardware in the DT. Problem solving belongs to the
> > driver.
>
> sorry for not agreeing with your points here.
>
> it is better to correct or remove 'swctrl-gpios' within DT binding spec at least
> for 'qcom,wcn7850-pmu' with below reasons:
>
> 1) provided that 'swctrl-gpios' is for pin SW_CTRL of datasheet, binding spec's
> both description and its expected usage are wrong.

Please correct it.

> 2) its driver does not parse and use the property 'swctrl-gpios', moreover, the
> property have no user within upstream DT tree.

There is no "driver" in the "DT bindings"

> 3) the property is not mandatory based on binding spec.

Which is expected, because on some platforms it might be not wired up
and on the other platforms the pin to which it is wired to might be
unknown (think about all the phones for which the community doesn't have
schematics).

> 4) upstream DT tree have had many such usages as mine which just set default pin
> configuration and not specify 'swctrl-gpios' explicitly.

I don't understand this part.

> 5) kaanapali-mtp is originally preinstalled with android OS which supports some
> qualcomm specific feature which have not been supported by up-stream kernel.
> so kaanapali-mtp H/W has some wired pins which is not used by up-stream
> kernel sometimes

Again, what does that have to do with the hardware description?

--
With best wishes
Dmitry