Re: [PATCH v2] arm64: dts: qcom: sc7280: Add bluetooth node on SC7280

[bgodavar]

Hi Stephen Boyd,

On 2021-10-12 22:54, Stephen Boyd wrote:
> Quoting Balakrishna Godavarthi (2021-10-12 06:01:38)
> > diff --git a/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi 
> > b/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> > index 272d5ca..09adc802 100644
> > --- a/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
> > @@ -393,6 +393,23 @@
> >                                 <&tlmm 31 IRQ_TYPE_EDGE_FALLING>;
> >         pinctrl-names = "default", "sleep";
> >         pinctrl-1 = <&qup_uart7_sleep_cts>, <&qup_uart7_sleep_rts>, 
> > <&qup_uart7_sleep_tx>, <&qup_uart7_sleep_rx>;
> > +
> > +       bluetooth: wcn6750-bt {
>
> bluetooth: bluetooth {
>
> Node names should be generic.

[Bala]: will update in next patch.

> > +               compatible = "qcom,wcn6750-bt";
> > +               pinctrl-names = "default";
> > +               pinctrl-0 = <&bt_en_default>;
> > +               enable-gpios = <&tlmm 85 GPIO_ACTIVE_HIGH>;
> > +               swctrl-gpios = <&tlmm 86 GPIO_ACTIVE_HIGH>;
>
> Is there any pinctrl config for gpio 86?
[Bala]: This is input GPIO to apps, BT SOC will handle configurations.

> > +               vddaon-supply = <&vreg_s7b_0p9>;
> > +               vddbtcxmx-supply = <&vreg_s7b_0p9>;
> > +               vddrfacmn-supply = <&vreg_s7b_0p9>;
> > +               vddrfa0p8-supply = <&vreg_s7b_0p9>;
> > +               vddrfa1p7-supply = <&vreg_s1b_1p8>;
> > +               vddrfa1p2-supply = <&vreg_s8b_1p2>;
> > +               vddrfa2p2-supply = <&vreg_s1c_2p2>;
> > +               vddasd-supply = <&vreg_l11c_2p8>;
> > +               max-speed = <3200000>;
> > +       };
> >  };
> >
> >  /* PINCTRL - additions to nodes defined in sc7280.dtsi */
> > @@ -504,6 +521,14 @@
> >                  */
> >                 bias-pull-up;
> >         };
> > +
> > +       bt_en_default: bt_en_default {
>
> bt_en: bt-en {
>
> Node names shouldn't have underscores and 'default' is redundant.
[Bala]: will update in next patch.

> > +               pins = "gpio85";
> > +               function = "gpio";
> > +               drive-strength = <2>;
> > +               output-low;
> > +               bias-pull-down;
>
> Why is there a pull down on an output gpio? Shouldn't this be
> bias-disable?

[Bala]: BT_EN pin is OP of apps and input to BT SoC.
by default we want the state of BT_EN to be low. so used pull down 
instead of bias-disable
as AFAIK bias-disable may trigger a tristate on BT_EN pin, which may 
trigger BT SoC enable
if it is not actually triggered.

> > +       };
> >  };
> >
> >  &sdc1_on {