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

From: bgodavar@codeaurora.org
To: Stephen Boyd <swboyd@chromium.org>
Cc: bjorn.andersson@linaro.org, johan.hedberg@gmail.com,
	marcel@holtmann.org, mka@chromium.org,
	linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
	hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org,
	pharish@codeaurora.org, rjliao@codeaurora.org,
	hbandi@codeaurora.org, saluvala@codeaurora.org,
	abhishekpandit@chromium.org
Subject: Re: [PATCH v2] arm64: dts: qcom: sc7280: Add bluetooth node on SC7280
Date: Wed, 13 Oct 2021 11:00:50 +0530	[thread overview]
Message-ID: <46cc793cf651822ef90c448682598a02@codeaurora.org> (raw)
In-Reply-To: <CAE-0n52uUh5TrKpJq9-qkJTdWWU_EZFvoROWFeGEjuc1Ebc8xg@mail.gmail.com>

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 {