WLAN rail was leaking power during RBSC/sleep even after turning BT off.
Change sleep pinctrl configuration to handle same.

Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>
---
v2: used bias-bus-hold as per review comments
v1: intial patch used bias-disable
---
 arch/arm64/boot/dts/qcom/sc7280-idp.dtsi | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi b/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
index d623d71..80ab2d8 100644
--- a/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280-idp.dtsi
@@ -516,10 +516,10 @@
 		pins = "gpio28";
 		function = "gpio";
 		/*
-		 * Configure a pull-down on CTS to match the pull of
-		 * the Bluetooth module.
+		 * Configure a bus-hold on CTS to lower power usage
+		 * when BT is turned off.
 		 */
-		bias-pull-down;
+		bias-bus-hold;
 	};
 
 	qup_uart7_sleep_rts: qup-uart7-sleep-rts {
-- 
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Hi,

On Fri, Mar 25, 2022 at 7:06 AM Vijaya Krishna Nivarthi
<quic_vnivarth@quicinc.com> wrote:
>
> WLAN rail was leaking power during RBSC/sleep even after turning BT off.
> Change sleep pinctrl configuration to handle same.
>
> Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>
> ---
> v2: used bias-bus-hold as per review comments
> v1: intial patch used bias-disable
> ---
>  arch/arm64/boot/dts/qcom/sc7280-idp.dtsi | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

No objections from me now. ...but we should probably be changing _all_
of them? ...and by "all" I mean _both_ the sleep and wake state of the
pins and this config across all the devices. In the very least all the
sc7280 ones, but maybe even the sc7180 ones.

$ git grep "Configure a pull-down on CTS" -- arch/arm64/boot/dts
arch/arm64/boot/dts/qcom/sc7180-idp.dts:                 * Configure a
pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7180-idp.dts:                         *
Configure a pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi:            * Configure a
pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi:                    *
Configure a pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts:      *
Configure a pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts:
  * Configure a pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-idp.dtsi:        * Configure a
pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-idp.dtsi:                * Configure a
pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi:     /* Configure a
pull-down on CTS to match the pull of the Bluetooth module. */
arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi:              * Configure a
pull-down on CTS to match the pull of

-Doug

Thank you very much.

So, we understand we could configure both default and sleep states of cts pin to bias-bus-hold.
We will test this change for power impact on sc7280 and post an update.
For sc7180, we will check and get back.


-----Original Message-----
From: Doug Anderson <dianders@chromium.org> 
Sent: Friday, March 25, 2022 8:13 PM
To: Vijaya Krishna Nivarthi (Temp) (QUIC) <quic_vnivarth@quicinc.com>
Cc: Andy Gross <agross@kernel.org>; bjorn.andersson@linaro.org; Rob Herring <robh+dt@kernel.org>; linux-arm-msm <linux-arm-msm@vger.kernel.org>; open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>; LKML <linux-kernel@vger.kernel.org>; quic_msavaliy <quic_msavaliy@quicinc.com>
Subject: Re: [PATCH V2] arm64: dts: qcom: sc7280-idp: Configure cts sleep pinctrl to bias-bus-hold

WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros.

Hi,

On Fri, Mar 25, 2022 at 7:06 AM Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com> wrote:
>
> WLAN rail was leaking power during RBSC/sleep even after turning BT off.
> Change sleep pinctrl configuration to handle same.
>
> Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>
> ---
> v2: used bias-bus-hold as per review comments
> v1: intial patch used bias-disable
> ---
>  arch/arm64/boot/dts/qcom/sc7280-idp.dtsi | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

No objections from me now. ...but we should probably be changing _all_ of them? ...and by "all" I mean _both_ the sleep and wake state of the pins and this config across all the devices. In the very least all the
sc7280 ones, but maybe even the sc7180 ones.

$ git grep "Configure a pull-down on CTS" -- arch/arm64/boot/dts
arch/arm64/boot/dts/qcom/sc7180-idp.dts:                 * Configure a
pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7180-idp.dts:                         *
Configure a pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi:            * Configure a
pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi:                    *
Configure a pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts:      *
Configure a pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts:
  * Configure a pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-idp.dtsi:        * Configure a
pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-idp.dtsi:                * Configure a
pull-down on CTS to match the pull of
arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi:     /* Configure a
pull-down on CTS to match the pull of the Bluetooth module. */
arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi:              * Configure a
pull-down on CTS to match the pull of

-Doug