arm64: dts: qcom: sc7280-qcard: Configure CTS pin to bias-bus-hold for bluetooth

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

Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1650556567-4995-3-git-send-email-quic_vnivarth@quicinc.com

diff --git a/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi b/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
index b833ba1e8f4af8d68d6fbaa00b39738854497f38..98b5cd70bca528b223b82f142b73a89a22157661 100644 (file)
--- a/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
@@ -398,8 +398,14 @@ mos_bt_uart: &uart7 {
 
 /* For mos_bt_uart */
 &qup_uart7_cts {
-       /* Configure a pull-down on CTS to match the pull of the Bluetooth module. */
-       bias-pull-down;
+       /*
+        * Configure a bias-bus-hold on CTS to lower power
+        * usage when Bluetooth is turned off. Bus hold will
+        * maintain a low power state regardless of whether
+        * the Bluetooth module drives the pin in either
+        * direction or leaves the pin fully unpowered.
+        */
+       bias-bus-hold;
 };
 
 /* For mos_bt_uart */
@@ -490,10 +496,13 @@ mos_bt_uart: &uart7 {
                pins = "gpio28";
                function = "gpio";
                /*
-                * Configure a pull-down on CTS to match the pull of
-                * the Bluetooth module.
+                * Configure a bias-bus-hold on CTS to lower power
+                * usage when Bluetooth is turned off. Bus hold will
+                * maintain a low power state regardless of whether
+                * the Bluetooth module drives the pin in either
+                * direction or leaves the pin fully unpowered.
                 */
-               bias-pull-down;
+               bias-bus-hold;
        };
 
        /* For mos_bt_uart */