[PATCH RFC 1/2] arm64: dts: qcom: sdm845-google: Describe Wi-Fi/BT properly

From: David Heidelberg via B4 Relay

Date: Fri Mar 27 2026 - 09:11:31 EST


From: David Heidelberg <david@xxxxxxx>

The onboard Wi-Fi / BT device, WCN3990, has a simple on-chip PMU, which
further spreads generated voltage. Describe the PMU in the device tree
and rewire Bluetooth and Wi-Fi supply properties to use the PMU LDO
outputs instead of referencing the SoC regulators directly.

Couldn't verify the swctrl GPIO thus omitted.

Assisted-by: Claude:claude-opus-4.6
Signed-off-by: David Heidelberg <david@xxxxxxx>
---
arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi | 42 ++++++++++++++++++----
1 file changed, 35 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi b/arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi
index fd9788d5c3f54..6930066857768 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi
+++ b/arch/arm64/boot/dts/qcom/sdm845-google-common.dtsi
@@ -131,6 +131,33 @@ vreg_s4a_1p8: regulator-vreg-s4a-1p8 {

vin-supply = <&vph_pwr>;
};
+
+ wcn3990-pmu {
+ compatible = "qcom,wcn3990-pmu";
+
+ vddio-supply = <&vreg_s4a_1p8>;
+ vddxo-supply = <&vreg_l7a_1p8>;
+ vddrf-supply = <&vreg_l17a_1p3>;
+ vddch0-supply = <&vreg_l25a_3p3>;
+
+ regulators {
+ vreg_pmu_io: ldo0 {
+ regulator-name = "vreg_pmu_io";
+ };
+
+ vreg_pmu_xo: ldo1 {
+ regulator-name = "vreg_pmu_xo";
+ };
+
+ vreg_pmu_rf: ldo2 {
+ regulator-name = "vreg_pmu_rf";
+ };
+
+ vreg_pmu_ch0: ldo3 {
+ regulator-name = "vreg_pmu_ch0";
+ };
+ };
+ };
};

&adsp_pas {
@@ -462,10 +489,11 @@ &uart6 {
bluetooth {
compatible = "qcom,wcn3990-bt";

- vddio-supply = <&vreg_s4a_1p8>;
- vddxo-supply = <&vreg_l7a_1p8>;
- vddrf-supply = <&vreg_l17a_1p3>;
- vddch0-supply = <&vreg_l25a_3p3>;
+ vddio-supply = <&vreg_pmu_io>;
+ vddxo-supply = <&vreg_pmu_xo>;
+ vddrf-supply = <&vreg_pmu_rf>;
+ vddch0-supply = <&vreg_pmu_ch0>;
+
max-speed = <3200000>;
};
};
@@ -526,9 +554,9 @@ &venus {

&wifi {
vdd-0.8-cx-mx-supply = <&vreg_l5a_0p8>;
- vdd-1.8-xo-supply = <&vreg_l7a_1p8>;
- vdd-1.3-rfa-supply = <&vreg_l17a_1p3>;
- vdd-3.3-ch0-supply = <&vreg_l25a_3p3>;
+ vdd-1.8-xo-supply = <&vreg_pmu_xo>;
+ vdd-1.3-rfa-supply = <&vreg_pmu_rf>;
+ vdd-3.3-ch0-supply = <&vreg_pmu_ch0>;

qcom,snoc-host-cap-8bit-quirk;


--
2.53.0