[PATCH 6/6] arm64: dts: qcom: sm7225-fairphone-fp4: Enable USB audio offload support

From: Luca Weiss
Date: Fri Apr 25 2025 - 06:52:45 EST


Enable USB audio offloading which allows to play audio via a USB-C
headset with lower power consumption and enabling some other features.

This can be used like the following:

$ amixer -c0 cset name='USB_RX Audio Mixer MultiMedia1' On
$ aplay --device=plughw:0,0 test.wav

Compared to regular playback to the USB sound card no interrupts should
appear on the xhci-hcd interrupts during playback, instead the ADSP will
be handling the playback.

Signed-off-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx>
---
arch/arm64/boot/dts/qcom/sm6350.dtsi | 3 ++
arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts | 37 +++++++++++++++++++++++
2 files changed, 40 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sm6350.dtsi b/arch/arm64/boot/dts/qcom/sm6350.dtsi
index 9a1b9f02282a0cf2e39bf2ade21989dbf4362bc1..ade69296cbc99eab3ee6dc020f2064d102a3b115 100644
--- a/arch/arm64/boot/dts/qcom/sm6350.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm6350.dtsi
@@ -2956,6 +2956,9 @@ wifi: wifi@18800000 {
};
};

+ sound: sound {
+ };
+
thermal-zones {
aoss0-thermal {
thermal-sensors = <&tsens0 0>;
diff --git a/arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts b/arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts
index 71e87ab929551b339216a5fa583833ed8661a606..0f8e0a988db0d32384f39537731c77344ec50cf2 100644
--- a/arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts
+++ b/arch/arm64/boot/dts/qcom/sm7225-fairphone-fp4.dts
@@ -19,6 +19,7 @@
#include <dt-bindings/leds/common.h>
#include <dt-bindings/pinctrl/qcom,pmic-gpio.h>
#include <dt-bindings/regulator/qcom,rpmh-regulator.h>
+#include <dt-bindings/sound/qcom,q6asm.h>
#include <dt-bindings/usb/pd.h>
#include "sm7225.dtsi"
#include "pm6150l.dtsi"
@@ -955,6 +956,12 @@ channel@644 {
};
};

+&q6asmdai {
+ dai@0 {
+ reg = <MSM_FRONTEND_DAI_MULTIMEDIA1>;
+ };
+};
+
&qup_uart1_cts {
/*
* Configure a bias-bus-hold on CTS to lower power
@@ -1023,6 +1030,35 @@ &sdhc_2 {
status = "okay";
};

+&sound {
+ compatible = "fairphone,fp4-sndcard";
+ model = "Fairphone 4";
+
+ mm1-dai-link {
+ link-name = "MultiMedia1";
+
+ cpu {
+ sound-dai = <&q6asmdai MSM_FRONTEND_DAI_MULTIMEDIA1>;
+ };
+ };
+
+ usb-dai-link {
+ link-name = "USB Playback";
+
+ cpu {
+ sound-dai = <&q6afedai USB_RX>;
+ };
+
+ codec {
+ sound-dai = <&q6usbdai USB_RX>;
+ };
+
+ platform {
+ sound-dai = <&q6routing>;
+ };
+ };
+};
+
&tlmm {
gpio-reserved-ranges = <13 4>, <56 2>;

@@ -1178,6 +1214,7 @@ &usb_1 {
&usb_1_dwc3 {
maximum-speed = "super-speed";
dr_mode = "otg";
+ num-hc-interrupters = /bits/ 16 <3>;
};

&usb_1_dwc3_hs_out {

--
2.49.0