[PATCH] arm64: dts: mediatek: mt8390-genio-common: Force ssusb2 dual role mode to host

[Louis-Alexis Eyraud]

On the Mediatek Genio 510-EVK and 700-EVK boards, ssusb2 controller is
one but has two ports: one is routed to the M.2 slot, the other is on
the RPi header who does support full OTG.
Since Mediatek Genio 700-EVK USB support was added, dual role mode
property is set to otg for ssusb2. This config prevents the M.2
Wifi/Bluetooth module, present on those boards and exposing Bluetooth
as an USB device to be properly detected at startup, so configure for
the ssusb2 dr_mode property as host instead.

Fixes: 1afaeca17238 ("arm64: dts: mediatek: mt8390-genio-700: Add USB, TypeC Controller, MUX")
Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud at collabora.com>
---
I've tested this patch on Mediatek Genio 510-EVK board with a kernel
based on linux-next (tag: next-20250331).
---
 arch/arm64/boot/dts/mediatek/mt8390-genio-common.dtsi | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt8390-genio-common.dtsi b/arch/arm64/boot/dts/mediatek/mt8390-genio-common.dtsi
index 60139e6dffd8e0e326690d922f3360d829ed026b..3a9d429f0f14b501ae41551dfe7272f242345138 100644
--- a/arch/arm64/boot/dts/mediatek/mt8390-genio-common.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8390-genio-common.dtsi
@@ -1199,7 +1199,13 @@ xhci_ss_ep: endpoint {
 };
 
 &ssusb2 {
-	dr_mode = "otg";
+	/*
+	 * the ssusb2 controller is one but we got two ports : one is routed
+	 * to the M.2 slot, the other is on the RPi header who does support
+	 * full OTG but we keep it disabled otherwise the BT on the M.2 slot
+	 * USB line goes obviously dead if switching to gadget mode.
+	 */
+	dr_mode = "host";
 	maximum-speed = "high-speed";
 	usb-role-switch;
 	vusb33-supply = <&mt6359_vusb_ldo_reg>;

---
base-commit: 1c4df70331c0dc7f82f724166575c16931ec66b3
change-id: 20250328-mtk-genio-510-700-fix-bt-detection-2711cbcbb2e4

Best regards,
-- 
Louis-Alexis Eyraud <louisalexis.eyraud at collabora.com>