[PATCH] arm64: dts: rockchip: Enable USB device mode on rk3399-roc-pc-plus

[PATCH] arm64: dts: rockchip: Enable USB device mode on rk3399-roc-pc-plus

[Fabio Estevam]

From: Fabio Estevam <festevam@nabladev.com>

The USB3 OTG controller on the rk3399-roc-pc-plus is forced to host
mode. As a result, it does not register a UDC and USB gadget drivers
fail with:

UDC core: g_mass_storage: couldn't find an available UDC

Describe the controller as a USB role switch and select peripheral as
the default role. This makes DWC3 register a UDC when no external role
provider has selected a host role, while retaining OTG operation and
both the USB2 and USB3 PHYs inherited from the SoC dtsi.

Tested by binding g_mass_storage and exposing the onboard eMMC to a
Linux host.

Fixes: 6d9a7bd6a13c ("arm64: dts: rockchip: add support for Firefly ROC-RK3399-PC-PLUS")
Signed-off-by: Fabio Estevam <festevam@nabladev.com>
---
 arch/arm64/boot/dts/rockchip/rk3399-roc-pc-plus.dts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-roc-pc-plus.dts b/arch/arm64/boot/dts/rockchip/rk3399-roc-pc-plus.dts
index 7e8039b19be7..c733429fd5d9 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-roc-pc-plus.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-roc-pc-plus.dts
@@ -270,7 +270,9 @@ bluetooth {
 };
 
 &usbdrd_dwc3_0 {
-	dr_mode = "host";
+	dr_mode = "otg";
+	role-switch-default-mode = "peripheral";
+	usb-role-switch;
 	status = "okay";
 };
 
-- 
2.43.0