[PATCH v16 6/6] usb: dwc3: rockchip: fix USB-C reconnect in gadget mode

[Sebastian Reichel]

When USB-C is configured in gadget mode and the cable is unplugged
the USB controller is suspended. After plugging in the cable again,
the USB controller stays suspended and thus the port status remains
not-attached.

Fix this by informing the USB core about VBUS updates when the PHY
mode changes.

Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
---
 drivers/usb/dwc3/Kconfig         |  1 +
 drivers/usb/dwc3/dwc3-rockchip.c | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 3c120ea9746d..344291daf1b2 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -193,6 +193,7 @@ config USB_DWC3_OCTEON
 config USB_DWC3_ROCKCHIP
 	tristate "Rockchip DWC3 Platform Driver"
 	depends on ARCH_ROCKCHIP || COMPILE_TEST
+	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
 	depends on OF
 	default USB_DWC3
 	help
diff --git a/drivers/usb/dwc3/dwc3-rockchip.c b/drivers/usb/dwc3/dwc3-rockchip.c
index 17b6c2ca9e19..ba8ffef2f27e 100644
--- a/drivers/usb/dwc3/dwc3-rockchip.c
+++ b/drivers/usb/dwc3/dwc3-rockchip.c
@@ -25,8 +25,17 @@ struct dwc3_rockchip {
 	struct dwc3		dwc;
 	struct dwc3_rk_phy_nb	usb3_phy_nb[DWC3_USB3_MAX_PORTS];
 	u8			phy_reset_active;
+	enum usb_role		role;
 };
 
+static void dwc3_rockchip_vbus_handler(struct dwc3 *dwc, bool present)
+{
+	if (!dwc->gadget || !dwc->gadget_driver)
+		return;
+
+	usb_udc_vbus_handler(dwc->gadget, present);
+}
+
 static int dwc3_usb3_phy_notify(struct notifier_block *nb,
 				unsigned long action, void *data)
 {
@@ -57,6 +66,8 @@ static int dwc3_usb3_phy_notify(struct notifier_block *nb,
 		if (!ret)
 			return NOTIFY_OK;
 
+		dwc3_rockchip_vbus_handler(dwc, false);
+
 		/*
 		 * Assert USB3 PHY soft reset within DWC3 before the external
 		 * PHY resets. This disconnects the PIPE interface, preventing
@@ -69,6 +80,7 @@ static int dwc3_usb3_phy_notify(struct notifier_block *nb,
 		reg |= DWC3_GUSB3PIPECTL_PHYSOFTRST;
 		dwc3_writel(dwc, DWC3_GUSB3PIPECTL(port), reg);
 		spin_unlock_irqrestore(&dwc->lock, flags);
+
 		break;
 
 	case PHY_NOTIFY_POST_RESET:
@@ -89,6 +101,8 @@ static int dwc3_usb3_phy_notify(struct notifier_block *nb,
 		dwc3_writel(dwc, DWC3_GUSB3PIPECTL(port), reg);
 		spin_unlock_irqrestore(&dwc->lock, flags);
 
+		dwc3_rockchip_vbus_handler(dwc, dwc_rk->role == USB_ROLE_DEVICE);
+
 		pm_runtime_put_autosuspend(dwc->dev);
 		break;
 	}
@@ -130,7 +144,16 @@ static int dwc3_rk_phy_register_notifiers(struct dwc3 *dwc)
 	return devm_add_action_or_reset(dwc->dev, dwc3_rk_phy_unregister_notifiers, dwc_rk);
 }
 
+static void dwc3_rockchip_set_role(struct dwc3 *dwc, enum usb_role role)
+{
+	struct dwc3_rockchip *dwc_rk = container_of(dwc, struct dwc3_rockchip, dwc);
+
+	dwc_rk->role = role;
+	dwc3_rockchip_vbus_handler(dwc, role == USB_ROLE_DEVICE);
+}
+
 static struct dwc3_glue_ops dwc3_rockchip_glue_ops = {
+	.pre_set_role = dwc3_rockchip_set_role,
 	.post_phy_registration = dwc3_rk_phy_register_notifiers,
 };
 

-- 
2.53.0