usb: dwc3: gadget: call gadget driver's ->suspend/->resume

When going into bus suspend/resume we _must_
call gadget driver's ->suspend/->resume callbacks
accordingly. This patch implements that very feature
which has been missing forever.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/gadget.c

@@ -2028,6 +2028,24 @@ static void dwc3_disconnect_gadget(struct dwc3 *dwc)
 	}
 }
 
+static void dwc3_suspend_gadget(struct dwc3 *dwc)
+{
+	if (dwc->gadget_driver && dwc->gadget_driver->disconnect) {
+		spin_unlock(&dwc->lock);
+		dwc->gadget_driver->suspend(&dwc->gadget);
+		spin_lock(&dwc->lock);
+	}
+}
+
+static void dwc3_resume_gadget(struct dwc3 *dwc)
+{
+	if (dwc->gadget_driver && dwc->gadget_driver->disconnect) {
+		spin_unlock(&dwc->lock);
+		dwc->gadget_driver->resume(&dwc->gadget);
+		spin_lock(&dwc->lock);
+	}
+}
+
 static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum, bool force)
 {
 	struct dwc3_ep *dep;
@@ -2414,6 +2432,23 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
 
 	dwc->link_state = next;
 
+	switch (next) {
+	case DWC3_LINK_STATE_U1:
+		if (dwc->speed == USB_SPEED_SUPER)
+			dwc3_suspend_gadget(dwc);
+		break;
+	case DWC3_LINK_STATE_U2:
+	case DWC3_LINK_STATE_U3:
+		dwc3_suspend_gadget(dwc);
+		break;
+	case DWC3_LINK_STATE_RESUME:
+		dwc3_resume_gadget(dwc);
+		break;
+	default:
+		/* do nothing */
+		break;
+	}
+
 	dev_vdbg(dwc->dev, "%s link %d\n", __func__, dwc->link_state);
 }