usb: dwc3: gadget: start core on Rx.Detect

When we set Run/Stop bit, we also move the
core to Rx.Detect state so that USB3 handshake
can start from a known location.

Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/core.h

@@ -202,6 +202,15 @@
 
 #define DWC3_DCTL_APPL1RES	(1 << 23)
 
+#define DWC3_DCTL_TRGTULST_MASK	(0x0f << 17)
+#define DWC3_DCTL_TRGTULST(n)	((n) << 17)
+
+#define DWC3_DCTL_TRGTULST_U2	(DWC3_DCTL_TRGTULST(2))
+#define DWC3_DCTL_TRGTULST_U3	(DWC3_DCTL_TRGTULST(3))
+#define DWC3_DCTL_TRGTULST_SS_DIS (DWC3_DCTL_TRGTULST(4))
+#define DWC3_DCTL_TRGTULST_RX_DET (DWC3_DCTL_TRGTULST(5))
+#define DWC3_DCTL_TRGTULST_SS_INACT (DWC3_DCTL_TRGTULST(6))
+
 #define DWC3_DCTL_INITU2ENA	(1 << 12)
 #define DWC3_DCTL_ACCEPTU2ENA	(1 << 11)
 #define DWC3_DCTL_INITU1ENA	(1 << 10)

drivers/usb/dwc3/gadget.c

@@ -1313,10 +1313,13 @@ static void dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on)
 	u32			timeout = 500;
 
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
-	if (is_on)
-		reg |= DWC3_DCTL_RUN_STOP;
-	else
+	if (is_on) {
+		reg &= ~DWC3_DCTL_TRGTULST_MASK;
+		reg |= (DWC3_DCTL_RUN_STOP
+				| DWC3_DCTL_TRGTULST_RX_DET);
+	} else {
 		reg &= ~DWC3_DCTL_RUN_STOP;
+	}
 
 	dwc3_writel(dwc->regs, DWC3_DCTL, reg);