usb: dwc3: gadget: add common endpoint configuration for dwc3 udc driver

This patch adds code to select standard, commonly used usb endpoint
configuration (ep1in-bulk, ep2out-bulk, ep3in-int) to dwc3 driver. This
ensures compatibility with old userspace and windows drivers, which
expects hardcoded endpoint numbers.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 0df4b2a..6ddbe83 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -220,7 +220,7 @@
 	struct usb_endpoint_descriptor	*desc
 )
 {
-	struct usb_ep	*ep;
+	struct usb_ep	*ep = NULL;
 	u8		type;
 
 	type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
@@ -261,6 +261,28 @@
 		ep = find_ep(gadget, "ep1-bulk");
 		if (ep && ep_matches(gadget, ep, desc))
 			return ep;
+	} else if (gadget_is_dwc3(gadget)) {
+		const char *name = NULL;
+		/*
+		 * First try standard, common configuration: ep1in-bulk,
+		 * ep2out-bulk, ep3in-int to match other udc drivers to avoid
+		 * confusion in already deployed software (endpoint numbers
+		 * hardcoded in userspace software/drivers)
+		 */
+		if ((desc->bEndpointAddress & USB_DIR_IN) &&
+		    type == USB_ENDPOINT_XFER_BULK)
+			name = "ep1in";
+		else if ((desc->bEndpointAddress & USB_DIR_IN) == 0 &&
+			 type == USB_ENDPOINT_XFER_BULK)
+			name = "ep2out";
+		else if ((desc->bEndpointAddress & USB_DIR_IN) &&
+			 type == USB_ENDPOINT_XFER_INT)
+			name = "ep3in";
+
+		if (name)
+			ep = find_ep(gadget, name);
+		if (ep && ep_matches(gadget, ep, desc))
+			return ep;
 	}
 
 	/* Second, look at endpoints until an unclaimed one looks usable */