usb: cdns3: gadget: add CHAIN and ISP bit for sg list use case

For sg buffer list use case, we need to add ISP for each TRB, and
add CHAIN bit for each TRB except for the last TRB.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/cdns3/gadget.c

@@ -1220,8 +1220,14 @@ static int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep,
 		else
 			priv_req->trb->control = cpu_to_le32(control);
 
-		if (sg_supported)
+		if (sg_supported) {
+			trb->control |= TRB_ISP;
+			/* Don't set chain bit for last TRB */
+			if (sg_iter < num_trb - 1)
+				trb->control |= TRB_CHAIN;
+
 			s = sg_next(s);
+		}
 
 		control = 0;
 		++sg_iter;