usb: dwc3: gadget: use generic map/unmap routines

those routines have everything we need to map/unmap
USB requests and it's better to use them.

In order to achieve that, we had to add a simple
change on how we allocate and use our setup buffer;
we cannot allocate it from coherent anymore otherwise
the generic map/unmap routines won't be able to easily
know that the GetStatus request already has a DMA
address.

Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index a1a04d0..1009e7e 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -54,70 +54,6 @@
 #include "gadget.h"
 #include "io.h"
 
-#define	DMA_ADDR_INVALID	(~(dma_addr_t)0)
-
-void dwc3_map_buffer_to_dma(struct dwc3_request *req)
-{
-	struct dwc3			*dwc = req->dep->dwc;
-
-	if (req->request.length == 0) {
-		/* req->request.dma = dwc->setup_buf_addr; */
-		return;
-	}
-
-	if (req->request.num_sgs) {
-		int	mapped;
-
-		mapped = dma_map_sg(dwc->dev, req->request.sg,
-				req->request.num_sgs,
-				req->direction ? DMA_TO_DEVICE
-				: DMA_FROM_DEVICE);
-		if (mapped < 0) {
-			dev_err(dwc->dev, "failed to map SGs\n");
-			return;
-		}
-
-		req->request.num_mapped_sgs = mapped;
-		return;
-	}
-
-	if (req->request.dma == DMA_ADDR_INVALID) {
-		req->request.dma = dma_map_single(dwc->dev, req->request.buf,
-				req->request.length, req->direction
-				? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-		req->mapped = true;
-	}
-}
-
-void dwc3_unmap_buffer_from_dma(struct dwc3_request *req)
-{
-	struct dwc3			*dwc = req->dep->dwc;
-
-	if (req->request.length == 0) {
-		req->request.dma = DMA_ADDR_INVALID;
-		return;
-	}
-
-	if (req->request.num_mapped_sgs) {
-		req->request.dma = DMA_ADDR_INVALID;
-		dma_unmap_sg(dwc->dev, req->request.sg,
-				req->request.num_sgs,
-				req->direction ? DMA_TO_DEVICE
-				: DMA_FROM_DEVICE);
-
-		req->request.num_mapped_sgs = 0;
-		return;
-	}
-
-	if (req->mapped) {
-		dma_unmap_single(dwc->dev, req->request.dma,
-				req->request.length, req->direction
-				? DMA_TO_DEVICE : DMA_FROM_DEVICE);
-		req->mapped = 0;
-		req->request.dma = DMA_ADDR_INVALID;
-	}
-}
-
 void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 		int status)
 {
@@ -144,14 +80,15 @@
 	if (req->request.status == -EINPROGRESS)
 		req->request.status = status;
 
-	dwc3_unmap_buffer_from_dma(req);
+	usb_gadget_unmap_request(&dwc->gadget, &req->request,
+			req->direction);
 
 	dev_dbg(dwc->dev, "request %p from %s completed %d/%d ===> %d\n",
 			req, dep->name, req->request.actual,
 			req->request.length, status);
 
 	spin_unlock(&dwc->lock);
-	req->request.complete(&req->dep->endpoint, &req->request);
+	req->request.complete(&dep->endpoint, &req->request);
 	spin_lock(&dwc->lock);
 }
 
@@ -563,7 +500,6 @@
 
 	req->epnum	= dep->number;
 	req->dep	= dep;
-	req->request.dma = DMA_ADDR_INVALID;
 
 	return &req->request;
 }
@@ -822,7 +758,8 @@
 		 * here and stop, unmap, free and del each of the linked
 		 * requests instead of we do now.
 		 */
-		dwc3_unmap_buffer_from_dma(req);
+		usb_gadget_unmap_request(&dwc->gadget, &req->request,
+				req->direction);
 		list_del(&req->list);
 		return ret;
 	}
@@ -838,6 +775,9 @@
 
 static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 {
+	struct dwc3		*dwc = dep->dwc;
+	int			ret;
+
 	req->request.actual	= 0;
 	req->request.status	= -EINPROGRESS;
 	req->direction		= dep->direction;
@@ -855,7 +795,11 @@
 	 * This will also avoid Host cancelling URBs due to too
 	 * many NACKs.
 	 */
-	dwc3_map_buffer_to_dma(req);
+	ret = usb_gadget_map_request(&dwc->gadget, &req->request,
+			dep->direction);
+	if (ret)
+		return ret;
+
 	list_add_tail(&req->list, &dep->request_list);
 
 	/*
@@ -2150,9 +2094,8 @@
 		goto err1;
 	}
 
-	dwc->setup_buf = dma_alloc_coherent(dwc->dev,
-			sizeof(*dwc->setup_buf) * 2,
-			&dwc->setup_buf_addr, GFP_KERNEL);
+	dwc->setup_buf = kzalloc(sizeof(*dwc->setup_buf) * 2,
+			GFP_KERNEL);
 	if (!dwc->setup_buf) {
 		dev_err(dwc->dev, "failed to allocate setup buffer\n");
 		ret = -ENOMEM;
@@ -2243,8 +2186,7 @@
 			dwc->ep0_bounce_addr);
 
 err3:
-	dma_free_coherent(dwc->dev, sizeof(*dwc->setup_buf) * 2,
-			dwc->setup_buf, dwc->setup_buf_addr);
+	kfree(dwc->setup_buf);
 
 err2:
 	dma_free_coherent(dwc->dev, sizeof(*dwc->ep0_trb),
@@ -2273,8 +2215,7 @@
 	dma_free_coherent(dwc->dev, 512, dwc->ep0_bounce,
 			dwc->ep0_bounce_addr);
 
-	dma_free_coherent(dwc->dev, sizeof(*dwc->setup_buf) * 2,
-			dwc->setup_buf, dwc->setup_buf_addr);
+	kfree(dwc->setup_buf);
 
 	dma_free_coherent(dwc->dev, sizeof(*dwc->ep0_trb),
 			dwc->ep0_trb, dwc->ep0_trb_addr);