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>

drivers/usb/dwc3/core.h

@@ -572,7 +572,6 @@ struct dwc3_request {
  * @ctrl_req_addr: dma address of ctrl_req
  * @ep0_trb: dma address of ep0_trb
  * @ep0_usb_req: dummy req used while handling STD USB requests
- * @setup_buf_addr: dma address of setup_buf
  * @ep0_bounce_addr: dma address of ep0_bounce
  * @lock: for synchronizing
  * @dev: pointer to our struct device
@@ -609,7 +608,6 @@ struct dwc3 {
 	u8			*setup_buf;
 	dma_addr_t		ctrl_req_addr;
 	dma_addr_t		ep0_trb_addr;
-	dma_addr_t		setup_buf_addr;
 	dma_addr_t		ep0_bounce_addr;
 	struct dwc3_request	ep0_usb_req;
 	/* device lock */

drivers/usb/dwc3/ep0.c

@@ -309,7 +309,7 @@ static int dwc3_ep0_handle_status(struct dwc3 *dwc,
 	dep = dwc->eps[0];
 	dwc->ep0_usb_req.dep = dep;
 	dwc->ep0_usb_req.request.length = sizeof(*response_pkt);
-	dwc->ep0_usb_req.request.dma = dwc->setup_buf_addr;
+	dwc->ep0_usb_req.request.buf = dwc->setup_buf;
 	dwc->ep0_usb_req.request.complete = dwc3_ep0_status_cmpl;
 
 	return __dwc3_gadget_ep0_queue(dep, &dwc->ep0_usb_req);
@@ -686,7 +686,12 @@ static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
 				DWC3_TRBCTL_CONTROL_DATA);
 	} else if ((req->request.length % dep->endpoint.maxpacket)
 			&& (event->endpoint_number == 0)) {
-		dwc3_map_buffer_to_dma(req);
+		ret = usb_gadget_map_request(&dwc->gadget, &req->request,
+				event->endpoint_number);
+		if (ret) {
+			dev_dbg(dwc->dev, "failed to map request\n");
+			return;
+		}
 
 		WARN_ON(req->request.length > dep->endpoint.maxpacket);
 
@@ -701,7 +706,12 @@ static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
 				dwc->ep0_bounce_addr, dep->endpoint.maxpacket,
 				DWC3_TRBCTL_CONTROL_DATA);
 	} else {
-		dwc3_map_buffer_to_dma(req);
+		ret = usb_gadget_map_request(&dwc->gadget, &req->request,
+				event->endpoint_number);
+		if (ret) {
+			dev_dbg(dwc->dev, "failed to map request\n");
+			return;
+		}
 
 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
 				req->request.dma, req->request.length,

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 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 	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 @@ static struct usb_request *dwc3_gadget_ep_alloc_request(struct usb_ep *ep,
 
 	req->epnum	= dep->number;
 	req->dep	= dep;
-	req->request.dma = DMA_ADDR_INVALID;
 
 	return &req->request;
 }
@@ -822,7 +758,8 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep, u16 cmd_param,
 		 * 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_kick_transfer(struct dwc3_ep *dep, u16 cmd_param,
 
 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 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 	 * 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 @@ int __devinit dwc3_gadget_init(struct dwc3 *dwc)
 		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 @@ int __devinit dwc3_gadget_init(struct dwc3 *dwc)
 			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 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 	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);

drivers/usb/dwc3/gadget.h

@@ -108,8 +108,6 @@ int dwc3_gadget_ep0_queue(struct usb_ep *ep, struct usb_request *request,
 int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value);
 int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
 		unsigned cmd, struct dwc3_gadget_ep_cmd_params *params);
-void dwc3_map_buffer_to_dma(struct dwc3_request *req);
-void dwc3_unmap_buffer_from_dma(struct dwc3_request *req);
 
 /**
  * dwc3_gadget_ep_get_transfer_index - Gets transfer index from HW