usb: renesas_usbhs: add DMAEngine support

USB DMA was installed on "normal DMAC" when SH7724 or older SuperH,
but the "USB-DMAC" was prepared on recent SuperH.
These 2 DMAC have a little bit different behavior.

This patch add DMAEngine code for "normal DMAC",
but it is still using PIO fifo.
The DMA fifo will be formally supported in the future.

You can enable DMA fifo by local fixup
usbhs_fifo_pio_push_handler -> usbhs_fifo_dma_push_handler
usbhs_fifo_pio_pop_handler  -> usbhs_fifo_dma_pop_handler
on usbhsg_ep_enable.

This DMAEngine was tested by g_file_storage on SH7724 Ecovec board

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/renesas_usbhs/mod_gadget.c

@@ -160,6 +160,71 @@ static void usbhsg_queue_done(struct usbhs_pkt *pkt)
 	usbhsg_queue_pop(uep, ureq, 0);
 }
 
+static int usbhsg_dma_map(struct device *dev,
+			  struct usbhs_pkt *pkt,
+			  enum dma_data_direction dir)
+{
+	struct usbhsg_request *ureq = usbhsg_pkt_to_ureq(pkt);
+	struct usb_request *req = &ureq->req;
+
+	if (pkt->dma != DMA_ADDR_INVALID) {
+		dev_err(dev, "dma is already mapped\n");
+		return -EIO;
+	}
+
+	if (req->dma == DMA_ADDR_INVALID) {
+		pkt->dma = dma_map_single(dev, pkt->buf, pkt->length, dir);
+	} else {
+		dma_sync_single_for_device(dev, req->dma, req->length, dir);
+		pkt->dma = req->dma;
+	}
+
+	if (dma_mapping_error(dev, pkt->dma)) {
+		dev_err(dev, "dma mapping error %x\n", pkt->dma);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int usbhsg_dma_unmap(struct device *dev,
+			    struct usbhs_pkt *pkt,
+			    enum dma_data_direction dir)
+{
+	struct usbhsg_request *ureq = usbhsg_pkt_to_ureq(pkt);
+	struct usb_request *req = &ureq->req;
+
+	if (pkt->dma == DMA_ADDR_INVALID) {
+		dev_err(dev, "dma is not mapped\n");
+		return -EIO;
+	}
+
+	if (req->dma == DMA_ADDR_INVALID)
+		dma_unmap_single(dev, pkt->dma, pkt->length, dir);
+	else
+		dma_sync_single_for_cpu(dev, req->dma, req->length, dir);
+
+	pkt->dma = DMA_ADDR_INVALID;
+
+	return 0;
+}
+
+static int usbhsg_dma_map_ctrl(struct usbhs_pkt *pkt, int map)
+{
+	struct usbhs_pipe *pipe = pkt->pipe;
+	struct usbhsg_uep *uep = usbhsg_pipe_to_uep(pipe);
+	struct usbhsg_gpriv *gpriv = usbhsg_uep_to_gpriv(uep);
+	struct device *dev = usbhsg_gpriv_to_dev(gpriv);
+	enum dma_data_direction dir;
+
+	dir = usbhs_pipe_is_dir_in(pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	if (map)
+		return usbhsg_dma_map(dev, pkt, dir);
+	else
+		return usbhsg_dma_unmap(dev, pkt, dir);
+}
+
 /*
  *		USB_TYPE_STANDARD / clear feature functions
  */
@@ -434,6 +499,8 @@ static struct usb_request *usbhsg_ep_alloc_request(struct usb_ep *ep,
 
 	usbhs_pkt_init(usbhsg_ureq_to_pkt(ureq));
 
+	ureq->req.dma = DMA_ADDR_INVALID;
+
 	return &ureq->req;
 }
 
@@ -569,7 +636,8 @@ static int usbhsg_try_start(struct usbhs_priv *priv, u32 status)
 	 * pipe initialize and enable DCP
 	 */
 	usbhs_pipe_init(priv,
-			usbhsg_queue_done);
+			usbhsg_queue_done,
+			usbhsg_dma_map_ctrl);
 	usbhs_fifo_init(priv);
 	usbhsg_uep_init(gpriv);