usb: musb: host: unmap the buffer for PIO data transfers

The USB stack maps the buffer for DMA if the controller supports DMA.
MUSB controller can perform DMA as well as PIO transfers.
The buffer needs to be unmapped before CPU can perform
PIO data transfers.

Export unmap_urb_for_dma() so that drivers can perform
the DMA unmapping in a sane way.

Signed-off-by: Maulik Mankad <x0082077@ti.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 3b571f1ffbb3..fe89f7c298aa 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -329,6 +329,7 @@ extern int usb_hcd_submit_urb(struct urb *urb, gfp_t mem_flags);
 extern int usb_hcd_unlink_urb(struct urb *urb, int status);
 extern void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb,
                 int status);
+extern void unmap_urb_for_dma(struct usb_hcd *, struct urb *);
 extern void usb_hcd_flush_endpoint(struct usb_device *udev,
                 struct usb_host_endpoint *ep);
 extern void usb_hcd_disable_endpoint(struct usb_device *udev,