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-rw-r--r--drivers/usb/gadget/udc-core.c52
-rw-r--r--include/linux/usb/gadget.h10
2 files changed, 62 insertions, 0 deletions
diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 0b0d12ccc487..56da49f31d6c 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -22,6 +22,7 @@
#include <linux/device.h>
#include <linux/list.h>
#include <linux/err.h>
+#include <linux/dma-mapping.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
@@ -49,6 +50,57 @@ static DEFINE_MUTEX(udc_lock);
/* ------------------------------------------------------------------------- */
+int usb_gadget_map_request(struct usb_gadget *gadget,
+ struct usb_request *req, int is_in)
+{
+ if (req->length == 0)
+ return 0;
+
+ if (req->num_sgs) {
+ int mapped;
+
+ mapped = dma_map_sg(&gadget->dev, req->sg, req->num_sgs,
+ is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+ if (mapped == 0) {
+ dev_err(&gadget->dev, "failed to map SGs\n");
+ return -EFAULT;
+ }
+
+ req->num_mapped_sgs = mapped;
+ } else {
+ req->dma = dma_map_single(&gadget->dev, req->buf, req->length,
+ is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+ if (dma_mapping_error(&gadget->dev, req->dma)) {
+ dev_err(&gadget->dev, "failed to map buffer\n");
+ return -EFAULT;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_map_request);
+
+void usb_gadget_unmap_request(struct usb_gadget *gadget,
+ struct usb_request *req, int is_in)
+{
+ if (req->length == 0)
+ return;
+
+ if (req->num_mapped_sgs) {
+ dma_unmap_sg(&gadget->dev, req->sg, req->num_mapped_sgs,
+ is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+ req->num_mapped_sgs = 0;
+ } else {
+ dma_unmap_single(&gadget->dev, req->dma, req->length,
+ is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+ }
+}
+EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
+
+/* ------------------------------------------------------------------------- */
+
/**
* usb_gadget_start - tells usb device controller to start up
* @gadget: The gadget we want to get started
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index da653b5c7134..9517466ababb 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -950,6 +950,16 @@ static inline void usb_free_descriptors(struct usb_descriptor_header **v)
/*-------------------------------------------------------------------------*/
+/* utility to simplify map/unmap of usb_requests to/from DMA */
+
+extern int usb_gadget_map_request(struct usb_gadget *gadget,
+ struct usb_request *req, int is_in);
+
+extern void usb_gadget_unmap_request(struct usb_gadget *gadget,
+ struct usb_request *req, int is_in);
+
+/*-------------------------------------------------------------------------*/
+
/* utility wrapping a simple endpoint selection policy */
extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,