dma: Add prototypes for dma mapping functions

Right now we only have the dma_sync_single_* functions, but no functions
for actually mapping a pointer. The mapping functions become necessary
when casting a pointer to unsigned long to get a dma address is not
enough. (I'm not even going so far that we'll add IOMMU support, but on
some architectures we need a place where we can check if a pointer is
DMA mappable at all)

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/dma.h b/include/dma.h
index 29d94c0a52..5fdcb1733c 100644
--- a/include/dma.h
+++ b/include/dma.h
@@ -30,6 +30,18 @@ static inline void dma_free(void *mem)
 }
 #endif
 
+dma_addr_t dma_map_single(struct device_d *dev, void *ptr, size_t size,
+			  enum dma_data_direction dir);
+void dma_unmap_single(struct device_d *dev, dma_addr_t addr, size_t size,
+		      enum dma_data_direction dir);
+
+#define DMA_ERROR_CODE  (~(dma_addr_t)0)
+
+static inline int dma_mapping_error(struct device_d *dev, dma_addr_t dma_addr)
+{
+	return dma_addr == DMA_ERROR_CODE;
+}
+
 /* streaming DMA - implement the below calls to support HAS_DMA */
 void dma_sync_single_for_cpu(dma_addr_t address, size_t size,
 			     enum dma_data_direction dir);