dma-mapping: add {map,unmap}_resource to dma_map_ops

Add methods to handle mapping of device resources from a physical
address. This is needed for example to be able to map MMIO FIFO
registers to a IOMMU.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

include/linux/dma-mapping.h

@@ -95,6 +95,12 @@ struct dma_map_ops {
 			 struct scatterlist *sg, int nents,
 			 enum dma_data_direction dir,
 			 unsigned long attrs);
+	dma_addr_t (*map_resource)(struct device *dev, phys_addr_t phys_addr,
+			       size_t size, enum dma_data_direction dir,
+			       unsigned long attrs);
+	void (*unmap_resource)(struct device *dev, dma_addr_t dma_handle,
+			   size_t size, enum dma_data_direction dir,
+			   unsigned long attrs);
 	void (*sync_single_for_cpu)(struct device *dev,
 				    dma_addr_t dma_handle, size_t size,
 				    enum dma_data_direction dir);