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authorNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>2016-08-10 11:22:16 (GMT)
committerVinod Koul <vinod.koul@intel.com>2016-09-26 16:46:41 (GMT)
commit6f3d87968f9c8b529bc81eff5a1f45e92553493d (patch)
tree977a550789b14f198154488a9c105cc2049c6b50 /Documentation/DMA-API.txt
parent0e74b34dfc3318bf4c7e51349d453d49fb8e9e16 (diff)
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dma-mapping: add dma_{map,unmap}_resource
Map/Unmap a device MMIO resource from a physical address. If no dma_map_ops method is available the operation is a no-op. Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'Documentation/DMA-API.txt')
-rw-r--r--Documentation/DMA-API.txt22
1 files changed, 17 insertions, 5 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 1d26eeb6..6b20128 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -277,14 +277,26 @@ and <size> parameters are provided to do partial page mapping, it is
recommended that you never use these unless you really know what the
cache width is.
+dma_addr_t
+dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size,
+ enum dma_data_direction dir, unsigned long attrs)
+
+void
+dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
+ enum dma_data_direction dir, unsigned long attrs)
+
+API for mapping and unmapping for MMIO resources. All the notes and
+warnings for the other mapping APIs apply here. The API should only be
+used to map device MMIO resources, mapping of RAM is not permitted.
+
int
dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
-In some circumstances dma_map_single() and dma_map_page() will fail to create
-a mapping. A driver can check for these errors by testing the returned
-DMA address with dma_mapping_error(). A non-zero return value means the mapping
-could not be created and the driver should take appropriate action (e.g.
-reduce current DMA mapping usage or delay and try again later).
+In some circumstances dma_map_single(), dma_map_page() and dma_map_resource()
+will fail to create a mapping. A driver can check for these errors by testing
+the returned DMA address with dma_mapping_error(). A non-zero return value
+means the mapping could not be created and the driver should take appropriate
+action (e.g. reduce current DMA mapping usage or delay and try again later).
int
dma_map_sg(struct device *dev, struct scatterlist *sg,