diff options
| author | Niklas Söderlund | 2016-08-10 13:22:16 +0200 |
|---|---|---|
| committer | Vinod Koul | 2016-09-26 22:16:41 +0530 |
| commit | 6f3d87968f9c8b529bc81eff5a1f45e92553493d (patch) | |
| tree | 977a550789b14f198154488a9c105cc2049c6b50 /Documentation | |
| parent | 0e74b34dfc3318bf4c7e51349d453d49fb8e9e16 (diff) | |
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')
| -rw-r--r-- | Documentation/DMA-API.txt | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 1d26eeb6b5f6..6b20128fab8a 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, |