From 6f3d87968f9c8b529bc81eff5a1f45e92553493d Mon Sep 17 00:00:00 2001 From: Niklas Söderlund Date: Wed, 10 Aug 2016 13:22:16 +0200 Subject: dma-mapping: add dma_{map,unmap}_resource MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Arnd Bergmann Signed-off-by: Vinod Koul --- Documentation/DMA-API.txt | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) (limited to 'Documentation/DMA-API.txt') 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 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, -- cgit v1.2.3-59-g8ed1b