diff options
Diffstat (limited to 'Documentation/dmaengine.txt')
| -rw-r--r-- | Documentation/dmaengine.txt | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/Documentation/dmaengine.txt b/Documentation/dmaengine.txt index 879b6e31e2da..573e28ce9751 100644 --- a/Documentation/dmaengine.txt +++ b/Documentation/dmaengine.txt | |||
| @@ -84,31 +84,32 @@ The slave DMA usage consists of following steps: | |||
| 84 | the given transaction. | 84 | the given transaction. |
| 85 | 85 | ||
| 86 | Interface: | 86 | Interface: |
| 87 | struct dma_async_tx_descriptor *(*chan->device->device_prep_slave_sg)( | 87 | struct dma_async_tx_descriptor *dmaengine_prep_slave_sg( |
| 88 | struct dma_chan *chan, struct scatterlist *sgl, | 88 | struct dma_chan *chan, struct scatterlist *sgl, |
| 89 | unsigned int sg_len, enum dma_data_direction direction, | 89 | unsigned int sg_len, enum dma_data_direction direction, |
| 90 | unsigned long flags); | 90 | unsigned long flags); |
| 91 | 91 | ||
| 92 | struct dma_async_tx_descriptor *(*chan->device->device_prep_dma_cyclic)( | 92 | struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic( |
| 93 | struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, | 93 | struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, |
| 94 | size_t period_len, enum dma_data_direction direction); | 94 | size_t period_len, enum dma_data_direction direction); |
| 95 | 95 | ||
| 96 | struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)( | 96 | struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma( |
| 97 | struct dma_chan *chan, struct dma_interleaved_template *xt, | 97 | struct dma_chan *chan, struct dma_interleaved_template *xt, |
| 98 | unsigned long flags); | 98 | unsigned long flags); |
| 99 | 99 | ||
| 100 | The peripheral driver is expected to have mapped the scatterlist for | 100 | The peripheral driver is expected to have mapped the scatterlist for |
| 101 | the DMA operation prior to calling device_prep_slave_sg, and must | 101 | the DMA operation prior to calling device_prep_slave_sg, and must |
| 102 | keep the scatterlist mapped until the DMA operation has completed. | 102 | keep the scatterlist mapped until the DMA operation has completed. |
| 103 | The scatterlist must be mapped using the DMA struct device. So, | 103 | The scatterlist must be mapped using the DMA struct device. |
| 104 | normal setup should look like this: | 104 | If a mapping needs to be synchronized later, dma_sync_*_for_*() must be |
| 105 | called using the DMA struct device, too. | ||
| 106 | So, normal setup should look like this: | ||
| 105 | 107 | ||
| 106 | nr_sg = dma_map_sg(chan->device->dev, sgl, sg_len); | 108 | nr_sg = dma_map_sg(chan->device->dev, sgl, sg_len); |
| 107 | if (nr_sg == 0) | 109 | if (nr_sg == 0) |
| 108 | /* error */ | 110 | /* error */ |
| 109 | 111 | ||
| 110 | desc = chan->device->device_prep_slave_sg(chan, sgl, nr_sg, | 112 | desc = dmaengine_prep_slave_sg(chan, sgl, nr_sg, direction, flags); |
| 111 | direction, flags); | ||
| 112 | 113 | ||
| 113 | Once a descriptor has been obtained, the callback information can be | 114 | Once a descriptor has been obtained, the callback information can be |
| 114 | added and the descriptor must then be submitted. Some DMA engine | 115 | added and the descriptor must then be submitted. Some DMA engine |
| @@ -188,7 +189,7 @@ Further APIs: | |||
| 188 | description of this API. | 189 | description of this API. |
| 189 | 190 | ||
| 190 | This can be used in conjunction with dma_async_is_complete() and | 191 | This can be used in conjunction with dma_async_is_complete() and |
| 191 | the cookie returned from 'descriptor->submit()' to check for | 192 | the cookie returned from dmaengine_submit() to check for |
| 192 | completion of a specific DMA transaction. | 193 | completion of a specific DMA transaction. |
| 193 | 194 | ||
| 194 | Note: | 195 | Note: |