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Diffstat (limited to 'Documentation/rapidio/tsi721.txt')
| -rw-r--r-- | Documentation/rapidio/tsi721.txt | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/Documentation/rapidio/tsi721.txt b/Documentation/rapidio/tsi721.txt index 335f3c6087dc..626052f403bb 100644 --- a/Documentation/rapidio/tsi721.txt +++ b/Documentation/rapidio/tsi721.txt @@ -20,13 +20,26 @@ II. Known problems None. -III. To do +III. DMA Engine Support - Add DMA data transfers (non-messaging). - Add inbound region (SRIO-to-PCIe) mapping. +Tsi721 mport driver supports DMA data transfers between local system memory and +remote RapidIO devices. This functionality is implemented according to SLAVE +mode API defined by common Linux kernel DMA Engine framework. + +Depending on system requirements RapidIO DMA operations can be included/excluded +by setting CONFIG_RAPIDIO_DMA_ENGINE option. Tsi721 miniport driver uses seven +out of eight available BDMA channels to support DMA data transfers. +One BDMA channel is reserved for generation of maintenance read/write requests. + +If Tsi721 mport driver have been built with RAPIDIO_DMA_ENGINE support included, +this driver will accept DMA-specific module parameter: + "dma_desc_per_channel" - defines number of hardware buffer descriptors used by + each BDMA channel of Tsi721 (by default - 128). IV. Version History + 1.1.0 - DMA operations re-worked to support data scatter/gather lists larger + than hardware buffer descriptors ring. 1.0.0 - Initial driver release. V. License |