Messages in this thread | | | Date | Fri, 14 Oct 2011 17:21:07 +0530 | Subject | Re: [PATCHv5] DMAEngine: Define interleaved transfer request api | From | Jassi Brar <> |
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On 14 October 2011 13:02, Barry Song <21cnbao@gmail.com> wrote: >> diff --git a/Documentation/dmaengine.txt b/Documentation/dmaengine.txt >> index 94b7e0f..962a2d3 100644 >> --- a/Documentation/dmaengine.txt >> +++ b/Documentation/dmaengine.txt >> @@ -75,6 +75,10 @@ The slave DMA usage consists of following steps: >> slave_sg - DMA a list of scatter gather buffers from/to a peripheral >> dma_cyclic - Perform a cyclic DMA operation from/to a peripheral till the >> operation is explicitly stopped. >> + interleaved_dma - This is common to Slave as well as M2M clients. For slave >> + address of devices' fifo could be already known to the driver. >> + Various types of operations could be expressed by setting >> + appropriate values to the 'dmaxfer_template' members. >> >> A non-NULL return of this transfer API represents a "descriptor" for >> the given transaction. >> @@ -89,6 +93,10 @@ The slave DMA usage consists of following steps: >> struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, >> size_t period_len, enum dma_data_direction direction); >> >> + struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)( >> + struct dma_chan *chan, struct dmaxfer_template *xt, >> + unsigned long flags); >> + > > what if i want a cyclic interleaved transfer? i think the cyclic > interleaved transfer is what i want for audio dma. > ... we need to restore 'bool frm_irq' and add new 'bool cyclic' that would replay the transfer(i.e, reset dma-pointers to src_start & dst_start) after 'numf' frames have been transferred. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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