tree c8a10b80bcc571c6de8a19c39b0f447ca61039d6
parent b30a3f6257ed2105259b404d419b4964e363928c
author Sascha Hauer <s.hauer@pengutronix.de> 1285854992 +0000
committer Dan Williams <dan.j.williams@intel.com> 1286318966 -0700

dmaengine: add possibility for cyclic transfers

Cyclic transfers are useful for audio where a single buffer divided
in periods has to be transfered endlessly until stopped. After being
prepared the transfer is started using the dma_async_descriptor->tx_submit
function. dma_async_descriptor->callback is called after each period.
The transfer is stopped using the DMA_TERMINATE_ALL callback.
While being used for cyclic transfers the channel cannot be used
for other transfer types.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>