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| author | Peter Ujfalusi <peter.ujfalusi@ti.com> | 2015-04-09 12:35:47 +0300 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2015-05-09 17:11:25 +0530 |
| commit | 56f13c0d9524c5816f5dc9c91b9d766d6b1064ca (patch) | |
| tree | 4cdec4de3dbde9fd36d757f50e900811506969c7 /drivers/dma/dmaengine.c | |
| parent | b787f68c36d49bb1d9236f403813641efa74a031 (diff) | |
| download | op-kernel-dev-56f13c0d9524c5816f5dc9c91b9d766d6b1064ca.zip op-kernel-dev-56f13c0d9524c5816f5dc9c91b9d766d6b1064ca.tar.gz | |
dmaengine: of_dma: Support for DMA routers
DMA routers are transparent devices used to mux DMA requests from
peripherals to DMA controllers. They are used when the SoC integrates more
devices with DMA requests then their controller can handle.
DRA7x is one example of such SoC, where the sDMA can hanlde 128 DMA request
lines, but in SoC level it has 205 DMA requests.
The of_dma_router will be registered as of_dma_controller with special
xlate function and additional parameters. The driver for the router is
responsible to craft the dma_spec (in the of_dma_route_allocate callback)
which can be used to requests a DMA channel from the real DMA controller.
This way the router can be transparent for the system while remaining generic
enough to be used in different environments.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/dmaengine.c')
| -rw-r--r-- | drivers/dma/dmaengine.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 0e035a8..9e59496 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -267,6 +267,13 @@ static void dma_chan_put(struct dma_chan *chan) /* This channel is not in use anymore, free it */ if (!chan->client_count && chan->device->device_free_chan_resources) chan->device->device_free_chan_resources(chan); + + /* If the channel is used via a DMA request router, free the mapping */ + if (chan->router && chan->router->route_free) { + chan->router->route_free(chan->router->dev, chan->route_data); + chan->router = NULL; + chan->route_data = NULL; + } } enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) |
