[PATCH v2 2/3] dmaengine: ti-dma-crossbar: dra7: Support for reserving DMA event ranges

Rob Herring
2015-11-06T21:53:10Z

On Fri, Oct 30, 2015 at 10:00:37AM +0200, Peter Ujfalusi wrote:
> In eDMA the events are directly mapped to a DMA channel (for example DMA
> event 14 can only be handled by DMA channel 14). If the memcpy is enabled
> on the eDMA, there is a possibility that the crossbar driver would assign
> DMA event number already allocated in eDMA for memcpy. Furthermore the
> eDMA can be shared with DSP in which case the crossbar driver should also
> avoid mapping xbar events to DSP used event numbers (or channels).
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> ---
> .../devicetree/bindings/dma/ti-dma-crossbar.txt | 6 +++
> drivers/dma/ti-dma-crossbar.c | 47 ++++++++++++++++++++--
> 2 files changed, 49 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
> index b152a75dceae..aead5869a28d 100644
> --- a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
> +++ b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
> @@ -14,6 +14,10 @@ The DMA controller node need to have the following poroperties:
>
> Optional properties:
> - ti,dma-safe-map: Safe routing value for unused request lines
> +- ti,reserved-dma-request-ranges: DMA request ranges which should not be used
> + when mapping xbar input to DMA request, they are either
> + allocated to be used by for example the DSP or they are used as
> + memcpy channels in eDMA.

How many requests are there? I think I'd rather see this as a mask
value.

Rob