Re: [PATCH 1/4] dt-bindings: Document the STM32 DMA bindings

[M'boumba Cedric Madianga]

Hi Arnd,

2015-10-08 17:43 GMT+02:00 Arnd Bergmann <arnd@xxxxxxxx>:
> On Thursday 08 October 2015 17:20:09 M'boumba Cedric Madianga wrote:
>> +Each dmas request consists of 5 cells:
>> +1. A phandle pointing to the STM32 DMA controller
>> +2. The channel id
>> +3. The request line number
>> +4. A 32bit mask specifying the DMA channel configuration
>>
>
> It's fairly unusual to encode the channel id here, rather than
> letting the driver pick one. Is that actually required here?
Yes it is required as in STM32 platform the channel/request DMA
mapping is done by hardware lines.
So, if one client wants to use DMA, he has to choose the correct
channel/request values according to the DMA mapping of his STM32
platform.

>
>         Arnd

 BR,
 Cedric
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