[alsa-devel] [PATCH v5] sound/soc/lapis: add platform driver for ML7213

[Tomoya MORINAGA]

On Thu, May 24, 2012 at 7:07 PM, Mark Brown
<broonie at opensource.wolfsonmicro.com> wrote:
>> > Nobody seems to be working on it as far as I can tell, I've certainly
>> > not seen any patches.
>
>> If so, could you accept current platform/machine driver ?
>
> Ideally what would be happening here is that you or other people who
> have such systems would be working to add the required support to the
> core code, there's clearly a need for common code here as there are a
> number of different systems that don't have cyclic DMA and it wouldn't
> be great to end up with duplicated code.
>
> Is there some great difficulty in factoring out the support for
> non-cyclic audio DMA on dmaengine - it seems like if there is we must
> have a serious problem in dmaengine which we should fix?  If there is a
> substantial difficulty then that's different but it doesn't feel like
> we've tried doing common code yet, if there's problems doing that I'd
> like to understand what they are before we jump ahead of ourselves.

I'm not so familiar with Linux's DMA idea.
So we don't know whether non-cyclic dmaengine has problem or not.

Until now, we've developed device drivers use DMA driver like UART, SPI.
These drivers are  implemented using the same way, you called
"non-cyclic", and already applied.

As you said, common code for DMA code can be best solution.
However, currently, the code is nothing.
So, I want you to accept our driver as first step.
Because I think supporting new device is more important for linux than
dmaengine common.

thanks
-- 
ROHM Co., Ltd.
tomoya