Re: [PATCH] ASoC: blackfin: add bf6xx audio dma driver

[Scott Jiang <scott.jiang.linux@gmail.com>]

2014-09-24 19:42 GMT+08:00 Mark Brown <broonie@kernel.org>:
> On Wed, Sep 24, 2014 at 06:02:40PM +0800, Scott Jiang wrote:
>> 2014-09-24 16:26 GMT+08:00 Mark Brown <broonie@kernel.org>:
>
>> > Can you go into a bit more detail on the differences - clearly there's
>> > some similarlities since the drivers got merged, can we really not share
>> > any code?
>
>> First, sport2 only supports i2s and left justified mode, while sport3
>> adds i2s packed
>> and right justified mode. Second, in tdm mode for sport2, tx and rx
>> are dependent and have
>> a window granularity of 8 channel. While sport3 doesn't have these
>> limits. What's more,
>> sport3 is not only used on blackfin. That means many patches can only
>> apply to this driver.
>
> These sound more like extended functionality and tweaks rather than
> massive updates which need a completely separate driver - new modes and
> so on.

Yes, it looks similar in i2s mode. But in tdm mode, because we don't need to
copy 2 channels user buffer to 8 channels dma buffer, it might looks
very different.
If you think this patch is not good, I'd send a new one after I merged
tdm driver.
By the way, if the channel order of hardware is different from what is
expected by alsa,
the copy work is left to plugin or driver?

Scott