From: Lars-Peter Clausen <lars@metafoo.de>
To: Kuninori Morimoto <kuninori.morimoto.gx@gmail.com>
Cc: Linux-ALSA <alsa-devel@alsa-project.org>,
Simon <horms@verge.net.au>, Mark Brown <broonie@kernel.org>,
Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
Liam Girdwood <lgirdwood@gmail.com>
Subject: Re: About snd_dmaengine_pcm_trigger()
Date: Tue, 11 Mar 2014 10:47:32 +0100 [thread overview]
Message-ID: <531EDBB4.1080008@metafoo.de> (raw)
In-Reply-To: <87pplttk8d.wl%kuninori.morimoto.gx@gmail.com>
On 03/11/2014 05:47 AM, Kuninori Morimoto wrote:
>
> Hi Lars, Mark
>
>> Make them ASoC components ;) I don't know the hardware, but looking at the
>> code it doesn't seem to be that different from other modern host side audio
>> processing units. But one step at a time, first maybe try and see if you can
>> switch over to using the dmaengine PCM helper functions. Then later thing
>> about how this all can be better integrated into the ASoC framework.
>
> In my quick check,
> I guess, my drivers (FSI/rcar) can use
> ${LINUX}/sound/core/pcm_dmaengine.c methods as 1st step.
>
> OTOH, these drivers has PIO transfer too.
> So, if ALSA has PIO method like pcm_pio.c (?) which has similar method,
> it seems easy to switch over.
> But what do you think ?
If there are other platforms that also do PIO in a very similar way it might
make sense to factor this out.
The reason why we factored out the dmaengine DMA stuff is because there is a
standard API that hides the implementation details and is supposed to behave
the same for each system. For PIO you do not have such a abstraction layer
that hides the details, so I'm not sure how similar PIO between different
platforms will actually be.
- Lars
next prev parent reply other threads:[~2014-03-11 9:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 5:20 About snd_dmaengine_pcm_trigger() Kuninori Morimoto
2014-03-05 7:42 ` Lars-Peter Clausen
2014-03-05 8:32 ` Kuninori Morimoto
2014-03-05 9:20 ` Lars-Peter Clausen
2014-03-06 0:22 ` Kuninori Morimoto
2014-03-06 4:36 ` Mark Brown
2014-03-06 4:39 ` Kuninori Morimoto
2014-03-11 4:47 ` Kuninori Morimoto
2014-03-11 9:47 ` Lars-Peter Clausen [this message]
2014-03-11 9:55 ` Mark Brown
2014-03-12 0:28 ` Kuninori Morimoto
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