[alsa-devel] ASoC: TWL4030 driver support multi channel playback

Peter Ujfalusi peter.ujfalusi at nokia.com
Tue Jun 2 07:16:41 CEST 2009


On Monday 01 June 2009 17:20:01 ext Naveen Krishna Ch wrote:
> Hi Peter,
> I am using linux 2.6.28 kernel,
> there is a requirement to support multi (4) channel play back .
> I guess TWL4030 ASoC driver now has full fledged support for both the
> DAC1(TX1) and  DAC2(TX2) paths in option 1 of codec operation.

Yes it does. It has support for TX1L/R, TX2L/R, RX1L/R and RX2L/R (four 
channel playback and recording)

> I am looking forward to back port the ASoC stuff drivers from 2.6.30 rc7 
> to 2.6.28.
> Is there any better way of meeting the requirement with out back porting
> the stuff

Well, I think this is not going to be an easy ride. It is not that hard, but 
takes some time. I could think of two approaches to get the twl4030 codec work 
backported (plus one):
1. Backport the the whole ASoC changes to 2.6.28
2. Backport the twl4030 codec driver with minimal amount of ASoC changes
3. Convince whoever you need to convince that you need to move to 2.6.30 ;)

1. Since ASoC has been dramatically changed since 2.6.28 this is not going to 
be easy, but you will have the current ASoC features and it will be easier to 
follow upstream.
2. Pick the changes to the twl4030 codec one-by-one apply it, compile the 
result, if it breaks, take the needed patches to fix the errors. Fair amunt of 
work, but you will end up a working twl4030 codec, but you need to backport 
the new patches from upstream every time..
3. This only exist in the ideal world.

In overall, I think your best bet is 1) You can take the 2) if you really know 
what you are doing...

> Suggestions please.
> Sorry for the english,,
> --
> Cheers
> (: Naveen Krishna Ch :)


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