[alsa-devel] [asoc-dev][RFC/PATCH 0/2] Generic DAPM register modifier widget

[Liam Girdwood]

On Wed, 2008-06-25 at 14:42 +0300, Jarkko Nikula wrote:
> Hi
> 
> At least tlv320aic3x codec has several use cases where multiple register
> bits are needed to change when widget power state changes and where
> these are not worth/safe to expose into user space. Like mic bias
> voltage.
> 
> Currently there is one use case for this multiple bit change in tlv320aic3x:
> 
> 	SND_SOC_DAPM_MICBIAS("Mic Bias AVDD", MICBIAS_CTRL, 6, 0),
> 	SND_SOC_DAPM_MICBIAS("Mic Bias AVDD", MICBIAS_CTRL, 7, 0),
> 
> There are two problems with that:
> 
> 1. Two widgets having the same name and thus snd_soc_dapm_add_route will
>    add only first one them into audio path
> 2. Even then bits aren't modified at once and thus some fault bit
>    configuration might be present while power state is changing.
> 
> So I came with this idea of generic register modifiers widget and event
> handler for it.
> 

Any chance you could also add a little text to
Docs/sound/alsa/soc/dapm.txt for this.

Thanks

Liam