[alsa-devel] ASoC: Hiding unused CODEC mixer widgets in the machine driver

Liam Girdwood lrg at slimlogic.co.uk
Fri Aug 6 13:34:13 CEST 2010

On Fri, 2010-08-06 at 12:19 +0100, Mark Brown wrote:
> On Fri, Aug 06, 2010 at 10:18:45AM +1000, Stuart Longland wrote:
> > Work has continued on the TLV320AIC3204 CODEC driver, and there have
> > been a number of fixes since the last patch was published.  However,
> > this CODEC is a rather complicated beast to drive, some may find the
> > controls a little unweildy, and as such, I was wondering if the machine
> > driver could be used to abstract this for a given target?
> The machine driver shouldn't be doing this - it's too fragile in the
> face of any changes in the drivers and means hard coding use cases into
> the kernel which is really bad practice since it's much slower than
> doing things from user space and much harder to change as new needs
> arise.
> Much of this should be being handled by use case management anyway, even
> the controls that actually exist usefully on a given system are normally
> way more detail than end applications should ever be seeing.  See
> 	http://www.slimlogic.co.uk/?p=40
> for the API which should deal with that.  

Please do give UCM (Use Case Manager) a test drive. We are in the late
development / early testing phase before upstreaming (still one or two
things todo).

You will need to checkout the use-case-verb branches of :-



There is a tool called alsaucm that allows changing the use case from
the command line. Best to use it's interactive (-i) mode atm.

There is also an initial repository for UCM use case configuration files
here :-


This will show the format required to describe use cases.


Freelance Developer, SlimLogic Ltd
ASoC and Voltage Regulator Maintainer.

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