[alsa-devel] [PATCH] ASoC drivers for the Freescale MPC8610 SoC

Jon Smirl jonsmirl at gmail.com
Thu Jan 10 06:41:18 CET 2008


On 1/9/08, David Gibson <david at gibson.dropbear.id.au> wrote:
> On Mon, Jan 07, 2008 at 06:28:54PM +0000, Mark Brown wrote:
> > On Mon, Jan 07, 2008 at 09:52:03AM -0600, Timur Tabi wrote:
> > > David Gibson wrote:
> >
> > > > Ok, but couldn't you strucutre your I2S or fabric driver so that it
> > > > only becomes fully operational once the codec driver has registered
> > > > with it?
> >
> > > Not in ASoC V1.  You have to understand, ASoC V1 was designed without any
> > > consideration for runtime-bindings and other OF goodies.  All connections
> > > between the drivers are static, literally.  In fact, I wouldn't be surprised if
> > > some ASoC drivers cannot be compiled as modules.
> >
> > I'd just like to emphasise this point - ASoC v1 really doesn't
> > understand the idea that the components of the sound subsystem might be
> > probed separately.  It's set up to handle bare hardware with everything
> > being probed from code in the machine/fabric driver.  This makes life
> > very messy for platforms with something like the device tree.
> >
> > As has been said, handling this properly is one of the major motivations
> > behind ASoC v2.
>
> Ick.  Ok.
>
> Nonetheless, messing up the device tree to workaround ASoC V1's silly
> limitations is not a good idea.  The device tree must represent the
> hardware as much as possible.  If that means we have to have a bunch
> of platform-specific hacks to instatiate the drivers in the correct
> order / combination, that's unfortunate, but there you go.

ASOC v2 is sitting on a Wolfson server out of tree. I have been using
it for several months without problem. The pace of it being merged
could probably be sped up.

>
> --
> David Gibson                    | I'll have my music baroque, and my code
> david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
>                                 | _way_ _around_!
> http://www.ozlabs.org/~dgibson
>


-- 
Jon Smirl
jonsmirl at gmail.com


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