[alsa-devel] Help for writting an ASoC driver

[Ernesto Torres]

Sorry for not being clear, I'm writting a driver for an external codec to
use instead of twl4030 not for the beagleboard
I'll check the clocking, thanks.


On Tue, Apr 7, 2009 at 5:19 PM, Mark Brown <broonie at sirena.org.uk> wrote:

> On Tue, Apr 07, 2009 at 12:18:25PM -0500, Ernesto Torres wrote:
>
> > Hi, i'm new to alsa and i would like some advice on where to get
> information
> > about writing an ASoC driver it would be for the beagle board, since is
> the
> > board i have available. I have already made some progress initializing
> and
>
> There is already a drier for the Beagle board in the kernel - see the
> omap3beagle driver.
>
> > I still don't know the exact way for playing via pcm with aplay or the
> order
> > of the callbacks. I have checked the web for info but not much about
> ASoC,
> > just the documentation with the linux kernel.
>
> ASoC jsust presents a standard sound card so applications such as aplay
> work as they normally do.  The callbacks are all called in the same
> order as the standard ALSA equivalents are, you can check how exactly
> things are mapped from the standard ALSA callbacks into ASoC in
> soc-core.c.
>
> > My driver actually tries to play with aplay, but gets stuck in :
> omap-pcm.c:
> > omap_pcm_pointer
> > It just won't send the frames.
>
> At a guess you've not got the clocking set up properly - either the pins
> for the clock signals are not configured in the appropriate mode or an
> inappropriate clock configuration has been set up in your machine
> driver.
>



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