[alsa-devel] Help for writting an ASoC driver

[Ernesto Torres]

from omap_pcm_hw_params:
    err = omap_request_dma(dma_data->dma_req, dma_data->name,
                   omap_pcm_dma_irq, substream, &prtd->dma_ch);

With twl4030 it successfully calls omap_pcm_dma_irq, but with my codec it
never get called, am I forgetting to set some value?

On Tue, Apr 7, 2009 at 6:26 PM, Ernesto Torres <skullmate at gmail.com> wrote:

> 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.
>>
>
>
>
> --
> ___________
> EhTd
>
>


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