[alsa-devel] [PATCH] ASoC: Add support for OMAP3 Pandora

Mark Brown broonie at sirena.org.uk
Thu Dec 4 16:07:15 CET 2008

On Thu, Dec 04, 2008 at 04:52:35PM +0200, Grazvydas Ignotas wrote:

> I'm not sure if splitting DAPM and widgets was good idea, I can adjust
> if needed.

That's a bit odd but fine - since the init is done per-DAI it makes some
sense, especially given that the output path is going via this external
DAC so is almost a separate device.

> The map is also not quite right, it says headphone jack is connected
> to TWL4030 codec OUTL and OUTR, but that is not really the case. It is
> connected to external DAC, and DAC is connected to OMAP. However DAC uses
> clock from TWL4030, so TWL needs to be active. I've basically done that
> connection to get event callback, where I can switch DAC and headphone
> amp on/off.

Hrm, interesting configuration.  It'd be good to put this in the driver
as comments somewhere so that someone picking up the driver knows what's
going on.  It'd be a bit nicer to handle this by adding widgets for the
DAC and amplifier but we don't have GPIO based DAPM widgets currently.

Also, I suspect that you'll get better pop/click performance if you
power the amp off before the DAC on teardown - as things stand you'll
amplify any artefacts you get when disabling the DAC.

> +/* Audio subsystem */
> +static struct snd_soc_device omap3pandora_snd_data = {
> +       .card = &snd_soc_card_omap3pandora,
> +       .platform = &omap_soc_platform,
> +       .codec_dev = &soc_codec_dev_twl4030,
> +};

Current git moves platform to the card structure.

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