Re: [PATCH v2 1/3] ASoC: hdmi-codec: Add event handler for hdmi TX

[Jiaxin Yu (俞家鑫)]

On Thu, 2022-12-01 at 15:23 +0000, Mark Brown wrote:
> On Thu, Dec 01, 2022 at 03:06:04PM +0000, Jiaxin Yu (俞家鑫) wrote:
> > On Tue, 2022-11-29 at 17:22 +0000, Mark Brown wrote:
> > >  static const struct snd_kcontrol_new
> > >  mt8186_mt6366_rt1019_rt5682s_controls[] = {
> > >          SOC_DAPM_PIN_SWITCH("Speakers"),
> > >          SOC_DAPM_PIN_SWITCH("Headphone"),
> > >          SOC_DAPM_PIN_SWITCH("Headset Mic"),
> > >          SOC_DAPM_PIN_SWITCH("HDMI1"),
> > >  };
> > Which operation should I use to inform bridge driver to control
> > audio
> > on or off? I'm curious why I don't see .trigger in the structure
> > hdmi_codec_ops compared to the structure snd_soc_dai_ops?
> 
> You'd need to add a callback that the user of hdmi-codec passes in
> which
> would be triggered by an event on a DAPM widget added in the audio
> path
> rather than trying to shoehorn this into a PCM operation - a big part
> of
> the problem here is that you're trying to add something that doesn't
> fit
> into a PCM operation.

Dear Mark,

1. I have added a DAPM widget that is "SDB", when we open or close HDMI
PIN_SWITCH, the callback 'hdmi_tx_event' registered in the widget will
be triggered. Maybe you mean I shouldn't use SNDRV_PCM_TRIGGER_START
and SNDRV_PCM_TRIGGER_STOP?

2. If I don't use hcd.ops->trigger notifies the bridge ic driver to
switch the audio, which ops should I use?
I actually want to know hdmi-codec.c and it6505.c except
hdmi_codec_ops, is there any other way to communicate?

My understanding is not deep enough, so please help explain more in
detail, thank you very much!

+static int hdmi_tx_event(struct snd_soc_dapm_widget *w,
+               struct snd_kcontrol *kcontrol, int event)
+{
+       struct snd_soc_component *component =
snd_soc_dapm_to_component(w->dapm);
+       struct hdmi_codec_priv *hcp =
snd_soc_component_get_drvdata(component);
+
+       switch (event) {
+       case SND_SOC_DAPM_PRE_PMU:
+               if (hcp->hcd.ops->trigger)
+                       hcp->hcd.ops->trigger(component->dev->parent,
SNDRV_PCM_TRIGGER_START);
+               break;
+       case SND_SOC_DAPM_POST_PMD:
+               if (hcp->hcd.ops->trigger)
+                       hcp->hcd.ops->trigger(component->dev->parent,
SNDRV_PCM_TRIGGER_STOP);
+               break;
+       default:
+               break;
+       }
+
+       return 0;
+}
+
 static const struct snd_soc_dapm_widget hdmi_widgets[] = {
+       SND_SOC_DAPM_OUT_DRV_E("SDB", SND_SOC_NOPM, 0, 0, NULL, 0,
hdmi_tx_event,
+                              SND_SOC_DAPM_POST_PMD |
SND_SOC_DAPM_PRE_PMU),
        SND_SOC_DAPM_OUTPUT("TX"),
        SND_SOC_DAPM_OUTPUT("RX"),
 };