On 9. 6. 2022, at 15:16, Mark Brown broonie@kernel.org wrote:
On Mon, Jun 06, 2022 at 09:19:10PM +0200, Martin Povišer wrote:
- ┌──────────┐ ┌───────────────► ┌─────┐ ┌──────────┐
- │ Primary ├───────┤ │ Mux │ ──► │ Speakers │
- └──────────┘ │ ┌──────────► └─────┘ └──────────┘
┌─── │ ───┘ ▲
- ┌──────────┐ │ │ │
- │Secondary ├──┘ │ ┌────────────┴┐
- └──────────┘ ├────►│Plug-in Demux│
│ └────────────┬┘
│ │
│ ▼
│ ┌─────┐ ┌──────────┐
└───────────────► │ Mux │ ──► │Headphones│
└─────┘ └──────────┘As far as I can tell this demux is entirely software based - why not just expose the routing control to userspace and let it handle switching (which I suspect may be more featureful than what's implemented here)?
Well, userspace should have the other two muxes at its disposal to implement any routing/switching it wishes -- but in addition we are also offering letting kernel take care of the switching, by pointing the muxes to the demux.
I assume (but I don’t know the extent of what’s possible with UCM files), that this will be of some value to users running plain ALSA with no sound server.
+static int macaudio_jack_event(struct notifier_block *nb, unsigned long event,
void *data)+{
struct snd_soc_jack *jack = data;struct macaudio_snd_data *ma = snd_soc_card_get_drvdata(jack->card);ma->jack_plugin_state = !!event;if (!ma->plugin_demux_kcontrol)return 0;snd_soc_dapm_mux_update_power(&ma->card.dapm, ma->plugin_demux_kcontrol,ma->jack_plugin_state,(struct soc_enum *) &macaudio_plugin_demux_enum, NULL);return 0;+}
This should be integrated with the core jack detection stuff in soc-jack.c and/or the core stuff that's wrapping - that way you'll ensure that events are generated and status readable via all the interfaces userspace might be looking for. The ASoC stuff also has some DAPM integration for turning on/off outputs which might DTRT for you if you do need it in kernel.
Aren’t all the right events to userspace generated already by the codec calling snd_soc_jack_report?
I looked at the existing DAPM integration but I couldn’t figure out how to switch the demux with it.