ALSA: usb-audio: Add connector notifier delegation

It turned out that ALC1220-VB USB-audio device gives the interrupt
event to some PCM terminals while those don't allow the connector
state request but only the actual I/O terminals return the request.
The recent commit 7dc3c5a0172e ("ALSA: usb-audio: Don't create jack
controls for PCM terminals") excluded those phantom terminals, so
those events are ignored, too.

My first thought was that this could be easily deduced from the
associated terminals, but some of them have even no associate terminal
ID, hence it's not too trivial to figure out.

Since the number of such terminals are small and limited, this patch
implements another quirk table for the simple mapping of the
connectors.  It's not really scalable, but let's hope that there will
be not many such funky devices in future.

Fixes: 7dc3c5a0172e ("ALSA: usb-audio: Don't create jack controls for PCM terminals")
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206873
Link: https://lore.kernel.org/r/20200422113320.26664-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 65d6d08c96f5..41ec9dc4139b 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -6,6 +6,13 @@
 
 struct media_mixer_ctl;
 
+struct usbmix_connector_map {
+	u8 id;
+	u8 delegated_id;
+	u8 control;
+	u8 channel;
+};
+
 struct usb_mixer_interface {
 	struct snd_usb_audio *chip;
 	struct usb_host_interface *hostif;
@@ -18,6 +25,9 @@ struct usb_mixer_interface {
 	/* the usb audio specification version this interface complies to */
 	int protocol;
 
+	/* optional connector delegation map */
+	const struct usbmix_connector_map *connector_map;
+
 	/* Sound Blaster remote control stuff */
 	const struct rc_config *rc_cfg;
 	u32 rc_code;