snd_hda: Implement automatic redirection between associations

For audio to be redirected to the headphones/headset after plugging the
jack, or back to the speaker/internal mic when unplugging it, the
speaker and headphone pins need to be part of the same association
(i.e., the same PCM device). This patch makes it possible to redirect
audio even between different associations, which can reduce the need for
manual pin patching.

The idea is that we issue a devctl_notify() from within the jack
detection callback whenever a jack is (un-)plugged to redirect audio to
the appropriate device. Then the snd.conf devd script is responsible for
using virtual_oss to change the playback/recording device to whatever
snd_hda(4) selected. The reason for requiring virtual_oss is that it has
hot-swapping support, which is necessary for jack redirection.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 days
Differential Revision:	https://reviews.freebsd.org/D50070

4 files changed, 84 insertions, 13 deletions

diff --git a/sbin/devd/Makefile b/sbin/devd/Makefile
index 5d5721d16884..f65eee93dd4b 100644
--- a/sbin/devd/Makefile
+++ b/sbin/devd/Makefile
@@ -51,6 +51,11 @@ NVMEDIR=		${DEVDDIR}
 NVME+=			nvmf.conf
 NVMEPACKAGE=		nvme-tools
 
+CONFGROUPS+=	SND
+SNDDIR=		${DEVDDIR}
+SND+=		snd.conf
+SNDPACKAGE=	snd
+
 .if ${MK_USB} != "no"
 DEVD+=	uath.conf ulpt.conf
 .endif
diff --git a/sbin/devd/devd.conf.5 b/sbin/devd/devd.conf.5
index baf4b9d3a183..8df3e910e076 100644
--- a/sbin/devd/devd.conf.5
+++ b/sbin/devd/devd.conf.5
@@ -652,6 +652,22 @@ and
 for details.
 .El
 .Pp
+.Bl -column "System" "Subsystem" "1234567" -compact
+.Sy "System" Ta Sy "Subsystem" Ta Sy "Type" Ta Sy "Description"
+.It Li SND Ta Ta Ta
+Events related to the
+.Xr sound 4
+driver.
+.It Li SND Ta Li CONN Ta Li IN Ta
+Connected input device specified in
+.Pa cdev
+variable.
+.It Li SND Ta Li CONN Ta Li OUT Ta
+Connected output device specified in
+.Pa cdev
+variable.
+.El
+.Pp
 .\"
 .\" End of tables
 .\"
diff --git a/sbin/devd/snd.conf b/sbin/devd/snd.conf
new file mode 100644
index 000000000000..cf9cd9e94191
--- /dev/null
+++ b/sbin/devd/snd.conf
@@ -0,0 +1,23 @@
+# Audio redirection
+notify 0 {
+	match "system"		"SND";
+	match "subsystem"	"CONN";
+	match "type"		"IN";
+	match "cdev"		"dsp[0-9]+";
+
+	# FIXME: We are hardcoding /dev/vdsp.ctl here, simply because it is a
+	# common virtual_oss control device name. Until we find a proper way to
+	# define control devices here, /dev/vdsp.ctl can be changed to the
+	# control device of choice.
+	action			"/usr/sbin/virtual_oss_cmd /dev/vdsp.ctl -R /dev/$cdev";
+};
+
+notify 0 {
+	match "system"		"SND";
+	match "subsystem"	"CONN";
+	match "type"		"OUT";
+	match "cdev"		"dsp[0-9]+";
+
+	# FIXME: See comment above.
+	action			"/usr/sbin/virtual_oss_cmd /dev/vdsp.ctl -P /dev/$cdev";
+};
diff --git a/sys/dev/sound/pci/hda/hdaa.c b/sys/dev/sound/pci/hda/hdaa.c
index 1e486b01b168..5dbb5c4f4453 100644
--- a/sys/dev/sound/pci/hda/hdaa.c
+++ b/sys/dev/sound/pci/hda/hdaa.c
@@ -532,9 +532,11 @@ static void
 hdaa_presence_handler(struct hdaa_widget *w)
 {
 	struct hdaa_devinfo *devinfo = w->devinfo;
-	struct hdaa_audio_as *as;
+	struct hdaa_audio_as *as, *asp;
+	char buf[32];
 	uint32_t res;
-	int connected, old;
+	int connected, old, i;
+	bool active;
 
 	if (w->enable == 0 || w->type !=
 	    HDA_PARAM_AUDIO_WIDGET_CAP_TYPE_PIN_COMPLEX)
@@ -552,13 +554,6 @@ hdaa_presence_handler(struct hdaa_widget *w)
 	if (connected == old)
 		return;
 	w->wclass.pin.connected = connected;
-	HDA_BOOTVERBOSE(
-		if (connected || old != 2) {
-			device_printf(devinfo->dev,
-			    "Pin sense: nid=%d sense=0x%08x (%sconnected)\n",
-			    w->nid, res, !connected ? "dis" : "");
-		}
-	);
 
 	as = &devinfo->as[w->bindas];
 	if (as->hpredir >= 0 && as->pins[15] == w->nid)
@@ -567,6 +562,38 @@ hdaa_presence_handler(struct hdaa_widget *w)
 		hdaa_autorecsrc_handler(as, w);
 	if (old != 2)
 		hdaa_channels_handler(as);
+
+	if (connected || old != 2) {
+		HDA_BOOTVERBOSE(
+			device_printf(devinfo->dev,
+			    "Pin sense: nid=%d sense=0x%08x (%sconnected)\n",
+			    w->nid, res, !connected ? "dis" : "");
+		);
+		if (as->hpredir >= 0)
+			return;
+		for (i = 0, active = false; i < devinfo->num_devs; i++) {
+			if (device_get_unit(devinfo->devs[i].dev) == snd_unit) {
+				active = true;
+				break;
+			}
+		}
+		/* Proceed only if we are currently using this codec. */
+		if (!active)
+			return;
+		for (i = 0; i < devinfo->ascnt; i++) {
+			asp = &devinfo->as[i];
+			if (!asp->enable)
+				continue;
+			if ((connected && asp->index == as->index) ||
+			    (!connected && asp->dir == as->dir)) {
+				snprintf(buf, sizeof(buf), "cdev=dsp%d",
+				    device_get_unit(asp->pdevinfo->dev));
+				devctl_notify("SND", "CONN",
+				    asp->dir == HDAA_CTL_IN ? "IN" : "OUT", buf);
+				break;
+			}
+		}
+	}
 }
 
 /*
@@ -6194,15 +6221,15 @@ hdaa_configure(device_t dev)
 	);
 	hdaa_patch_direct(devinfo);
 	HDA_BOOTHVERBOSE(
-		device_printf(dev, "Pin sense init...\n");
-	);
-	hdaa_sense_init(devinfo);
-	HDA_BOOTHVERBOSE(
 		device_printf(dev, "Creating PCM devices...\n");
 	);
 	hdaa_unlock(devinfo);
 	hdaa_create_pcms(devinfo);
 	hdaa_lock(devinfo);
+	HDA_BOOTHVERBOSE(
+		device_printf(dev, "Pin sense init...\n");
+	);
+	hdaa_sense_init(devinfo);
 
 	HDA_BOOTVERBOSE(
 		if (devinfo->quirks != 0) {