CRAS: alsa_jack - Monitor UAC2 jack controls

With commit 5a222e849452 ("ALSA: usb-audio: UAC2 jack detection"),
the usb card for a supported UAC2 device will have boolean kcontrols
named "* - Input Jack" and "* - Output Jack" exposing jack status,
where * is the usb terminal name.

If the device provides a string in iTerminal, it'll be used as the
terminal name. Otherwise a standard name is given based on wTerminalType.
See sound/usb/mixer.c get_term_name for the complete list.
Common ones we are interested in are "Headset", "Headphone", "Mic",
"Speaker".

This patch adds the jack names so CRAS can watch the kcontrols for
plug/unplug event.

BUG=b:74149899
TEST=Test dongle with UAC2 jack detect with various headsets on meowth.
Unplug headset but keep usb dongle attached, cras_test_client --dump_s
shows the correct ionode plug status for the usb card.
Test dongles without UAC2 jack detect and verify ionode is set to
plugged by default.

Change-Id: Iba19612841dad5d764b08715a791d1ad64f9e541
Signed-off-by: Ben Zhang <benzh@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1237315
Reviewed-by: Dylan Reid <dgreid@chromium.org>

2 files changed, 40 insertions, 5 deletions

diff --git a/cras/src/server/cras_alsa_io.c b/cras/src/server/cras_alsa_io.c
index f525c89f..3dafb50e 100644
--- a/cras/src/server/cras_alsa_io.c
+++ b/cras/src/server/cras_alsa_io.c
@@ -1378,6 +1378,21 @@ static struct alsa_input_node *get_input_node_from_jack(
 	return ain;
 }
 
+static const struct cras_alsa_jack *get_jack_from_node(struct cras_ionode *node)
+{
+	const struct cras_alsa_jack *jack = NULL;
+
+	if (node == NULL)
+		return NULL;
+
+	if (node->dev->direction == CRAS_STREAM_OUTPUT)
+		jack = ((struct alsa_output_node *)node)->jack;
+	else if (node->dev->direction == CRAS_STREAM_INPUT)
+		jack = ((struct alsa_input_node *)node)->jack;
+
+	return jack;
+}
+
 /*
  * Returns the dsp name specified in the ucm config. If there is a dsp
  * name specified for the jack of the active node, use that. Otherwise
@@ -2164,8 +2179,10 @@ int alsa_iodev_legacy_complete_init(struct cras_iodev *iodev)
 				   first_plugged_node(&aio->base),
 				   0);
 
-	/* Set plugged for the first USB device per card when it appears. */
-	if (aio->card_type == ALSA_CARD_TYPE_USB && is_first)
+	/* Set plugged for the first USB device per card when it appears if
+	 * there is no jack reporting plug status. */
+	if (aio->card_type == ALSA_CARD_TYPE_USB && is_first &&
+			!get_jack_from_node(iodev->active_node))
 		cras_iodev_set_node_attr(iodev->active_node,
 					 IONODE_ATTR_PLUGGED, 1);
 
@@ -2251,8 +2268,10 @@ void alsa_iodev_ucm_complete_init(struct cras_iodev *iodev)
 				   first_plugged_node(&aio->base),
 				   0);
 
-	/* Set plugged for the first USB device per card when it appears. */
-	if (aio->card_type == ALSA_CARD_TYPE_USB && aio->is_first)
+	/* Set plugged for the first USB device per card when it appears if
+	 * there is no jack reporting plug status. */
+	if (aio->card_type == ALSA_CARD_TYPE_USB && aio->is_first &&
+			!get_jack_from_node(iodev->active_node))
 		cras_iodev_set_node_attr(iodev->active_node,
 					 IONODE_ATTR_PLUGGED, 1);
 
diff --git a/cras/src/server/cras_alsa_jack.c b/cras/src/server/cras_alsa_jack.c
index 70cad544..b74af25d 100644
--- a/cras/src/server/cras_alsa_jack.c
+++ b/cras/src/server/cras_alsa_jack.c
@@ -74,6 +74,12 @@ struct cras_gpio_jack {
  *    edid_file - File to read the EDID from (if available, HDMI only).
  *    display_info_timer - Timer used to poll display info for HDMI jacks.
  *    display_info_retries - Number of times to retry reading display info.
+ *
+ *    mixer_output/mixer_input fields are only used to find the node for this
+ *    jack. These are not used for setting volume or mute. There should be a
+ *    1:1 map between node and jack. node->jack follows the pointer; jack->node
+ *    is done by either searching node->jack pointers or searching the node that
+ *    has the same mixer_control as the jack.
  */
 struct cras_alsa_jack {
 	unsigned is_gpio;	/* !0 -> 'gpio' valid
@@ -863,6 +869,15 @@ static int is_jack_control_in_list(const char * const *list,
 	return 0;
 }
 
+/* Check if the given name is a jack created for the connector control of a
+ * input/output terminal entity on a USB Audio Class 2.0 device. */
+static int is_jack_uac2(const char *jack_name,
+			enum CRAS_STREAM_DIRECTION direction)
+{
+	return jack_matches_regex(jack_name, direction == CRAS_STREAM_OUTPUT ?
+				  "^.* - Output Jack$" : "^.* - Input Jack$");
+}
+
 /* Looks for any JACK controls.  Monitors any found controls for changes and
  * decides to route based on plug/unlpug events. */
 static int find_jack_controls(struct cras_alsa_jack_list *jack_list)
@@ -904,7 +919,8 @@ static int find_jack_controls(struct cras_alsa_jack_list *jack_list)
 		if (iface != SND_CTL_ELEM_IFACE_CARD)
 			continue;
 		name = snd_hctl_elem_get_name(elem);
-		if (!is_jack_control_in_list(jack_names, num_jack_names, name))
+		if (!is_jack_control_in_list(jack_names, num_jack_names, name) &&
+		    !is_jack_uac2(name, jack_list->direction))
 			continue;
 		if (hctl_jack_device_index(name) != jack_list->device_index)
 			continue;