---
 plugins/bluetooth.c |   71 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 71 insertions(+), 0 deletions(-)

diff --git a/plugins/bluetooth.c b/plugins/bluetooth.c
index b90852d..3560440 100644
--- a/plugins/bluetooth.c
+++ b/plugins/bluetooth.c
@@ -79,6 +79,8 @@ struct hfp_data {
 	char *path;
 	guint16 r_features;
 	guint watch;
+	int mic_gain;
+	int mic_pending;
 };
 
 void bluetooth_create_path(const char *dev_addr, const char *adapter_addr,
@@ -268,6 +270,37 @@ fail:
 	};
 }
 
+static void emulator_vgm_cb(struct ofono_emulator *em,
+			struct ofono_emulator_request *req, void *userdata)
+{
+	struct hfp_data *hfp = userdata;
+	struct ofono_error result;
+	int val;
+
+	switch (ofono_emulator_request_get_type(req)) {
+	case OFONO_EMULATOR_REQUEST_TYPE_SET:
+		if (!ofono_emulator_request_next_number(req, &val))
+			goto fail;
+
+		if (val < 0 && val > 15)
+			goto fail;
+
+		if (hfp->mic_pending != -1)
+			ofono_error("Receiving AT+VGM while processing one");
+
+		hfp->mic_pending = val;
+		audio_transport_set_property(hfp, "MicrophoneGain",
+							DBUS_TYPE_UINT16, &val);
+		break;
+
+	default:
+fail:
+		result.error = 0;
+		result.type = OFONO_ERROR_TYPE_FAILURE;
+		ofono_emulator_send_final(em, &result);
+	};
+}
+
 static gboolean audio_property_changed(DBusConnection *connection,
 					DBusMessage *message, void *user_data)
 {
@@ -303,6 +336,41 @@ static gboolean audio_property_changed(DBusConnection *connection,
 
 		sprintf(buf, "+BSIR: %d", value);
 		ofono_emulator_send_unsolicited(hfp->em, buf);
+	} else if (g_str_equal(property, "MicrophoneGain") == TRUE) {
+		DBusMessageIter variant;
+		int value;
+
+		if (!(hfp->r_features & HFP_HF_FEATURE_REMOTE_VOLUME_CONTROL))
+			return TRUE;
+
+		if (!dbus_message_iter_next(&iter))
+			return TRUE;
+
+		if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT)
+			return TRUE;
+
+		dbus_message_iter_recurse(&iter, &variant);
+
+		if (dbus_message_iter_get_arg_type(&variant) !=
+							DBUS_TYPE_UINT16)
+			return TRUE;
+
+		dbus_message_iter_get_basic(&variant, &value);
+
+		/* Send unsolicited +VGM only if :
+		 *   - the value has changed
+		 *   - and this is not a side effect of AT+VGM
+		 * But, if we receive a value change while waiting for another
+		 * pending change, we may have to send +VGM for other changes
+		 * (multiple AT+VGM received) to keep mic gain in sync
+		 */
+		if (hfp->mic_pending != value && hfp->mic_gain != value) {
+			sprintf(buf, "+VGM: %d", value);
+			ofono_emulator_send_unsolicited(hfp->em, buf);
+			hfp->mic_pending = -1;
+		} else if (hfp->mic_pending == value)
+			hfp->mic_pending = -1;
+		hfp->mic_gain = value;
 	}
 
 	return TRUE;
@@ -315,6 +383,7 @@ void bluetooth_free_audio_management(void *data)
 	DBG("");
 
 	ofono_emulator_remove_handler(hfp->em, "+NREC");
+	ofono_emulator_remove_handler(hfp->em, "+VGM");
 
 	g_dbus_remove_watch(connection, hfp->watch);
 
@@ -333,8 +402,10 @@ void *bluetooth_set_audio_management(void *em, const char *path,
 	hfp->em = em;
 	hfp->path = g_strdup(path);
 	hfp->r_features = features;
+	hfp->mic_pending = -1;
 
 	ofono_emulator_add_handler(em, "+NREC", emulator_nrec_cb, hfp, NULL);
+	ofono_emulator_add_handler(em, "+VGM", emulator_vgm_cb, hfp, NULL);
 
 	hfp->watch = g_dbus_add_signal_watch(connection, NULL, path,
 						BLUEZ_TRANSPORT_INTERFACE,
-- 
1.7.1