Remove Voicecall.Busy method

According to 22.030, UDUB or CHLD=0 can only be invoked on waiting
calls.  Most AT command based modems do not support using CHLD=0 on an
incoming call.  So we remove the Busy method and invoke set_udub on
a call that is in the waiting state.

2 files changed, 28 insertions, 40 deletions

diff --git a/doc/voicecall-api.txt b/doc/voicecall-api.txt
index b360cca3..c8e34a47 100644
--- a/doc/voicecall-api.txt
+++ b/doc/voicecall-api.txt
@@ -7,21 +7,11 @@ Object path	[variable prefix]/{modem0,modem1,...}/{voicecall01,voicecall02,...}
 
 Methods		dict GetProperties()
 
-			Returns all global system properties. See the
+			Returns all properties for this object. See the
 			properties section for available properties.
 
 			Possible Errors: [service].Error.InvalidArguments
 
-		void Busy()
-
-			Notifies the incoming or waiting call that the user
-			is busy. This is done by setting the User Determined
-			User Busy (UDUB) condition. This method is only valid
-			if there is an incoming or waiting call.
-
-			This functionality is generally implemented by using
-			the +CHLD=0 AT command.
-
 		void Deflect(string number)
 
 			Deflects the incoming or waiting call to number given
@@ -39,8 +29,19 @@ Methods		dict GetProperties()
 
 			Hangs up the voice call.
 
-			This functionality is generally implemented by
-			+CHLD=1X, +CHUP or ATH AT commands.
+			For an incoming call, the call is hung up using ATH or
+			equivalent.  For a waiting call, the remote party is
+			notified by using the User Determined User Busy (UDUB)
+			condition.  This is generally implemented using CHLD=0.
+
+			Please note that the GSM specification does not allow
+			the release of a held call when a waiting call exists,
+			or the release of a particular party in a held
+			multiparty call.
+
+			Note that releasing a held call or a particular party
+			of a held multiparty call might not be possible on some
+			implementations.
 
 		void Answer()
 
diff --git a/src/voicecall.c b/src/voicecall.c
index ee903f12..02ec484c 100644
--- a/src/voicecall.c
+++ b/src/voicecall.c
@@ -211,30 +211,6 @@ static DBusMessage *voicecall_get_properties(DBusConnection *conn,
 	return reply;
 }
 
-static DBusMessage *voicecall_busy(DBusConnection *conn,
-					DBusMessage *msg, void *data)
-{
-	struct voicecall *v = data;
-	struct ofono_voicecall *vc = v->vc;
-	struct ofono_call *call = v->call;
-
-	if (call->status != CALL_STATUS_INCOMING &&
-		call->status != CALL_STATUS_WAITING)
-		return __ofono_error_failed(msg);
-
-	if (!vc->driver->set_udub)
-		return __ofono_error_not_implemented(msg);
-
-	if (vc->pending)
-		return __ofono_error_busy(msg);
-
-	vc->pending = dbus_message_ref(msg);
-
-	vc->driver->set_udub(vc, generic_callback, vc);
-
-	return NULL;
-}
-
 static DBusMessage *voicecall_deflect(DBusConnection *conn,
 					DBusMessage *msg, void *data)
 {
@@ -277,6 +253,7 @@ static DBusMessage *voicecall_hangup(DBusConnection *conn,
 	struct voicecall *v = data;
 	struct ofono_voicecall *vc = v->vc;
 	struct ofono_call *call = v->call;
+	int num_calls;
 
 	if (call->status == CALL_STATUS_DISCONNECTED)
 		return __ofono_error_failed(msg);
@@ -297,7 +274,19 @@ static DBusMessage *voicecall_hangup(DBusConnection *conn,
 		return NULL;
 	}
 
-	if ((g_slist_length(vc->call_list) == 1) && vc->driver->hangup &&
+	if (call->status == CALL_STATUS_WAITING) {
+		if (vc->driver->set_udub == NULL)
+			return __ofono_error_not_implemented(msg);
+
+		vc->pending = dbus_message_ref(msg);
+		vc->driver->set_udub(vc, generic_callback, vc);
+
+		return NULL;
+	}
+
+	num_calls = g_slist_length(vc->call_list);
+
+	if (num_calls == 1 && vc->driver->hangup &&
 			(call->status == CALL_STATUS_ACTIVE ||
 				call->status == CALL_STATUS_DIALING ||
 				call->status == CALL_STATUS_ALERTING)) {
@@ -342,8 +331,6 @@ static DBusMessage *voicecall_answer(DBusConnection *conn,
 
 static GDBusMethodTable voicecall_methods[] = {
 	{ "GetProperties",	"",	"a{sv}",	voicecall_get_properties },
-	{ "Busy",		"",	"",		voicecall_busy,
-							G_DBUS_METHOD_FLAG_ASYNC },
 	{ "Deflect",		"s",	"",		voicecall_deflect,
 							G_DBUS_METHOD_FLAG_ASYNC },
 	{ "Hangup",		"",	"",		voicecall_hangup,