Import upstream version 0.9.13
diff --git a/include/openbsc/rs232.h b/include/openbsc/rs232.h
new file mode 100644
index 0000000..61187ca
--- /dev/null
+++ b/include/openbsc/rs232.h
@@ -0,0 +1,9 @@
+#ifndef _RS232_H
+#define _RS232_H
+
+int rs232_setup(const char *serial_port, unsigned int delay_ms,
+		struct gsm_bts *bts);
+
+int handle_serial_msg(struct msgb *msg);
+
+#endif /* _RS232_H */