v4.19.13 snapshot.
diff --git a/net/bluetooth/cmtp/Kconfig b/net/bluetooth/cmtp/Kconfig
new file mode 100644
index 0000000..939da0f
--- /dev/null
+++ b/net/bluetooth/cmtp/Kconfig
@@ -0,0 +1,11 @@
+config BT_CMTP
+	tristate "CMTP protocol support"
+	depends on BT_BREDR && ISDN_CAPI
+	help
+	  CMTP (CAPI Message Transport Protocol) is a transport layer
+	  for CAPI messages.  CMTP is required for the Bluetooth Common
+	  ISDN Access Profile.
+
+	  Say Y here to compile CMTP support into the kernel or say M to
+	  compile it as module (cmtp).
+