--- zzzz-none-000/linux-4.1.38/drivers/rtc/Kconfig	2017-01-18 18:48:06.000000000 +0000
+++ bcm63-7582-715/linux-4.1.38/drivers/rtc/Kconfig	2020-11-25 10:06:48.000000000 +0000
@@ -1555,5 +1555,11 @@
 	  If this driver is compiled as a module, it will be named
 	  rtc-hid-sensor-time.
 
+config RTC_DRV_AVM_REF_CLOCK
+    tristate "RTC Driver for external Clock source (DECT)"
+    depends on RTC_CLASS || AVM_DECT || ISDN_CAPI
+    default n
+    help
+        Clock source for Calibrate RTC device driver
 
 endif # RTC_CLASS