--- zzzz-none-000/linux-3.10.107/Documentation/devicetree/bindings/rtc/stmp3xxx-rtc.txt	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/Documentation/devicetree/bindings/rtc/stmp3xxx-rtc.txt	2021-02-04 17:41:59.000000000 +0000
@@ -7,6 +7,11 @@
   region.
 - interrupts: rtc alarm interrupt
 
+Optional properties:
+- stmp,crystal-freq: override crystal frequency as determined from fuse bits.
+  Only <32000> and <32768> are possible for the hardware.  Use <0> for
+  "no crystal".
+
 Example:
 
 rtc@80056000 {