Set the RTC time based on NTP synchronization

modulename: systohc.ko

configname: CONFIG_RTC_SYSTOHC

Linux Kernel Configuration
└─>Device Drivers
└─>Real Time Clock
└─>Set the RTC time based on NTP synchronization
In linux kernel since version 3.1 (release Date: 2011-10-24)  
If you say yes here, the system time (wall clock) will be stored
in the RTC specified by RTC_HCTOSYS_DEVICE approximately every 11
minutes if userspace reports synchronized NTP status.

source code: