Nintendo GameCube, Wii and Wii U RTC

modulename: rtc-gamecube.ko

configname: CONFIG_RTC_DRV_GAMECUBE

Linux Kernel Configuration
└─>Device Drivers
└─>Real Time Clock
└─>Nintendo GameCube, Wii and Wii U RTC
In linux kernel since version 5.2 (release Date: 2019-07-07)  
If you say yes here you will get support for the RTC subsystem
of the Nintendo GameCube, Wii and Wii U.

This driver can also be built as a module. If so, the module
will be called "rtc-gamecube".

source code:
selects
CONFIG_REGMAP

depends
CONFIG_RTC_CLASS
CONFIG_COMPILE_TEST or CONFIG_GAMECUBE or CONFIG_WII