Raspberry Pi voltage monitor

modulename: raspberrypi-hwmon.ko

configname: CONFIG_SENSORS_RASPBERRYPI_HWMON

Linux Kernel Configuration
└─>Device Drivers
└─>Hardware Monitoring support
└─>Raspberry Pi voltage monitor
In linux kernel since version 4.2 (release Date: 2015-08-30)  
If you say yes here you get support for voltage sensor on the
Raspberry Pi.

This driver can also be built as a module. If so, the module
will be called raspberrypi-hwmon.

source code:
depends
CONFIG_HWMON
CONFIG_RASPBERRYPI_FIRMWARE or CONFIG_COMPILE_TEST
NOT CONFIG_RASPBERRYPI_FIRMWARE