Richtek RT5033 Power Management IC

modulename: rt5033.ko

configname: CONFIG_MFD_RT5033

Linux Kernel Configuration
└─>Device Drivers
└─>Multifunction device drivers
└─>Richtek RT5033 Power Management IC
In linux kernel since version 4 (release Date: 2015-04-12)  
This driver provides for the Richtek RT5033 Power Management IC,
which includes the I2C driver and the Core APIs. This driver provides
common support for accessing the device. The device supports multiple
sub-devices like charger, fuel gauge, flash LED, current source,
LDO and Buck.

source code:
drivers/mfd//rt5033.c