Allwinner sun6i internal P2WI controller

modulename: i2c-sun6i-p2wi.ko

configname: CONFIG_I2C_SUN6I_P2WI

Linux Kernel Configuration
└─>Device Drivers
└─>I2C support
└─>I2C Hardware Bus support
└─>Allwinner sun6i internal P2WI controller
In linux kernel since version 3.16 (release Date: 2014-08-03)  
If you say yes to this option, support will be included for the
P2WI (Push/Pull 2 Wire Interface) controller embedded in some sunxi
SOCs.
The P2WI looks like an SMBus controller (which supports only byte
accesses), except that it only supports one slave device.
This interface is used to connect to specific PMIC devices (like the
AXP221).

source code: