USB251XB Hub Controller Configuration Driver

modulename: usb251xb.ko

configname: CONFIG_USB_HUB_USB251XB

Linux Kernel Configuration
└─>Device Drivers
└─>USB support
└─>USB251XB Hub Controller Configuration Driver
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This option enables support for configuration via SMBus of the
Microchip USB251x/xBi USB 2.0 Hub Controller series. Configuration
parameters may be set in devicetree or platform data.
Say Y or M here if you need to configure such a device via SMBus.

source code: