CONFIG_USB_PHY (not configurable)

modulename: phy.ko

configname: CONFIG_USB_PHY

Linux Kernel Configuration
└─>Device Drivers
└─>USB support
└─>USB Physical Layer drivers
└─>USB_PHY
In linux kernel since version 3.1 (release Date: 2011-10-24)  
source code:
drivers/usb/phy/phy.c