Function filesystem (FunctionFS)

configname: CONFIG_USB_CONFIGFS_F_FS

USB Gadget Drivers
└─>Function filesystem (FunctionFS)
In linux kernel since version 3.14 (release Date: 2014-03-30)  
The Function Filesystem (FunctionFS) lets one create USB
composite functions in user space in the same way GadgetFS
lets one create USB gadgets in user space. This allows creation
of composite gadgets such that some of the functions are
implemented in kernel space (for instance Ethernet, serial or
mass storage) and other are implemented in user space.

selects
CONFIG_USB_F_FS

depends
CONFIG_USB_CONFIGFS |
| CONFIG_USB_GADGET or CONFIG_USB_SUPPORT