Configuring USB3322 not to check VBUS

We have built a device based on the BeagleBoard design
and use the USB3322 for an internal EHCI port.

Since the whole device runs from battery and the USB client
connected to the USB3322 is completely self-powered,
we don't have a real 5V rail for VUSB. Therefore we need to
disable the VBUS > 4.4V comparator and switch the USB3322 to
"DrvVbusExternal" and/or "UseExternalVbus Indicator".

Please can someone direct me where to look in the Linux
kernel drivers for the initialization of the OTG control register
of the USB3322?