Before enabling the device the first time (so probably meaningless):
REG_PORTSC1: 80001
REG_USBMODE: 80001
REG_USBCMD : 80001

After DEV_EN and DEV_RS

REG_PORTSC1: 20000004
REG_USBMODE: 0
REG_USBCMD : 80002

After disabling, connect and re-enable

REG_PORTSC1: 20000C04
REG_USBMODE: 0
REG_USBCMD : 80000

After initializing the controller:

REG_PORTSC1: 20000404
REG_USBMODE: 2
REG_USBCMD : 80001