HelenOS sources

PORT_SPEED         63 uspace/drv/bus/usb/xhci/hc.c 	[1] = PORT_SPEED(FULL, 2, 2, 12),
PORT_SPEED         64 uspace/drv/bus/usb/xhci/hc.c 	[2] = PORT_SPEED(LOW, 2, 1, 1500),
PORT_SPEED         65 uspace/drv/bus/usb/xhci/hc.c 	[3] = PORT_SPEED(HIGH, 2, 2, 480),
PORT_SPEED         66 uspace/drv/bus/usb/xhci/hc.c 	[4] = PORT_SPEED(SUPER, 3, 3, 5),
HelenOS homepage, sources at GitHub