DS90UB960 : How to use the two csi ports of 960 chip

Hi teams

Recently, we are using the chip of DS90UB960

First,we use four camera sensors (720P)  connect the 960.it shows the video ok.

like below:

sensor A ---------------|__________________|

sensor B ---------------|      DS90UB960          |________port 0   ---MIPI-A  ok

sensor C ---------------|                                    |________port 1   ---MIPI-B

sensor D ---------------|__________________|

There are four video nodes corresponding to four sensors.

sensor-A---video0

sensor-B---video1

sensor-C---video2

sensor-D---video3

As I know,960 chip can be port mirrored output.

When I want to get the port1 data,how to get it?

Do I need to register a new video node ? (like video4-7)

BRs

thanks