Please check below explanation about the usb port mapping,
nvidia,lane_owner is to set the owner of PCIe lane pad. It could be XUSB, PCIe x7 or Sata x1.
such as for 0xff56, it means lane P6 is used as SSP0 and lane P5 is used as SSP1.
The other lanes(0xf) are not assigned, may be allocated for PCIe or Sata controller.
nvidia,portmap is to define which usb/xusb port will be enabled. BIT0 - BIT7 : SS ports. BIT8 - BIT15 : USB2 UTMI ports
such as for 0x0e03, LSB 0x03 means SSP0 and SSP1 are enabled, MSB 0x0E means USBP1, USBP2, USBP3 are enabled
nvidia,ss_portmap is to map xusb port with desire usb port. ss_portmap[0:3] = SS0 map, ss_portmap[4:7] = SS1 map
such as for 0x21, it means SSP0 on USB2P1 and SSP1 on USB2P2
You may refer to the following dts file to configure the device tree
$TOP/kernel/arch/arm64/boot/dts/tegra210-ers-e2220-1180-a00-00-common.dts
Also, please enable xotg/xudc from device tree and kconfig to get xotg working.
https://devtalk.nvidia.com/default/topic/933330/?comment=4962197