hello fh2077,
please check pinmux spreadsheets for the mappings of signal name and also ball name. you may check the board configuration files for confirmation,
i.e. $OUT/Linux_for_Tegra/bootloader/t186ref/BCT/tegra19x-mb1-pinmux-p3668-a01.cfg
taking uart2_tx_px4 as an example,
it use signaling (DT property), UART2_TX; there’s a GPIO pin after ‘p’, so it’s TEGRA194_MAIN_GPIO(X, 4),
for example,
pinmux.0x0243d070 = 0x00000400; # uart2_tx_px4: uartb, tristate-disable, input-disable, io_high_voltage-disable, lpdr-disable
note,
Xavier and Xavier NX is based-on tegra194 series.
you may check the header files for reference,
i.e. $L4T_Sources/r32.5/Linux_for_Tegra/source/public/kernel/nvidia/include/dt-bindings/gpio/tegra194-gpio.h