hello 840764397,
you may refer to kernel initial messages, check all mounted serial ports,
for example,
$ dmesg | grep THS
[ 1.637719] 3100000.serial: ttyTHS0 at MMIO 0x3100000 (irq = 51, base_baud = 0) is a TEGRA_UART
[ 1.638901] 3110000.serial: ttyTHS1 at MMIO 0x3110000 (irq = 52, base_baud = 0) is a TEGRA_UART
[ 1.639652] 3140000.serial: ttyTHS4 at MMIO 0x3140000 (irq = 53, base_baud = 0) is a TEGRA_UART
here’s configuration files for combined uart,
you can have modification in cfg files to change combine uart settings,
$Linux_for_Tegra/bootloader/tegra194-mb1-bct-misc-l4t.cfg
enable_combined_uart = 1;
you may also refer to device tree for the relationships.
for example,
$L4T_Sources/r32.4.2/Linux_for_Tegra/source/public/hardware/nvidia/soc/t19x/kernel-dts/tegra194-soc/tegra194-soc-uart.dtsi