Cannot find UART on /dev/ttyS

Hello!

I am trying to use UART but cannot find the port.
I installed setserial and when i do

setserial -g /dev/ttyS[0123]

I get

/dev/ttyS0, UART: unknown, Port: 0x0000, IRQ: 0
/dev/ttyS1, UART: unknown, Port: 0x0000, IRQ: 0
/dev/ttyS2, UART: unknown, Port: 0x0000, IRQ: 0
/dev/ttyS3, UART: unknown, Port: 0x0000, IRQ: 0

We have a custom device tree and I believe that the UART is activated. Here it is and the overlay
paletto.dtso (312 Bytes)
.
imx8mm-verdin-data.dtsi (34.3 KB)

Please post the entire contents of your /dev directory along with the kernel startup in verbose mode

it’s expected, please check this article

Yes we found the correct port for the Verdin.

Turns out it also appeared that a resistor had been poorly soldered on.