gpio serial port(uart-a) not working

[Jose L Moffa]

Hello everyone,

 

I'm currently working on a bananaPi M2S and trying to set up serial communication through the GPIO port on my device. I am using the provided overlay for UART-A. The overlay seems to work as it registers the serial device, as indicated by the dmesg output:

bash

 

[ 0.000277] printk: console [tty1] enabled 
[ 0.734433] ff803000.serial: ttyAML0 at MMIO 0xff803000 (irq = 14, base_baud = 1500000) is a meson_uart 
[ 0.734458] printk: console [ttyAML0] enabled 
[ 0.735241] ffd24000.serial: ttyAML6 at MMIO 0xffd24000 (irq = 15, base_baud = 1500000) is a meson_uart 
[ 0.735395] serial serial0: tty port ttyAML6 registered 
[ 2.663304] systemd[1]: Created slice Slice /system/serial-getty. 
[ 3.140660] systemd[1]: Found device /dev/ttyAML0. 

 

However, the device /dev/ttyAML6 does not appear in the /dev folder.

 

Here are the steps I've taken so far:

 

• Loaded the UART-A overlay.
• Verified registration through dmesg logs, which show that ttyAML6 is indeed registered.

 

What I've checked:

• I ran ls /dev/ttyAML* and /dev/tty* but didn't find ttyAML6.

 

Questions:

 

Is there a known issue with this overlay or an additional step I'm missing to make the device node appear in /dev?

Are there specific udev rules I need to add or modify to automatically create the device node?

 

Any help or pointers would be greatly appreciated!

Thank you in advance!