Need Help Using UART6 via A-35 on STM32MP257F-EV1

[rishiWimate]

Hello,

I’m trying to enable UART6 on the STM32MP257F-EV1 board using the A-35 processor. UART6 is connected to PF13 (TX) and PF14 (RX) on the extended GPIO. I’m using the OpenST Linux distribution and STM32CubeMX.

What I’ve Tried:

1. Configured UART6 in CubeMX:

   • Set runtime context to A35/Linux with PF13 and PF14 assigned.
   • Generated the device tree, but UART6 doesn’t show up in /dev/ttySTM*.

2. Device Tree Configurations:

   • Updated as follows:

1. • &usart6 { status = "okay"; pinctrl-names = "default"; pinctrl-0 = <&usart6_pins_a>; };
     Pinmux for USART6_TX and USART6_RX is set to AF7.

2. Checked Linux:

   • Ran ls -l /dev/ttySTM* and dmesg | grep ttySTM but found no output for UART6.

3. CubeMX Pin Conflicts:

   • PF13 and PF14 conflict with other peripherals like ETH3_PHY_INTN. Disabled conflicting peripherals but still no success.

Questions:

1. How can I make UART6 appear as /dev/ttySTM6 in Linux?
2. Are there additional steps needed in the device tree or Linux configuration?
3. Has anyone successfully used UART6 on the extended GPIO of this board?

Any help would be greatly appreciated!

Thank you!