Unable to access the UART port using A55 core of imx93 board (Digi coreconnect 93)

[rk4]

Dear NXP Support Team,

I want to attach a sensor in the UART port of the board and access via A55 core.

I have tried below things but neither of them worked.

• Total available port from UART1 to UART8 – 8 Nos

• The UART4 port as a Xbee interface is available like ttyXBee, so I also attempted to transfer data using c code and directly using command line but none of them where worked.

• Followed the URAT instruction from this website, and I am getting port ttyLP3, ttyLP5 and ttyLP6 port. The port ttyLP3 and ttyLP5 have no pinout on the board. The ttyLP6 is connected with the console port which is ttyACM0 (UART to USB), so we cannot use it.

• Tried to configure UART7 (Mikroe interface) but the tty node is not created, maybe it missed configuration from dts side. (I am unsure about it)

• The UART1 is connected to the Bluetooth chip, so it cannot be accessible.

• No details found from UART2 and UART8.

Can you guide me how to access the UART port using A55 core of the board and C language programming?

[rk4]

Dear @Chavira , 

Thanks for prompt response.

Could you tell me how to create a ttynode for UART7 (MIKROE interface) in A55 core? OR if its already available in it, can you tell me what is the name of it?

[Chavira]

HI @rk4!

Please share your device tree file.

[rk4]

Hello @Chavira , 

Please find attached dts file that I am using.

[Chavira · Accepted solution]

Hi @rk4!

Your UART7 is configured as a rs485 in file ccimx93-dvk.dts

&lpuart7 {
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_uart7>;
	linux,rs485-enabled-at-boot-time;
	digi,rts-gpio = <&gpio2 10 GPIO_ACTIVE_HIGH>;
	/delete-property/dmas;
	/delete-property/dma-names;
	status = "okay";
};

only delete the line linux,rs485-enabled-at-boot-time; and the uart7 should be listed in the device folder with the name ttyLP6

Best Regards!

Chavira

[Chavira]

HI @rk4!

Thank you for contacting NXP Support!

I don´t have access to the device tree of that board since is not an NXP board.

I can help you to analyze the device tree if you can share the device tree with me.

Unfortunately we don´t have any guide of how to use UART ports in Linux, but you can check some guides in internet like this guide.

For Further support please contact to digi support.

Best Regards!

Chavira