AM62 UART

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UART

UART Overview

The exposes up to seven LPUART interfaces, some of which are multiplexed with other peripherals.

Serial Port	Device Node	Device Tree	Note
UART0	/dev/ttyS0	main_uart0	Connected to Symphony board serial console
UART2	/dev/ttyS2	main_uart2	Connected to Symphony board J18.7 and J18.9
UART5	/dev/ttyS5	main_uart5	Used on SOM for Bluetooth interface and can be accessible only if the [/blob//recipes-connectivity/bcm43xx-utils/bcm43xx-utils/am62x-var-som/variscite-bt variscite-bt] Systemd service is disabled or SOM without "WBD" and "WB"
UART6	/dev/ttyS6	main_uart6	Connected to Symphony board J18.3 and J18.5

Testing UART0

Short J18.7 and J18.9 pins and run the following commands:

# stty -F /dev/ttyS0 -echo -onlcr 115200
# cat /dev/ttyS0 &
# echo hello > /dev/ttyS0

For each invocation of echo command the "hello" string should appear on the terminal.

Testing UART6

Short J18.3 and J18.5 pins and run the following commands:

# stty -F /dev/ttyS6 -echo -onlcr 115200
# cat /dev/ttyS6 &
# echo hello > /dev/ttyS6

For each invocation of echo command the "hello" string should appear on the terminal.

Disabling UART6

To disable UART5 edit arch/arm64/boot/dts/ti/ under kernel source directory and modify

&main_uart6 {
        ...
        status = "okay";
};

to

&main_uart6 {
        ...
        status = "disabled";
};

Other UARTs can be disabled in a similar manner by referencing the table above.