uart mapping to /dev/tty on Beaglebone AI

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1

I’m trying to set up UART3 on the Beaglebone AI to work as a serial port, but I’m not sure what is involved. I configured P9.21b and P9.22b to be in mode 1, which is mapped to uart3_tx and uart3_rx. How do I get those pins bound to a tty device under /dev? Maybe they already are and I don’t know which one?

2

Adding this to my device tree overlay seemed to make /dev/ttyO2 show up:

&uart3 {
status = “okay”;
};

I am not able to receive data, though, only send. Any ideas?

3

This works!

DRA7XX_CORE_IOPAD( 0x34F0, PIN_INPUT | MUX_MODE14 ) // P9.21a
DRA7XX_CORE_IOPAD( 0x37C4, PIN_OUTPUT_PULLUP | INPUT_EN | MUX_MODE1 ) // P9.21b
DRA7XX_CORE_IOPAD( 0x369C, PIN_INPUT | MUX_MODE14 ) // P9.22a
DRA7XX_CORE_IOPAD( 0x37C0, PIN_OUTPUT_PULLUP | INPUT_EN | MUX_MODE1 ) // P9.22b