The EN751221 has 2 UART ports:
0xBFBF0000 - Wired to the accessible UART pins0xBFBF0300This UART is identical to ns16550 with a register width of 4 bytes, the only difference is that the speed converted into a clock rate using a formula that is not in ns16550.
Example DT for a EN751221 UART set to 115200:
serial@1fbf0000 {
compatible = "ns16550";
reg = <0x1fbf0000 0x30>;
reg-io-width = <4>;
reg-shift = <2>;
interrupt-parent = <&intc>;
interrupts = <0>;
clock-frequency = <1843200>;
};
There is a patch under review for adding an EcoNet/Airoha UART driver which will correctly compute the clock in order to adjust the UART baud rate.