Add RS485 mode on ls1028

[Eddy1]

Hi：

How do I configure Duart to operate in half-duplex RS485 mode? Currently, I am using the duart1 port, and the default configuration is as follows: 

      duart1: serial@21c0600 {
                        compatible = "fsl,ns16550", "ns16550a";
                        reg = <0x00 0x21c0600 0x0 0x100>;
                        interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
                        clocks = <&clockgen 4 1>;
                        status = "disabled";
                };

[June_Lu]

First, you should confirm the customer HW mode of UART in RS485.

If the direction of the RS485 is controlled by the extra signal, you should add it in the DTS, and modify the SW driver.

If the direction of the RS485 is controlled by the RTS, I don't think it needs extra modification.

[Eddy1 · Accepted solution]

Hi：

Thank you for your reply. I have modified the SW driver, and it can now send and receive