T113-86 Screen RS485 Expansion Board

The T113-86 screen RS485 expansion board, used in conjunction with the T113-S3 smart home 86-screen V5 version, is
demonstrated in a video :
https://www.bilibili.com/video/BV1sx4y167s9/ .
Usage instructions :
After soldering according to the BOM and PCB specifications, connect the 86-screen PCB using a PH2.0 8P cable.
Then, begin porting the driver, referring to the T527 BSP kernel sunxi_uart.c, adding the sw_uport->rs485_en code section:
https://github.com/chainsx/linux-t527/blob/main/bsp/drivers/uart/sunxi-uart.c
. Configure the device tree as follows:
&uart3 { pinctrl-names = "default", "sleep"; pinctrl-0 = ; pinctrl-1 = ; status = "okay";
        sunxi,uart-rs485 = ; sunxi,uart-485fl = ; sunxi,uart-485oe-gpios = ;};
&uart5 { pinctrl-names = "default", "sleep"; pinctrl-0 = ; pinctrl-1 = ; status = "okay";
        sunxi,uart-rs485 = ; sunxi,uart-485fl = ; sunxi,uart-485oe-gpios = ;};
Parameters:
        sunxi,uart-rs485 = ; // Whether to enable 485 sunxi,uart-485fl = ; // 485 directional line polarity sunxi,uart-485oe-gpios = ; //
After configuring the 485 directional line I/O, make menuconfig find minicom and enable it for testing
entering the system and using minicom Configure the serial port with the -s option, and be sure to disable flow control. Then, connect
the terminal cable to the computer via an RS485 to USB adapter for normal use. Refer to the purchase link for the terminal cable
(color: 8P, length: 80mm, terminals: double-ended (same direction)):
https://item.taobao.com/item.htm?_u=r2dklb45e5e6&id=607000261049&spm=a1z09.2.0.0.24152e8dFFf8qN