BEAGL-BONE-BLACK: Help to create dts file for rs485 half duplex in uart2

/*      pins
function        GPIO        BB PINS
RXD		        GPIO0_2		P9.22
TXD		        GPIO0_3		P9.21
LCD_DATA9/RTSN	GPIO2_15	P8.38*/

/dts-v1/;
/plugin/;

#include <dt-bindings/board/am335x-bbw-bbb-base.h>
#include <dt-bindings/pinctrl/am33xx.h>

/ {
	compatible = "ti,beaglebone", "ti,beaglebone-black", "ti,beaglebone-green";

	// identification
	part-number = "BB-UART2-RS485";
	version = "00A4";

	// resources this cape uses
	exclusive-use =						//edw ta dika mas pins 8a htan
		"P9.21",		// uart2_txd	//GPIO0_3
		"P9.22",		// uart2_rxd	//GPIO0_2
		"P8.38",		// uart2_rtsn	//GPIO2_15	//uart2_rtsn

		"uart2";		// hardware ip used

	/*
	 * Helper to show loaded overlays under: /proc/device-tree/chosen/overlays/
	 */
	fragment@0 {
		target-path="/";
		__overlay__ {

			chosen {
				overlays {
					BB-UART2-RS485-00A4 = __TIMESTAMP__;
				};
			};
		};
	};

	/*
	 * Free up the pins used by the cape from the pinmux helpers.
	 */
	fragment@1 {
		target = <&ocp>;
		__overlay__ {
			P9_21_pinmux { status = "disabled"; };
			P9_22_pinmux { status = "disabled"; };
			P8_38_pinmux { status = "disabled"; }; 
		};
	};

	fragment@2 {
		target = <&am33xx_pinmux>;
		__overlay__ {
			bb_uart2_rs485_pins: pinmux_bb_uart2_rs485_pins {
				pinctrl-single,pins = <
					BONE_P9_21 (PIN_OUTPUT | MUX_MODE1)	
					BONE_P9_22 (PIN_INPUT  | MUX_MODE1)	
					BONE_P8_38 (MUX_MODE6) //0x06
				>;
			};
		};
	};

	fragment@3 {
		target = <&uart2>;
		__overlay__ {
			status = "okay";
			pinctrl-names = "default";
			pinctrl-0 = <&bb_uart2_rs485_pins>;
			rs485-rts-delay = <0 0>;

			rts-gpio = <&gpio2 15 1>; /*  GPIO_ACTIVE_HIGH>; */
			rs485-rts-active-high;
    //      // rs485-rts-before-send = <&gpio2 15 1>;
	// 		// rs485-rts-after-send = <&gpio2 15 0>;
	// 		// rs485-rts-after-recv = <&gpio2 15 1>;
			linux,rs485-enabled-at-boot-time;
		};
	};
};

import serial
import struct
from base64 import encode

# open serial port
#ser = serial.Serial('/dev/ttyS2', 9600, timeout=1)
ser = serial.Serial(
            '/dev/ttyS2',
            baudrate=9600,
            bytesize=8,
            timeout=1,
            stopbits=serial.STOPBITS_ONE,
            parity=serial.PARITY_NONE
        )
# configure RS485 settings
command = [1, 4, 0, 1, 0, 2, 32, 11]
data = bytearray(command)

# ser.setRTS(False)
ser.write(data)
#ser.setDTR(True)
#ser.write(b'\x01\x04\x00\x01\x00\x02\x20\x0B')
ser.flush()
# ser.setRTS(True)
#ser.setDTR(False)

# read response
response = ser.read(9)
# temperature = response[3] + response[4]
# humidity = response[5] + response[6]

# (temp,) = struct.unpack(">h", temperature)
# print("temperature " + str(temp))
# (humi,) = struct.unpack(">h", humidity)
# print("humidity " + str(humi))
print("Temp and Humid Read.")

# print response
print(response)

# close serial port
ser.close()