Use the following example dts overlay (.dtso) to enable DSI. The code is also available Texas Instruments' kernel source page.

// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
/**
 * DT Overlay for RPi 7inch touchscreen panel interfaced with DSI on
 * AM62P5-SK EVM.
 *
 * RPi DSI Panel: https://www.raspberrypi.com/products/raspberry-pi-touch-display/
 *
 * Copyright (C) 2024 Texas Instruments Incorporated - https://www.ti.com/
 */

/dts-v1/;
/plugin/;

#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/interrupt-controller/irq.h>

#include "k3-pinctrl.h"

&{/} {
	panel0 {
		compatible = "raspberrypi,7inch-dsi", "simple-panel";
		backlight = <&display_reg>;
		power-supply = <&display_reg>;

		port {

			panel_in: endpoint {
				remote-endpoint = <&panel_bridge_out>;
			};
		};
	};

	bridge_reg: bridge-regulator {
		compatible = "regulator-fixed";
		regulator-name = "bridge-reg";
		gpio = <&display_reg 0 0>;
		vin-supply = <&display_reg>;
		enable-active-high;
	};
};

&dphy_tx0 {
	status = "okay";
};

&main_i2c0 {
	#address-cells = <1>;
	#size-cells = <0>;

	display_reg: regulator@45 {
		compatible = "raspberrypi,7inch-touchscreen-panel-regulator";
		reg = <0x45>;
		gpio-controller;
		#gpio-cells = <2>;
	};
};

&dss1 {
	status = "okay";
};

&dss1_ports {
	#address-cells = <1>;
	#size-cells = <0>;

	/* DSS1-VP1: DSI Output */
	port@1 {
		reg = <1>;

		dss1_dpi1_out: endpoint {
			remote-endpoint = <&dsi0_in>;
		};
	};
};

&dsi0 {
	status = "okay";
	#address-cells = <1>;
	#size-cells = <0>;

	ports {
		#address-cells = <1>;
		#size-cells = <0>;

		port@0 {
			reg = <0>;

			dsi0_out: endpoint {
				remote-endpoint = <&panel_bridge_in>;
			};
		};

		port@1 {
			reg = <1>;

			dsi0_in: endpoint {
				remote-endpoint = <&dss1_dpi1_out>;
			};
		};
	};

	bridge@0 {
		status = "okay";
		compatible = "toshiba,tc358762";
		reg = <0>;
		vddc-supply = <&bridge_reg>;

		ports {
			#address-cells = <1>;
			#size-cells = <0>;

			port@0 {
				reg = <0>;

				panel_bridge_in: endpoint {
					remote-endpoint = <&dsi0_out>;
				};
			};

			port@1 {
				reg = <1>;

				panel_bridge_out: endpoint {
					remote-endpoint = <&panel_in>;
				};
			};
		};
	};
};

• The DSI output is derived through a Cadence DSI/DPHY bridge interfaced with the DPI output from DSS1 VP1. Details about this bridge driver is located at Texas Instruments' kernel source page. This bridge is internal to the SoC.
• The DSI output is connected to the DSI_in of the Raspberry Pi DSI panel,which uses a Toshiba bridge internally to convert DSI to DPI. Implement the driver in the same dtso. See Texas Instruments' kernel source page for additional documentation.