Camera adaptation

This page is only for experienced users. It requires knowledge and experience about the following topics:

Kernel development
Devicetree syntax

The Nvidia forum and its documentation about the Jetson family is a good way to get started with those kinds of work. You may start with taking a look at the Camera Adaption Guide from Nvidia.

Auvidea can also provide a quote, if you need a custom devicetree for your CSI camera on the J20, if needed. Contact sales@auvidea.eu or support@auvidea.eu for more information.

Implementing GPIO extender

The GPIO expander populated on the J20 is used to control the mclock and power-down GPIO's on each CSI connector. Auvidea recommends implementing this chip in the Devicetree as GPIO-Chip in order to use those GPIO's directly as reset-gpio in the camera device node.

GPIO

Note

Represented in the device tree for the AGX Orin would look like this:

j20_port_extender.dtsi

/*
 * Copyright (c) 2023, AUVIDEA. All rights reserved.
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or any
 * later version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 */

/ {
	i2c@3180000 {
		tca6416_cam: cam_gpio_expander@20 {
			compatible = "ti,tca6416";
			reg = <0x20>;
			gpio-controller;
			#gpio-cells = <2>;
 
			led {
				gpio-hog;
				gpios = <0 0>;
				output-low;
				line-name = "led";
			};

			cam_g_rst {
				gpio-hog;
				gpios = <6 0>;
				output-high;
				line-name = "cam_g_mclk";
			};
			cam_g_pwdn {
				gpio-hog;
				gpios = <4 0>;
				output-low;
				line-name = "cam_g_pwdn";
			};
			cam_e_rst {
				gpio-hog;
				gpios = <7 0>;
				output-high;
				line-name = "cam_e_mclk";
			};
			cam_e_pwdn {
				gpio-hog;
				gpios = <5 0>;
				output-low;
				line-name = "cam_e_pwdn";
			};
			cam_d_rst {
				gpio-hog;
				gpios = <10 0>;
				output-high;
				line-name = "cam_d_mclk";
			};
			cam_d_pwdn {
				gpio-hog;
				gpios = <8 0>;
				output-low;
				line-name = "cam_d_pwdn";
			};
			cam_c_rst {
				gpio-hog;
				gpios = <11 0>;
				output-high;
				line-name = "cam_c_mclk";
			};
			cam_c_pwdn {
				gpio-hog;
				gpios = <9 0>;
				output-low;
				line-name = "cam_c_pwdn";
			};
			cam_b_rst {
				gpio-hog;
				gpios = <14 0>;
				output-high;
				line-name = "cam_b_mclk";
			};
			cam_b_pwdn {
				gpio-hog;
				gpios = <12 0>;
				output-low;
				line-name = "cam_b_pwdn";
			};
			cam_a_rst {
				gpio-hog;
				gpios = <15 0>;
				output-high;
				line-name = "cam_a_mclk";
			};
			cam_a_pwdn {
				gpio-hog;
				gpios = <13 0>;
				output-low;
				line-name = "cam_a_pwdn";
			};
		};
	};
};

Each camera node (if the driver supports this feature) contains a reset-gpio that can be assinged to one of the implemented GPIO's in the code above. An example usage of one of those GPIO's can be found in the following code in the reset-gpio property.

imx219.dtsi

[...]
	i2c@31e0000 {
		rbpcv2_imx219_a@10 {
			status="okay";
			compatible = "sony,imx219";
			reg = <0x10>;
			
			// Here is the GPIO of the gpio epander used as reset-gpio
			reset-gpios = <&tca6416_cam 15 GPIO_ACTIVE_HIGH>;

			devnode = "video0";

			physical_w = "3.680";
			physical_h = "2.760";

			sensor_model = "imx219";

			use_sensor_mode_id = "true";

			mode0 { // IMX219_MODE_3280x2464_21FPS //
				mclk_khz = "24000";
				num_lanes = "2";
				tegra_sinterface = "serial_a";
[...]

Port configuration register

0: Output 1: Input

i2cset -y -f 2 0x20 0x06 0x0e

P10

P12

P11

P10

i2cset -y -f 2 0x20 0x07 0x00

Port output register

0: Logical HIGH 1: Logical LOW

Input pins will be ignored by this setting

i2cset -y -f 2 0x20 0x02 0xff

P10

P12

P11

P10

i2cset -y -f 2 0x20 0x03 0xff

Script

enable_imx219.sh

#!/bin/bash

# Port configuration register

# 0: Output
# 1: Input

# | P7  | P6  | P5  | P4  | P3  | P2  | P1  | P0  |
# | --- | --- | --- | --- | --- | --- | --- | --- |
# | 0   | 0   | 0   | 0   | 1   | 1   | 1   | 0   |

i2cset -y -f 2 0x20 0x06 0x0e

# | P8  | P9  | P10 | P12 | P11 | P10 | P9  | P8  |
# | --- | --- | --- | --- | --- | --- | --- | --- |
# | 0   | 0   | 0   | 0   | 0   | 0   | 0   | 0   |

i2cset -y -f 2 0x20 0x07 0x00

# Port output register

# 0: Logical HIGH
# 1: Logical LOW

# (Input pins will be ignored)

# | P7  | P6  | P5  | P4  | P3  | P2  | P1  | P0  |
# | --- | --- | --- | --- | --- | --- | --- | --- |
# | 1   | 1   | 1   | 1   | 1   | 1   | 1    | 1  |

i2cset -y -f 2 0x20 0x02 0xff

# | P8  | P9  | P10 | P12 | P11 | P10 | P9  | P8  |
# | --- | --- | --- | --- | --- | --- | --- | --- |
# | 1   | 1   | 1   | 1   | 1   | 1   | 1    | 1  |

i2cset -y -f 2 0x20 0x03 0xff

CSI-Routing

The following documentation assumes that you are comfortable with the CSI/VI interface from the Nvidia Jetson family

Example CSI/VI implementation

The following example CSI/VI devicetree would implement the J20 on the AGX Orin Devkit

The TX1-Devkit uses a different CSI-Lanes than the AGX-Xavier and AGX-Orin Devkit as shown above. -> There might be some differences in the Devicetree implementation for the AGX-Orin Devkit.

tegra234-p3737-0000-camera-vicsi-imx219-J20.dtsi

/ {
	tegra-capture-vi {
		status = "okay";
		num-channels = <6>;
		ports {
			status = "okay";
			#address-cells = <1>;
			#size-cells = <0>;
			port@0 { // CSI A
				status="okay";
				reg = <0>;
				imx219_vi_in0: endpoint {
					status="okay";
					port-index = <0>;
					bus-width = <2>;
					remote-endpoint = <&imx219_csi_out0>;
				};
			};
			port@1 { // CSI B
				status="okay";
				reg = <1>;
				imx219_vi_in1: endpoint {
					status="okay";
					port-index = <1>;
					bus-width = <2>;
					remote-endpoint = <&imx219_csi_out1>;
				};
			};
			port@2 { // CSI C
				status="okay";
				reg = <2>;
				imx219_vi_in2: endpoint {
					status="okay";
					port-index = <2>;
					bus-width = <2>;
					remote-endpoint = <&imx219_csi_out2>;
				};
			};
			port@3 { // CSI D
				status="okay";
				reg = <3>;
				imx219_vi_in3: endpoint {
					status="okay";
					port-index = <3>;
					bus-width = <2>;
					remote-endpoint = <&imx219_csi_out3>;
				};
			};
			port@4 { // CSI E
				status="okay";
				reg = <4>;
				imx219_vi_in4: endpoint {
					status="okay";
					port-index = <4>;
					bus-width = <2>;
					remote-endpoint = <&imx219_csi_out4>;
				};
			};
			port@5 { // CSI G
				status="okay";
				reg = <5>;
				imx219_vi_in6: endpoint {
					status="okay";
					port-index = <5>;
					bus-width = <2>;
					remote-endpoint = <&imx219_csi_out6>;
				};
			};
		};
	};

	host1x@13e00000 {
		nvcsi@15a00000 {
			status = "okay";
			num-channels = <6>;
			#address-cells = <1>;
			#size-cells = <0>;
			channel@0 { // CSI A
				reg = <0>;
				ports {
					status="okay";
					#address-cells = <1>;
					#size-cells = <0>;
					port@0 {
						reg = <0>;
						status="okay";
						imx219_csi_in0: endpoint@0 {
							port-index = <0>;
							bus-width = <2>;
							remote-endpoint = <&imx219_out0>;
							status="okay";
						};
					};
					port@1 {
						reg = <1>;
						status="okay";
						imx219_csi_out0: endpoint@1 {
							remote-endpoint = <&imx219_vi_in0>;
							status="okay";
						};
					};
				};
			};
			channel@1 {// CSI B
				reg = <1>;
				ports {
					#address-cells = <1>;
					#size-cells = <0>;
					port@0 {
						reg = <0>;
						imx219_csi_in1: endpoint@2 {
							port-index = <1>;
							bus-width = <2>;
							remote-endpoint = <&imx219_out1>;
						};
					};
					port@1 {
						reg = <1>;
						imx219_csi_out1: endpoint@3 {
							remote-endpoint = <&imx219_vi_in1>;
						};
					};
				};
			};
			channel@2 { // CSI C
				reg = <2>;
				ports {
					#address-cells = <1>;
					#size-cells = <0>;
					port@0 {
						reg = <0>;
						imx219_csi_in2: endpoint@4 {
							port-index = <2>;
							bus-width = <2>;
							remote-endpoint = <&imx219_out2>;
						};
					};
					port@1 {
						reg = <1>;
						imx219_csi_out2: endpoint@5 {
							remote-endpoint = <&imx219_vi_in2>;
						};
					};
				};
			};
			channel@3 { // CSI D
				reg = <3>;
				ports {
					status="okay";
					#address-cells = <1>;
					#size-cells = <0>;
					port@0 {
						reg = <0>;
						status="okay";
						imx219_csi_in3: endpoint@6 {
							port-index = <3>;
							bus-width = <2>;
							remote-endpoint = <&imx219_out3>;
							status="okay";
						};
					};
					port@1 {
						reg = <1>;
						status="okay";
						imx219_csi_out3: endpoint@7 {
							remote-endpoint = <&imx219_vi_in3>;
							status="okay";
						};
					};
				};
			};
			channel@4 { // CSI E
				reg = <4>;
				ports {
					status="okay";
					#address-cells = <1>;
					#size-cells = <0>;
					port@0 {
						reg = <0>;
						status="okay";
						imx219_csi_in4: endpoint@8 {
							port-index = <4>;
							bus-width = <2>;
							remote-endpoint = <&imx219_out4>;
							status="okay";
						};
					};
					port@1 {
						reg = <1>;
						status="okay";
						imx219_csi_out4: endpoint@9 {
							remote-endpoint = <&imx219_vi_in4>;
							status="okay";
						};
					};
				};
			};
			channel@5 { // CSI G
				reg = <5>;
				ports {
					status="okay";
					#address-cells = <1>;
					#size-cells = <0>;
					port@0 {
						reg = <0>;
						status="okay";
						imx219_csi_in6: endpoint@10 {
							port-index = <6>;
							bus-width = <2>;
							remote-endpoint = <&imx219_out6>;
							status="okay";
						};
					};
					port@1 {
						reg = <1>;
						status="okay";
						imx219_csi_out6: endpoint@11 {
							remote-endpoint = <&imx219_vi_in6>;
							status="okay";
						};
					};
				};
			};
		};
	};
};