Creating custom sensor DTSI file

Hi,

I’m creating a custom sensor driver with custom adapter board (or “Camera Interposer Module” as stated in “NVIDIA Jetson AGX Xavier Series Camera Module Hardware Design Guide”).

I’m having some troubles with creating the device tree files. The adapter board is simply a pass through board, so no eeprom in board or either in the camera module. Therefore I cannot use the Plugin Manager, but I have to use Main Platform Device Tree File. The documentation (https://docs.nvidia.com/jetson/l4t/#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fcamera_sensor_prog.html%23wwpID0E0YF0HA) states that first I would have to edit the “/hardware/nvidia/platform/t19x/common/kernel-dts/t19x-common-modules/tegra194-cvb-p2822-0000-a00.dtsi” file and remove a line "#include “tegra194-camera-plugin-manager.dtsi”. This line however does not exists in the file and instead there is code:

plugin-manager {
		fragement-tegra-wdt-en {
			odm-data = "enable-denver-wdt";

Also the fourth step states that I would have to replace "#include “tegra194-p2822-camera-modules.dtsi” with my own dtsi file.

I assume that the this line should have to include the custom sensor driver dtsi file? I’m also wondering if in that dtsi file I have to include gpio (reset/pwdn) setup similar to one in “tegra194-p2822-camera-modules.dtsi” file? Also where do I declare what regulators are used? Is there any example of dtsi files of using simple pass-through adapter board design?

I’m using L4T R32.2.1.

hello notolli,

due to plugin-manager is enabled by default, we don’t have examples for the pass-through configuration.
during the kernel compile process, all these device tree will built as single dtb and flashing into Xavier’s kernel-dtb partition.
for example,
$OUT/Linux_for_Tegra/kernel/dtb/tegra194-p2888-0001-p2822-0000.dtb

hence, please refer to below two dtsi files as an example.
you’ll found common folder specify sensor properties and port bindings.
$l4t-r32.2.1/public_sources/hardware/nvidia/platform/t19x/common/kernel-dts/t19x-common-modules/tegra194-camera-imx185-a00.dtsi
the galen folder specify the regulators and also gpios were used by the sensor modules.
$l4t-r32.2.1/public_sources/hardware/nvidia/platform/t19x/galen/kernel-dts/common/tegra194-p2822-0000-camera-imx185-a00.dtsi