MIPI CSI-2 Camera without I2C Trouble

Robotics & Edge Computing Jetson & Embedded Systems Jetson Orin Nano
1

For reference, this is mostly a follow-on of this issue: MIPI CSI Camera without i2c
I am attempting to create a driver for a MIPI CSI-2 DPHY 4-lane camera with no i2c interface (camera is always on) on a Jetson Orin Nano Development Kit running Jetpack 6.2.

I have cannibalized the imx185 driver and device tree overlay and changed names and values in order to produce a driver module and device tree overlay for my purposes. Working on the Jetson Orin Nano with Jetpack 6.2, I downloaded the source files, made my modifications, and followed the directions for building and installing my changes (my kernel module (.ko file) copied to the appropriate subdirectory of /lib/modules, .dtbo overlay file copied to /boot, kernel rebuilt and installed (in /boot with config file edited to use the new kernel image and overlay file), and executed ‘sudo nv-update-initrd’) The end result is … nothing. My probe() method does not get called at all, and I don’t see anything from dmesg or in the syslog that indicates system knows I did anything other than loading a new kernel.

nv_mira.c.txt (4.8 KB)
tegra234-camera-mira-a00.dtsi.txt (8.6 KB)
tegra234-p3737-0000-camera-mira-a00.dtsi.txt (1.4 KB)
tegra234-p3737-camera-mira-overlay.dts.txt (5.0 KB)

Could you please take a look at the attached files and see if you can give me a hint as to what the trouble may be?

Thanks in advance!

3

Dump the device tree to confirm your modification is applied.

sudo dtc -I fs -O dts -o extracted_proc.dts /proc/device-tree
4

Thank you! That does seem to be the problem. Now to figure out why it is not being applied. I will churn on that for a bit and see if I can figure it out. Thanks again for the help!

5

So, I used the same configuration as the imx185, omitting a few things like the board_configuration node, as it does not apply in my case, and only including one mode “mode0”. I also replaced the Leopard Imaging part of the name with nothing, i.e. replaced “liimx185” with “mira”. I get the same warnings as the imx185 when building dtbs, no errors, and I think that I have done all the same things as the imx185 driver with the exception of all of the i2c read and writes which are not relevant for this driver.

One thing I am seeing that I did not do is modify the file:
nvidia-oot/drivers/media/i2c/pca9570.c
to include handling of mira in place of imx185. It looks like this is not a generated file?

6

So, my new kernel image is getting loaded, but my overlay files seems to be completely ignored. Is there any way to get debugging information to see why the device tree overlay is not applied?

7

Have a check below document for the overlay implemnetation.