Add ST BrightSense camera sensors support

[bemug-st]

Again, better late than never 😉

As we briefly discussed at Embedded Recipes with @naushir and @davidplowman, I would like to enable ST BrightSense cameras in the Raspberry Pi kernel to allow users to utilize them with minimal modifications to a fresh RaspiOS, if possible.
Following @naushir's advice, here is the pull request adding this support.

Currently, kernel drivers and libcamera support are mainlined for both vd55g1 and vd56g3.

This pull request adds the remaining integration for Raspberry Pis

• Device tree overlays
• Drivers compiled as modules by default

By merging this code, users will only need to specify the device tree overlay in /boot/firmware/config.txt with dtoverlay=<sensor> to enable the camera functionality. Please note that automatic camera detection is beyond the scope of this pull request.

I'm not fully aware of how you manage your branches. Since 6.18 is expected to be the next LTS this pull request targets this branch, but it applies successfully down to 6.16. Feel free to rebase it onto whichever branch you find most appropriate.

Please share your thoughts on this pull request and let me know if any changes are needed.

Thank you.

[6by9]

Hi Benjamin - thanks for the PR.

Targeting 6.18 is fine - it should become the default branch within the next few months.

The 2 defconfig patches may as well get squashed together - they get regenerated and squashed as a whole on each revision bump anyway.

Seeing as the overlays for vd56g3 and vd66gy are duplicates other than the node name and compatible, it'd be nicer to put all the common part in a dtsi file, with the individual overlays just setting the compatible. We do a similar thing with imx290, imx327 and imx462 which all pull in imx290_327-overlay.dtsi.
The only downside is that the sensor node name is either generic or only adopts one of the sensor names.

Same for vd55g1 and vd65g4.

Overlays need to be documented in https://github.com/raspberrypi/linux/blob/rpi-6.12.y/arch/arm/boot/dts/overlays/README

Camera autodetection is not supported for third party sensors, only those made by Raspberry Pi.

I assume this works with the ST eval boards for these sensors, eg https://www.st.com/en/evaluation-tools/steval-56g3mai.html ? It's probably worth us buying in a couple for basic support purposes.

[bemug-st]

Thank you for your review. I updated this pull request accordingly.

I assume this works with the ST eval boards for these sensors, eg https://www.st.com/en/evaluation-tools/steval-56g3mai.html ? It's probably worth us buying in a couple for basic support purposes.

Exactly, we can ship some boards to you for free if you want. Please provide the quantities and the shipping address, and I'll get that sorted.

[6by9]

One very minor observation that fragment 5 which is activated by the media-controller=0 override isn't redirected to csi0 by the cam0 override. I'm not that bothered as almost all use cases use media controller for configuration.

I'll drop you an email regarding samples, although 3 of the 4 appear to be stocked by Farnell so are easy enough to source anyway.
It's nice being able to suggest further options for global shutter sensors that are easily available.

[bemug-st]

One very minor observation that fragment 5 which is activated by the media-controller=0 override isn't redirected to csi0 by the cam0 override. I'm not that bothered as almost all use cases use media controller for configuration.

Just to make sure, imx290_327-overlay.dtsi have the same issue right ?

[pelwell]

Just be make sure, imx290_327-overlay.dtsi have the same issue right ?

Yes, it does.