Add ST cameras as third party sensors in rpicam-apps intro

[bemug-st]

Hi,

Following raspberrypi/linux#7189 and raspberrypi/linux#7463 PRs, some ST global shutter sensors are now supported as third party sensors.
This PR lists them in the rpicam-apps intro document, along with other third party sensor.

Thank you.

[stevedavies-rp]

Many thanks for this contribution.

As far as I can see, only VD55G1 and VD56G3 are fully supported by Raspberry Pi. Do you have a source to support the claim that the others on your list are fully supported?

[bemug-st]

Sure, apologize for not pointing this earlier.

You can see in the vd55g1.c file that the while the driver is effectively called vd55g1, it supports vd55g4 and vd65g4 variants too thanks to Dave backporting my patches in the raspberry pi kernel tree : https://github.com/raspberrypi/linux/blob/rpi-6.18.y/drivers/media/i2c/vd55g1.c#L2079

Same for vd56g3 that also supports vd66gy : https://github.com/raspberrypi/linux/blob/rpi-6.18.y/drivers/media/i2c/vd56g3.c#L1559

All corresponding device tree overlays are available in the raspberry pi kernel here, also thanks to Dave : https://github.com/raspberrypi/linux/tree/rpi-6.18.y/arch/arm/boot/dts/overlays

Note that the vd55g4 overlay is missing, as it is a very recent addition in the kernel. I added it to the third party sensor list in this commit but maybe it could be removed until I effectively submit a PR for adding its overlay ?

[stevedavies-rp]

For it to be fully supported, it needs to have the library files as well as the kernel files. I don't see anything in the libcamera repo for the others: https://github.com/raspberrypi/libcamera/tree/main/src/ipa/rpi/pisp/data. Are these on the way?

[bemug-st]

Libcamera picks a tuning file according to the driver name and its color mode :

• vd55g1 and vd55g4 are mono cameras depending on vd55g1 driver, and therefore will use : vd55g1_mono.json
• vd64g4 (color) : vd55g1.json
• vd56g3 (mono) : vd56g3_mono.json
• vd66gy (color) : vd56g3.json

I tested all these sensors successfully with the latest Raspberry PI OS release.

[stevedavies-rp]

Thank you. I've talked to the engineers and they are happy with your proposed edits, so I will get those into the documentation.