The Analog Camera Adapter V2.0B works out of the box with an Apalis iMX6. I tested this right now with a 2.8b2 (kernel version 4.9.84-2.8.2+gb2a7f2f) and with 2.7 (kernel version 4.1.44-2.7.4+gb1555bf).
Note that the color encoding (PAL vs. NTSC) is detected when you start streaming, i.e. when you open /dev/videoX. From then on the detected color encoding is used until you stop the streaming.
So you cannot change the color encoding on the fly, you do have to stop e.g. a running gstreamer pipeline, change the color encoding and then start the gstreamer pipeline again.
If you start a pipeline without an input signal the system will default to PAL.
The first two posts you reference talk about different Video ADCs in combination with a different computer module. The third one uses a ADV7280-M to talk to a Apalis TK1 over MIPI-CSI2. All these posts are not applicable to your HW setup.
Thank you for your answer. The customer has asked to make the form factor of the custom card smaller so I may have to do this with colibri imx6 512 MB.
I checked the datasheet of viola plus and section 3.8.3 paralel camera interface suggests that I should change pin multiplexers in software.
I understand that after doing this, I will be able to use the adv7280 camera adaptor without issues. Is there anything that I am missing?
On Colibri iMX6 we provide a device-tree which already does the right pinmuxing.
imx6dl-colibri-cam-eval-v3.dtb
I never tried to connect the ACA to a Viola Plus. I expect that to work though. The signals are sort of high speed, so I would not make the cabling unnecessarily long and try to have the length for all signals about the same.