before i start accessing a /dev/video3 device, i would like to check if there is an actual camera connected to it. How do i do this .
For USB cameras this is easy, as if the camera is disconnected it won’t have a device
for cameras connected to an analog->MIPI capture boards it is a bit more difficult as there are always 4 devices /dev/video…/dev/video3 … however not all (or none for that matter) may have an analog camera attached to it.
how about checking the kernel logs during kernel initial stage. you may looking for 54080000.vi.
for example,
it shows IMX219 camera sensor has actually register to 7-0010.
$ dmesg | grep 54080000.vi
[ 0.464245] iommu: Adding device 54080000.vi to group 11
[ 5.152109] vi 54080000.vi: vi_probe: ++
[ 5.154775] vi 54080000.vi: initialized
[ 5.156791] vi 54080000.vi: subdev nvcsi--2 bound
[ 5.156804] vi 54080000.vi: subdev imx219 7-0010 bound
[ 5.157528] vi 54080000.vi: subdev nvcsi--1 bound
to be honest , i don’t know. The card image was given to me. I’ll ask them.
I can check the logs for events, I was hoping there was a more direct way to figure this out via v4l or some sort of MIPI tool ? or even checking the /sys/ tree ? Maybe what i’m hoping is not what is available.
There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.
Thanks
hello tomschuring,
could you please share the details of digitisation card,
should we expect those video nodes were removed if the board disconnected.