I'm using the Pi 4 compute module to connect to a IMX219 camera using the mipi interface. Well, actually putting the mipi through a FPGA interface first but the basic question is:
Can I use the Pi to check if the differential mipi clk is running?
I need to check if the FPGA output is working. I can otherwise interface with the camera but e.g. raspistill won't take a picture, timing out with the "no data received" error.
So I implemented a CSI bridge on the FPGA (Lattice Crosslink) and confirmed via oscilloscope that there are high speed CSI2 signals and clock being output by the FPGA. But I'm still getting the
Camera control callback cmd=0x4f525245mmal: No data received from sensor. Check all connections, including the Sunny one on the camera board error. I checked the Pi and Camera on a different board and they both work just fine (i.e. can take pictures with raspistill).
So is there any way to check if a CSI clk is received? Or if any data is received, just not valid MIPI data?