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Devicetree for unsupported FMC card

Question asked by mike.ericson on Feb 12, 2015
Latest reply on Feb 13, 2015 by larsc



I have an unsupported FMC card with an AD9680 on it and I would like to be able to connect it to a ZC706, get it to be recognized as an iio device, and be able to use it with linux applications like iio-oscilloscope.


I've spent a few days going through wiki pages and engineer zone discussions, but I am new at working with devicetrees and haven't been able to figure it out on my own.


So far, I've tried taking the devicetree zynq-zc706-adv7511-daq2.dts, which includes the AD9680, and reusing the DAQ2 HDL reference design with an updated pinout for the new FMC card, but the only iio device that gets recognized is the xadc on the FPGA.


I'm concerned about this warning on Linux with HDMI video output on the ZED and ZC702, ZC706 boards [Analog Devices Wiki]:

The devicetree must match the HDL reference design that is used. It is not possible to use a adv7511 only devicetree for a AD-FMCOMMS1-EBZ reference HDL design, even if the AD-FMCOMMS1-EBZ is not connected to the FMC slot.


Does this mean that I have a lot more work to do that I originally thought?  Would it be better to start with zynq-zc706-adv7511.dts and try to add the AD9680 to that file?  Also, there's mention of some preprocessing that has to be run on .dts files before running dtc to convert them to .dtb files; does that apply here?


Finally, there are a number of boot-up messages about devices being recognized and things happening like a pll being locked ... where is the code that is controlling this and generating those messages?


Thanks very much for any help that you can offer,