ad7768 not enumerated in iio_info

I am trying to use the AD7768 eval board on a zedboard.

I have built the ad7768evb hdl project using both the latest version, as well as 2019_R2.  I have built the linux kernel with both the latest version as well as 2019_R2.

I am using the `zynq-zed-adv7511-ad7768` dts file and a linux config file based on xilinx_zynq_defconfig (although its not modified to add IIO support).

When I `modprobe ad7768` I don't see any entries in dmesg.  

I see the following sys entries:

# find / -name *ad7768*

I added a bunch of printk statements and found that ad7768_register() calls a function that eventually fails on dma_request_chan().

[edited by: jay_col at 8:15 PM (GMT -4) on 28 Mar 2021]