HDL requirements for IIO Driver support

I have a project working with one of the ADI hdl reference designs and the Linux IIO subsystem.  I am looking to add another device to my project that doesn't have a reference design, but does have an IIO subsystem driver. 

In looking at the reference designs it appears that there is a non-trivial amount of HDL that goes in to supporting the IIO subsystem.  In the case of the AD7768 there is ad7768_if.v that appears to do crc calculations, an ad7768 instantiation of the utils_cpack IP, and an AXI gpio block.  And this is in addition to the DMA and SPI requirements, which I suppose I can find in the device tree requirements section of the linux driver manual.

My question is, if I go to incorporate a new device like the AD5064 for which there is an IIO driver, but I don't see a reference design, how do I know what hdl components the driver needs? I posted a similar question in the Linux Driver forum and was told that a device like the AD5064 just requires SPI and the GPIO should be user controlled.  But where should I look to find this out?  And this is especially true for a device like the AD7768 which seems to require the additional HDL I mentioned above.