FMCOMMS3/4/5 Linux driver -- controlling the GPO Lines

Hello,

I am trying to manually control the four GPO lines on the AD9361.  What is the best way to do this using the AD9361 Linux driver?  I couldn't find any straightforward way to do it via any of the sysfs handles exposed.  debugfs seems to directly expose the AD9361's SPI registers through the direct_reg_access handle; however, I'm not exactly sure how to use it.

Thanks in advance for your help.

-Dan Fay