Ben
GPIO support was added as part of the PSP 04.00.00.10 release. This was primarily used in the context of controlling the PMIC instance on the EVM. We havent specifically exercised the sysfs interface for GPIO.
The release can be downloaded from http://software-dl.ti.com/dsps/dsps_public_sw/psp/LinuxPSP/DM816x_04_00/04_00_00_10/index_FDS.html
Regards
Sriram