ssio —
National Semiconductor PC87560 Legacy IO
The ssio driver provides support for the National
  Semiconductor PC87560 Legacy IO chip on systems with PA-8500 and later 64-bit
  CPUs. It configures the Programmable Interrupt Controllers integrated on the
  chip to route interrupts for the integrated
  ohci(4) USB controller (which
  appears as a separate PCI device).
NetBSD provides support for the following
    devices:
  - com(4)
- serial communications interface
- lpt(4)
- parallel port driver
 
The ssio driver appeared in OpenBSD
  4.2. It was ported to NetBSD 6.0 by Nick
  Hudson.