ustir —
SigmaTel STIr4200-based USB-IrDA bridge support
ustir* at uhub?
irframe* at ustir?
The ustir driver provides support for USB-IrDA bridges
  based on the SigmaTel STIr4200. The driver is known to work with the following
  adapters:
  - Mars II 740 USB IrDA Adapter
Access to the IrDA device is through the
    irframe(4) driver.
The ustir driver appeared in NetBSD
  1.6.
The STIr4200 cannot notify the driver when it has received data, instead it has
  to be continuously polled. This driver polls (when idle) at a fairly low rate
  of 10 times per second, which means that system performance is not overly
  affected by rapid polling, but latency is fairly high.