The function comedi_dio_config() configures individual channels in a digital I/O subdevice to be either input or output, depending on the value of parameter direction. Valid directions are COMEDI_INPUT or COMEDI_OUTPUT.
Depending on the capabilities of the hardware device, multiple channels may be grouped together to determine direction. In this case, a single call to comedi_dio_config() for any channel in the group will affect the entire group.
If sucessful, 0 is returned, otherwise -1.