Comedi Documentation . ... comedi_find_subdevice_by_type -- search for subdevice type . ... int comedi_find_subdevice_by_type (comedi_t * device, int type, unsigned int start_subdevice); . The function comedi_find_subdevice_by_type() tries to locate a subdevice belonging to comedi device device, having type type, starting with the subdevice start_subdevice. ... If it does not locate the requested subdevice, it returns -1 and sets the Comedilib error number to XXX "subdevice not found". ...