nullop             81 bsp/drv/include/ddi.h int	 nullop(void);
nullop             69 include/sys/device.h #define	no_open		((devop_open_t)nullop)
nullop             70 include/sys/device.h #define	no_close	((devop_close_t)nullop)
nullop             74 include/sys/device.h #define	no_devctl	((devop_devctl_t)nullop)