Device (dev_t) Functions
The device functions are:
- ddi_create_minor_node()
- Create a minor node for a device 
- ddi_getiminor()
- Get kernel internal minor number from an external dev_t 
- ddi_remove_minor_node()
- Remove a minor mode for a device 
- getmajor()
- Get major device number 
- getminor()
- Get minor device number 
- makedevice()
- Make device number from major and minor numbers