Kernel Functions for Drivers                 ddigetinstance(9F)



NAME
     ddigetinstance - get device instance number

SYNOPSIS
     #include 
     #include 



     int ddigetinstance(devinfot *dip);


INTERFACE LEVEL
     Solaris DI specific (Solaris DI).

PARAMETERS
     dip    Pointer to devinfo structure.


DESCRIPTION
     The ddigetinstance() function returns the instance  number
     of the device corresponding to dip.


     The system assigns  an  instance  number  to  every  device.
     Instance  numbers   for  devices attached to the same driver
     are unique.  This provides a way  for  the  system  and  the
     driver  to uniquely identify one or more devices of the same
     type. The instance number is derived by the system from dif-
     ferent properties for different device types in an implemen-
     tation specific manner.


     Once an instance number has been assigned to  a  device,  it
     will  remain  the  same  even  across  reconfigurations  and
     reboots. Therefore, instance numbers seen by  a  driver  may
     not  appear to be in consecutive order. For example, if dev-
     ice foo0 has been assigned an instance number of 0 and  dev-
     ice  foo1 has been assigned an instance number of 1, if foo0
     is  removed,  foo1  will  continue  to  be  associated  with
     instance  number  1 (even though foo1 is now the only device
     of its type on the system).

RETURN VALUES
     The ddigetinstance() function returns the instance  number
     of the device corresponding to dip.

CONTEXT
     The ddigetinstance() function can  be  called  from  user,
     interrupt, or kernel context.





SunOS 5.11          Last change: 16 Jan 2006                    1






Kernel Functions for Drivers                 ddigetinstance(9F)



SEE ALSO
     pathtoinst(4)


     Writing Device Drivers


















































SunOS 5.11          Last change: 16 Jan 2006                    2