ddi_get_instance(9F)

NAME

     ddi_get_instance - get device instance number

SYNOPSIS

     #include <sys/ddi.h>
     #include <sys/sunddi.h>

     int ddi_get_instance(dev_info_t *dip);

INTERFACE LEVEL

     Solaris DDI specific (Solaris DDI).

PARAMETERS

     dip   Pointer to dev_info structure.

DESCRIPTION

     ddi_get_instance() 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
     different  properties  for  different  device  types  in  an
     implementation 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

     ddi_get_instance() returns the instance number of the device
     corresponding to  dip.

CONTEXT

     ddi_get_instance()can be called from user or interrupt  con-
     text.

SEE ALSO

     path_to_inst(4)

     Writing Device Drivers