man/man9f/ddi_get_instance.9f

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 DDI_GET_INSTANCE 9F "Jan 16, 2006"
 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

The ddi_get_instance() 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 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 device
foo0 has been assigned an instance number of 0 and device
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 ddi_get_instance() function returns the instance number of the device
corresponding to dip.
 CONTEXT

The ddi_get_instance() function can be called from user, interrupt, or
kernel context.
 SEE ALSO

path_to_inst(4)

Writing Device Drivers