xref: /titanic_51/usr/src/man/man9f/ddi_get_instance.9f (revision 21ad40f5447a73ac8a7ed2b9b66dd73ff1b088c1)
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Copyright (c) 2006 Sun Microsystems, Inc.
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When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
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