GETINFO(9E) Driver Entry Points GETINFO(9E)

NAME

getinfo - get device driver information

SYNOPSIS

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


int prefixgetinfo(dev_info_t *dip, ddi_info_cmd_t cmd,
void *arg, void **resultp);

INTERFACE LEVEL

illumos DDI specific (illumos DDI). This entry point is required for
drivers which export cb_ops(9S) entry points.

ARGUMENTS

dip
Do not use.


cmd
Command argument - valid command values are
DDI_INFO_DEVT2DEVINFO and DDI_INFO_DEVT2INSTANCE.


arg
Command specific argument.


resultp
Pointer to where the requested information is stored.

DESCRIPTION

When cmd is set to DDI_INFO_DEVT2DEVINFO, getinfo() should return the
dev_info_t pointer associated with the dev_t arg. The dev_info_t pointer
should be returned in the field pointed to by resultp.


When cmd is set to DDI_INFO_DEVT2INSTANCE, getinfo() should return the
instance number associated with the dev_t arg. The instance number should
be returned in the field pointed to by resultp.


Drivers which do not export cb_ops(9S) entry points are not required to
provide a getinfo() entry point, and may use nodev(9F) in the
devo_getinfo field of the dev_ops(9S) structure. A SCSI HBA driver is an
example of a driver which is not required to provide cb_ops(9S) entry
points.

RETURN VALUES

getinfo() should return:

DDI_SUCCESS
on success.


DDI_FAILURE
on failure.

EXAMPLES

Example 1 getinfo() implementation

/*ARGSUSED*/
static int
rd_getinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
void **resultp)
{
/*
* Note that in this simple example
* the minor number is the instance
* number.
*/

devstate_t *sp;
int error = DDI_FAILURE;
switch (infocmd) {
case DDI_INFO_DEVT2DEVINFO:
if ((sp = ddi_get_soft_state(statep,
getminor((dev_t) arg))) != NULL) {
*resultp = sp->devi;
error = DDI_SUCCESS;
} else
*result = NULL;
break;

case DDI_INFO_DEVT2INSTANCE:
*resultp = (void *) (uintptr_t) getminor((dev_t) arg);
error = DDI_SUCCESS;
break;
}

return (error);
}

SEE ALSO

ddi_no_info(9F), nodev(9F), cb_ops(9S), dev_ops(9S)


Writing Device Drivers

NOTES

Non-gld(4D)-based DLPI network streams drivers are encouraged to switch
to gld(4D). Failing this, a driver that creates DLPI style-2 minor
nodes must specify CLONE_DEV for its style-2 ddi_create_minor_node(9F)
nodes and use qassociate(9F). A driver that supports both style-1 and
style-2 minor nodes should return DDI_FAILURE for DDI_INFO_DEVT2INSTANCE
and DDI_INFO_DEVT2DEVINFO getinfo() calls to style-2 minor nodes. (The
correct association is already established by qassociate(9F)). A driver
that only supports style-2 minor nodes can use ddi_no_info(9F) for its
getinfo() implementation. For drivers that do not follow these rules, the
results of a modunload(8) of the driver or a cfgadm(8) remove of hardware
controlled by the driver are undefined.

January 16, 2008 GETINFO(9E)