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

cmd

arg

resultp

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

DDI_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.