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

getinfo - get device driver information

#include <sys/ddi.h>
#include <sys/sunddi.h>
int prefixgetinfo(dev_info_t *dip, ddi_info_cmd_t cmd,
     void *arg, void **resultp);

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

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.

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.

getinfo() should return:

DDI_SUCCESS

on success.

DDI_FAILURE

on failure.

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);
}

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

Writing Device Drivers

Non-gld(7D)-based DLPI network streams drivers are encouraged to switch to gld(7D). 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(1M) of the driver or a cfgadm(1M) remove of hardware controlled by the driver are undefined.
January 16, 2008 OmniOS