man pages section 9: DDI and DKI 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

Solaris DDI specific (Solaris 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);
}

Notes

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.

SunOS 5.10 Last Revised 16 Jan 2008