Driver Entry Points                                     probe(9E)

NAME
     probe  -  determine  if  a  non-self-identifying  device  is
     present

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

     static intprefixprobe(dev_info_t *dip);

INTERFACE LEVEL
     Solaris DDI specific (Solaris  DDI).  This  entry  point  is
     required  for  non-self-identifying devices.  You must write
     it  for  such   devices.   For   self-identifying   devices,
     nulldev(9F) should be specified in the dev_ops(9S) structure
     if a probe routine is not necessary.

ARGUMENTS
     dip   Pointer to the device's  dev_info structure.

DESCRIPTION
     probe() determines whether the device corresponding  to  dip
     actually  exists  and  is  a  valid  device for this driver.
     probe() is called after identify(9E) and  before  attach(9E)
     for  a  given  dip. For example, the probe() routine can map
     the device registers using ddi_map_regs(9F) then attempt  to
     access  the  hardware using ddi_peek(9F) or ddi_poke(9F) and
     determine if the device exists.  Then the  device  registers
     should be unmapped using ddi_unmap_regs(9F).

     probe() should only probe the device. It should  not  create
     or  change any software state.  Device initialization should
     be done in attach(9E).

     For a self-identifying  device,  this  entry  point  is  not
     necessary.  However,  if  a  device  exists  in  both  self-
     identifying and non-self-identifying forms, a  probe()  rou-
     tine    can    be   provided   to   simplify   the   driver.
     ddi_dev_is_sid(9F) can then be  used  to  determine  whether
     probe()  needs to do any work. See ddi_dev_is_sid(9F) for an
     example.

RETURN VALUES
     DDI_PROBE_SUCCESS
           If the probe was successful.

     DDI_PROBE_FAILURE
           If the probe failed.

     DDI_PROBE_DONTCARE
           If the probe was unsuccessful, yet  attach(9E)  should

SunOS 5.8           Last change: 18 Nov 1992                    1

Driver Entry Points                                     probe(9E)

           still be called.

     DDI_PROBE_PARTIAL
           If the instance is not present now, but may be present
           in the future.

SEE ALSO
     attach(9E),        identify(9E),         ddi_dev_is_sid(9F),
     ddi_map_regs(9F),  ddi_peek(9F),  ddi_poke(9F), nulldev(9F),
     dev_ops(9S)

     Writing Device Drivers

SunOS 5.8           Last change: 18 Nov 1992                    2