probe(9E)							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).

       To  probe a device that was left powered off after the last detach(), it might be necessary to power it up. If so, the driver must power up
       the device by accessing device registers directly. pm_raise_power(9F) will be not be available until  attach(9E).   The	framework  ensures
       that  the ancestors of the node being probed and all relevant platform-specific power management hardware is at full power at the time that
       probe() is called.

       probe() should only probe the device. It should not change any software state and should not create any software state.	Device initializa-
       tion 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-iden-
       tifying forms, a  probe() routine 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

       "small and bold">DDI_PROIf_theCprobe was successful.

       DDI_PROBE_FAILURE       If the probe failed.

       DDI_PROBE_DONTCARE      If the probe was unsuccessful, yet attach(9E) should 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 5.10							    18 Nov 1992 							 probe(9E)