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 int prefixprobe(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) and/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( ) 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

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 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