nulldev(9F) Kernel Functions for Drivers nulldev(9F)NAME
nulldev - zero return function
Architecture independent level 1 (DDI/DKI).
nulldev() returns 0. It is intended to be used in the cb_ops(9S) data structure of a device driver for device entry points that do noth-
nulldev() returns a 0.
nulldev() can be called from any context.
SEE ALSO nodev(9F), cb_ops(9S)
Writing Device Drivers
SunOS 5.10 11 Apr 1991 nulldev(9F)
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probe(9E) Driver Entry Points probe(9E)NAME
probe - determine if a non-self-identifying device is present
static intprefixprobe(dev_info_t *dip);
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.
dip Pointer to the device's dev_info structure.
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.
"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)