/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* nulldriver - null device driver
*
* The nulldriver is used to associate a solaris driver with a specific
* device without enabling external device access.
*
* The driver can be used to:
*
* o Prevent external access to specific devices/hardware by associating a
* high-precedence 'compatible' binding, including a path-oriented alias,
* with nulldriver.
*
* o Enable a nexus bus_config implementation to perform dynamic child
* discovery by creating a child 'probe' devinfo node, bound to
* nulldriver, at the specific child @unit-addresses associated with
* discovery. With a nulldriver bound 'probe' node, nexus driver
* bus_config discovery code can use the same devinfo node oriented
* transport services for both discovery and normal-operation: which
* is a significant simplification. While nulldriver prevents external
* device access, a nexus driver can still internally use the transport
* services.
*
* A scsi(4) example of this type of use is SCSA enumeration services
* issuing a scsi REPORT_LUN command to a lun-0 'probe' node bound to
* nulldriver in order to discover all luns supported by a target.
*/
#include <sys/modctl.h>
#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/cmn_err.h>
static int nulldriver_getinfo(dev_info_t *, ddi_info_cmd_t, void *, void **);
static int nulldriver_probe(dev_info_t *);
static int nulldriver_attach(dev_info_t *, ddi_attach_cmd_t);
static int nulldriver_detach(dev_info_t *, ddi_detach_cmd_t);
static struct cb_ops nulldriver_cb_ops = {
nodev, /* open */
nodev, /* close */
nodev, /* strategy */
nodev, /* print */
nodev, /* dump */
nodev, /* read */
nodev, /* write */
nodev, /* ioctl */
nodev, /* devmap */
nodev, /* mmap */
nodev, /* segmap */
nochpoll, /* poll */
ddi_prop_op, /* cb_prop_op */
0, /* streamtab */
D_MP | D_NEW | D_HOTPLUG /* Driver compatibility flag */
};
static struct dev_ops nulldriver_dev_ops = {
DEVO_REV, /* devo_rev, */
0, /* refcnt */
nulldriver_getinfo, /* info */
nodev, /* identify */
nulldriver_probe, /* probe */
nulldriver_attach, /* attach */
nulldriver_detach, /* detach */
nodev, /* reset */
&nulldriver_cb_ops, /* driver operations */
(struct bus_ops *)0, /* bus operations */
NULL, /* power */
ddi_quiesce_not_needed, /* quiesce */
};
static struct modldrv modldrv = {
&mod_driverops, "nulldriver 1.1", &nulldriver_dev_ops
};
static struct modlinkage modlinkage = {
MODREV_1, &modldrv, NULL
};
int
_init(void)
{
return (mod_install(&modlinkage));
}
int
_fini(void)
{
return (mod_remove(&modlinkage));
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
/*ARGSUSED*/
static int
nulldriver_getinfo(dev_info_t *dip, ddi_info_cmd_t infocmd,
void *arg, void **result)
{
return (DDI_FAILURE);
}
/*ARGSUSED*/
static int
nulldriver_probe(dev_info_t *dip)
{
/*
* We want to succeed probe so that the node gets assigned a unit
* address "@addr".
*/
if (ddi_dev_is_sid(dip) == DDI_SUCCESS)
return (DDI_PROBE_DONTCARE);
return (DDI_PROBE_DONTCARE);
}
/*
* nulldriver_attach()
* attach(9e) entrypoint.
*/
/* ARGSUSED */
static int
nulldriver_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
switch (cmd) {
case DDI_ATTACH:
case DDI_RESUME:
return (DDI_SUCCESS);
case DDI_PM_RESUME:
default:
return (DDI_FAILURE);
}
}
/*
* nulldriver_detach()
* detach(9E) entrypoint
*/
/* ARGSUSED */
static int
nulldriver_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
switch (cmd) {
case DDI_DETACH:
case DDI_SUSPEND:
return (DDI_SUCCESS);
case DDI_PM_SUSPEND:
default:
return (DDI_FAILURE);
}
}