xref: /freebsd/sys/kern/device_if.m (revision 6990ffd8a95caaba6858ad44ff1b3157d1efba8f) 
1#
2# Copyright (c) 1998 Doug Rabson
3# All rights reserved.
4#
5# Redistribution and use in source and binary forms, with or without
6# modification, are permitted provided that the following conditions
7# are met:
8# 1. Redistributions of source code must retain the above copyright
9#    notice, this list of conditions and the following disclaimer.
10# 2. Redistributions in binary form must reproduce the above copyright
11#    notice, this list of conditions and the following disclaimer in the
12#    documentation and/or other materials provided with the distribution.
13#
14# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24# SUCH DAMAGE.
25#
26# $FreeBSD$
27#
28
29#include <sys/bus.h>
30
31INTERFACE device;
32
33#
34# Default implementations of some methods.
35#
36CODE {
37	static int null_shutdown(device_t dev)
38	{
39	    return 0;
40	}
41
42	static int null_suspend(device_t dev)
43	{
44	    return 0;
45	}
46
47	static int null_resume(device_t dev)
48	{
49	    return 0;
50	}
51};
52
53#
54# Probe to see if the device is present.  Return 0 if the device exists,
55# ENXIO if it cannot be found. If some other error happens during the
56# probe (such as a memory allocation failure), an appropriate error code
57# should be returned. For cases where more than one driver matches a
58# device, a priority value can be returned.  In this case, success codes
59# are values less than or equal to zero with the highest value representing
60# the best match.  Failure codes are represented by positive values and
61# the regular unix error codes should be used for the purpose.
62
63# If a driver returns a success code which is less than zero, it must
64# not assume that it will be the same driver which is attached to the
65# device. In particular, it must not assume that any values stored in
66# the softc structure will be available for its attach method and any
67# resources allocated during probe must be released and re-allocated
68# if the attach method is called.  If a success code of zero is
69# returned, the driver can assume that it will be the one attached.
70#
71# Devices which implement busses should use this method to probe for
72# the existence of devices attached to the bus and add them as
73# children.  If this is combined with the use of bus_generic_attach,
74# the child devices will be automatically probed and attached.
75#
76METHOD int probe {
77	device_t dev;
78};
79
80#
81# Called by a parent bus to add new devices to the bus.
82#
83STATICMETHOD void identify {
84	driver_t *driver;
85	device_t parent;
86};
87
88#
89# Attach a device to the system.  The probe method will have been
90# called and will have indicated that the device exists.  This routine
91# should initialise the hardware and allocate other system resources
92# (such as devfs entries).  Returns 0 on success.
93#
94METHOD int attach {
95	device_t dev;
96};
97
98#
99# Detach a device.  This can be called if the user is replacing the
100# driver software or if a device is about to be physically removed
101# from the system (e.g. for pccard devices).  Returns 0 on success.
102#
103METHOD int detach {
104	device_t dev;
105};
106
107#
108# This is called during system shutdown to allow the driver to put the
109# hardware into a consistent state for rebooting the computer.
110#
111METHOD int shutdown {
112	device_t dev;
113} DEFAULT null_shutdown;
114
115#
116# This is called by the power-management subsystem when a suspend has been
117# requested by the user or by some automatic mechanism.  This gives
118# drivers a chance to veto the suspend or save their configuration before
119# power is removed.
120#
121METHOD int suspend {
122	device_t dev;
123} DEFAULT null_suspend;
124
125METHOD int resume {
126	device_t dev;
127} DEFAULT null_resume;
128