xref: /freebsd/share/man/man9/device_get_state.9 (revision a0ee8cc6)
1.\" -*- nroff -*-
2.\"
3.\" Copyright (c) 1998 Doug Rabson
4.\"
5.\" All rights reserved.
6.\"
7.\" This program is free software.
8.\"
9.\" Redistribution and use in source and binary forms, with or without
10.\" modification, are permitted provided that the following conditions
11.\" are met:
12.\" 1. Redistributions of source code must retain the above copyright
13.\"    notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\"    notice, this list of conditions and the following disclaimer in the
16.\"    documentation and/or other materials provided with the distribution.
17.\"
18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28.\"
29.\" $FreeBSD$
30.\"
31.Dd June 16, 1998
32.Dt DEVICE_GET_STATE 9
33.Os
34.Sh NAME
35.Nm device_get_state ,
36.Nm device_busy ,
37.Nm device_unbusy ,
38.Nm device_is_alive ,
39.Nm device_is_attached
40.Nd manipulate device state
41.Sh SYNOPSIS
42.In sys/param.h
43.In sys/bus.h
44.Ft device_state_t
45.Fn device_get_state "device_t dev"
46.Ft void
47.Fn device_busy "device_t dev"
48.Ft void
49.Fn device_unbusy "device_t dev"
50.Ft int
51.Fn device_is_alive "device_t dev"
52.Ft int
53.Fn device_is_attached "device_t dev"
54.Sh DESCRIPTION
55The current state of a device is accessed by calling
56.Fn device_get_state
57which returns
58.Dv DS_NOTPRESENT ,
59.Dv DS_ALIVE ,
60.Dv DS_ATTACHED
61or
62.Dv DS_BUSY
63(described in
64.Xr device 9 ) .
65To test see if a device was successfully probed, call
66.Fn device_is_alive
67which simply returns if the state is greater or equal to
68.Dv DS_ALIVE .
69To test see if a device was successfully attached, call
70.Fn device_is_attached
71which simply returns if the state is greater or equal to
72.Dv DS_ATTACHED .
73.Pp
74Each device has a busy count which is incremented when
75.Fn device_busy
76is called and decremented when
77.Fn device_unbusy
78is called.
79Both routines return an error if the device state is less than
80.Dv DS_ATTACHED .
81.Pp
82When
83.Fn device_busy
84is called on a device in the
85.Dv DS_ATTACHED
86state, the device changes to the
87.Dv DS_BUSY
88state.
89When
90.Fn device_unbusy
91is called and after decrementing, the busy count for the device is
92zero, the device changes to the
93.Dv DS_ATTACHED
94state.
95.Sh SEE ALSO
96.Xr device 9
97.Sh AUTHORS
98This manual page was written by
99.An Doug Rabson .
100