1.\" -*- nroff -*-
2.\"
3.\" Copyright (c) 1998 Doug Rabson
4.\"
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7.\" This program is free software.
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| 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: head/share/man/man9/DEVICE_PROBE.9 108257 2002-12-24 13:41:48Z ru $
| 29.\" $FreeBSD: head/share/man/man9/DEVICE_PROBE.9 108260 2002-12-24 16:52:31Z ru $
|
30.\"
31.Dd June 16, 1998
32.Dt DEVICE_PROBE 9
33.Os
34.Sh NAME
35.Nm DEVICE_PROBE
36.Nd probe for device existence
37.Sh SYNOPSIS
38.In sys/param.h
39.In sys/bus.h
40.Ft int
41.Fn DEVICE_PROBE "device_t dev"
42.Sh DESCRIPTION
43This device method should probe to see if the device is present.
44It should return 0 if the device exists,
45.Er ENXIO
46if it cannot be found.
47If some other error happens during the probe (such as a memory
48allocation failure), an appropriate error code should be returned.
49For
50cases where more than one driver matches a device, a priority value can
51be returned. In this case, success codes are values less than or equal
52to zero with the highest value representing the best match. Failure
53codes are represented by positive values and the regular
54.Ux
55error
56codes should be used for the purpose.
57.Pp
58If a driver returns a success code which is less than zero, it must
59not assume that it will be the same driver which is attached to the
60device.
61In particular, it must not assume that any values stored in
62the softc structure will be available for its attach method and any
63resources allocated during probe must be released and re-allocated
64if the attach method is called.
65If a success code of zero is
66returned, the driver can assume that it will be the one attached.
67.Pp
68Devices which implement busses should use this method to probe for
69the existence of devices attached to the bus and add them as
70children.
71If this is combined with the use of
72.Xr bus_generic_attach 9
73the child devices will be automatically probed and attached.
74.Sh RETURN VALUES
75A value equal to or less than zero indicates success, greater than
76zero indicates an error (errno). For values equal to or less than
77zero: zero indicates highest priority, no further probing is done;
| 30.\"
31.Dd June 16, 1998
32.Dt DEVICE_PROBE 9
33.Os
34.Sh NAME
35.Nm DEVICE_PROBE
36.Nd probe for device existence
37.Sh SYNOPSIS
38.In sys/param.h
39.In sys/bus.h
40.Ft int
41.Fn DEVICE_PROBE "device_t dev"
42.Sh DESCRIPTION
43This device method should probe to see if the device is present.
44It should return 0 if the device exists,
45.Er ENXIO
46if it cannot be found.
47If some other error happens during the probe (such as a memory
48allocation failure), an appropriate error code should be returned.
49For
50cases where more than one driver matches a device, a priority value can
51be returned. In this case, success codes are values less than or equal
52to zero with the highest value representing the best match. Failure
53codes are represented by positive values and the regular
54.Ux
55error
56codes should be used for the purpose.
57.Pp
58If a driver returns a success code which is less than zero, it must
59not assume that it will be the same driver which is attached to the
60device.
61In particular, it must not assume that any values stored in
62the softc structure will be available for its attach method and any
63resources allocated during probe must be released and re-allocated
64if the attach method is called.
65If a success code of zero is
66returned, the driver can assume that it will be the one attached.
67.Pp
68Devices which implement busses should use this method to probe for
69the existence of devices attached to the bus and add them as
70children.
71If this is combined with the use of
72.Xr bus_generic_attach 9
73the child devices will be automatically probed and attached.
74.Sh RETURN VALUES
75A value equal to or less than zero indicates success, greater than
76zero indicates an error (errno). For values equal to or less than
77zero: zero indicates highest priority, no further probing is done;
|
78for a value less then zero, the lower the value the lower the
| 78for a value less than zero, the lower the value the lower the
|
79priority, e.g. -100 indicates a lower priority than -50.
80.Sh SEE ALSO
81.Xr device 9 ,
82.Xr DEVICE_DETACH 9 ,
83.Xr DEVICE_IDENTIFY 9 ,
84.Xr DEVICE_SHUTDOWN 9
85.Sh AUTHORS
86This man page was written by
87.An Doug Rabson .
| 79priority, e.g. -100 indicates a lower priority than -50.
80.Sh SEE ALSO
81.Xr device 9 ,
82.Xr DEVICE_DETACH 9 ,
83.Xr DEVICE_IDENTIFY 9 ,
84.Xr DEVICE_SHUTDOWN 9
85.Sh AUTHORS
86This man page was written by
87.An Doug Rabson .
|