xref: /freebsd/share/man/man9/device_get_state.9 (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
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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