1.\" Copyright (c) 1998 Doug Rabson 2.\" 3.\" All rights reserved. 4.\" 5.\" This program is free software. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" 27.\" $FreeBSD: src/share/man/man9/device_get_state.9,v 1.3.2.5 2001/12/17 11:30:18 ru Exp $ 28.\" $DragonFly: src/share/man/man9/device_get_state.9,v 1.3 2004/06/01 11:36:53 hmp Exp $ 29.\" 30.Dd June 16, 1998 31.Dt DEVICE_GET_STATE 9 32.Os 33.Sh NAME 34.Nm device_get_state , 35.Nm device_busy , 36.Nm device_unbusy , 37.Nm device_is_alive 38.Nd manipulate device state 39.Sh SYNOPSIS 40.In sys/param.h 41.In sys/bus.h 42.Ft device_state_t 43.Fn device_get_state "device_t dev" 44.Ft void 45.Fn device_busy "device_t dev" 46.Ft void 47.Fn device_unbusy "device_t dev" 48.Ft int 49.Fn device_is_alive "device_t dev" 50.Sh DESCRIPTION 51The current state of a device is accessed by calling 52.Xr device_get_state 9 53which returns 54.Dv DS_NOTPRESENT , 55.Dv DS_ALIVE , 56.Dv DS_ATTACHED 57or 58.Dv DS_BUSY 59(described in 60.Xr device 9 ) . 61To test see if a device was successfully probed, call 62.Xr device_is_alive 9 63which simply returns if the state is greater or equal to 64.Dv DS_ALIVE . 65.Pp 66Each device has a busy count which is incremented when 67.Xr device_busy 9 68is called and decremented when 69.Xr device_unbusy 9 70is called. Both routines return an error if the device state is less 71than 72.Dv DS_ATTACHED . 73.Pp 74When 75.Xr device_busy 9 76is called on a device in the 77.Dv DS_ATTACHED 78state, the device changes to the 79.Dv DS_BUSY 80state. 81When 82.Xr device_unbusy 9 83is called and after decrementing, the busy count for the device is 84zero, the device changes to the 85.Dv DS_ATTACHED 86state. 87.Sh SEE ALSO 88.Xr device 9 89.Sh AUTHORS 90This man page was written by 91.An Doug Rabson . 92