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 BUS_READ_IVAR 9 33.Os 34.Sh NAME 35.Nm BUS_READ_IVAR , 36.Nm BUS_WRITE_IVAR 37.Nd manipulate bus-specific device instance variables 38.Sh SYNOPSIS 39.In sys/param.h 40.In sys/bus.h 41.Ft int 42.Fn BUS_READ_IVAR "device_t dev" "device_t child" "int index" "uintptr_t *result" 43.Ft int 44.Fn BUS_WRITE_IVAR "device_t dev" "device_t child" "int index" "uintptr_t value" 45.Sh DESCRIPTION 46These two methods manage a bus specific set of instance variables of 47a child device. The intention is that each different type of bus 48defines a set of appropriate instance variables (such as ports and 49irqs for ISA bus etc.) 50.Pp 51This information could be given to the child device as a struct but 52that makes it hard for a bus to add or remove variables without 53forcing an edit and recompile for all drivers which may not be 54possible for vendor supplied binary drivers. 55.Sh RETURN VALUES 56Zero is returned on success, otherwise an appropriate error is returned. 57.Sh SEE ALSO 58.Xr device 9 , 59.Xr driver 9 60.Sh AUTHORS 61This man page was written by 62.An Doug Rabson . 63