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diff --git a/share/man/man9/DEVICE_IDENTIFY.9 b/share/man/man9/DEVICE_IDENTIFY.9 new file mode 100644 index 000000000000..4257407eac8b --- /dev/null +++ b/share/man/man9/DEVICE_IDENTIFY.9 @@ -0,0 +1,94 @@ +.\" -*- nroff -*- +.\" +.\" Copyright (c) 2001 Alexander Langer +.\" +.\" All rights reserved. +.\" +.\" This program is free software. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, +.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd May 13, 2004 +.Dt DEVICE_IDENTIFY 9 +.Os +.Sh NAME +.Nm DEVICE_IDENTIFY +.Nd identify a device, register it +.Sh SYNOPSIS +.In sys/param.h +.In sys/bus.h +.Ft void +.Fn DEVICE_IDENTIFY "driver_t *driver" "device_t parent" +.Sh DESCRIPTION +The identify function for a device is only needed for devices on busses +that cannot identify their children independently, e.g.\& the ISA bus. +It is used to recognize the device (usually done by accessing non-ambiguous +registers in the hardware) and to tell the kernel about it and thus +creating a new device instance. +.Pp +.Xr BUS_ADD_CHILD 9 +is used to register the device as a child of the bus. +The device's resources (such as IRQ and I/O ports) are registered +with the kernel by calling +.Fn bus_set_resource +for each resource (refer to +.Xr bus_set_resource 9 +for more information). +.Pp +Since the device tree and the device driver tree are disjoint, the +.Fn DEVICE_IDENTIFY +routine needs to take this into account. +If you load and unload your device driver that has the identify +routine, the child node has the potential for adding the same node +multiple times unless specific measure are taken to preclude that +possibility. +.Sh EXAMPLES +The following pseudo-code shows an example of a function that +probes for a piece of hardware and registers it and its resource +(an I/O port) with the kernel. +.Bd -literal +void +foo_identify(driver_t *driver, device_t parent) +{ + device_t child; + + retrieve_device_information; + if (devices matches one of your supported devices && + not already in device tree) { + child = BUS_ADD_CHILD(parent, 0, "foo", -1); + bus_set_resource(child, SYS_RES_IOPORT, 0, FOO_IOADDR, 1); + } +} +.Ed +.Sh SEE ALSO +.Xr BUS_ADD_CHILD 9 , +.Xr bus_set_resource 9 , +.Xr device 9 , +.Xr device_add_child 9 , +.Xr DEVICE_ATTACH 9 , +.Xr DEVICE_DETACH 9 , +.Xr DEVICE_PROBE 9 , +.Xr DEVICE_SHUTDOWN 9 +.Sh AUTHORS +This manual page was written by +.An Alexander Langer Aq alex@FreeBSD.org . |