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diff --git a/static/freebsd/man9/DEVICE_IDENTIFY.9 b/static/freebsd/man9/DEVICE_IDENTIFY.9 new file mode 100644 index 00000000..564699b5 --- /dev/null +++ b/static/freebsd/man9/DEVICE_IDENTIFY.9 @@ -0,0 +1,91 @@ +.\" -*- 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. +.\" +.Dd February 5, 2025 +.Dt DEVICE_IDENTIFY 9 +.Os +.Sh NAME +.Nm DEVICE_IDENTIFY +.Nd identify new child devices and register them +.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 method of a device driver is used to add devices that cannot be +enumerated by the standard method on a bus device. +Devices can be enumerated in various ways including accessing non-ambiguous +device registers and parsing firmware tables. +Software-only pseudo devices are also often enumerated via identify methods. +.Pp +For each newly identified device, +a new device instance should be created by invoking the +.Xr BUS_ADD_CHILD 9 +method. +If the identify method is able to discover other properties about the new +device, those should also be set. +For example, device resources should be added to the device by calling +.Xr bus_set_resource 9 +for each resource. +.Pp +An identify method might be invoked multiple times. +If a device driver is unloaded and loaded, +the identify method will be called a second time after being reloaded. +As a result, the identify method should avoid duplicate devices. +Devices added by identify methods typically use a fixed device name +in which case +.Xr device_find_child 9 +can be used to detect existing devices. +.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 parent bus device. +.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 && + device_find_child(parent, "foo", DEVICE_UNIT_ANY) == NULL) { + child = BUS_ADD_CHILD(parent, 0, "foo", DEVICE_UNIT_ANY); + bus_set_resource(child, SYS_RES_IOPORT, 0, FOO_IOADDR, 1); + } +} +.Ed +.Sh SEE ALSO +.Xr BUS_ADD_CHILD 9 , +.Xr bus_identify_children 9 , +.Xr bus_set_resource 9 , +.Xr device 9 , +.Xr device_find_child 9 +.Sh AUTHORS +This manual page was written by +.An Alexander Langer Aq Mt alex@FreeBSD.org . |