xref: /freebsd/share/man/man9/DEVICE_IDENTIFY.9 (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
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29.\" $FreeBSD$
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31.Dd March 10, 2001
32.Dt DEVICE_IDENTIFY 9
33.Os
34.Sh NAME
35.Nm DEVICE_IDENTIFY
36.Nd identify a device, register it
37.Sh SYNOPSIS
38.Fd #include <sys/param.h>
39.Fd #include <sys/bus.h>
40.Ft void
41.Fn DEVICE_IDENTIFY "driver_t *driver" "device_t parent"
42.Sh DESCRIPTION
43.Pp
44The identify function for a device is only needed for devices on busses
45that cannot identify their childs independently, e.g. the ISA bus.
46It is used to recognize the device (usually done by accessing non-ambigous
47registers in the hardware) and to tell the kernel about it and thus
48creating a new device instance.
49.Pp
50.Xr BUS_ADD_CHILD 9
51is used to register the device as a child of the bus.
52The device's resources (such as IRQ and I/O ports) are registered
53with the kernel by calling
54.Fn bus_set_resource
55for each resource (refer to
56.Xr bus_set_resource 9
57for more information).
58.Sh EXAMPLES
59.Pp
60The following pseudo-code shows an example of a function that
61probes for a piece of hardware and registers it and its resource
62(an I/O port) with the kernel.
63It also sets the description of the device.
64.Bd -literal
65void
66foo_identify(driver_t *driver, device_t parent)
67{
68	device_t child;
69
70	retrieve_device_information;
71	if (devices matches one of your supported devices) {
72		child = BUS_ADD_CHILD(parent, 0, "foo", -1);
73		device_set_desc_copy(child, "foo chip ver.123");
74		device_set_driver(child, driver);
75		bus_set_resource(child, SYS_RES_IOPORT, 0, FOO_IOADDR, 1);
76	}
77}
78.Ed
79.Sh RETURN VALUES
80.Pp
81Zero is returned on success,
82otherwise an appropriate error is returned (see
83.Xr errno 2 ) .
84.Sh SEE ALSO
85.Xr device 9 ,
86.Xr BUS_ADD_CHILD 9 ,
87.Xr device_add_child 9 ,
88.Xr device_set_desc_copy 9 ,
89.Xr device_set_driver 9 ,
90.Xr DEVICE_ATTACH 9 ,
91.Xr DEVICE_DETACH 9 ,
92.Xr DEVICE_PROBE 9 ,
93.Xr DEVICE_SHUTDOWN 9 ,
94.Xr bus_set_resource 9
95.Sh AUTHORS
96This man page was written by
97.An Alexander Langer Aq alex@FreeBSD.org .
98