xref: /freebsd/share/man/man9/BUS_GET_PROPERTY.9 (revision 2008043f386721d58158e37e0d7e50df8095942d)
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26.Dd February 18, 2022
27.Dt BUS_GET_PROPERTY 9
28.Os
29.Sh NAME
30.Nm BUS_GET_PROPERTY
31.Nd get child's specific property
32.Sh SYNOPSIS
33.In sys/param.h
34.In sys/bus.h
35.Ft ssize_t
36.Fn BUS_GET_PROPERTY "device_t dev" "device_t child" "const char *propname" \
37    "void *propvalue" "size_t size" "device_property_type_t type"
38.Sh DESCRIPTION
39The
40.Fn BUS_GET_PROPERTY
41method
42is called from driver code which wants to access a child's specific data stored
43on the bus.
44A property has a name and an associated value.
45Implementation shall copy to
46.Fa propvalue
47at most
48.Fa size
49bytes.
50.Pp
51.Fn BUS_GET_PROPERTY
52supports different property types specified via the
53.Fa type
54argument.
55The
56.Fa size
57is guaranteed to be a multiple of the underlying property type.
58If a type is not supported,
59.Fn BUS_GET_PROPERTY
60shall return -1.
61.Sh NOTES
62If
63.Fa propvalue
64is NULL or
65.Fa size
66is zero, the implementation shall return only the size of the property.
67.Sh RETURN VALUES
68The property size if successful, otherwise -1.
69.Sh SEE ALSO
70.Xr device 9 ,
71.Xr device_get_property 9
72.Sh AUTHORS
73This manual page was written by
74.An Bartlomiej Grzesik .
75