xref: /freebsd/share/man/man9/device_get_property.9 (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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26.Dd September 29, 2022
27.Dt DEVICE_GET_PROPERTY 9
28.Os
29.Sh NAME
30.Nm device_get_property ,
31.Nm device_has_property
32.Nd access device specific data
33.Sh SYNOPSIS
34.In sys/param.h
35.In sys/bus.h
36.Ft ssize_t
37.Fn device_get_property "device_t dev" "const char *prop" "void *val" "size_t sz" \
38    "device_property_type_t type"
39.Ft bool
40.Fn device_has_property "device_t dev" "const char *prop"
41.Sh DESCRIPTION
42Access device specific data provided by the parent bus.
43Drivers can use these properties to obtain device capabilities and set
44necessary quirks.
45.Pp
46The underlying property type is specified with the
47.Fa type
48argument.
49Currently the following types are supported:
50.Bl -tag -width ".Dv DEVICE_PROP_BUFFER"
51.It Dv DEVICE_PROP_BUFFER
52The underlying property is a string of bytes.
53.It Dv DEVICE_PROP_ANY
54Wildcard property type.
55.It Dv DEVICE_PROP_HANDLE
56Following a reference the underlying property is a handle of the
57respective bus.
58.It Dv DEVICE_PROP_UINT32
59The underlying property is an array of unsigned 32 bit integers.
60The
61.Fa sz
62argument shall be a multiple of 4.
63.It Dv DEVICE_PROP_UINT64
64The underlying property is an array of unsigned 64 bit integers.
65The
66.Fa sz
67argument shall be a multiple of 8.
68.El
69.Sh NOTES
70You can pass NULL as pointer to property's value when calling
71.Fn device_get_property
72to obtain its size.
73.Pp
74Currently this interface is implemented by
75.Xr simplebus 4
76and
77.Xr acpi 4 .
78.Sh RETURN VALUES
79.Fn device_get_property
80if successful returns property's size, otherwise returns -1.
81.Pp
82.Fn device_has_property
83returns true if given property was found.
84.Sh SEE ALSO
85.Xr acpi 4 ,
86.Xr simplebus 4 ,
87.Xr device 9
88.Sh AUTHORS
89This manual page was written by
90.An Bartlomiej Grzesik .
91