xref: /freebsd/share/man/man9/device_get_property.9 (revision 4f5890a0fb086324a657f3cd7ba1abc57274e0db)
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26.\" $FreeBSD$
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28.Dd February 18, 2022
29.Dt DEVICE_GET_PROPERTY 9
30.Os
31.Sh NAME
32.Nm device_get_property ,
33.Nm device_has_property
34.Nd access device specific data
35.Sh SYNOPSIS
36.In sys/param.h
37.In sys/bus.h
38.Ft ssize_t
39.Fn device_get_property "device_t dev" "const char *prop" "void *val" "size_t sz" \
40    "device_property_type_t type"
41.Ft bool
42.Fn device_has_property "device_t dev" "const char *prop"
43.Sh DESCRIPTION
44Access device specific data provided by the parent bus.
45Drivers can use these properties to obtain device capabilities and set
46necessary quirks.
47.Pp
48The underlying property type is specified with the
49.Fa type
50argument.
51Currently the following types are supported:
52.Bl -tag -width ".Dv DEVICE_PROP_BUFFER"
53.It Dv DEVICE_PROP_BUFFER
54The underlying property is a string of bytes.
55.It Dv DEVICE_PROP_ANY
56Wildcard property type.
57.It Dv DEVICE_PROP_UINT32
58The underlying property is an array of unsigned 32 bit integers.
59The
60.Fa sz
61argument shall be a multiple of 4.
62.It Dv DEVICE_PROP_UINT64
63The underlying property is an array of unsigned 64 bit integers.
64The
65.Fa sz
66argument shall be a multiple of 8.
67.El
68.Sh NOTES
69You can pass NULL as pointer to property's value when calling
70.Fn device_get_property
71to obtain its size.
72.Pp
73Currently this interface is implemented by
74.Xr simplebus 4
75and
76.Xr acpi 4 .
77.Sh RETURN VALUES
78.Fn device_get_property
79if successful returns property's size, otherwise returns -1.
80.Pp
81.Fn device_has_property
82returns true if given property was found.
83.Sh SEE ALSO
84.Xr acpi 4 ,
85.Xr simplebus 4 ,
86.Xr device 9
87.Sh AUTHORS
88This manual page was written by
89.An Bartlomiej Grzesik .
90