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.Dd September 29, 2022
.Dt DEVICE_GET_PROPERTY 9
.Os
.Sh NAME
.Nm device_get_property ,
.Nm device_has_property
.Nd access device specific data
.Sh SYNOPSIS
.In sys/param.h
.In sys/bus.h
.Ft ssize_t
.Fn device_get_property "device_t dev" "const char *prop" "void *val" "size_t sz" \
    "device_property_type_t type"
.Ft bool
.Fn device_has_property "device_t dev" "const char *prop"
.Sh DESCRIPTION
Access device specific data provided by the parent bus.
Drivers can use these properties to obtain device capabilities and set
necessary quirks.
.Pp
The underlying property type is specified with the
.Fa type
argument.
Currently the following types are supported:
.Bl -tag -width ".Dv DEVICE_PROP_BUFFER"
.It Dv DEVICE_PROP_BUFFER
The underlying property is a string of bytes.
.It Dv DEVICE_PROP_ANY
Wildcard property type.
.It Dv DEVICE_PROP_HANDLE
Following a reference the underlying property is a handle of the
respective bus.
.It Dv DEVICE_PROP_UINT32
The underlying property is an array of unsigned 32 bit integers.
The
.Fa sz
argument shall be a multiple of 4.
.It Dv DEVICE_PROP_UINT64
The underlying property is an array of unsigned 64 bit integers.
The
.Fa sz
argument shall be a multiple of 8.
.El
.Sh NOTES
You can pass NULL as pointer to property's value when calling
.Fn device_get_property
to obtain its size.
.Pp
Currently this interface is implemented by
.Xr simplebus 4
and
.Xr acpi 4 .
.Sh RETURN VALUES
.Fn device_get_property
if successful returns property's size, otherwise returns -1.
.Pp
.Fn device_has_property
returns true if given property was found.
.Sh SEE ALSO
.Xr acpi 4 ,
.Xr simplebus 4 ,
.Xr device 9
.Sh AUTHORS
This manual page was written by
.An Bartlomiej Grzesik .