freebsd-nq/share/man/man9/device_get_property.9
Bartlomiej Grzesik 3f9a00e3b5 device: add device_get_property and device_has_property
Generialize bus specific property accessors. Those functions allow driver code
to access device specific information.

Currently there is only support for FDT and ACPI buses.

Reviewed by: manu, mw
Sponsored by: Semihalf
Differential revision: https://reviews.freebsd.org/D31597
2021-09-20 17:17:57 +02:00

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.Dd August 19, 2021
.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"
.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.
.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 .