device_get_property9
Access device specific data
Usage
#include <sys/param.h>
#include <sys/bus.h>
ssize_t
device_get_property(device_t dev, const char *prop, void *val, size_t sz, device_property_type_t type);
bool
device_has_property(device_t dev, const char *prop);
Overview
Access device specific data provided by the parent bus. Drivers can use these properties to obtain device capabilities and set necessary quirks.
The underlying property type is specified with the type argument. Currently the following types are supported:
- DEVICE_PROP_BUFFER
-
The underlying property is a string of bytes.
- DEVICE_PROP_ANY
-
Wildcard property type.
- DEVICE_PROP_HANDLE
-
Following a reference the underlying property is a handle of the respective bus.
- DEVICE_PROP_UINT32
-
The underlying property is an array of unsigned 32 bit integers. The sz argument shall be a multiple of 4.
- DEVICE_PROP_UINT64
-
The underlying property is an array of unsigned 64 bit integers. The sz argument shall be a multiple of 8.
Notes
You can pass NULL as pointer to property's value when calling device_get_property() to obtain its size.
Currently this interface is implemented by simplebus(4) and acpi(4).
Return values
device_get_property() if successful returns property's size, otherwise returns -1.
device_has_property() returns true if given property was found.
Releases
13 releases since FreeBSD 13.2-RELEASE; the text changed 1 time.