device property: Introduce fwnode_property_get_reference_args

The new fwnode_property_get_reference_args() interface amends the fwnode
property API with the functionality of both of_parse_phandle_with_args()
and __acpi_node_get_property_reference().

The semantics is slightly different: the cells property is ignored on ACPI
as the number of arguments can be explicitly obtained from the firmware
interface.

Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
diff --git a/include/linux/property.h b/include/linux/property.h
index edff3f8..6bebee1 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -73,6 +73,10 @@ int fwnode_property_read_string(const struct fwnode_handle *fwnode,
 				const char *propname, const char **val);
 int fwnode_property_match_string(const struct fwnode_handle *fwnode,
 				 const char *propname, const char *string);
+int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
+				       const char *prop, const char *nargs_prop,
+				       unsigned int nargs, unsigned int index,
+				       struct fwnode_reference_args *args);
 
 struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode);
 struct fwnode_handle *fwnode_get_next_parent(