[PATCH 1/1] of: Make return types of to_of_node and of_fwnode_handle macros consistent

[Sakari Ailus]

to_of_node() macro checks whether the fwnode_handle passed to it is not an
OF node, and if so, returns NULL in order to be NULL-safe. Otherwise it
returns the pointer to the OF node which the fwnode_handle contains.

The problem with returning NULL is that its type was void *, which
sometimes matters. Explicitly return struct device_node * instead.

Make a similar change to of_fwnode_handle() as well.

Fixes: d20dc1493db4 ("of: Support const and non-const use for to_of_node()")
Fixes: debd3a3b27c7 ("of: Make of_fwnode_handle() safer")
Signed-off-by: Sakari Ailus <sakari.ailus at linux.intel.com>
---
Hi Mauro,

Could you check whether this addresses the smatch issue with the xilinx
driver?

Thanks.

 include/linux/of.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/of.h b/include/linux/of.h
index b240ed69dc96..0651231c115e 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -161,7 +161,7 @@ static inline bool is_of_node(const struct fwnode_handle *fwnode)
 		is_of_node(__to_of_node_fwnode) ?			\
 			container_of(__to_of_node_fwnode,		\
 				     struct device_node, fwnode) :	\
-			NULL;						\
+			(struct device_node *)NULL;			\
 	})
 
 #define of_fwnode_handle(node)						\
@@ -169,7 +169,8 @@ static inline bool is_of_node(const struct fwnode_handle *fwnode)
 		typeof(node) __of_fwnode_handle_node = (node);		\
 									\
 		__of_fwnode_handle_node ?				\
-			&__of_fwnode_handle_node->fwnode : NULL;	\
+			&__of_fwnode_handle_node->fwnode :		\
+			(struct fwnode_handle *)NULL;			\
 	})
 
 static inline bool of_have_populated_dt(void)
-- 
2.11.0