[PATCH 01/20] of: add of_property_for_each_u32_new()

[Luca Ceresoli]

The of_property_for_each_u32() macro needs five parameters, two of which
are often only used internally by the macro itself (in the for()
clause).

Now that the kernel uses C11 to build these two parameters can be avoided
by declaring them internally. Add a new macro for that, which is meant to
eventually replace the existing one.

Since two variables cannot be declared in the for clause, declare one
struct that contain the two variables we actually need. Since the variables
inside this struct are not meant to be used by users of this macro, give
the struct instance the noticeable name "_it" so it is visible during code
reviews, helping to avoid new code to use it directly.

Signed-off-by: Luca Ceresoli <luca.ceresoli at bootlin.com>
---
 .clang-format      |  1 +
 include/linux/of.h | 11 ++++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/.clang-format b/.clang-format
index ccc9b93972a9..db25cde2651a 100644
--- a/.clang-format
+++ b/.clang-format
@@ -570,6 +570,7 @@ ForEachMacros:
   - 'of_for_each_phandle'
   - 'of_property_for_each_string'
   - 'of_property_for_each_u32'
+  - 'of_property_for_each_u32_new'
   - 'pci_bus_for_each_resource'
   - 'pci_dev_for_each_resource'
   - 'pcl_for_each_chunk'
diff --git a/include/linux/of.h b/include/linux/of.h
index a0bedd038a05..756847539384 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -430,11 +430,9 @@ extern int of_detach_node(struct device_node *);
 #define of_match_ptr(_ptr)	(_ptr)
 
 /*
- * struct property *prop;
- * const __be32 *p;
  * u32 u;
  *
- * of_property_for_each_u32(np, "propname", prop, p, u)
+ * of_property_for_each_u32_new(np, "propname", u)
  *         printk("U32 value: %x\n", u);
  */
 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
@@ -1437,6 +1435,13 @@ static inline int of_property_read_s32(const struct device_node *np,
 		p;						\
 		p = of_prop_next_u32(prop, p, &u))
 
+#define of_property_for_each_u32_new(np, propname, u)			\
+	for (struct {struct property *prop; const __be32 *item; } _it =	\
+		{of_find_property(np, propname, NULL),			\
+		 of_prop_next_u32(_it.prop, NULL, &u)};			\
+	     _it.item;							\
+	     _it.item = of_prop_next_u32(_it.prop, _it.item, &u))
+
 #define of_property_for_each_string(np, propname, prop, s)	\
 	for (prop = of_find_property(np, propname, NULL),	\
 		s = of_prop_next_string(prop, NULL);		\

-- 
2.34.1