of: Introduce of_for_each_phandle() helper macro

With this macro any user can easily iterate over a list of
phandles. The patch also converts __of_parse_phandle_with_args()
to make use of the macro.

The of_count_phandle_with_args() function is not converted,
because the macro hides the return value of of_phandle_iterator_init(),
which is needed in there.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Rob Herring <robh@kernel.org>

2 files changed, 7 insertions, 6 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index fcff2b62ec10..ea5a13d3c5a5 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1543,13 +1543,8 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
         struct of_phandle_iterator it;
         int rc, cur_index = 0;
 
-        rc = of_phandle_iterator_init(&it, np, list_name,
-                                      cells_name, cell_count);
-        if (rc)
-                return rc;
-
         /* Loop over the phandles until all the requested entry is found */
-        while ((rc = of_phandle_iterator_next(&it)) == 0) {
+        of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
                 /*
                  * All of the error cases bail out of the loop, so at
                  * this point, the parsing is successful. If the requested
diff --git a/include/linux/of.h b/include/linux/of.h
index 1f5e108f6716..b0b80716fbfb 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -908,6 +908,12 @@ static inline int of_property_read_s32(const struct device_node *np,
         return of_property_read_u32(np, propname, (u32*) out_value);
 }
 
+#define of_for_each_phandle(it, err, np, ln, cn, cc)                    \
+        for (of_phandle_iterator_init((it), (np), (ln), (cn), (cc)),    \
+             err = of_phandle_iterator_next(it);                        \
+             err == 0;                                                  \
+             err = of_phandle_iterator_next(it))
+
 #define of_property_for_each_u32(np, propname, prop, p, u)      \
         for (prop = of_find_property(np, propname, NULL),       \
                 p = of_prop_next_u32(prop, NULL, &u);           \