of: Introduce struct of_phandle_iterator

This struct carrys all necessary information to iterate over
a list of phandles and extract the arguments. Add an
init-function for the iterator and make use of it in
__of_parse_phandle_with_args().

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

1 files changed, 33 insertions, 0 deletions

diff --git a/include/linux/of.h b/include/linux/of.h
index 7fcb681baadf..0f187dbb890b 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -75,6 +75,23 @@ struct of_phandle_args {
         uint32_t args[MAX_PHANDLE_ARGS];
 };
 
+struct of_phandle_iterator {
+        /* Common iterator information */
+        const char *cells_name;
+        int cell_count;
+        const struct device_node *parent;
+
+        /* List size information */
+        const __be32 *list_end;
+        const __be32 *phandle_end;
+
+        /* Current position state */
+        const __be32 *cur;
+        uint32_t cur_count;
+        phandle phandle;
+        struct device_node *node;
+};
+
 struct of_reconfig_data {
         struct device_node      *dn;
         struct property         *prop;
@@ -334,6 +351,13 @@ extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
 extern int of_count_phandle_with_args(const struct device_node *np,
         const char *list_name, const char *cells_name);
 
+/* phandle iterator functions */
+extern int of_phandle_iterator_init(struct of_phandle_iterator *it,
+                                    const struct device_node *np,
+                                    const char *list_name,
+                                    const char *cells_name,
+                                    int cell_count);
+
 extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align));
 extern int of_alias_get_id(struct device_node *np, const char *stem);
 extern int of_alias_get_highest_id(const char *stem);
@@ -608,6 +632,15 @@ static inline int of_count_phandle_with_args(struct device_node *np,
         return -ENOSYS;
 }
 
+static inline int of_phandle_iterator_init(struct of_phandle_iterator *it,
+                                           const struct device_node *np,
+                                           const char *list_name,
+                                           const char *cells_name,
+                                           int cell_count)
+{
+        return -ENOSYS;
+}
+
 static inline int of_alias_get_id(struct device_node *np, const char *stem)
 {
         return -ENOSYS;