of: Move phandle walking to of_phandle_iterator_next()

Move the code to walk over the phandles out of the loop in
__of_parse_phandle_with_args() to a separate function that
just works with the iterator handle: of_phandle_iterator_next().

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

2 files changed, 81 insertions, 56 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 1c6f43b5737d..69286ec206f7 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1465,6 +1465,75 @@ int of_phandle_iterator_init(struct of_phandle_iterator *it,
         return 0;
 }
 
+int of_phandle_iterator_next(struct of_phandle_iterator *it)
+{
+        uint32_t count = 0;
+
+        if (it->node) {
+                of_node_put(it->node);
+                it->node = NULL;
+        }
+
+        if (!it->cur || it->phandle_end >= it->list_end)
+                return -ENOENT;
+
+        it->cur = it->phandle_end;
+
+        /* If phandle is 0, then it is an empty entry with no arguments. */
+        it->phandle = be32_to_cpup(it->cur++);
+
+        if (it->phandle) {
+
+                /*
+                 * Find the provider node and parse the #*-cells property to
+                 * determine the argument length.
+                 */
+                it->node = of_find_node_by_phandle(it->phandle);
+
+                if (it->cells_name) {
+                        if (!it->node) {
+                                pr_err("%s: could not find phandle\n",
+                                       it->parent->full_name);
+                                goto err;
+                        }
+
+                        if (of_property_read_u32(it->node, it->cells_name,
+                                                 &count)) {
+                                pr_err("%s: could not get %s for %s\n",
+                                       it->parent->full_name,
+                                       it->cells_name,
+                                       it->node->full_name);
+                                goto err;
+                        }
+                } else {
+                        count = it->cell_count;
+                }
+
+                /*
+                 * Make sure that the arguments actually fit in the remaining
+                 * property data length
+                 */
+                if (it->cur + count > it->list_end) {
+                        pr_err("%s: arguments longer than property\n",
+                               it->parent->full_name);
+                        goto err;
+                }
+        }
+
+        it->phandle_end = it->cur + count;
+        it->cur_count = count;
+
+        return 0;
+
+err:
+        if (it->node) {
+                of_node_put(it->node);
+                it->node = NULL;
+        }
+
+        return -EINVAL;
+}
+
 static int __of_parse_phandle_with_args(const struct device_node *np,
                                         const char *list_name,
                                         const char *cells_name,
@@ -1480,59 +1549,9 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
                 return rc;
 
         /* Loop over the phandles until all the requested entry is found */
-        while (it.cur < it.list_end) {
-                rc = -EINVAL;
-                it.cur_count = 0;
-
-                /*
-                 * If phandle is 0, then it is an empty entry with no
-                 * arguments.  Skip forward to the next entry.
-                 */
-                it.phandle = be32_to_cpup(it.cur++);
-                if (it.phandle) {
-                        /*
-                         * Find the provider node and parse the #*-cells
-                         * property to determine the argument length.
-                         *
-                         * This is not needed if the cell count is hard-coded
-                         * (i.e. cells_name not set, but cell_count is set),
-                         * except when we're going to return the found node
-                         * below.
-                         */
-                        if (it.cells_name || cur_index == index) {
-                                it.node = of_find_node_by_phandle(it.phandle);
-                                if (!it.node) {
-                                        pr_err("%s: could not find phandle\n",
-                                                it.parent->full_name);
-                                        goto err;
-                                }
-                        }
-
-                        if (it.cells_name) {
-                                if (of_property_read_u32(it.node, it.cells_name,
-                                                         &it.cur_count)) {
-                                        pr_err("%s: could not get %s for %s\n",
-                                                it.parent->full_name, it.cells_name,
-                                                it.node->full_name);
-                                        goto err;
-                                }
-                        } else {
-                                it.cur_count = it.cell_count;
-                        }
-
-                        /*
-                         * Make sure that the arguments actually fit in the
-                         * remaining property data length
-                         */
-                        if (it.cur + it.cur_count > it.list_end) {
-                                pr_err("%s: arguments longer than property\n",
-                                         it.parent->full_name);
-                                goto err;
-                        }
-                }
-
+        while ((rc = of_phandle_iterator_next(&it)) == 0) {
                 /*
-                 * All of the error cases above bail out of the loop, so at
+                 * All of the error cases bail out of the loop, so at
                  * this point, the parsing is successful. If the requested
                  * index matches, then fill the out_args structure and return,
                  * or return -ENOENT for an empty entry.
@@ -1558,9 +1577,6 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
                         return 0;
                 }
 
-                of_node_put(it.node);
-                it.node = NULL;
-                it.cur += it.cur_count;
                 cur_index++;
         }
 
@@ -1570,7 +1586,9 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
          * -EINVAL : parsing error on data
          * [1..n]  : Number of phandle (count mode; when index = -1)
          */
-        rc = index < 0 ? cur_index : -ENOENT;
+        if (rc == -ENOENT && index < 0)
+                rc = cur_index;
+
  err:
         if (it.node)
                 of_node_put(it.node);
diff --git a/include/linux/of.h b/include/linux/of.h
index 0f187dbb890b..1f5e108f6716 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -358,6 +358,8 @@ extern int of_phandle_iterator_init(struct of_phandle_iterator *it,
                                     const char *cells_name,
                                     int cell_count);
 
+extern int of_phandle_iterator_next(struct of_phandle_iterator *it);
+
 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);
@@ -641,6 +643,11 @@ static inline int of_phandle_iterator_init(struct of_phandle_iterator *it,
         return -ENOSYS;
 }
 
+static inline int of_phandle_iterator_next(struct of_phandle_iterator *it)
+{
+        return -ENOSYS;
+}
+
 static inline int of_alias_get_id(struct device_node *np, const char *stem)
 {
         return -ENOSYS;