Iterating over a property containing a list of phandles with arguments
is a common operation for device drivers. This patch adds a new
of_property_for_each_phandle_with_args() macro to make the iteration
simpler.
Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
Cc: Rob Herring <robherring2@xxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxx>
Reviewed-by: Stephen Warren <swarren@xxxxxxxxxx>
---
drivers/of/base.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 86 insertions(+)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 03e7fc6c93e8..9c6834794fd5 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1492,6 +1492,56 @@ void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
printk("\n");
}
+void of_phandle_iter_next(struct of_phandle_iter *iter)
+{
+ struct device_node *dn;
+ int i, count;
+
+ if (!iter->cur || (iter->cur >= iter->end))
+ goto err_out;
+
+ dn = of_find_node_by_phandle(be32_to_cpup(iter->cur++));
+ if (!dn)
+ goto err_out;
+
+ if (iter->cells_name) {
+ if (of_property_read_u32(dn, iter->cells_name, &count))
+ goto err_out;
+ } else {
+ count = iter->cell_count;
+ }
+
+ iter->out_args.np = dn;
+ iter->out_args.args_count = count;
+ for (i = 0; i < count; i++)
+ iter->out_args.args[i] = be32_to_cpup(iter->cur++);
+
+ return;
+
+err_out:
+ iter->cur = NULL;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iter_next);
+
+void of_phandle_iter_start(struct of_phandle_iter *iter,
+ const struct device_node *np,
+ const char *list_name, const char *cells_name,
+ int cell_count)
+{
+ size_t bytes;
+
+ iter->cur = of_get_property(np, list_name, &bytes);
+ if (!iter->cur)
+ return;
+ iter->end = iter->cur;
+ if (bytes)
+ iter->end += bytes / sizeof(*iter->cur);
+ iter->cells_name = cells_name;
+ iter->cell_count = cell_count;
+ of_phandle_iter_next(iter);
+}
+EXPORT_SYMBOL_GPL(of_phandle_iter_start);
+
static int __of_parse_phandle_with_args(const struct device_node *np,
const char *list_name,
const char *cells_name,
diff --git a/include/linux/of.h b/include/linux/of.h
index fa362867b453..f925f16ef1a8 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -74,6 +74,18 @@ struct of_phandle_args {
uint32_t args[MAX_PHANDLE_ARGS];
};
+/*
+ * keep the state at iterating a list of phandles with variable number
+ * of args
+ */
+struct of_phandle_iter {
+ const __be32 *cur; /* current phandle */
+ const __be32 *end; /* end of the last phandle */
+ const char *cells_name;
+ int cell_count;
+ struct of_phandle_args out_args;
+};
+
extern int of_node_add(struct device_node *node);
/* initialize a node */
@@ -303,6 +315,12 @@ 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);
+extern void of_phandle_iter_start(struct of_phandle_iter *iter,
+ const struct device_node *np,
+ const char *list_name,
+ const char *cells_name, int cell_count);
+extern void of_phandle_iter_next(struct of_phandle_iter *iter);
+
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);
@@ -554,6 +572,18 @@ static inline int of_count_phandle_with_args(struct device_node *np,
return -ENOSYS;
}
+static inline void of_phandle_iter_start(struct of_phandle_iter *iter,
+ const struct device_node *np,
+ const char *list_name,
+ const char *cells_name,
+ int cell_count);
+{
+}
+
+static inline void of_phandle_iter_next(struct of_phandle_iter *iter)
+{
+}
+
static inline int of_alias_get_id(struct device_node *np, const char *stem)
{
return -ENOSYS;
@@ -742,6 +772,12 @@ static inline int of_property_read_u32(const struct device_node *np,
for (dn = of_find_node_with_property(NULL, prop_name); dn; \
dn = of_find_node_with_property(dn, prop_name))
+#define of_property_for_each_phandle_with_args(iter, np, list_name, \
+ cells_name, cell_count) \
+ for (of_phandle_iter_start(&iter, np, list_name, \
+ cells_name, cell_count); \
+ iter.cur; of_phandle_iter_next(&iter))
+
static inline int of_get_child_count(const struct device_node *np)
{
struct device_node *child;
--
2.0.0.rc1.15.g7e76a2f
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