[PATCH v6 2/5] device property: Introduce fwnode_for_each_parent_node()

From: Andy Shevchenko
Date: Fri Apr 08 2022 - 14:50:00 EST


In a few cases the functionality of fwnode_for_each_parent_node()
is already in use. Introduce a common helper macro for it.

It may be used by others as well in the future.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
v6: added tag (Sakari)
drivers/base/property.c | 56 +++++++++++++++++++++-------------------
include/linux/property.h | 9 +++++--
2 files changed, 36 insertions(+), 29 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 6ecc1398b0ba..f0ac31d28798 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -596,17 +596,17 @@ EXPORT_SYMBOL_GPL(fwnode_get_next_parent);
*/
struct device *fwnode_get_next_parent_dev(struct fwnode_handle *fwnode)
{
+ struct fwnode_handle *parent;
struct device *dev;

- fwnode_handle_get(fwnode);
- do {
- fwnode = fwnode_get_next_parent(fwnode);
- if (!fwnode)
- return NULL;
+ fwnode_for_each_parent_node(fwnode, parent) {
dev = get_dev_from_fwnode(fwnode);
- } while (!dev);
- fwnode_handle_put(fwnode);
- return dev;
+ if (dev) {
+ fwnode_handle_put(parent);
+ return dev;
+ }
+ }
+ return NULL;
}

/**
@@ -617,13 +617,11 @@ struct device *fwnode_get_next_parent_dev(struct fwnode_handle *fwnode)
*/
unsigned int fwnode_count_parents(const struct fwnode_handle *fwnode)
{
- struct fwnode_handle *__fwnode;
- unsigned int count;
-
- __fwnode = fwnode_get_parent(fwnode);
+ struct fwnode_handle *parent;
+ unsigned int count = 0;

- for (count = 0; __fwnode; count++)
- __fwnode = fwnode_get_next_parent(__fwnode);
+ fwnode_for_each_parent_node(fwnode, parent)
+ count++;

return count;
}
@@ -644,15 +642,16 @@ EXPORT_SYMBOL_GPL(fwnode_count_parents);
struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode,
unsigned int depth)
{
- fwnode_handle_get(fwnode);
+ struct fwnode_handle *parent;

- do {
- if (depth-- == 0)
- break;
- fwnode = fwnode_get_next_parent(fwnode);
- } while (fwnode);
+ if (depth == 0)
+ return fwnode_handle_get(fwnode);

- return fwnode;
+ fwnode_for_each_parent_node(fwnode, parent) {
+ if (--depth == 0)
+ return parent;
+ }
+ return NULL;
}
EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);

@@ -669,17 +668,20 @@ EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
bool fwnode_is_ancestor_of(struct fwnode_handle *test_ancestor,
struct fwnode_handle *test_child)
{
+ struct fwnode_handle *parent;
+
if (IS_ERR_OR_NULL(test_ancestor))
return false;

- fwnode_handle_get(test_child);
- do {
- if (test_child == test_ancestor) {
- fwnode_handle_put(test_child);
+ if (test_child == test_ancestor)
+ return true;
+
+ fwnode_for_each_parent_node(test_child, parent) {
+ if (parent == test_ancestor) {
+ fwnode_handle_put(parent);
return true;
}
- test_child = fwnode_get_next_parent(test_child);
- } while (test_child);
+ }
return false;
}

diff --git a/include/linux/property.h b/include/linux/property.h
index 4cd4b326941f..15d6863ae962 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -83,9 +83,14 @@ struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode,

const char *fwnode_get_name(const struct fwnode_handle *fwnode);
const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode);
+
struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode);
-struct fwnode_handle *fwnode_get_next_parent(
- struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode);
+
+#define fwnode_for_each_parent_node(fwnode, parent) \
+ for (parent = fwnode_get_parent(fwnode); parent; \
+ parent = fwnode_get_next_parent(parent))
+
struct device *fwnode_get_next_parent_dev(struct fwnode_handle *fwnode);
unsigned int fwnode_count_parents(const struct fwnode_handle *fwn);
struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwn,
--
2.35.1