[net-next: PATCH v4 5/8] device property: introduce fwnode_find_parent_dev_match

[Marcin Wojtas]

Add a new generic routine fwnode_find_parent_dev_match that can be used
e.g. as a callback for class_find_device(). It searches for the struct
device corresponding to a struct fwnode_handle by iterating over device
and its parents.

Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx>
---
 include/linux/property.h |  1 +
 drivers/base/property.c  | 23 ++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/linux/property.h b/include/linux/property.h
index 37179e3abad5..4ae20d7c5103 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -109,6 +109,7 @@ 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,
 					    unsigned int depth);
+int fwnode_find_parent_dev_match(struct device *dev, const void *data);
 bool fwnode_is_ancestor_of(struct fwnode_handle *ancestor, struct fwnode_handle *child);
 struct fwnode_handle *fwnode_get_next_child_node(
 	const struct fwnode_handle *fwnode, struct fwnode_handle *child);
diff --git a/drivers/base/property.c b/drivers/base/property.c
index bbb3e499ff4a..84849d4934cc 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -693,6 +693,29 @@ struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode,
 }
 EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);
 
+/**
+ * fwnode_find_parent_dev_match - look for a device matching the struct fwnode_handle
+ * @dev: the struct device to initiate the search
+ * @data: pointer passed for comparison
+ *
+ * Looks up the device structure corresponding with the fwnode by iterating
+ * over @dev and its parents.
+ * The routine can be used e.g. as a callback for class_find_device().
+ *
+ * Returns: %1 - match is found
+ *          %0 - match not found
+ */
+int fwnode_find_parent_dev_match(struct device *dev, const void *data)
+{
+	for (; dev; dev = dev->parent) {
+		if (device_match_fwnode(dev, data))
+			return 1;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fwnode_find_parent_dev_match);
+
 /**
  * fwnode_is_ancestor_of - Test if @ancestor is ancestor of @child
  * @ancestor: Firmware which is tested for being an ancestor
-- 
2.29.0