[PATCH v3 1/3] software node: Add software_node_find_by_name()

[Heikki Krogerus]

Function that searches software nodes by node name.

Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Tested-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
 drivers/base/swnode.c    | 37 +++++++++++++++++++++++++++++++++++++
 include/linux/property.h |  4 ++++
 2 files changed, 41 insertions(+)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index e7b3aa3bd55a..ee2a405cca9a 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -620,6 +620,43 @@ static const struct fwnode_operations software_node_ops = {
 
 /* -------------------------------------------------------------------------- */
 
+/**
+ * software_node_find_by_name - Find software node by name
+ * @parent: Parent of the software node
+ * @name: Name of the software node
+ *
+ * The function will find a node that is child of @parent and that is named
+ * @name. If no node is found, the function returns NULL.
+ *
+ * NOTE: you will need to drop the reference with fwnode_handle_put() after use.
+ */
+const struct software_node *
+software_node_find_by_name(const struct software_node *parent, const char *name)
+{
+	struct swnode *swnode;
+	struct kobject *k;
+
+	if (!name)
+		return NULL;
+
+	spin_lock(&swnode_kset->list_lock);
+
+	list_for_each_entry(k, &swnode_kset->list, entry) {
+		swnode = kobj_to_swnode(k);
+		if (parent == swnode->node->parent && swnode->node->name &&
+		    !strcmp(name, swnode->node->name)) {
+			kobject_get(&swnode->kobj);
+			break;
+		}
+		swnode = NULL;
+	}
+
+	spin_unlock(&swnode_kset->list_lock);
+
+	return swnode ? swnode->node : NULL;
+}
+EXPORT_SYMBOL_GPL(software_node_find_by_name);
+
 static int
 software_node_register_properties(struct software_node *node,
 				  const struct property_entry *properties)
diff --git a/include/linux/property.h b/include/linux/property.h
index 5a910ad79591..9b3d4ca3a73a 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -421,6 +421,10 @@ bool is_software_node(const struct fwnode_handle *fwnode);
 const struct software_node *to_software_node(struct fwnode_handle *fwnode);
 struct fwnode_handle *software_node_fwnode(const struct software_node *node);
 
+const struct software_node *
+software_node_find_by_name(const struct software_node *parent,
+			   const char *name);
+
 int software_node_register_nodes(const struct software_node *nodes);
 void software_node_unregister_nodes(const struct software_node *nodes);
 
-- 
2.23.0.rc1