[PATCH 01/23] component: Add common helper for compare/release functions

[Yong Wu <yong.wu@xxxxxxxxxxxx>]

The component requires the compare/release functions, there are so many
copies in current kernel. Just define four common helpers for them.

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
I have run "make htmldocs". Due to my poor english, If the grammer is
wrong or need more comments, please help to correct or supplement.
Thanks.
---
 drivers/base/component.c  | 58 +++++++++++++++++++++++++++++++++++++++
 include/linux/component.h |  6 ++++
 2 files changed, 64 insertions(+)

diff --git a/drivers/base/component.c b/drivers/base/component.c
index 2d25a6416587..3d72d2820d7d 100644
--- a/drivers/base/component.c
+++ b/drivers/base/component.c
@@ -11,6 +11,7 @@
 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
+#include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/debugfs.h>
 
@@ -287,6 +288,63 @@ static void take_down_master(struct master *master)
 	}
 }
 
+/**
+ * component_compare_of - A common component compare function for of_node
+ * @dev: component device
+ * @data: @compare_data from component_match_add_release()
+ *
+ * A common compare function when compare_data is device of_node. e.g.
+ * component_match_add_release(masterdev, &match, component_release_of,
+ * component_compare_of, component_dev_of_node)
+ */
+int component_compare_of(struct device *dev, void *data)
+{
+	return device_match_of_node(dev, data);
+}
+EXPORT_SYMBOL_GPL(component_compare_of);
+
+/**
+ * component_release_of - A common component release function for of_node
+ * @dev: component device
+ * @data: @compare_data from component_match_add_release()
+ *
+ * About the example, Please see component_compare_of().
+ */
+void component_release_of(struct device *dev, void *data)
+{
+	of_node_put(data);
+}
+EXPORT_SYMBOL_GPL(component_release_of);
+
+/**
+ * component_compare_dev - A common component compare function for dev
+ * @dev: component device
+ * @data: @compare_data from component_match_add_release()
+ *
+ * A common compare function when compare_data is struce device. e.g.
+ * component_match_add(masterdev, &match, component_compare_dev, component_dev)
+ */
+int component_compare_dev(struct device *dev, void *data)
+{
+	return dev == data;
+}
+EXPORT_SYMBOL_GPL(component_compare_dev);
+
+/**
+ * component_compare_dev_name - A common component compare function for device name
+ * @dev: component device
+ * @data: @compare_data from component_match_add_release()
+ *
+ * A common compare function when compare_data is device name string. e.g.
+ * component_match_add(masterdev, &match, component_compare_dev_name,
+ * "component_dev_name")
+ */
+int component_compare_dev_name(struct device *dev, void *data)
+{
+	return device_match_name(dev, data);
+}
+EXPORT_SYMBOL_GPL(component_compare_dev_name);
+
 static void devm_component_match_release(struct device *parent, void *res)
 {
 	struct component_match *match = res;
diff --git a/include/linux/component.h b/include/linux/component.h
index 16de18f473d7..6bc1c6e7f76d 100644
--- a/include/linux/component.h
+++ b/include/linux/component.h
@@ -82,6 +82,12 @@ struct component_master_ops {
 	void (*unbind)(struct device *master);
 };
 
+/* A set helper functions for component compare/release */
+int component_compare_of(struct device *dev, void *data);
+void component_release_of(struct device *dev, void *data);
+int component_compare_dev(struct device *dev, void *data);
+int component_compare_dev_name(struct device *dev, void *data);
+
 void component_master_del(struct device *,
 	const struct component_master_ops *);
 
-- 
2.18.0