[PATCH] of: Add of_device_destroy_children() function

[Sylwester Nawrocki]

This patch adds a helper function to unregister devices which
were created by an of_platform_populate() call. The pattern
used here can already be found in multiple drivers. This helper
can now be used instead of repeating similar code in drivers.

Signed-off-by: Sylwester Nawrocki <s.nawrocki at samsung.com>
Acked-by: Kyungmin Park <kyungmin.park at samsung.com>
---

This patch has been tested on ARM only (on Exynos4412 Trats2 board).

 drivers/of/device.c       |   24 ++++++++++++++++++++++++
 include/linux/of_device.h |    3 +++
 2 files changed, 27 insertions(+)

diff --git a/drivers/of/device.c b/drivers/of/device.c
index dafb973..9303197 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -190,3 +190,27 @@ int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)

 	return 0;
 }
+
+static int __remove_child_device(struct device *dev, void *unused)
+{
+	if (of_match_node(of_default_bus_match_table, dev->of_node))
+		of_device_destroy_children(dev);
+
+	device_unregister(dev);
+	return 0;
+}
+
+/**
+ * of_device_destroy_children - unregister @parent's child devices
+ * @parent: the parent device to start with
+ *
+ * Destroy all child devices of the @parent device, any grandchildren
+ * compatible with values listed in the of_default_bus_match_table will
+ * also be unregistered recursively.  This function can be used to
+ * destroy devices created by an of_platform_populate() call.
+ */
+void of_device_destroy_children(struct device *parent)
+{
+	device_for_each_child(parent, NULL, __remove_child_device);
+}
+EXPORT_SYMBOL(of_device_destroy_children);
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index ef37021..0c41e0b 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -32,6 +32,7 @@ extern void of_dev_put(struct platform_device *dev);
 extern int of_device_add(struct platform_device *pdev);
 extern int of_device_register(struct platform_device *ofdev);
 extern void of_device_unregister(struct platform_device *ofdev);
+extern void of_device_destroy_children(struct device *parent);

 extern ssize_t of_device_get_modalias(struct device *dev,
 					char *str, ssize_t len);
@@ -64,6 +65,8 @@ static inline int of_driver_match_device(struct device *dev,
 static inline void of_device_uevent(struct device *dev,
 			struct kobj_uevent_env *env) { }

+static inline void of_device_destroy_children(struct device *parent) { }
+
 static inline int of_device_get_modalias(struct device *dev,
 				   char *str, ssize_t len)
 {
--
1.7.9.5