[PATCH 03/22] dm: core: add support for device re-parenting

[Claudiu Beznea]

In common clock framework the relation b/w parent and child clocks is
determined based on the udevice parent/child information. A clock
parent could be changed based on devices needs. In case this is happen
the functionalities for clock who's parent is changed are broken. Add
a function that reparent a device. This will be used in clk-uclass.c
to reparent a clock device.

Signed-off-by: Claudiu Beznea <claudiu.beznea at microchip.com>
---
 drivers/core/device.c        | 26 ++++++++++++++++++++++++++
 include/dm/device-internal.h |  9 +++++++++
 2 files changed, 35 insertions(+)

diff --git a/drivers/core/device.c b/drivers/core/device.c
index a7408d9c76c6..f149d55ac1e1 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -267,6 +267,32 @@ int device_bind_by_name(struct udevice *parent, bool pre_reloc_only,
 			devp);
 }
 
+int device_reparent(struct udevice *dev, struct udevice *new_parent)
+{
+	struct udevice *cparent;
+	struct udevice *pos, *n;
+
+	if (!dev || !new_parent)
+		return -EINVAL;
+
+	if (!dev->parent)
+		return -ENODEV;
+
+	list_for_each_entry_safe(pos, n, &dev->parent->child_head,
+				 sibling_node) {
+		if (pos->driver != dev->driver)
+			continue;
+
+		list_del(&dev->sibling_node);
+		list_add_tail(&dev->sibling_node, &new_parent->child_head);
+		dev->parent = new_parent;
+
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
 static void *alloc_priv(int size, uint flags)
 {
 	void *priv;
diff --git a/include/dm/device-internal.h b/include/dm/device-internal.h
index 294d6c18105a..c5d7ec0650f9 100644
--- a/include/dm/device-internal.h
+++ b/include/dm/device-internal.h
@@ -84,6 +84,15 @@ int device_bind_by_name(struct udevice *parent, bool pre_reloc_only,
 			const struct driver_info *info, struct udevice **devp);
 
 /**
+ * device_reparent: reparent the device to a new parent
+ *
+ * @dev: pointer to device to be reparented
+ * @new_parent: pointer to new parent device
+ * @return 0 if OK, -ve on error
+ */
+int device_reparent(struct udevice *dev, struct udevice *new_parent);
+
+/**
  * device_ofdata_to_platdata() - Read platform data for a device
  *
  * Read platform data for a device (typically from the device tree) so that
-- 
2.7.4