dm: core: Add functions to find parent and OF data

Add dev_get_parent() as a convenience to obtain the parent of a device.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@ti.com>
Acked-by: Heiko Schocher <hs@denx.de>

drivers/core/device.c

@@ -381,6 +381,11 @@ int device_find_next_child(struct udevice **devp)
 	return 0;
 }
 
+struct udevice *dev_get_parent(struct udevice *child)
+{
+	return child->parent;
+}
+
 ulong dev_get_of_data(struct udevice *dev)
 {
 	return dev->of_id->data;

include/dm/device.h

@@ -207,6 +207,14 @@ void *dev_get_parentdata(struct udevice *dev);
  */
 void *dev_get_priv(struct udevice *dev);
 
+/**
+ * struct dev_get_parent() - Get the parent of a device
+ *
+ * @child:	Child to check
+ * @return parent of child, or NULL if this is the root device
+ */
+struct udevice *dev_get_parent(struct udevice *child);
+
 /**
  * dev_get_of_data() - get the device tree data used to bind a device
  *