dm: core: Add operations on device tree references
Since U-Boot supports both a live tree and a flat tree, we need an easy
way to access the tree without worrying about which is currently active.
To support this, U-Boot has the concept of an ofnode, which can refer
either to a live tree node or a flat tree node.
For the live tree, the reference contains a pointer to the node (struct
device_node *) or NULL if the node is invalid. For the flat tree, the
reference contains the node offset or -1 if the node is invalid.
Add a basic set of operations using ofnodes. These are implemented by
using either libfdt functions (in the case of a flat DT reference) or
the live-tree of_...() functions.
Note that it is not possible to have both live and flat references active
at the same time. As soon as the live tree is available, everything in
U-Boot should switch to using that. This avoids confusion and allows us to
assume that the type of a reference is simply based on whether we have a
live tree yet, or not.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/Makefile b/drivers/core/Makefile
index 4211fd1..c25288e 100644
--- a/drivers/core/Makefile
+++ b/drivers/core/Makefile
@@ -12,3 +12,4 @@
obj-$(CONFIG_$(SPL_)REGMAP) += regmap.o
obj-$(CONFIG_$(SPL_)SYSCON) += syscon-uclass.o
obj-$(CONFIG_OF_LIVE) += of_access.o
+obj-$(CONFIG_OF_CONTROL) += ofnode.o