[PATCH 34/35] libfdt: overlay: make overlay_get_target() public

[Sebastian Huber]

From: Vikram Garhwal <fnu.vikram at xilinx.com>

This is done to get the target path for the overlay nodes which is very useful
in many cases. For example, Xen hypervisor needs it when applying overlays
because Xen needs to do further processing of the overlay nodes, e.g. mapping of
resources(IRQs and IOMMUs) to other VMs, creation of SMMU pagetables, etc.

Signed-off-by: Vikram Garhwal <fnu.vikram at xilinx.com>
Message-Id: <1637204036-382159-2-git-send-email-fnu.vikram at xilinx.com>
Signed-off-by: David Gibson <david at gibson.dropbear.id.au>
---
 cpukit/include/libfdt.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/cpukit/include/libfdt.h b/cpukit/include/libfdt.h
index 7f117e8815..a7f432c80c 100644
--- a/cpukit/include/libfdt.h
+++ b/cpukit/include/libfdt.h
@@ -2116,6 +2116,24 @@ int fdt_del_node(void *fdt, int nodeoffset);
  */
 int fdt_overlay_apply(void *fdt, void *fdto);
 
+/**
+ * fdt_overlay_target_offset - retrieves the offset of a fragment's target
+ * @fdt: Base device tree blob
+ * @fdto: Device tree overlay blob
+ * @fragment_offset: node offset of the fragment in the overlay
+ * @pathp: pointer which receives the path of the target (or NULL)
+ *
+ * fdt_overlay_target_offset() retrieves the target offset in the base
+ * device tree of a fragment, no matter how the actual targeting is
+ * done (through a phandle or a path)
+ *
+ * returns:
+ *      the targeted node offset in the base device tree
+ *      Negative error code on error
+ */
+int fdt_overlay_target_offset(const void *fdt, const void *fdto,
+			      int fragment_offset, char const **pathp);
+
 /**********************************************************************/
 /* Debugging / informational functions                                */
 /**********************************************************************/
-- 
2.31.1