dt: add helper for phandle references

Phandles are the fancy device tree name for "pointer to another node".
To create a phandle property, we most likely want to reference to the
node we're pointing to by its path. So create a helper that allows
us to do so.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@petalogix.com>

2 files changed, 11 insertions, 0 deletions

diff --git a/device_tree.c b/device_tree.c
index 94a239e987..2905f9afe4 100644
--- a/device_tree.c
+++ b/device_tree.c
@@ -132,6 +132,14 @@ int qemu_devtree_setprop_string(void *fdt, const char *node_path,
     return r;
 }
 
+int qemu_devtree_setprop_phandle(void *fdt, const char *node_path,
+                                 const char *property,
+                                 const char *target_node_path)
+{
+    uint32_t phandle = fdt_get_phandle(fdt, findnode_nofail(fdt, target_node_path));
+    return qemu_devtree_setprop_cell(fdt, node_path, property, phandle);
+}
+
 int qemu_devtree_nop_node(void *fdt, const char *node_path)
 {
     int r;
diff --git a/device_tree.h b/device_tree.h
index 1e671e2506..754bd2b2ec 100644
--- a/device_tree.h
+++ b/device_tree.h
@@ -22,6 +22,9 @@ int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
                               const char *property, uint32_t val);
 int qemu_devtree_setprop_string(void *fdt, const char *node_path,
                                 const char *property, const char *string);
+int qemu_devtree_setprop_phandle(void *fdt, const char *node_path,
+                                 const char *property,
+                                 const char *target_node_path);
 int qemu_devtree_nop_node(void *fdt, const char *node_path);
 int qemu_devtree_add_subnode(void *fdt, const char *name);