dm: core: Inline a few ofnode functions in SPL

A recent change to unify the flattree/livetree code introduced a small
size increase in SPL on some boards. For example SPL code size for
px30-core-ctouch2-px30 increased by 40 bytes.

To address this we can take advantage of the fact that some of the ofnode
functions are only called a few times in SPL, so it is worth inlining
them.

Add new Kconfig options to control this. These functions are not inlined
for U-Boot proper, since this increases code size.

Fixes: 2ebea5eaebf ("dm: core: Combine the flattree and livetree binding code")
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
index 53f04ac..5b08865 100644
--- a/include/dm/ofnode.h
+++ b/include/dm/ofnode.h
@@ -10,6 +10,7 @@
 /* TODO(sjg@chromium.org): Drop fdtdec.h include */
 #include <fdtdec.h>
 #include <dm/of.h>
+#include <dm/of_access.h>
 #include <log.h>
 
 /* Enable checks to protect against invalid calls */
@@ -357,17 +358,6 @@
  */
 int ofnode_read_u32_array(ofnode node, const char *propname,
 			  u32 *out_values, size_t sz);
-/**
- * ofnode_is_enabled() - Checks whether a node is enabled.
- * This looks for a 'status' property. If this exists, then returns true if
- * the status is 'okay' and false otherwise. If there is no status property,
- * it returns true on the assumption that anything mentioned should be enabled
- * by default.
- *
- * @node: node to examine
- * @return false (not enabled) or true (enabled)
- */
-bool ofnode_is_enabled(ofnode node);
 
 /**
  * ofnode_read_bool() - read a boolean value from a property
@@ -388,6 +378,49 @@
  */
 ofnode ofnode_find_subnode(ofnode node, const char *subnode_name);
 
+#if CONFIG_IS_ENABLED(DM_INLINE_OFNODE)
+static inline bool ofnode_is_enabled(ofnode node)
+{
+	if (ofnode_is_np(node)) {
+		return of_device_is_available(ofnode_to_np(node));
+	} else {
+		return fdtdec_get_is_enabled(gd->fdt_blob,
+					     ofnode_to_offset(node));
+	}
+}
+
+static inline ofnode ofnode_first_subnode(ofnode node)
+{
+	assert(ofnode_valid(node));
+	if (ofnode_is_np(node))
+		return np_to_ofnode(node.np->child);
+
+	return offset_to_ofnode(
+		fdt_first_subnode(gd->fdt_blob, ofnode_to_offset(node)));
+}
+
+static inline ofnode ofnode_next_subnode(ofnode node)
+{
+	assert(ofnode_valid(node));
+	if (ofnode_is_np(node))
+		return np_to_ofnode(node.np->sibling);
+
+	return offset_to_ofnode(
+		fdt_next_subnode(gd->fdt_blob, ofnode_to_offset(node)));
+}
+#else
+/**
+ * ofnode_is_enabled() - Checks whether a node is enabled.
+ * This looks for a 'status' property. If this exists, then returns true if
+ * the status is 'okay' and false otherwise. If there is no status property,
+ * it returns true on the assumption that anything mentioned should be enabled
+ * by default.
+ *
+ * @node: node to examine
+ * @return false (not enabled) or true (enabled)
+ */
+bool ofnode_is_enabled(ofnode node);
+
 /**
  * ofnode_first_subnode() - find the first subnode of a parent node
  *
@@ -405,6 +438,7 @@
  * has no more siblings)
  */
 ofnode ofnode_next_subnode(ofnode node);
+#endif /* DM_INLINE_OFNODE */
 
 /**
  * ofnode_get_parent() - get the ofnode's parent (enclosing ofnode)