dm: core: add ofnode and dev function to iterate on node property

Add functions to iterate on all property with livetree
- dev_read_first_prop
- dev_read_next_prop
- dev_read_prop_by_prop
and
- ofnode_get_first_property
- ofnode_get_next_property
- ofnode_get_property_by_prop

And helper: dev_for_each_property

For example:
struct ofprop property;

dev_for_each_property(property, config) {
	value = dev_read_prop_by_prop(&property, &propname, &len);

or:

for (res = ofnode_get_first_property(node, &property);
     !res;
     res = ofnode_get_next_property(&property))
{
     value = ofnode_get_property_by_prop(&property, &propname, &len);
....
}

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/core/ofnode.c

@@ -571,6 +571,54 @@ const void *ofnode_get_property(ofnode node, const char *propname, int *lenp)
 				   propname, lenp);
 }
 
+int ofnode_get_first_property(ofnode node, struct ofprop *prop)
+{
+	prop->node = node;
+
+	if (ofnode_is_np(node)) {
+		prop->prop = of_get_first_property(ofnode_to_np(prop->node));
+		if (!prop->prop)
+			return -FDT_ERR_NOTFOUND;
+	} else {
+		prop->offset =
+			fdt_first_property_offset(gd->fdt_blob,
+						  ofnode_to_offset(prop->node));
+		if (prop->offset < 0)
+			return prop->offset;
+	}
+
+	return 0;
+}
+
+int ofnode_get_next_property(struct ofprop *prop)
+{
+	if (ofnode_is_np(prop->node)) {
+		prop->prop = of_get_next_property(ofnode_to_np(prop->node),
+						  prop->prop);
+		if (!prop->prop)
+			return -FDT_ERR_NOTFOUND;
+	} else {
+		prop->offset = fdt_next_property_offset(gd->fdt_blob,
+							prop->offset);
+		if (prop->offset  < 0)
+			return prop->offset;
+	}
+
+	return 0;
+}
+
+const void *ofnode_get_property_by_prop(const struct ofprop *prop,
+					const char **propname, int *lenp)
+{
+	if (ofnode_is_np(prop->node))
+		return of_get_property_by_prop(ofnode_to_np(prop->node),
+					       prop->prop, propname, lenp);
+	else
+		return fdt_getprop_by_offset(gd->fdt_blob,
+					     prop->offset,
+					     propname, lenp);
+}
+
 bool ofnode_is_available(ofnode node)
 {
 	if (ofnode_is_np(node))