1 files changed, 118 insertions, 0 deletions
diff --git a/src/vppinfra/devicetree.h b/src/vppinfra/devicetree.h
new file mode 100644
index 00000000000..db7d8411a11
--- /dev/null
+++ b/src/vppinfra/devicetree.h
@@ -0,0 +1,118 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright (c) 2024 Cisco Systems, Inc.
+ */
+
+#ifndef CLIB_DEVICETREE_H_
+#define CLIB_DEVICETREE_H_
+
+#include <vppinfra/clib.h>
+#include <vlib/vlib.h>
+
+#ifdef __linux
+#define CLIB_DT_LINUX_PREFIX "/sys/firmware/devicetree/base"
+#endif
+
+typedef struct
+{
+  char name[32];
+  u32 size;
+  u8 data[];
+} clib_dt_property_t;
+
+typedef struct clib_dt_main clib_dt_main_t;
+
+typedef struct clib_dt_node
+{
+  u8 *path;
+  struct clib_dt_node *parent;
+  struct clib_dt_node *prev;
+  struct clib_dt_node *next;
+  struct clib_dt_node **child_nodes;
+  u8 depth;
+  clib_dt_property_t *name;
+  clib_dt_property_t **properties;
+  clib_dt_main_t *dt_main;
+} clib_dt_node_t;
+
+typedef struct clib_dt_main
+{
+  clib_dt_node_t **nodes;
+  clib_dt_node_t *root;
+  uword *node_by_path;
+  uword *node_by_phandle;
+} clib_dt_main_t;
+
+__clib_export clib_dt_node_t *clib_dt_get_child_node (clib_dt_node_t *n,
+						      char *fmt, ...);
+clib_dt_node_t *clib_dt_get_node_with_path (clib_dt_main_t *dm, char *fmt,
+					    ...);
+clib_dt_property_t *clib_dt_get_node_property_by_name (clib_dt_node_t *,
+						       char *);
+int clib_dt_node_is_compatible (clib_dt_node_t *, char *);
+clib_dt_node_t *clib_dt_dereference_node (clib_dt_node_t *, char *);
+#ifdef __linux
+clib_error_t *clib_dt_read_from_sysfs (clib_dt_main_t *dm);
+#endif
+
+format_function_t format_clib_dt_desc;
+format_function_t format_clib_dt_property_data;
+
+static_always_inline int
+clib_dt_property_is_u32 (clib_dt_property_t *p)
+{
+  if (p == 0 || p->size != 4)
+    return 0;
+  return 1;
+}
+
+static_always_inline u32
+clib_dt_property_get_u32 (clib_dt_property_t *p)
+{
+  return clib_net_to_host_u32 (*(u32u *) p->data);
+}
+
+static_always_inline char *
+clib_dt_property_get_string (clib_dt_property_t *p)
+{
+  return (char *) p->data;
+}
+
+static_always_inline clib_dt_node_t *
+clib_dt_get_root_node (clib_dt_node_t *n)
+{
+  return n->dt_main->root;
+}
+
+static_always_inline clib_dt_node_t *
+foreach_clib_dt_tree_node_helper (clib_dt_node_t *first, clib_dt_node_t **prev,
+				  clib_dt_node_t *n)
+{
+  clib_dt_node_t *next;
+
+again:
+  if ((!*prev || (*prev)->parent != n) && vec_len (n->child_nodes) > 0)
+    next = n->child_nodes[0];
+  else if (n->next)
+    next = n->next;
+  else
+    {
+      next = n->parent;
+      *prev = n;
+      n = next;
+      if (n == first)
+	return 0;
+      goto again;
+    }
+
+  *prev = n;
+  return next == first ? 0 : next;
+}
+
+#define foreach_clib_dt_child_node(_cn, _n)                                   \
+  vec_foreach_pointer (_cn, (_n)->child_nodes)
+
+#define foreach_clib_dt_tree_node(_n, _first)                                 \
+  for (clib_dt_node_t *__last = 0, *(_n) = _first; _n;                        \
+       _n = foreach_clib_dt_tree_node_helper (_first, &__last, _n))
+
+#endif /* CLIB_DEVICETREE_H_ */