libfdt: Import libfdt source (2 of 2)
This adds the applicable libfdt source files (unmodified) and a README
to explain where the source came from.
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
new file mode 100644
index 0000000..9112c6a
--- /dev/null
+++ b/libfdt/fdt_ro.c
@@ -0,0 +1,229 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2006 David Gibson, IBM Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "libfdt_env.h"
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "libfdt_internal.h"
+
+#define CHECK_HEADER(fdt) \
+ { \
+ int err; \
+ if ((err = _fdt_check_header(fdt)) != 0) \
+ return err; \
+ }
+
+static int offset_streq(const void *fdt, int offset,
+ const char *s, int len)
+{
+ const char *p = fdt_offset_ptr(fdt, offset, len+1);
+
+ if (! p)
+ /* short match */
+ return 0;
+
+ if (memcmp(p, s, len) != 0)
+ return 0;
+
+ if (p[len] != '\0')
+ return 0;
+
+ return 1;
+}
+
+char *fdt_string(const void *fdt, int stroffset)
+{
+ return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
+}
+
+int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
+ const char *name, int namelen)
+{
+ int level = 0;
+ uint32_t tag;
+ int offset, nextoffset;
+
+ CHECK_HEADER(fdt);
+
+ tag = _fdt_next_tag(fdt, parentoffset, &nextoffset);
+ if (tag != FDT_BEGIN_NODE)
+ return -FDT_ERR_BADOFFSET;
+
+ do {
+ offset = nextoffset;
+ tag = _fdt_next_tag(fdt, offset, &nextoffset);
+
+ switch (tag) {
+ case FDT_END:
+ return -FDT_ERR_TRUNCATED;
+
+ case FDT_BEGIN_NODE:
+ level++;
+ if (level != 1)
+ continue;
+ if (offset_streq(fdt, offset+FDT_TAGSIZE, name, namelen))
+ /* Found it! */
+ return offset;
+ break;
+
+ case FDT_END_NODE:
+ level--;
+ break;
+
+ case FDT_PROP:
+ case FDT_NOP:
+ break;
+
+ default:
+ return -FDT_ERR_BADSTRUCTURE;
+ }
+ } while (level >= 0);
+
+ return -FDT_ERR_NOTFOUND;
+}
+
+int fdt_subnode_offset(const void *fdt, int parentoffset,
+ const char *name)
+{
+ return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
+}
+
+int fdt_path_offset(const void *fdt, const char *path)
+{
+ const char *end = path + strlen(path);
+ const char *p = path;
+ int offset = 0;
+
+ CHECK_HEADER(fdt);
+
+ if (*path != '/')
+ return -FDT_ERR_BADPATH;
+
+ while (*p) {
+ const char *q;
+
+ while (*p == '/')
+ p++;
+ if (! *p)
+ return -FDT_ERR_BADPATH;
+ q = strchr(p, '/');
+ if (! q)
+ q = end;
+
+ offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
+ if (offset < 0)
+ return offset;
+
+ p = q;
+ }
+
+ return offset;
+}
+
+struct fdt_property *fdt_get_property(const void *fdt,
+ int nodeoffset,
+ const char *name, int *lenp)
+{
+ int level = 0;
+ uint32_t tag;
+ struct fdt_property *prop;
+ int namestroff;
+ int offset, nextoffset;
+ int err;
+
+ if ((err = _fdt_check_header(fdt)) != 0)
+ goto fail;
+
+ err = -FDT_ERR_BADOFFSET;
+ if (nodeoffset % FDT_TAGSIZE)
+ goto fail;
+
+ tag = _fdt_next_tag(fdt, nodeoffset, &nextoffset);
+ if (tag != FDT_BEGIN_NODE)
+ goto fail;
+
+ do {
+ offset = nextoffset;
+
+ tag = _fdt_next_tag(fdt, offset, &nextoffset);
+ switch (tag) {
+ case FDT_END:
+ err = -FDT_ERR_TRUNCATED;
+ goto fail;
+
+ case FDT_BEGIN_NODE:
+ level++;
+ break;
+
+ case FDT_END_NODE:
+ level--;
+ break;
+
+ case FDT_PROP:
+ if (level != 0)
+ continue;
+
+ err = -FDT_ERR_BADSTRUCTURE;
+ prop = fdt_offset_ptr_typed(fdt, offset, prop);
+ if (! prop)
+ goto fail;
+ namestroff = fdt32_to_cpu(prop->nameoff);
+ if (streq(fdt_string(fdt, namestroff), name)) {
+ /* Found it! */
+ int len = fdt32_to_cpu(prop->len);
+ prop = fdt_offset_ptr(fdt, offset,
+ sizeof(*prop)+len);
+ if (! prop)
+ goto fail;
+
+ if (lenp)
+ *lenp = len;
+
+ return prop;
+ }
+ break;
+
+ case FDT_NOP:
+ break;
+
+ default:
+ err = -FDT_ERR_BADSTRUCTURE;
+ goto fail;
+ }
+ } while (level >= 0);
+
+ err = -FDT_ERR_NOTFOUND;
+ fail:
+ if (lenp)
+ *lenp = err;
+ return NULL;
+}
+
+void *fdt_getprop(const void *fdt, int nodeoffset,
+ const char *name, int *lenp)
+{
+ const struct fdt_property *prop;
+
+ prop = fdt_get_property(fdt, nodeoffset, name, lenp);
+ if (! prop)
+ return NULL;
+
+ return prop->data;
+}
