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.

1 files changed, 229 insertions, 0 deletions

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;
+}