libfdt/fdt_ro.c - filogic/uboot - Gitiles

 /*
  * libfdt - Flat Device Tree manipulation
  * Copyright (C) 2006 David Gibson, IBM Corporation.
  *
  * libfdt is dual licensed: you can use it either under the terms of
  * the GPL, or the BSD license, at your option.
  *
  *  a) This library is free software; you can redistribute it and/or
  *     modify it under the terms of the GNU General Public License as
  *     published by the Free Software Foundation; either version 2 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 General Public License for more details.
  *
  *     You should have received a copy of the GNU 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
  *
  * Alternatively,
  *
  *  b) Redistribution and use in source and binary forms, with or
  *     without modification, are permitted provided that the following
  *     conditions are met:
  *
  *     1. Redistributions of source code must retain the above
  *        copyright notice, this list of conditions and the following
  *        disclaimer.
  *     2. Redistributions in binary form must reproduce the above
  *        copyright notice, this list of conditions and the following
  *        disclaimer in the documentation and/or other materials
  *        provided with the distribution.
  *
  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include "libfdt_env.h"

 #ifndef USE_HOSTCC
 #include <fdt.h>
 #include <libfdt.h>
 #else
 #include "fdt_host.h"
 #endif

 #include "libfdt_internal.h"

 static int _fdt_nodename_eq(const void *fdt, int offset,
 			    const char *s, int len)
 {
 	const char *p = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, len+1);

 	if (! p)
 		/* short match */
 		return 0;

 	if (memcmp(p, s, len) != 0)
 		return 0;

 	if (p[len] == '\0')
 		return 1;
 	else if (!memchr(s, '@', len) && (p[len] == '@'))
 		return 1;
 	else
 		return 0;
 }

 const char *fdt_string(const void *fdt, int stroffset)
 {
 	return (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
 }

 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
 {
 	FDT_CHECK_HEADER(fdt);
 	*address = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->address);
 	*size = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->size);
 	return 0;
 }

 int fdt_num_mem_rsv(const void *fdt)
 {
 	int i = 0;

 	while (fdt64_to_cpu(_fdt_mem_rsv(fdt, i)->size) != 0)
 		i++;
 	return i;
 }

 int fdt_subnode_offset_namelen(const void *fdt, int offset,
 			       const char *name, int namelen)
 {
 	int depth;

 	FDT_CHECK_HEADER(fdt);

 	for (depth = 0;
 	     offset >= 0;
 	     offset = fdt_next_node(fdt, offset, &depth)) {
 		if (depth < 0)
 			return -FDT_ERR_NOTFOUND;
 		else if ((depth == 1)
 			 && _fdt_nodename_eq(fdt, offset, name, namelen))
 			return offset;
 	}

 	return offset; /* error */
 }

 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;

 	FDT_CHECK_HEADER(fdt);

 	if (*path != '/')
 		return -FDT_ERR_BADPATH;

 	while (*p) {
 		const char *q;

 		while (*p == '/')
 			p++;
 		if (! *p)
 			return offset;
 		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;
 }

 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
 {
 	const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset);
 	int err;

 	if (((err = fdt_check_header(fdt)) != 0)
 	    || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
 			goto fail;

 	if (len)
 		*len = strlen(nh->name);

 	return nh->name;

  fail:
 	if (len)
 		*len = err;
 	return NULL;
 }

 const struct fdt_property *fdt_get_property(const void *fdt,
 					    int nodeoffset,
 					    const char *name, int *lenp)
 {
 	uint32_t tag;
 	const struct fdt_property *prop;
 	int namestroff;
 	int offset, nextoffset;
 	int err;

 	if (((err = fdt_check_header(fdt)) != 0)
 	    || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
 			goto fail;

 	nextoffset = err;
 	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:
 		case FDT_END_NODE:
 		case FDT_NOP:
 			break;

 		case FDT_PROP:
 			err = -FDT_ERR_BADSTRUCTURE;
 			prop = fdt_offset_ptr(fdt, offset, sizeof(*prop));
 			if (! prop)
 				goto fail;
 			namestroff = fdt32_to_cpu(prop->nameoff);
 			if (strcmp(fdt_string(fdt, namestroff), name) == 0) {
 				/* 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;

 		default:
 			err = -FDT_ERR_BADSTRUCTURE;
 			goto fail;
 		}
 	} while ((tag != FDT_BEGIN_NODE) && (tag != FDT_END_NODE));

 	err = -FDT_ERR_NOTFOUND;
  fail:
 	if (lenp)
 		*lenp = err;
 	return NULL;
 }

 const 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;
 }

 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
 {
 	const uint32_t *php;
 	int len;

 	php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
 	if (!php || (len != sizeof(*php)))
 		return 0;

 	return fdt32_to_cpu(*php);
 }

 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
 {
 	int pdepth = 0, p = 0;
 	int offset, depth, namelen;
 	const char *name;

 	FDT_CHECK_HEADER(fdt);

 	if (buflen < 2)
 		return -FDT_ERR_NOSPACE;

 	for (offset = 0, depth = 0;
 	     (offset >= 0) && (offset <= nodeoffset);
 	     offset = fdt_next_node(fdt, offset, &depth)) {
 		if (pdepth < depth)
 			continue; /* overflowed buffer */

 		while (pdepth > depth) {
 			do {
 				p--;
 			} while (buf[p-1] != '/');
 			pdepth--;
 		}

 		name = fdt_get_name(fdt, offset, &namelen);
 		if (!name)
 			return namelen;
 		if ((p + namelen + 1) <= buflen) {
 			memcpy(buf + p, name, namelen);
 			p += namelen;
 			buf[p++] = '/';
 			pdepth++;
 		}

 		if (offset == nodeoffset) {
 			if (pdepth < (depth + 1))
 				return -FDT_ERR_NOSPACE;

 			if (p > 1) /* special case so that root path is "/", not "" */
 				p--;
 			buf[p] = '\0';
 			return p;
 		}
 	}

 	if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 		return -FDT_ERR_BADOFFSET;
 	else if (offset == -FDT_ERR_BADOFFSET)
 		return -FDT_ERR_BADSTRUCTURE;

 	return offset; /* error from fdt_next_node() */
 }

 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 				 int supernodedepth, int *nodedepth)
 {
 	int offset, depth;
 	int supernodeoffset = -FDT_ERR_INTERNAL;

 	FDT_CHECK_HEADER(fdt);

 	if (supernodedepth < 0)
 		return -FDT_ERR_NOTFOUND;

 	for (offset = 0, depth = 0;
 	     (offset >= 0) && (offset <= nodeoffset);
 	     offset = fdt_next_node(fdt, offset, &depth)) {
 		if (depth == supernodedepth)
 			supernodeoffset = offset;

 		if (offset == nodeoffset) {
 			if (nodedepth)
 				*nodedepth = depth;

 			if (supernodedepth > depth)
 				return -FDT_ERR_NOTFOUND;
 			else
 				return supernodeoffset;
 		}
 	}

 	if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
 		return -FDT_ERR_BADOFFSET;
 	else if (offset == -FDT_ERR_BADOFFSET)
 		return -FDT_ERR_BADSTRUCTURE;

 	return offset; /* error from fdt_next_node() */
 }

 int fdt_node_depth(const void *fdt, int nodeoffset)
 {
 	int nodedepth;
 	int err;

 	err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
 	if (err)
 		return (err < 0) ? err : -FDT_ERR_INTERNAL;
 	return nodedepth;
 }

 int fdt_parent_offset(const void *fdt, int nodeoffset)
 {
 	int nodedepth = fdt_node_depth(fdt, nodeoffset);

 	if (nodedepth < 0)
 		return nodedepth;
 	return fdt_supernode_atdepth_offset(fdt, nodeoffset,
 					    nodedepth - 1, NULL);
 }

 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
 				  const char *propname,
 				  const void *propval, int proplen)
 {
 	int offset;
 	const void *val;
 	int len;

 	FDT_CHECK_HEADER(fdt);

 	/* FIXME: The algorithm here is pretty horrible: we scan each
 	 * property of a node in fdt_getprop(), then if that didn't
 	 * find what we want, we scan over them again making our way
 	 * to the next node.  Still it's the easiest to implement
 	 * approach; performance can come later. */
 	for (offset = fdt_next_node(fdt, startoffset, NULL);
 	     offset >= 0;
 	     offset = fdt_next_node(fdt, offset, NULL)) {
 		val = fdt_getprop(fdt, offset, propname, &len);
 		if (val && (len == proplen)
 		    && (memcmp(val, propval, len) == 0))
 			return offset;
 	}

 	return offset; /* error from fdt_next_node() */
 }

 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
 {
 	if ((phandle == 0) || (phandle == -1))
 		return -FDT_ERR_BADPHANDLE;
 	phandle = cpu_to_fdt32(phandle);
 	return fdt_node_offset_by_prop_value(fdt, -1, "linux,phandle",
 					     &phandle, sizeof(phandle));
 }

 static int _fdt_stringlist_contains(const char *strlist, int listlen,
 				    const char *str)
 {
 	int len = strlen(str);
 	const char *p;

 	while (listlen >= len) {
 		if (memcmp(str, strlist, len+1) == 0)
 			return 1;
 		p = memchr(strlist, '\0', listlen);
 		if (!p)
 			return 0; /* malformed strlist.. */
 		listlen -= (p-strlist) + 1;
 		strlist = p + 1;
 	}
 	return 0;
 }

 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
 			      const char *compatible)
 {
 	const void *prop;
 	int len;

 	prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
 	if (!prop)
 		return len;
 	if (_fdt_stringlist_contains(prop, len, compatible))
 		return 0;
 	else
 		return 1;
 }

 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 				  const char *compatible)
 {
 	int offset, err;

 	FDT_CHECK_HEADER(fdt);

 	/* FIXME: The algorithm here is pretty horrible: we scan each
 	 * property of a node in fdt_node_check_compatible(), then if
 	 * that didn't find what we want, we scan over them again
 	 * making our way to the next node.  Still it's the easiest to
 	 * implement approach; performance can come later. */
 	for (offset = fdt_next_node(fdt, startoffset, NULL);
 	     offset >= 0;
 	     offset = fdt_next_node(fdt, offset, NULL)) {
 		err = fdt_node_check_compatible(fdt, offset, compatible);
 		if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
 			return err;
 		else if (err == 0)
 			return offset;
 	}

 	return offset; /* error from fdt_next_node() */
 }
	/*
	* libfdt - Flat Device Tree manipulation
	* Copyright (C) 2006 David Gibson, IBM Corporation.
	*
	* libfdt is dual licensed: you can use it either under the terms of
	* the GPL, or the BSD license, at your option.
	*
	* a) This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 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 General Public License for more details.
	*
	* You should have received a copy of the GNU 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
	*
	* Alternatively,
	*
	* b) Redistribution and use in source and binary forms, with or
	* without modification, are permitted provided that the following
	* conditions are met:
	*
	* 1. Redistributions of source code must retain the above
	* copyright notice, this list of conditions and the following
	* disclaimer.
	* 2. Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials
	* provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
	* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
	* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
	* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
	* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/
	#include "libfdt_env.h"

	#ifndef USE_HOSTCC
	#include <fdt.h>
	#include <libfdt.h>
	#else
	#include "fdt_host.h"
	#endif

	#include "libfdt_internal.h"

	static int _fdt_nodename_eq(const void *fdt, int offset,
	const char *s, int len)
	{
	const char *p = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, len+1);

	if (! p)
	/* short match */
	return 0;

	if (memcmp(p, s, len) != 0)
	return 0;

	if (p[len] == '\0')
	return 1;
	else if (!memchr(s, '@', len) && (p[len] == '@'))
	return 1;
	else
	return 0;
	}

	const char fdt_string(const void fdt, int stroffset)
	{
	return (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
	}

	int fdt_get_mem_rsv(const void fdt, int n, uint64_t address, uint64_t *size)
	{
	FDT_CHECK_HEADER(fdt);
	*address = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->address);
	*size = fdt64_to_cpu(_fdt_mem_rsv(fdt, n)->size);
	return 0;
	}

	int fdt_num_mem_rsv(const void *fdt)
	{
	int i = 0;

	while (fdt64_to_cpu(_fdt_mem_rsv(fdt, i)->size) != 0)
	i++;
	return i;
	}

	int fdt_subnode_offset_namelen(const void *fdt, int offset,
	const char *name, int namelen)
	{
	int depth;

	FDT_CHECK_HEADER(fdt);

	for (depth = 0;
	offset >= 0;
	offset = fdt_next_node(fdt, offset, &depth)) {
	if (depth < 0)
	return -FDT_ERR_NOTFOUND;
	else if ((depth == 1)
	&& _fdt_nodename_eq(fdt, offset, name, namelen))
	return offset;
	}

	return offset; /* error */
	}

	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;

	FDT_CHECK_HEADER(fdt);

	if (*path != '/')
	return -FDT_ERR_BADPATH;

	while (*p) {
	const char *q;

	while (*p == '/')
	p++;
	if (! *p)
	return offset;
	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;
	}

	const char fdt_get_name(const void fdt, int nodeoffset, int *len)
	{
	const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset);
	int err;

	if (((err = fdt_check_header(fdt)) != 0)
	\|\| ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
	goto fail;

	if (len)
	*len = strlen(nh->name);

	return nh->name;

	fail:
	if (len)
	*len = err;
	return NULL;
	}

	const struct fdt_property fdt_get_property(const void fdt,
	int nodeoffset,
	const char name, int lenp)
	{
	uint32_t tag;
	const struct fdt_property *prop;
	int namestroff;
	int offset, nextoffset;
	int err;

	if (((err = fdt_check_header(fdt)) != 0)
	\|\| ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
	goto fail;

	nextoffset = err;
	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:
	case FDT_END_NODE:
	case FDT_NOP:
	break;

	case FDT_PROP:
	err = -FDT_ERR_BADSTRUCTURE;
	prop = fdt_offset_ptr(fdt, offset, sizeof(*prop));
	if (! prop)
	goto fail;
	namestroff = fdt32_to_cpu(prop->nameoff);
	if (strcmp(fdt_string(fdt, namestroff), name) == 0) {
	/* 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;

	default:
	err = -FDT_ERR_BADSTRUCTURE;
	goto fail;
	}
	} while ((tag != FDT_BEGIN_NODE) && (tag != FDT_END_NODE));

	err = -FDT_ERR_NOTFOUND;
	fail:
	if (lenp)
	*lenp = err;
	return NULL;
	}

	const 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;
	}

	uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
	{
	const uint32_t *php;
	int len;

	php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
	if (!php \|\| (len != sizeof(*php)))
	return 0;

	return fdt32_to_cpu(*php);
	}

	int fdt_get_path(const void fdt, int nodeoffset, char buf, int buflen)
	{
	int pdepth = 0, p = 0;
	int offset, depth, namelen;
	const char *name;

	FDT_CHECK_HEADER(fdt);

	if (buflen < 2)
	return -FDT_ERR_NOSPACE;

	for (offset = 0, depth = 0;
	(offset >= 0) && (offset <= nodeoffset);
	offset = fdt_next_node(fdt, offset, &depth)) {
	if (pdepth < depth)
	continue; /* overflowed buffer */

	while (pdepth > depth) {
	do {
	p--;
	} while (buf[p-1] != '/');
	pdepth--;
	}

	name = fdt_get_name(fdt, offset, &namelen);
	if (!name)
	return namelen;
	if ((p + namelen + 1) <= buflen) {
	memcpy(buf + p, name, namelen);
	p += namelen;
	buf[p++] = '/';
	pdepth++;
	}

	if (offset == nodeoffset) {
	if (pdepth < (depth + 1))
	return -FDT_ERR_NOSPACE;

	if (p > 1) /* special case so that root path is "/", not "" */
	p--;
	buf[p] = '\0';
	return p;
	}
	}

	if ((offset == -FDT_ERR_NOTFOUND) \|\| (offset >= 0))
	return -FDT_ERR_BADOFFSET;
	else if (offset == -FDT_ERR_BADOFFSET)
	return -FDT_ERR_BADSTRUCTURE;

	return offset; /* error from fdt_next_node() */
	}

	int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
	int supernodedepth, int *nodedepth)
	{
	int offset, depth;
	int supernodeoffset = -FDT_ERR_INTERNAL;

	FDT_CHECK_HEADER(fdt);

	if (supernodedepth < 0)
	return -FDT_ERR_NOTFOUND;

	for (offset = 0, depth = 0;
	(offset >= 0) && (offset <= nodeoffset);
	offset = fdt_next_node(fdt, offset, &depth)) {
	if (depth == supernodedepth)
	supernodeoffset = offset;

	if (offset == nodeoffset) {
	if (nodedepth)
	*nodedepth = depth;

	if (supernodedepth > depth)
	return -FDT_ERR_NOTFOUND;
	else
	return supernodeoffset;
	}
	}

	if ((offset == -FDT_ERR_NOTFOUND) \|\| (offset >= 0))
	return -FDT_ERR_BADOFFSET;
	else if (offset == -FDT_ERR_BADOFFSET)
	return -FDT_ERR_BADSTRUCTURE;

	return offset; /* error from fdt_next_node() */
	}

	int fdt_node_depth(const void *fdt, int nodeoffset)
	{
	int nodedepth;
	int err;

	err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
	if (err)
	return (err < 0) ? err : -FDT_ERR_INTERNAL;
	return nodedepth;
	}

	int fdt_parent_offset(const void *fdt, int nodeoffset)
	{
	int nodedepth = fdt_node_depth(fdt, nodeoffset);

	if (nodedepth < 0)
	return nodedepth;
	return fdt_supernode_atdepth_offset(fdt, nodeoffset,
	nodedepth - 1, NULL);
	}

	int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
	const char *propname,
	const void *propval, int proplen)
	{
	int offset;
	const void *val;
	int len;

	FDT_CHECK_HEADER(fdt);

	/* FIXME: The algorithm here is pretty horrible: we scan each
	* property of a node in fdt_getprop(), then if that didn't
	* find what we want, we scan over them again making our way
	* to the next node. Still it's the easiest to implement
	* approach; performance can come later. */
	for (offset = fdt_next_node(fdt, startoffset, NULL);
	offset >= 0;
	offset = fdt_next_node(fdt, offset, NULL)) {
	val = fdt_getprop(fdt, offset, propname, &len);
	if (val && (len == proplen)
	&& (memcmp(val, propval, len) == 0))
	return offset;
	}

	return offset; /* error from fdt_next_node() */
	}

	int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
	{
	if ((phandle == 0) \|\| (phandle == -1))
	return -FDT_ERR_BADPHANDLE;
	phandle = cpu_to_fdt32(phandle);
	return fdt_node_offset_by_prop_value(fdt, -1, "linux,phandle",
	&phandle, sizeof(phandle));
	}

	static int _fdt_stringlist_contains(const char *strlist, int listlen,
	const char *str)
	{
	int len = strlen(str);
	const char *p;

	while (listlen >= len) {
	if (memcmp(str, strlist, len+1) == 0)
	return 1;
	p = memchr(strlist, '\0', listlen);
	if (!p)
	return 0; /* malformed strlist.. */
	listlen -= (p-strlist) + 1;
	strlist = p + 1;
	}
	return 0;
	}

	int fdt_node_check_compatible(const void *fdt, int nodeoffset,
	const char *compatible)
	{
	const void *prop;
	int len;

	prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
	if (!prop)
	return len;
	if (_fdt_stringlist_contains(prop, len, compatible))
	return 0;
	else
	return 1;
	}

	int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
	const char *compatible)
	{
	int offset, err;

	FDT_CHECK_HEADER(fdt);

	/* FIXME: The algorithm here is pretty horrible: we scan each
	* property of a node in fdt_node_check_compatible(), then if
	* that didn't find what we want, we scan over them again
	* making our way to the next node. Still it's the easiest to
	* implement approach; performance can come later. */
	for (offset = fdt_next_node(fdt, startoffset, NULL);
	offset >= 0;
	offset = fdt_next_node(fdt, offset, NULL)) {
	err = fdt_node_check_compatible(fdt, offset, compatible);
	if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
	return err;
	else if (err == 0)
	return offset;
	}

	return offset; /* error from fdt_next_node() */
	}