You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

261 lines
6.0 KiB

/*
* 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"
#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;
}
const struct fdt_property *fdt_get_property(const void *fdt,
int nodeoffset,
const char *name, int *lenp)
{
int level = 0;
uint32_t tag;
const 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;
}
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;
}