fdt_ro.c

/*
 * 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"
 
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;
}
 
static int
_fdt_string_eq (
  const void  *fdt,
  int         stroffset,
  const char  *s,
  int         len
  )
{
  const char  *p = fdt_string (fdt, stroffset);
 
  return (strlen (p) == len) && (memcmp (p, s, len) == 0);
}
 
uint32_t
fdt_get_max_phandle (
  const void  *fdt
  )
{
  uint32_t  max_phandle = 0;
  int       offset;
 
  for (offset = fdt_next_node (fdt, -1, NULL); ;
       offset = fdt_next_node (fdt, offset, NULL))
  {
    uint32_t  phandle;
 
    if (offset == -FDT_ERR_NOTFOUND) {
      return max_phandle;
    }
 
    if (offset < 0) {
      return (uint32_t)-1;
    }
 
    phandle = fdt_get_phandle (fdt, offset);
    if (phandle == (uint32_t)-1) {
      continue;
    }
 
    if (phandle > max_phandle) {
      max_phandle = phandle;
    }
  }
 
  return 0;
}
 
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;
}
 
static int
_nextprop (
  const void  *fdt,
  int         offset
  )
{
  uint32_t  tag;
  int       nextoffset;
 
  do {
    tag = fdt_next_tag (fdt, offset, &nextoffset);
 
    switch (tag) {
      case FDT_END:
        if (nextoffset >= 0) {
          return -FDT_ERR_BADSTRUCTURE;
        } else {
          return nextoffset;
        }
 
      case FDT_PROP:
        return offset;
    }
 
    offset = nextoffset;
  } while (tag == FDT_NOP);
 
  return -FDT_ERR_NOTFOUND;
}
 
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) && (depth >= 0);
       offset = fdt_next_node (fdt, offset, &depth))
  {
    if (  (depth == 1)
       && _fdt_nodename_eq (fdt, offset, name, namelen))
    {
      return offset;
    }
  }
 
  if (depth < 0) {
    return -FDT_ERR_NOTFOUND;
  }
 
  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_namelen (
  const void  *fdt,
  const char  *path,
  int         namelen
  )
{
  const char  *end   = path + namelen;
  const char  *p     = path;
  int         offset = 0;
 
  FDT_CHECK_HEADER (fdt);
 
  /* see if we have an alias */
  if (*path != '/') {
    const char  *q = memchr (path, '/', end - p);
 
    if (!q) {
      q = end;
    }
 
    p = fdt_get_alias_namelen (fdt, p, q - p);
    if (!p) {
      return -FDT_ERR_BADPATH;
    }
 
    offset = fdt_path_offset (fdt, p);
 
    p = q;
  }
 
  while (p < end) {
    const char  *q;
 
    while (*p == '/') {
      p++;
      if (p == end) {
        return offset;
      }
    }
 
    q = memchr (p, '/', end - p);
    if (!q) {
      q = end;
    }
 
    offset = fdt_subnode_offset_namelen (fdt, offset, p, q-p);
    if (offset < 0) {
      return offset;
    }
 
    p = q;
  }
 
  return offset;
}
 
int
fdt_path_offset (
  const void  *fdt,
  const char  *path
  )
{
  return fdt_path_offset_namelen (fdt, path, strlen (path));
}
 
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;
}
 
int
fdt_first_property_offset (
  const void  *fdt,
  int         nodeoffset
  )
{
  int  offset;
 
  if ((offset = _fdt_check_node_offset (fdt, nodeoffset)) < 0) {
    return offset;
  }
 
  return _nextprop (fdt, offset);
}
 
int
fdt_next_property_offset (
  const void  *fdt,
  int         offset
  )
{
  if ((offset = _fdt_check_prop_offset (fdt, offset)) < 0) {
    return offset;
  }
 
  return _nextprop (fdt, offset);
}
 
const struct fdt_property *
fdt_get_property_by_offset (
  const void  *fdt,
  int         offset,
  int         *lenp
  )
{
  int                        err;
  const struct fdt_property  *prop;
 
  if ((err = _fdt_check_prop_offset (fdt, offset)) < 0) {
    if (lenp) {
      *lenp = err;
    }
 
    return NULL;
  }
 
  prop = _fdt_offset_ptr (fdt, offset);
 
  if (lenp) {
    *lenp = fdt32_to_cpu (prop->len);
  }
 
  return prop;
}
 
const struct fdt_property *
fdt_get_property_namelen (
  const void  *fdt,
  int         offset,
  const char  *name,
  int         namelen,
  int         *lenp
  )
{
  for (offset = fdt_first_property_offset (fdt, offset);
       (offset >= 0);
       (offset = fdt_next_property_offset (fdt, offset)))
  {
    const struct fdt_property  *prop;
 
    if (!(prop = fdt_get_property_by_offset (fdt, offset, lenp))) {
      offset = -FDT_ERR_INTERNAL;
      break;
    }
 
    if (_fdt_string_eq (
          fdt,
          fdt32_to_cpu (prop->nameoff),
          name,
          namelen
          ))
    {
      return prop;
    }
  }
 
  if (lenp) {
    *lenp = offset;
  }
 
  return NULL;
}
 
const struct fdt_property *
fdt_get_property (
  const void  *fdt,
  int         nodeoffset,
  const char  *name,
  int         *lenp
  )
{
  return fdt_get_property_namelen (
           fdt,
           nodeoffset,
           name,
           strlen (name),
           lenp
           );
}
 
const void *
fdt_getprop_namelen (
  const void  *fdt,
  int         nodeoffset,
  const char  *name,
  int         namelen,
  int         *lenp
  )
{
  const struct fdt_property  *prop;
 
  prop = fdt_get_property_namelen (fdt, nodeoffset, name, namelen, lenp);
  if (!prop) {
    return NULL;
  }
 
  return prop->data;
}
 
const void *
fdt_getprop_by_offset (
  const void  *fdt,
  int         offset,
  const char  **namep,
  int         *lenp
  )
{
  const struct fdt_property  *prop;
 
  prop = fdt_get_property_by_offset (fdt, offset, lenp);
  if (!prop) {
    return NULL;
  }
 
  if (namep) {
    *namep = fdt_string (fdt, fdt32_to_cpu (prop->nameoff));
  }
 
  return prop->data;
}
 
const void *
fdt_getprop (
  const void  *fdt,
  int         nodeoffset,
  const char  *name,
  int         *lenp
  )
{
  return fdt_getprop_namelen (fdt, nodeoffset, name, strlen (name), lenp);
}
 
uint32_t
fdt_get_phandle (
  const void  *fdt,
  int         nodeoffset
  )
{
  const fdt32_t  *php;
  int            len;
 
  /* FIXME: This is a bit sub-optimal, since we potentially scan
   * over all the properties twice. */
  php = fdt_getprop (fdt, nodeoffset, "phandle", &len);
  if (!php || (len != sizeof (*php))) {
    php = fdt_getprop (fdt, nodeoffset, "linux,phandle", &len);
    if (!php || (len != sizeof (*php))) {
      return 0;
    }
  }
 
  return fdt32_to_cpu (*php);
}
 
const char *
fdt_get_alias_namelen (
  const void  *fdt,
  const char  *name,
  int         namelen
  )
{
  int  aliasoffset;
 
  aliasoffset = fdt_path_offset (fdt, "/aliases");
  if (aliasoffset < 0) {
    return NULL;
  }
 
  return fdt_getprop_namelen (fdt, aliasoffset, name, namelen, NULL);
}
 
const char *
fdt_get_alias (
  const void  *fdt,
  const char  *name
  )
{
  return fdt_get_alias_namelen (fdt, name, strlen (name));
}
 
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))
  {
    while (pdepth > depth) {
      do {
        p--;
      } while (buf[p-1] != '/');
 
      pdepth--;
    }
 
    if (pdepth >= depth) {
      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 0;
    }
  }
 
  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
  )
{
  int  offset;
 
  if ((phandle == 0) || (phandle == -1)) {
    return -FDT_ERR_BADPHANDLE;
  }
 
  FDT_CHECK_HEADER (fdt);
 
  /* FIXME: The algorithm here is pretty horrible: we
   * potentially scan each property of a node in
   * fdt_get_phandle(), 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, -1, NULL);
       offset >= 0;
       offset = fdt_next_node (fdt, offset, NULL))
  {
    if (fdt_get_phandle (fdt, offset) == phandle) {
      return offset;
    }
  }
 
  return offset;       /* error from fdt_next_node() */
}
 
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_stringlist_count (
  const void  *fdt,
  int         nodeoffset,
  const char  *property
  )
{
  const char  *list, *end;
  int         length, count = 0;
 
  list = fdt_getprop (fdt, nodeoffset, property, &length);
  if (!list) {
    return length;
  }
 
  end = list + length;
 
  while (list < end) {
    length = strnlen (list, end - list) + 1;
 
    /* Abort if the last string isn't properly NUL-terminated. */
    if (list + length > end) {
      return -FDT_ERR_BADVALUE;
    }
 
    list += length;
    count++;
  }
 
  return count;
}
 
int
fdt_stringlist_search (
  const void  *fdt,
  int         nodeoffset,
  const char  *property,
  const char  *string
  )
{
  int         length, len, idx = 0;
  const char  *list, *end;
 
  list = fdt_getprop (fdt, nodeoffset, property, &length);
  if (!list) {
    return length;
  }
 
  len = strlen (string) + 1;
  end = list + length;
 
  while (list < end) {
    length = strnlen (list, end - list) + 1;
 
    /* Abort if the last string isn't properly NUL-terminated. */
    if (list + length > end) {
      return -FDT_ERR_BADVALUE;
    }
 
    if ((length == len) && (memcmp (list, string, length) == 0)) {
      return idx;
    }
 
    list += length;
    idx++;
  }
 
  return -FDT_ERR_NOTFOUND;
}
 
const char *
fdt_stringlist_get (
  const void  *fdt,
  int         nodeoffset,
  const char  *property,
  int         idx,
  int         *lenp
  )
{
  const char  *list, *end;
  int         length;
 
  list = fdt_getprop (fdt, nodeoffset, property, &length);
  if (!list) {
    if (lenp) {
      *lenp = length;
    }
 
    return NULL;
  }
 
  end = list + length;
 
  while (list < end) {
    length = strnlen (list, end - list) + 1;
 
    /* Abort if the last string isn't properly NUL-terminated. */
    if (list + length > end) {
      if (lenp) {
        *lenp = -FDT_ERR_BADVALUE;
      }
 
      return NULL;
    }
 
    if (idx == 0) {
      if (lenp) {
        *lenp = length - 1;
      }
 
      return list;
    }
 
    list += length;
    idx--;
  }
 
  if (lenp) {
    *lenp = -FDT_ERR_NOTFOUND;
  }
 
  return NULL;
}
 
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;
  }
 
  return !fdt_stringlist_contains (prop, len, compatible);
}
 
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() */
}