/*
 * 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);
}

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 (const void *fdt, const char *path)
{
  const char *end = path + strlen (path);
  const char *p = path;
  int offset = 0;

  FDT_CHECK_HEADER (fdt);

  /* see if we have an alias */
  if (*path != '/')
    {
      const char *q = strchr (path, '/');

      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)
    {
      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;
}

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 uint32_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() */
}

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() */
}