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tree.c

/* $Id: tree.c,v 1.26 2000/08/26 02:38:03 anton Exp $
 * tree.c: Basic device tree traversal/scanning for the Linux
 *         prom library.
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 */

#define PROMLIB_INTERNAL

#include <linux/string.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/ctype.h>

#include <asm/openprom.h>
#include <asm/oplib.h>

extern void restore_current(void);

static char promlib_buf[128];

/* Internal version of prom_getchild that does not alter return values. */
int __prom_getchild(int node)
{
      unsigned long flags;
      int cnode;

      spin_lock_irqsave(&prom_lock, flags);
      cnode = prom_nodeops->no_child(node);
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);

      return cnode;
}

/* Return the child of node 'node' or zero if no this node has no
 * direct descendent.
 */
int prom_getchild(int node)
{
      int cnode;

      if (node == -1)
            return 0;

      cnode = __prom_getchild(node);
      if (cnode == 0 || cnode == -1)
            return 0;

      return cnode;
}

/* Internal version of prom_getsibling that does not alter return values. */
int __prom_getsibling(int node)
{
      unsigned long flags;
      int cnode;

      spin_lock_irqsave(&prom_lock, flags);
      cnode = prom_nodeops->no_nextnode(node);
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);

      return cnode;
}

/* Return the next sibling of node 'node' or zero if no more siblings
 * at this level of depth in the tree.
 */
int prom_getsibling(int node)
{
      int sibnode;

      if (node == -1)
            return 0;

      sibnode = __prom_getsibling(node);
      if (sibnode == 0 || sibnode == -1)
            return 0;

      return sibnode;
}

/* Return the length in bytes of property 'prop' at node 'node'.
 * Return -1 on error.
 */
int prom_getproplen(int node, char *prop)
{
      int ret;
      unsigned long flags;

      if((!node) || (!prop))
            return -1;
            
      spin_lock_irqsave(&prom_lock, flags);
      ret = prom_nodeops->no_proplen(node, prop);
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);
      return ret;
}

/* Acquire a property 'prop' at node 'node' and place it in
 * 'buffer' which has a size of 'bufsize'.  If the acquisition
 * was successful the length will be returned, else -1 is returned.
 */
int prom_getproperty(int node, char *prop, char *buffer, int bufsize)
{
      int plen, ret;
      unsigned long flags;

      plen = prom_getproplen(node, prop);
      if((plen > bufsize) || (plen == 0) || (plen == -1))
            return -1;
      /* Ok, things seem all right. */
      spin_lock_irqsave(&prom_lock, flags);
      ret = prom_nodeops->no_getprop(node, prop, buffer);
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);
      return ret;
}

/* Acquire an integer property and return its value.  Returns -1
 * on failure.
 */
int prom_getint(int node, char *prop)
{
      static int intprop;

      if(prom_getproperty(node, prop, (char *) &intprop, sizeof(int)) != -1)
            return intprop;

      return -1;
}

/* Acquire an integer property, upon error return the passed default
 * integer.
 */
int prom_getintdefault(int node, char *property, int deflt)
{
      int retval;

      retval = prom_getint(node, property);
      if(retval == -1) return deflt;

      return retval;
}

/* Acquire a boolean property, 1=TRUE 0=FALSE. */
int prom_getbool(int node, char *prop)
{
      int retval;

      retval = prom_getproplen(node, prop);
      if(retval == -1) return 0;
      return 1;
}

/* Acquire a property whose value is a string, returns a null
 * string on error.  The char pointer is the user supplied string
 * buffer.
 */
void prom_getstring(int node, char *prop, char *user_buf, int ubuf_size)
{
      int len;

      len = prom_getproperty(node, prop, user_buf, ubuf_size);
      if(len != -1) return;
      user_buf[0] = 0;
      return;
}


/* Does the device at node 'node' have name 'name'?
 * YES = 1   NO = 0
 */
int prom_nodematch(int node, char *name)
{
      int error;

      static char namebuf[128];
      error = prom_getproperty(node, "name", namebuf, sizeof(namebuf));
      if (error == -1) return 0;
      if(strcmp(namebuf, name) == 0) return 1;
      return 0;
}

/* Search siblings at 'node_start' for a node with name
 * 'nodename'.  Return node if successful, zero if not.
 */
int prom_searchsiblings(int node_start, char *nodename)
{

      int thisnode, error;

      for(thisnode = node_start; thisnode;
          thisnode=prom_getsibling(thisnode)) {
            error = prom_getproperty(thisnode, "name", promlib_buf,
                               sizeof(promlib_buf));
            /* Should this ever happen? */
            if(error == -1) continue;
            if(strcmp(nodename, promlib_buf)==0) return thisnode;
      }

      return 0;
}

/* Interal version of nextprop that does not alter return values. */
char * __prom_nextprop(int node, char * oprop)
{
      unsigned long flags;
      char *prop;

      spin_lock_irqsave(&prom_lock, flags);
      prop = prom_nodeops->no_nextprop(node, oprop);
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);

      return prop;
}

/* Return the first property name for node 'node'. */
/* buffer is unused argument, but as v9 uses it, we need to have the same interface */
char * prom_firstprop(int node, char *bufer)
{
      if (node == 0 || node == -1)
            return "";

      return __prom_nextprop(node, "");
}

/* Return the property type string after property type 'oprop'
 * at node 'node' .  Returns empty string if no more
 * property types for this node.
 */
char * prom_nextprop(int node, char *oprop, char *buffer)
{
      if (node == 0 || node == -1)
            return "";

      return __prom_nextprop(node, oprop);
}

int prom_finddevice(char *name)
{
      char nbuf[128];
      char *s = name, *d;
      int node = prom_root_node, node2;
      unsigned int which_io, phys_addr;
      struct linux_prom_registers reg[PROMREG_MAX];

      while (*s++) {
            if (!*s) return node; /* path '.../' is legal */
            node = prom_getchild(node);

            for (d = nbuf; *s != 0 && *s != '@' && *s != '/';)
                  *d++ = *s++;
            *d = 0;
            
            node = prom_searchsiblings(node, nbuf);
            if (!node)
                  return 0;

            if (*s == '@') {
                  if (isxdigit(s[1]) && s[2] == ',') {
                        which_io = simple_strtoul(s+1, NULL, 16);
                        phys_addr = simple_strtoul(s+3, &d, 16);
                        if (d != s + 3 && (!*d || *d == '/')
                            && d <= s + 3 + 8) {
                              node2 = node;
                              while (node2 && node2 != -1) {
                                    if (prom_getproperty (node2, "reg", (char *)reg, sizeof (reg)) > 0) {
                                          if (which_io == reg[0].which_io && phys_addr == reg[0].phys_addr) {
                                                node = node2;
                                                break;
                                          }
                                    }
                                    node2 = prom_getsibling(node2);
                                    if (!node2 || node2 == -1)
                                          break;
                                    node2 = prom_searchsiblings(prom_getsibling(node2), nbuf);
                              }
                        }
                  }
                  while (*s != 0 && *s != '/') s++;
            }
      }
      return node;
}

int prom_node_has_property(int node, char *prop)
{
      char *current_property = "";

      do {
            current_property = prom_nextprop(node, current_property, NULL);
            if(!strcmp(current_property, prop))
               return 1;
      } while (*current_property);
      return 0;
}

/* Set property 'pname' at node 'node' to value 'value' which has a length
 * of 'size' bytes.  Return the number of bytes the prom accepted.
 */
int prom_setprop(int node, char *pname, char *value, int size)
{
      unsigned long flags;
      int ret;

      if(size == 0) return 0;
      if((pname == 0) || (value == 0)) return 0;
      spin_lock_irqsave(&prom_lock, flags);
      ret = prom_nodeops->no_setprop(node, pname, value, size);
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);
      return ret;
}

int prom_inst2pkg(int inst)
{
      int node;
      unsigned long flags;
      
      spin_lock_irqsave(&prom_lock, flags);
      node = (*romvec->pv_v2devops.v2_inst2pkg)(inst);
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);
      if (node == -1) return 0;
      return node;
}

/* Return 'node' assigned to a particular prom 'path'
 * FIXME: Should work for v0 as well
 */
int prom_pathtoinode(char *path)
{
      int node, inst;
      
      inst = prom_devopen (path);
      if (inst == -1) return 0;
      node = prom_inst2pkg (inst);
      prom_devclose (inst);
      if (node == -1) return 0;
      return node;
}

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