/* Prom tree handling
   
   Copyright (C) 1996 David S. Miller
   
   This program 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 program 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 program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "silo.h"

static char promlib_buf[128];

/* 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_nodeops->no_child (node);
    if ((cnode == 0) || (cnode == -1))
	return 0;
    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_nodeops->no_nextnode (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)
{
    if ((!node) || (!prop))
	return -1;
    return prom_nodeops->no_proplen (node, prop);
}

/* 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;

    plen = prom_getproplen (node, prop);
    if ((plen > bufsize) || (plen == 0) || (plen == -1))
	return -1;

    /* Ok, things seem all right. */
    return prom_nodeops->no_getprop (node, prop, buffer);
}

/* 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)
{
    static char namebuf[128];
    prom_getproperty (node, "name", namebuf, sizeof (namebuf));
    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;
}

/* Return the first property type for node 'node'.
 */
char *prom_firstprop (int node)
{
    if (node == -1)
	return "";
    return prom_nodeops->no_nextprop (node, (char *) 0x0);
}

/* Return the property type string after property type 'oprop'
 * at node 'node' .  Returns NULL string if no more
 * property types for this node.
 */
char *prom_nextprop (int node, char *oprop)
{
    if (node == -1)
	return "";
    return prom_nodeops->no_nextprop (node, oprop);
}

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

    do {
	current_property = prom_nextprop (node, current_property);
	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)
{
    if (size == 0)
	return 0;
    if ((pname == 0) || (value == 0))
	return 0;
    return prom_nodeops->no_setprop (node, pname, value, size);
}