// SPDX-License-Identifier: GPL-2.0
/*
 * tree.c: Basic device tree traversal/scanning for the Linux
 *         prom library.
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 */

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

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

static phandle prom_node_to_node(const char *type, phandle node)
{
        unsigned long args[5];

        args[0] = (unsigned long) type;
        args[1] = 1;
        args[2] = 1;
        args[3] = (unsigned int) node;
        args[4] = (unsigned long) -1;

        p1275_cmd_direct(args);

        return (phandle) args[4];
}

/* Return the child of node 'node' or zero if no this node has no
 * direct descendent.
 */
inline phandle __prom_getchild(phandle node)
{
        return prom_node_to_node("child", node);
}

phandle prom_getchild(phandle node)
{
        phandle cnode;

        if ((s32)node == -1)
                return 0;
        cnode = __prom_getchild(node);
        if ((s32)cnode == -1)
                return 0;
        return cnode;
}
EXPORT_SYMBOL(prom_getchild);

inline phandle prom_getparent(phandle node)
{
        phandle cnode;

        if ((s32)node == -1)
                return 0;
        cnode = prom_node_to_node("parent", node);
        if ((s32)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.
 */
inline phandle __prom_getsibling(phandle node)
{
        return prom_node_to_node(prom_peer_name, node);
}

phandle prom_getsibling(phandle node)
{
        phandle sibnode;

        if ((s32)node == -1)
                return 0;
        sibnode = __prom_getsibling(node);
        if ((s32)sibnode == -1)
                return 0;

        return sibnode;
}
EXPORT_SYMBOL(prom_getsibling);

/* Return the length in bytes of property 'prop' at node 'node'.
 * Return -1 on error.
 */
int prom_getproplen(phandle node, const char *prop)
{
        unsigned long args[6];

        if (!node || !prop)
                return -1;

        args[0] = (unsigned long) "getproplen";
        args[1] = 2;
        args[2] = 1;
        args[3] = (unsigned int) node;
        args[4] = (unsigned long) prop;
        args[5] = (unsigned long) -1;

        p1275_cmd_direct(args);

        return (int) args[5];
}
EXPORT_SYMBOL(prom_getproplen);

/* 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(phandle node, const char *prop,
                     char *buffer, int bufsize)
{
        unsigned long args[8];
        int plen;

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

        args[0] = (unsigned long) prom_getprop_name;
        args[1] = 4;
        args[2] = 1;
        args[3] = (unsigned int) node;
        args[4] = (unsigned long) prop;
        args[5] = (unsigned long) buffer;
        args[6] = bufsize;
        args[7] = (unsigned long) -1;

        p1275_cmd_direct(args);

        return (int) args[7];
}
EXPORT_SYMBOL(prom_getproperty);

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

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

        return -1;
}
EXPORT_SYMBOL(prom_getint);

/* Acquire an integer property, upon error return the passed default
 * integer.
 */

int prom_getintdefault(phandle node, const char *property, int deflt)
{
        int retval;

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

        return retval;
}
EXPORT_SYMBOL(prom_getintdefault);

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

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

/* 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(phandle node, const 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;
}
EXPORT_SYMBOL(prom_getstring);

/* Does the device at node 'node' have name 'name'?
 * YES = 1   NO = 0
 */
int prom_nodematch(phandle node, const char *name)
{
        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.
 */
phandle prom_searchsiblings(phandle node_start, const char *nodename)
{
        phandle thisnode;
        int error;
        char promlib_buf[128];

        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;
}
EXPORT_SYMBOL(prom_searchsiblings);

static const char *prom_nextprop_name = "nextprop";

/* Return the first property type for node 'node'.
 * buffer should be at least 32B in length
 */
char *prom_firstprop(phandle node, char *buffer)
{
        unsigned long args[7];

        *buffer = 0;
        if ((s32)node == -1)
                return buffer;

        args[0] = (unsigned long) prom_nextprop_name;
        args[1] = 3;
        args[2] = 1;
        args[3] = (unsigned int) node;
        args[4] = 0;
        args[5] = (unsigned long) buffer;
        args[6] = (unsigned long) -1;

        p1275_cmd_direct(args);

        return buffer;
}
EXPORT_SYMBOL(prom_firstprop);

/* 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(phandle node, const char *oprop, char *buffer)
{
        unsigned long args[7];
        char buf[32];

        if ((s32)node == -1) {
                *buffer = 0;
                return buffer;
        }
        if (oprop == buffer) {
                strscpy(buf, oprop);
                oprop = buf;
        }

        args[0] = (unsigned long) prom_nextprop_name;
        args[1] = 3;
        args[2] = 1;
        args[3] = (unsigned int) node;
        args[4] = (unsigned long) oprop;
        args[5] = (unsigned long) buffer;
        args[6] = (unsigned long) -1;

        p1275_cmd_direct(args);

        return buffer;
}
EXPORT_SYMBOL(prom_nextprop);

phandle prom_finddevice(const char *name)
{
        unsigned long args[5];

        if (!name)
                return 0;
        args[0] = (unsigned long) "finddevice";
        args[1] = 1;
        args[2] = 1;
        args[3] = (unsigned long) name;
        args[4] = (unsigned long) -1;

        p1275_cmd_direct(args);

        return (int) args[4];
}
EXPORT_SYMBOL(prom_finddevice);

int prom_node_has_property(phandle node, const char *prop)
{
        char buf [32];
        
        *buf = 0;
        do {
                prom_nextprop(node, buf, buf);
                if (!strcmp(buf, prop))
                        return 1;
        } while (*buf);
        return 0;
}
EXPORT_SYMBOL(prom_node_has_property);

/* 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(phandle node, const char *pname, char *value, int size)
{
        unsigned long args[8];

        if (size == 0)
                return 0;
        if ((pname == NULL) || (value == NULL))
                return 0;
        
#ifdef CONFIG_SUN_LDOMS
        if (ldom_domaining_enabled) {
                ldom_set_var(pname, value);
                return 0;
        }
#endif
        args[0] = (unsigned long) "setprop";
        args[1] = 4;
        args[2] = 1;
        args[3] = (unsigned int) node;
        args[4] = (unsigned long) pname;
        args[5] = (unsigned long) value;
        args[6] = size;
        args[7] = (unsigned long) -1;

        p1275_cmd_direct(args);

        return (int) args[7];
}
EXPORT_SYMBOL(prom_setprop);

inline phandle prom_inst2pkg(int inst)
{
        unsigned long args[5];
        phandle node;
        
        args[0] = (unsigned long) "instance-to-package";
        args[1] = 1;
        args[2] = 1;
        args[3] = (unsigned int) inst;
        args[4] = (unsigned long) -1;

        p1275_cmd_direct(args);

        node = (int) args[4];
        if ((s32)node == -1)
                return 0;
        return node;
}

int prom_ihandle2path(int handle, char *buffer, int bufsize)
{
        unsigned long args[7];

        args[0] = (unsigned long) "instance-to-path";
        args[1] = 3;
        args[2] = 1;
        args[3] = (unsigned int) handle;
        args[4] = (unsigned long) buffer;
        args[5] = bufsize;
        args[6] = (unsigned long) -1;

        p1275_cmd_direct(args);

        return (int) args[6];
}