// SPDX-License-Identifier: GPL-2.0
/*
* tree.c: Basic device tree traversal/scanning for the Linux
* prom library.
*
* Copyright (C) 1995 David S. Miller ([email protected])
*/
#include <linux/string.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/module.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. */
static phandle __prom_getchild(phandle node)
{
unsigned long flags;
phandle 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.
*/
phandle prom_getchild(phandle node)
{
phandle cnode;
if ((s32)node == -1)
return 0;
cnode = __prom_getchild(node);
if (cnode == 0 || (s32)cnode == -1)
return 0;
return cnode;
}
EXPORT_SYMBOL(prom_getchild);
/* Internal version of prom_getsibling that does not alter return values. */
static phandle __prom_getsibling(phandle node)
{
unsigned long flags;
phandle 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.
*/
phandle prom_getsibling(phandle node)
{
phandle sibnode;
if ((s32)node == -1)
return 0;
sibnode = __prom_getsibling(node);
if (sibnode == 0 || (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)
{
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;
}
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)
{
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;
}
EXPORT_SYMBOL(prom_getproperty);
/* Acquire an integer property and return its value. Returns -1
* on failure.
*/
int prom_getint(phandle node, char *prop)
{
static 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, 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, 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, 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);
/* Search siblings at 'node_start' for a node with name
* 'nodename'. Return node if successful, zero if not.
*/
phandle prom_searchsiblings(phandle node_start, char *nodename)
{
phandle thisnode;
int 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;
}
EXPORT_SYMBOL(prom_searchsiblings);
/* Interal version of nextprop that does not alter return values. */
static char *__prom_nextprop(phandle 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 property type string after property type 'oprop'
* at node 'node' . Returns empty string if no more
* property types for this node.
*/
char *prom_nextprop(phandle node, char *oprop, char *buffer)
{
if (node == 0 || (s32)node == -1)
return "";
return __prom_nextprop(node, oprop);
}
EXPORT_SYMBOL(prom_nextprop);
phandle prom_finddevice(char *name)
{
char nbuf[128];
char *s = name, *d;
phandle 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 && (s32)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 || (s32)node2 == -1)
break;
node2 = prom_searchsiblings(prom_getsibling(node2), nbuf);
}
}
}
while (*s != 0 && *s != '/') s++;
}
}
return node;
}
EXPORT_SYMBOL(prom_finddevice);
/* 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 flags;
int ret;
if (size == 0)
return 0;
if ((pname == NULL) || (value == NULL))
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;
}
EXPORT_SYMBOL(prom_setprop);
phandle prom_inst2pkg(int inst)
{
phandle 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 ((s32)node == -1)
return 0;
return node;
}
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