311 lines
7.1 KiB
C
311 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* tree.c: Basic device tree traversal/scanning for the Linux
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* prom library.
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*
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* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
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*/
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/ctype.h>
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#include <linux/module.h>
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#include <asm/openprom.h>
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#include <asm/oplib.h>
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extern void restore_current(void);
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static char promlib_buf[128];
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/* Internal version of prom_getchild that does not alter return values. */
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static phandle __prom_getchild(phandle node)
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{
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unsigned long flags;
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phandle cnode;
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spin_lock_irqsave(&prom_lock, flags);
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cnode = prom_nodeops->no_child(node);
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restore_current();
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spin_unlock_irqrestore(&prom_lock, flags);
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return cnode;
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}
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/* Return the child of node 'node' or zero if no this node has no
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* direct descendent.
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*/
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phandle prom_getchild(phandle node)
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{
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phandle cnode;
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if ((s32)node == -1)
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return 0;
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cnode = __prom_getchild(node);
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if (cnode == 0 || (s32)cnode == -1)
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return 0;
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return cnode;
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}
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EXPORT_SYMBOL(prom_getchild);
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/* Internal version of prom_getsibling that does not alter return values. */
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static phandle __prom_getsibling(phandle node)
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{
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unsigned long flags;
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phandle cnode;
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spin_lock_irqsave(&prom_lock, flags);
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cnode = prom_nodeops->no_nextnode(node);
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restore_current();
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spin_unlock_irqrestore(&prom_lock, flags);
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return cnode;
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}
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/* Return the next sibling of node 'node' or zero if no more siblings
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* at this level of depth in the tree.
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*/
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phandle prom_getsibling(phandle node)
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{
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phandle sibnode;
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if ((s32)node == -1)
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return 0;
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sibnode = __prom_getsibling(node);
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if (sibnode == 0 || (s32)sibnode == -1)
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return 0;
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return sibnode;
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}
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EXPORT_SYMBOL(prom_getsibling);
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/* Return the length in bytes of property 'prop' at node 'node'.
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* Return -1 on error.
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*/
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int prom_getproplen(phandle node, const char *prop)
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{
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int ret;
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unsigned long flags;
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if((!node) || (!prop))
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return -1;
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spin_lock_irqsave(&prom_lock, flags);
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ret = prom_nodeops->no_proplen(node, prop);
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restore_current();
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spin_unlock_irqrestore(&prom_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(prom_getproplen);
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/* Acquire a property 'prop' at node 'node' and place it in
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* 'buffer' which has a size of 'bufsize'. If the acquisition
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* was successful the length will be returned, else -1 is returned.
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*/
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int prom_getproperty(phandle node, const char *prop, char *buffer, int bufsize)
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{
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int plen, ret;
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unsigned long flags;
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plen = prom_getproplen(node, prop);
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if((plen > bufsize) || (plen == 0) || (plen == -1))
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return -1;
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/* Ok, things seem all right. */
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spin_lock_irqsave(&prom_lock, flags);
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ret = prom_nodeops->no_getprop(node, prop, buffer);
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restore_current();
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spin_unlock_irqrestore(&prom_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(prom_getproperty);
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/* Acquire an integer property and return its value. Returns -1
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* on failure.
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*/
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int prom_getint(phandle node, char *prop)
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{
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static int intprop;
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if(prom_getproperty(node, prop, (char *) &intprop, sizeof(int)) != -1)
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return intprop;
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return -1;
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}
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EXPORT_SYMBOL(prom_getint);
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/* Acquire an integer property, upon error return the passed default
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* integer.
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*/
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int prom_getintdefault(phandle node, char *property, int deflt)
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{
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int retval;
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retval = prom_getint(node, property);
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if(retval == -1) return deflt;
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return retval;
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}
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EXPORT_SYMBOL(prom_getintdefault);
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/* Acquire a boolean property, 1=TRUE 0=FALSE. */
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int prom_getbool(phandle node, char *prop)
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{
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int retval;
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retval = prom_getproplen(node, prop);
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if(retval == -1) return 0;
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return 1;
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}
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EXPORT_SYMBOL(prom_getbool);
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/* Acquire a property whose value is a string, returns a null
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* string on error. The char pointer is the user supplied string
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* buffer.
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*/
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void prom_getstring(phandle node, char *prop, char *user_buf, int ubuf_size)
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{
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int len;
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len = prom_getproperty(node, prop, user_buf, ubuf_size);
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if(len != -1) return;
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user_buf[0] = 0;
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}
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EXPORT_SYMBOL(prom_getstring);
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/* Search siblings at 'node_start' for a node with name
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* 'nodename'. Return node if successful, zero if not.
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*/
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phandle prom_searchsiblings(phandle node_start, char *nodename)
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{
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phandle thisnode;
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int error;
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for(thisnode = node_start; thisnode;
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thisnode=prom_getsibling(thisnode)) {
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error = prom_getproperty(thisnode, "name", promlib_buf,
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sizeof(promlib_buf));
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/* Should this ever happen? */
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if(error == -1) continue;
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if(strcmp(nodename, promlib_buf)==0) return thisnode;
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}
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return 0;
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}
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EXPORT_SYMBOL(prom_searchsiblings);
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/* Interal version of nextprop that does not alter return values. */
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static char *__prom_nextprop(phandle node, char * oprop)
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{
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unsigned long flags;
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char *prop;
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spin_lock_irqsave(&prom_lock, flags);
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prop = prom_nodeops->no_nextprop(node, oprop);
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restore_current();
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spin_unlock_irqrestore(&prom_lock, flags);
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return prop;
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}
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/* Return the property type string after property type 'oprop'
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* at node 'node' . Returns empty string if no more
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* property types for this node.
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*/
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char *prom_nextprop(phandle node, char *oprop, char *buffer)
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{
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if (node == 0 || (s32)node == -1)
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return "";
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return __prom_nextprop(node, oprop);
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}
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EXPORT_SYMBOL(prom_nextprop);
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phandle prom_finddevice(char *name)
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{
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char nbuf[128];
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char *s = name, *d;
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phandle node = prom_root_node, node2;
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unsigned int which_io, phys_addr;
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struct linux_prom_registers reg[PROMREG_MAX];
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while (*s++) {
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if (!*s) return node; /* path '.../' is legal */
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node = prom_getchild(node);
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for (d = nbuf; *s != 0 && *s != '@' && *s != '/';)
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*d++ = *s++;
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*d = 0;
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node = prom_searchsiblings(node, nbuf);
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if (!node)
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return 0;
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if (*s == '@') {
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if (isxdigit(s[1]) && s[2] == ',') {
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which_io = simple_strtoul(s+1, NULL, 16);
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phys_addr = simple_strtoul(s+3, &d, 16);
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if (d != s + 3 && (!*d || *d == '/')
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&& d <= s + 3 + 8) {
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node2 = node;
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while (node2 && (s32)node2 != -1) {
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if (prom_getproperty (node2, "reg", (char *)reg, sizeof (reg)) > 0) {
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if (which_io == reg[0].which_io && phys_addr == reg[0].phys_addr) {
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node = node2;
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break;
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}
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}
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node2 = prom_getsibling(node2);
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if (!node2 || (s32)node2 == -1)
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break;
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node2 = prom_searchsiblings(prom_getsibling(node2), nbuf);
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}
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}
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}
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while (*s != 0 && *s != '/') s++;
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}
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}
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return node;
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}
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EXPORT_SYMBOL(prom_finddevice);
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/* Set property 'pname' at node 'node' to value 'value' which has a length
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* of 'size' bytes. Return the number of bytes the prom accepted.
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*/
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int prom_setprop(phandle node, const char *pname, char *value, int size)
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{
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unsigned long flags;
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int ret;
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if (size == 0)
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return 0;
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if ((pname == NULL) || (value == NULL))
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return 0;
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spin_lock_irqsave(&prom_lock, flags);
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ret = prom_nodeops->no_setprop(node, pname, value, size);
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restore_current();
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spin_unlock_irqrestore(&prom_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(prom_setprop);
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phandle prom_inst2pkg(int inst)
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{
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phandle node;
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unsigned long flags;
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spin_lock_irqsave(&prom_lock, flags);
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node = (*romvec->pv_v2devops.v2_inst2pkg)(inst);
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restore_current();
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spin_unlock_irqrestore(&prom_lock, flags);
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if ((s32)node == -1)
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return 0;
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return node;
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}
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