tree_32.c

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/*
 * 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;
}