/*
* Functions for working with the Flattened Device Tree data format
*
* Copyright 2009 Benjamin Herrenschmidt, IBM Corp
* benh@kernel.crashing.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*/
#include <linux/of.h>
#include <linux/of_fdt.h>
struct boot_param_header *initial_boot_params;
char *find_flat_dt_string(u32 offset)
{
return ((char *)initial_boot_params) +
initial_boot_params->off_dt_strings + offset;
}
/**
* of_scan_flat_dt - scan flattened tree blob and call callback on each.
* @it: callback function
* @data: context data pointer
*
* This function is used to scan the flattened device-tree, it is
* used to extract the memory information at boot before we can
* unflatten the tree
*/
int __init of_scan_flat_dt(int (*it)(unsigned long node,
const char *uname, int depth,
void *data),
void *data)
{
unsigned long p = ((unsigned long)initial_boot_params) +
initial_boot_params->off_dt_struct;
int rc = 0;
int depth = -1;
do {
u32 tag = *((u32 *)p);
char *pathp;
p += 4;
if (tag == OF_DT_END_NODE) {
depth--;
continue;
}
if (tag == OF_DT_NOP)
continue;
if (tag == OF_DT_END)
break;
if (tag == OF_DT_PROP) {
u32 sz = *((u32 *)p);
p += 8;
if (initial_boot_params->version < 0x10)
p = _ALIGN(p, sz >= 8 ? 8 : 4);
p += sz;
p = _ALIGN(p, 4);
continue;
}
if (tag != OF_DT_BEGIN_NODE) {
pr_err("Invalid tag %x in flat device tree!\n", tag);
return -EINVAL;
}
depth++;
pathp = (char *)p;
p = _ALIGN(p + strlen(pathp) + 1, 4);
if ((*pathp) == '/') {
char *lp, *np;
for (lp = NULL, np = pathp; *np; np++)
if ((*np) == '/')
lp = np+1;
if (lp != NULL)
pathp = lp;
}
rc = it(p, pathp, depth, data);
if (rc != 0)
break;
} while (1);
return rc;
}
/**
* of_get_flat_dt_root - find the root node in the flat blob
*/
unsigned long __init of_get_flat_dt_root(void)
{
unsigned long p = ((unsigned long)initial_boot_params) +
initial_boot_params->off_dt_struct;
while (*((u32 *)p) == OF_DT_NOP)
p += 4;
BUG_ON(*((u32 *)p) != OF_DT_BEGIN_NODE);
p += 4;
return _ALIGN(p + strlen((char *)p) + 1, 4);
}
/**
* of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
*
* This function can be used within scan_flattened_dt callback to get
* access to properties
*/
void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
unsigned long *size)
{
unsigned long p = node;
do {
u32 tag = *((u32 *)p);
u32 sz, noff;
const char *nstr;
p += 4;
if (tag == OF_DT_NOP)
continue;
if (tag != OF_DT_PROP)
return NULL;
sz = *((u32 *)p);
noff = *((u32 *)(p + 4));
p += 8;
if (initial_boot_params->version < 0x10)
p = _ALIGN(p, sz >= 8 ? 8 : 4);
nstr = find_flat_dt_string(noff);
if (nstr == NULL) {
pr_warning("Can't find property index name !\n");
return NULL;
}
if (strcmp(name, nstr) == 0) {
if (size)
*size = sz;
return (void *)p;
}
p += sz;
p = _ALIGN(p, 4);
} while (1);
}
/**
* of_flat_dt_is_compatible - Return true if given node has compat in compatible list
* @node: node to test
* @compat: compatible string to compare with compatible list.
*/
int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
{
const char *cp;
unsigned long cplen, l;
cp = of_get_flat_dt_prop(node, "compatible", &cplen);
if (cp == NULL)
return 0;
while (cplen > 0) {
if (strncasecmp(cp, compat, strlen(compat)) == 0)
return 1;
l = strlen(cp) + 1;
cp += l;
cplen -= l;
}
return 0;
}
static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
unsigned long align)
{
void *res;
*mem = _ALIGN(*mem, align);
res = (void *)*mem;
*mem += size;
return res;
}
/**
* unflatten_dt_node - Alloc and populate a device_node from the flat tree
* @p: pointer to node in flat tree
* @dad: Parent struct device_node
* @allnextpp: pointer to ->allnext from last allocated device_node
* @fpsize: Size of the node path up at the current depth.
*/
unsigned long __init unflatten_dt_node(unsigned long mem,
unsigned long *p,
struct device_node *dad,
struct device_node ***allnextpp,
unsigned long fpsize)
{
struct device_node *np;
struct property *pp, **prev_pp = NULL;
char *pathp;
u32 tag;
unsigned int l, allocl;
int has_name = 0;
int new_format = 0;
tag = *((u32 *)(*p));
if (tag != OF_DT_BEGIN_NODE) {
pr_err("Weird tag at start of node: %x\n", tag);
return mem;
}
*p += 4;
pathp = (char *)*p;
l = allocl = strlen(pathp) + 1;
*p = _ALIGN(*p + l, 4);
/* version 0x10 has a more compact unit name here instead of the full
* path. we accumulate the full path size using "fpsize", we'll rebuild
* it later. We detect this because the first character of the name is
* not '/'.
*/
if ((*pathp) != '/') {
new_format = 1;
if (fpsize == 0) {
/* root node: special case. fpsize accounts for path
* plus terminating zero. root node only has '/', so
* fpsize should be 2, but we want to avoid the first
* level nodes to have two '/' so we use fpsize 1 here
*/
fpsize = 1;
allocl = 2;
} else {
/* account for '/' and path size minus terminal 0
* already in 'l'
*/
fpsize += l;
allocl = fpsize;
}
}
np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
__alignof__(struct device_node));
if (allnextpp) {
memset(np, 0, sizeof(*np));
np->full_name = ((char *)np) + sizeof(struct device_node);
if (new_format) {
char *fn = np->full_name;
/* rebuild full path for new format */
if (dad && dad->parent) {
strcpy(fn, dad->full_name);
#ifdef DEBUG
if ((strlen(fn) + l + 1) != allocl) {
pr_debug("%s: p: %d, l: %d, a: %d\n",
pathp, (int)strlen(fn),
l, allocl);
}
#endif
fn += strlen(fn);
}
*(fn++) = '/';
memcpy(fn, pathp, l);
} else
memcpy(np->full_name, pathp, l);
prev_pp = &np->properties;
**allnextpp = np;
*allnextpp = &np->allnext;
if (dad != NULL) {
np->parent = dad;
/* we temporarily use the next field as `last_child'*/
if (dad->next == NULL)
dad->child = np;
else
dad->next->sibling = np;
dad->next = np;
}
kref_init(&np->kref);
}
while (1) {
u32 sz, noff;
char *pname;
tag = *((u32 *)(*p));
if (tag == OF_DT_NOP) {
*p += 4;
continue;
}
if (tag != OF_DT_PROP)
break;
*p += 4;
sz = *((u32 *)(*p));
noff = *((u32 *)((*p) + 4));
*p += 8;
if (initial_boot_params->version < 0x10)
*p = _ALIGN(*p, sz >= 8 ? 8 : 4);
pname = find_flat_dt_string(noff);
if (pname == NULL) {
pr_info("Can't find property name in list !\n");
break;
}
if (strcmp(pname, "name") == 0)
has_name = 1;
l = strlen(pname) + 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property),
__alignof__(struct property));
if (allnextpp) {
if (strcmp(pname, "linux,phandle") == 0) {
np->node = *((u32 *)*p);
if (np->linux_phandle == 0)
np->linux_phandle = np->node;
}
if (strcmp(pname, "ibm,phandle") == 0)
np->linux_phandle = *((u32 *)*p);
pp->name = pname;
pp->length = sz;
pp->value = (void *)*p;
*prev_pp = pp;
prev_pp = &pp->next;
}
*p = _ALIGN((*p) + sz, 4);
}
/* with version 0x10 we may not have the name property, recreate
* it here from the unit name if absent
*/
if (!has_name) {
char *p1 = pathp, *ps = pathp, *pa = NULL;
int sz;
while (*p1) {
if ((*p1) == '@')
pa = p1;
if ((*p1) == '/')
ps = p1 + 1;
p1++;
}
if (pa < ps)
pa = p1;
sz = (pa - ps) + 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
__alignof__(struct property));
if (allnextpp) {
pp->name = "name";
pp->length = sz;
pp->value = pp + 1;
*prev_pp = pp;
prev_pp = &pp->next;
memcpy(pp->value, ps, sz - 1);
((char *)pp->value)[sz - 1] = 0;
pr_debug("fixed up name for %s -> %s\n", pathp,
(char *)pp->value);
}
}
if (allnextpp) {
*prev_pp = NULL;
np->name = of_get_property(np, "name", NULL);
np->type = of_get_property(np, "device_type", NULL);
if (!np->name)
np->name = "<NULL>";
if (!np->type)
np->type = "<NULL>";
}
while (tag == OF_DT_BEGIN_NODE) {
mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
tag = *((u32 *)(*p));
}
if (tag != OF_DT_END_NODE) {
pr_err("Weird tag at end of node: %x\n", tag);
return mem;
}
*p += 4;
return mem;
}
