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of/flattree: Add non-boottime device tree functions 

In preparation for providing run-time handling of device trees, factor
out some of the basic functions so that they take an arbitrary blob,
rather than relying on the single boot-time tree.

V2:
- functions have of_fdt_* names
- removed find_flat_dt_string
- blob argument is first

Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Stephen Neuendorffer 2010-11-18 15:54:59 -08:00 committed by Grant Likely
parent e6ce1324e4
commit 9706a36e35
2 changed files with 90 additions and 54 deletions
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133
drivers/of/fdt.c
View File

@ -22,6 +22,82 @@
#include <asm/page.h>
char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
{
return ((char *)blob) +
be32_to_cpu(blob->off_dt_strings) + offset;
}
/**
* of_fdt_get_property - Given a node in the given flat blob, return
* the property ptr
*/
void *of_fdt_get_property(struct boot_param_header *blob,
unsigned long node, const char *name,
unsigned long *size)
{
unsigned long p = node;
do {
u32 tag = be32_to_cpup((__be32 *)p);
u32 sz, noff;
const char *nstr;
p += 4;
if (tag == OF_DT_NOP)
continue;
if (tag != OF_DT_PROP)
return NULL;
sz = be32_to_cpup((__be32 *)p);
noff = be32_to_cpup((__be32 *)(p + 4));
p += 8;
if (be32_to_cpu(blob->version) < 0x10)
p = ALIGN(p, sz >= 8 ? 8 : 4);
nstr = of_fdt_get_string(blob, 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_fdt_is_compatible - Return true if given node from the given blob has
* compat in its compatible list
* @blob: A device tree blob
* @node: node to test
* @compat: compatible string to compare with compatible list.
*/
int of_fdt_is_compatible(struct boot_param_header *blob,
unsigned long node, const char *compat)
{
const char *cp;
unsigned long cplen, l;
cp = of_fdt_get_property(blob, node, "compatible", &cplen);
if (cp == NULL)
return 0;
while (cplen > 0) {
if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
return 1;
l = strlen(cp) + 1;
cp += l;
cplen -= l;
}
return 0;
}
/* Everything below here references initial_boot_params directly. */
int __initdata dt_root_addr_cells;
int __initdata dt_root_size_cells;
@ -29,12 +105,6 @@ struct boot_param_header *initial_boot_params;
#ifdef CONFIG_OF_EARLY_FLATTREE
char *find_flat_dt_string(u32 offset)
{
return ((char *)initial_boot_params) +
be32_to_cpu(initial_boot_params->off_dt_strings) + offset;
}
/**
* of_scan_flat_dt - scan flattened tree blob and call callback on each.
* @it: callback function
@ -123,38 +193,7 @@ unsigned long __init of_get_flat_dt_root(void)
void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
unsigned long *size)
{
unsigned long p = node;
do {
u32 tag = be32_to_cpup((__be32 *)p);
u32 sz, noff;
const char *nstr;
p += 4;
if (tag == OF_DT_NOP)
continue;
if (tag != OF_DT_PROP)
return NULL;
sz = be32_to_cpup((__be32 *)p);
noff = be32_to_cpup((__be32 *)(p + 4));
p += 8;
if (be32_to_cpu(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);
return of_fdt_get_property(initial_boot_params, node, name, size);
}
/**
@ -164,21 +203,7 @@ void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
*/
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 (of_compat_cmp(cp, compat, strlen(compat)) == 0)
return 1;
l = strlen(cp) + 1;
cp += l;
cplen -= l;
}
return 0;
return of_fdt_is_compatible(initial_boot_params, node, compat);
}
static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
@ -303,7 +328,7 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
if (be32_to_cpu(initial_boot_params->version) < 0x10)
*p = ALIGN(*p, sz >= 8 ? 8 : 4);
pname = find_flat_dt_string(noff);
pname = of_fdt_get_string(initial_boot_params, noff);
if (pname == NULL) {
pr_info("Can't find property name in list !\n");
break;

11
include/linux/of_fdt.h
View File

@ -58,6 +58,17 @@ struct boot_param_header {
};
#if defined(CONFIG_OF_FLATTREE)
/* For scanning an arbitrary device-tree at any time */
extern char *of_fdt_get_string(struct boot_param_header *blob, u32 offset);
extern void *of_fdt_get_property(struct boot_param_header *blob,
unsigned long node,
const char *name,
unsigned long *size);
extern int of_fdt_is_compatible(struct boot_param_header *blob,
unsigned long node,
const char *compat);
/* TBD: Temporary export of fdt globals - remove when code fully merged */
extern int __initdata dt_root_addr_cells;
extern int __initdata dt_root_size_cells;