Add fdt_find_node_by_type() and fdt_find_compatible_node() to LIBFDT

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Gerald Van Baren <vanbaren@cideas.com>
This commit is contained in:
Gerald Van Baren 2007-05-17 23:54:36 -04:00
parent 1a861169bc
commit 9675ee7208
2 changed files with 149 additions and 18 deletions

View File

@ -78,6 +78,12 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
int fdt_find_node_by_path(const void *fdt, const char *path);
int fdt_find_node_by_type(const void *fdt, int nodeoffset, const char *type);
int fdt_node_is_compatible(const void *fdt, int nodeoffset,
const char *compat);
int fdt_find_compatible_node(const void *fdt, int nodeoffset,
const char *type, const char *compat);
struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
const char *name, int *lenp);

View File

@ -50,6 +50,33 @@ static int offset_streq(const void *fdt, int offset,
return 1;
}
/*
* Checks if the property name matches.
*/
static int prop_name_eq(const void *fdt, int offset, const char *name,
struct fdt_property **prop, int *lenp)
{
int namestroff, len;
*prop = fdt_offset_ptr_typed(fdt, offset, *prop);
if (! *prop)
return -FDT_ERR_BADSTRUCTURE;
namestroff = fdt32_to_cpu((*prop)->nameoff);
if (streq(fdt_string(fdt, namestroff), name)) {
len = fdt32_to_cpu((*prop)->len);
*prop = fdt_offset_ptr(fdt, offset,
sizeof(**prop) + len);
if (*prop) {
if (lenp)
*lenp = len;
return 1;
} else
return -FDT_ERR_BADSTRUCTURE;
}
return 0;
}
/*
* Return a pointer to the string at the given string offset.
*/
@ -58,6 +85,118 @@ char *fdt_string(const void *fdt, int stroffset)
return (char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
}
/*
* Check if the specified node is compatible by comparing the tokens
* in its "compatible" property with the specified string:
*
* nodeoffset - starting place of the node
* compat - the string to match to one of the tokens in the
* "compatible" list.
*/
int fdt_node_is_compatible(const void *fdt, int nodeoffset,
const char *compat)
{
const char* cp;
int cplen, len;
cp = fdt_getprop(fdt, nodeoffset, "compatible", &cplen);
if (cp == NULL)
return 0;
while (cplen > 0) {
if (strncmp(cp, compat, strlen(compat)) == 0)
return 1;
len = strlen(cp) + 1;
cp += len;
cplen -= len;
}
return 0;
}
/*
* Find a node by its device type property. On success, the offset of that
* node is returned or an error code otherwise:
*
* nodeoffset - the node to start searching from or 0, the node you pass
* will not be searched, only the next one will; typically,
* you pass 0 to start the search and then what the previous
* call returned.
* type - the device type string to match against.
*/
int fdt_find_node_by_type(const void *fdt, int nodeoffset, const char *type)
{
int offset, nextoffset;
struct fdt_property *prop;
uint32_t tag;
int len, ret;
CHECK_HEADER(fdt);
tag = fdt_next_tag(fdt, nodeoffset, &nextoffset, NULL);
if (tag != FDT_BEGIN_NODE)
return -FDT_ERR_BADOFFSET;
if (nodeoffset)
nodeoffset = 0; /* start searching with next node */
while (1) {
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);
switch (tag) {
case FDT_BEGIN_NODE:
nodeoffset = offset;
break;
case FDT_PROP:
if (nodeoffset == 0)
break;
ret = prop_name_eq(fdt, offset, "device_type",
&prop, &len);
if (ret < 0)
return ret;
else if (ret > 0 &&
strncmp(prop->data, type, len - 1) == 0)
return nodeoffset;
break;
case FDT_END_NODE:
case FDT_NOP:
break;
case FDT_END:
return -FDT_ERR_NOTFOUND;
default:
return -FDT_ERR_BADSTRUCTURE;
}
}
}
/*
* Find a node based on its device type and one of the tokens in its its
* "compatible" property. On success, the offset of that node is returned
* or an error code otherwise:
*
* nodeoffset - the node to start searching from or 0, the node you pass
* will not be searched, only the next one will; typically,
* you pass 0 to start the search and then what the previous
* call returned.
* type - the device type string to match against.
* compat - the string to match to one of the tokens in the
* "compatible" list.
*/
int fdt_find_compatible_node(const void *fdt, int nodeoffset,
const char *type, const char *compat)
{
int offset;
offset = fdt_find_node_by_type(fdt, nodeoffset, type);
if (offset < 0 || fdt_node_is_compatible(fdt, offset, compat))
return offset;
return -FDT_ERR_NOTFOUND;
}
/*
* Return the node offset of the node specified by:
* parentoffset - starting place (0 to start at the root)
@ -187,7 +326,6 @@ struct fdt_property *fdt_get_property(const void *fdt,
int level = 0;
uint32_t tag;
struct fdt_property *prop;
int namestroff;
int offset, nextoffset;
int err;
@ -227,24 +365,11 @@ struct fdt_property *fdt_get_property(const void *fdt,
if (level != 0)
continue;
err = -FDT_ERR_BADSTRUCTURE;
prop = fdt_offset_ptr_typed(fdt, offset, prop);
if (! prop)
goto fail;
namestroff = fdt32_to_cpu(prop->nameoff);
if (streq(fdt_string(fdt, namestroff), name)) {
/* Found it! */
int len = fdt32_to_cpu(prop->len);
prop = fdt_offset_ptr(fdt, offset,
sizeof(*prop)+len);
if (! prop)
goto fail;
if (lenp)
*lenp = len;
err = prop_name_eq(fdt, offset, name, &prop, lenp);
if (err > 0)
return prop;
}
else if (err < 0)
goto fail;
break;
case FDT_NOP: