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-rw-r--r--libfdt/fdt_ro.c161
1 files changed, 143 insertions, 18 deletions
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
index 1a03109..923c389 100644
--- a/libfdt/fdt_ro.c
+++ b/libfdt/fdt_ro.c
@@ -51,6 +51,33 @@ static int offset_streq(const void *fdt, int offset,
}
/*
+ * 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.
*/
char *fdt_string(const void *fdt, int stroffset)
@@ -59,6 +86,118 @@ char *fdt_string(const void *fdt, int 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)
* name - name being searched for
@@ -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: