fdt: Introduce fdtdec_get_alias_highest_id()
Find out the highest alias ID used for certain subsystem.
This call will be used for alocating IDs for i2c buses which are not
described in DT.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/fdtdec.h b/include/fdtdec.h
index f1bcbf8..c2dd87e 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -626,6 +626,19 @@
int *seqp);
/**
+ * Get the highest alias number for susbystem.
+ *
+ * It parses all aliases and find out highest recorded alias for subsystem.
+ * Aliases are of the form <base><num> where <num> is the sequence number.
+ *
+ * @param blob Device tree blob (if NULL, then error is returned)
+ * @param base Base name for alias susbystem (before the number)
+ *
+ * @return 0 highest alias ID, -1 if not found
+ */
+int fdtdec_get_alias_highest_id(const void *blob, const char *base);
+
+/**
* Get a property from the /chosen node
*
* @param blob Device tree blob (if NULL, then NULL is returned)
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 18663ce..5581197 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -549,6 +549,39 @@
return -ENOENT;
}
+int fdtdec_get_alias_highest_id(const void *blob, const char *base)
+{
+ int base_len = strlen(base);
+ int prop_offset;
+ int aliases;
+ int max = -1;
+
+ debug("Looking for highest alias id for '%s'\n", base);
+
+ aliases = fdt_path_offset(blob, "/aliases");
+ for (prop_offset = fdt_first_property_offset(blob, aliases);
+ prop_offset > 0;
+ prop_offset = fdt_next_property_offset(blob, prop_offset)) {
+ const char *prop;
+ const char *name;
+ int len, val;
+
+ prop = fdt_getprop_by_offset(blob, prop_offset, &name, &len);
+ debug(" - %s, %s\n", name, prop);
+ if (*prop != '/' || prop[len - 1] ||
+ strncmp(name, base, base_len))
+ continue;
+
+ val = trailing_strtol(name);
+ if (val > max) {
+ debug("Found seq %d\n", val);
+ max = val;
+ }
+ }
+
+ return max;
+}
+
const char *fdtdec_get_chosen_prop(const void *blob, const char *name)
{
int chosen_node;