dm: core: Add ofnode_read_string_count()
This provides a way to find the number of strings in a string list. Add it
and also fix up the comment for ofnode_read_string_index().
Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-on: Beaver, Jetson-TK1
diff --git a/include/dm/of_access.h b/include/dm/of_access.h
index 142f0f4..d282700 100644
--- a/include/dm/of_access.h
+++ b/include/dm/of_access.h
@@ -261,6 +261,24 @@
}
/**
+ * of_property_count_strings() - Find and return the number of strings from a
+ * multiple strings property.
+ * @np: device node from which the property value is to be read.
+ * @propname: name of the property to be searched.
+ *
+ * Search for a property in a device tree node and retrieve the number of null
+ * terminated string contain in it. Returns the number of strings on
+ * success, -EINVAL if the property does not exist, -ENODATA if property
+ * does not have a value, and -EILSEQ if the string is not null-terminated
+ * within the length of the property data.
+ */
+static inline int of_property_count_strings(const struct device_node *np,
+ const char *propname)
+{
+ return of_property_read_string_helper(np, propname, NULL, 0, 0);
+}
+
+/**
* of_parse_phandle - Resolve a phandle property to a device_node pointer
* @np: Pointer to device node holding phandle property
* @phandle_name: Name of property holding a phandle value