diff --git a/drivers/mfd/wm8400-core.c b/drivers/mfd/wm8400-core.c
index 3055d6f47afc..0fe32a05421b 100644
--- a/drivers/mfd/wm8400-core.c
+++ b/drivers/mfd/wm8400-core.c
@@ -108,6 +108,8 @@ static const struct regmap_config wm8400_regmap_config = {
 /**
  * wm8400_reset_codec_reg_cache - Reset cached codec registers to
  * their default values.
+ *
+ * @wm8400: pointer to local driver data structure
  */
 void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
 {