diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 52069d2..9455595 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -82,7 +82,7 @@
 }
 
 static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
-	unsigned int num)
+	size_t num)
 {
 	unsigned int i;