diff --git a/src/soc/rockchip/rk3288/clock.c b/src/soc/rockchip/rk3288/clock.c
index 2c56376..a2e8d88 100644
--- a/src/soc/rockchip/rk3288/clock.c
+++ b/src/soc/rockchip/rk3288/clock.c
@@ -21,6 +21,7 @@
 #include <assert.h>
 #include <console/console.h>
 #include <delay.h>
+#include <lib.h>
 #include <soc/addressmap.h>
 #include <soc/clock.h>
 #include <soc/grf.h>
@@ -236,22 +237,6 @@
 	return 0;
 }
 
-/*
-    TODO:
-    it should be replaced by lib.h function
-   'unsigned long log2(unsigned long x)'
-*/
-static unsigned int log2(unsigned int value)
-{
-	unsigned int div = 0;
-
-	while (value != 1) {
-		div++;
-		value = ALIGN_UP(value, 2) / 2;
-	}
-	return div;
-}
-
 void rkclk_init(void)
 {
 	u32 aclk_div;