+#define MN10300_SRC_IOCLK MN10300_IOCLK
+
+#ifndef HZ
+# error HZ undeclared.
+#endif /* !HZ */
+/* use as little prescaling as possible to avoid losing accuracy */
+#if (MN10300_SRC_IOCLK + HZ / 2) / HZ - 1 <= TMJCBR_MAX
+# define IOCLK_PRESCALE 1
+# define JC_TIMER_CLKSRC TM0MD_SRC_IOCLK
+# define TSC_TIMER_CLKSRC TM4MD_SRC_IOCLK
+#elif (MN10300_SRC_IOCLK / 8 + HZ / 2) / HZ - 1 <= TMJCBR_MAX
+# define IOCLK_PRESCALE 8
+# define JC_TIMER_CLKSRC TM0MD_SRC_IOCLK_8
+# define TSC_TIMER_CLKSRC TM4MD_SRC_IOCLK_8
+#elif (MN10300_SRC_IOCLK / 32 + HZ / 2) / HZ - 1 <= TMJCBR_MAX
+# define IOCLK_PRESCALE 32
+# define JC_TIMER_CLKSRC TM0MD_SRC_IOCLK_32
+# define TSC_TIMER_CLKSRC TM4MD_SRC_IOCLK_32
+#else
+# error You lose.
+#endif
+
+#define MN10300_JCCLK (MN10300_SRC_IOCLK / IOCLK_PRESCALE)
+#define MN10300_TSCCLK (MN10300_SRC_IOCLK / IOCLK_PRESCALE)
+
+#define MN10300_JC_PER_HZ ((MN10300_JCCLK + HZ / 2) / HZ)
+#define MN10300_TSC_PER_HZ ((MN10300_TSCCLK + HZ / 2) / HZ)
+
+static inline void stop_jiffies_counter(void)