From 4b34ff6903521cc1550122c93d673eab257ca1a3 Mon Sep 17 00:00:00 2001
From: Erik van der Kouwe <erik@minix3.org>
Date: Mon, 3 May 2010 19:41:04 +0000
Subject: [PATCH] Add syslib function to obtain CPU frequency

---
 include/minix/sysutil.h | 1 +
 lib/libsys/tsc_util.c   | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/include/minix/sysutil.h b/include/minix/sysutil.h
index c6e4edb33..e596e9635 100644
--- a/include/minix/sysutil.h
+++ b/include/minix/sysutil.h
@@ -57,6 +57,7 @@ _PROTOTYPE( void util_stacktrace_strcat, (char *));
 _PROTOTYPE( int micro_delay, (u32_t micros));
 _PROTOTYPE( u32_t tsc_64_to_micros, (u64_t tsc));
 _PROTOTYPE( u32_t tsc_to_micros, (u32_t low, u32_t high));
+_PROTOTYPE( u32_t tsc_get_khz, (void));
 _PROTOTYPE( u32_t micros_to_ticks, (u32_t micros));
 _PROTOTYPE( void ser_putc, (char c));
 _PROTOTYPE( void get_randomness, (struct k_randomness *, int));
diff --git a/lib/libsys/tsc_util.c b/lib/libsys/tsc_util.c
index dfb1218e0..815d8840f 100644
--- a/lib/libsys/tsc_util.c
+++ b/lib/libsys/tsc_util.c
@@ -111,3 +111,9 @@ u32_t tsc_to_micros(u32_t low, u32_t high)
 	return micros;
 }
 
+u32_t tsc_get_khz(void)
+{
+	CALIBRATE;
+
+	return calib_tsc / (CALIBRATE_TICKS(Hz) * MICROSPERTICK(Hz)) * 1000;
+}