From 73a8098d79d84292ff56674f843f73753520fcbd Mon Sep 17 00:00:00 2001
From: Vadim Bendebury <vbendeb@chromium.org>
Date: Thu, 30 Jul 2015 14:36:32 -0700
Subject: [PATCH] export MSDN clock() function

TPM implementation requires a free running clock with granularity
better than a 10 us. clock_t definition comes from the toolchain
includes.

BRANCH=none
BUG=chrome-os-partner:43025
TEST=none yet

Change-Id: Id3de5fd055aa598afe15657011b88d2c6be4cdfb
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/289953
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
---
 common/timer.c  | 5 +++++
 include/timer.h | 9 +++++++++
 2 files changed, 14 insertions(+)

diff --git a/common/timer.c b/common/timer.c
index 8538635218..4fa2e6b93b 100644
--- a/common/timer.c
+++ b/common/timer.c
@@ -184,6 +184,11 @@ timestamp_t get_time(void)
 	return ts;
 }
 
+clock_t clock(void)
+{
+	return (clock_t) __hw_clock_source_read();
+}
+
 void force_time(timestamp_t ts)
 {
 	clksrc_high = ts.le.hi;
diff --git a/include/timer.h b/include/timer.h
index ddeb79a318..2c439e959e 100644
--- a/include/timer.h
+++ b/include/timer.h
@@ -8,6 +8,8 @@
 #ifndef __CROS_EC_TIMER_H
 #define __CROS_EC_TIMER_H
 
+#include <sys/types.h>
+
 #include "common.h"
 #include "task_id.h"
 
@@ -146,4 +148,11 @@ static inline unsigned time_since32(timestamp_t start)
 	return get_time().le.lo - start.le.lo;
 }
 
+/**
+ * Returns a free running high resolution (ten us or better) clock.
+ *
+ * Used by third party libraries requiring MSDN services.
+ */
+clock_t clock(void);
+
 #endif  /* __CROS_EC_TIMER_H */