From: Tony Lindgren <tony@atomide.com>
Date: Tue, 16 Aug 2005 12:00:09 +0000 (-0700)
Subject: ARM: OMAP: Add sched_clock() for 32k timer
X-Git-Tag: v2.6.13-omap1~22
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=85049d4c9c497778614a9b49172d08262bca98ee;p=linux-2.6-omap-h63xx.git

ARM: OMAP: Add sched_clock() for 32k timer

Add sched_clock() for 32k timer
---

diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
index d540539c9bb..e36b58c5052 100644
--- a/arch/arm/mach-omap1/time.c
+++ b/arch/arm/mach-omap1/time.c
@@ -296,13 +296,22 @@ static inline void omap_32k_timer_stop(void)
 }
 
 /*
- * Rounds down to nearest usec
+ * Rounds down to nearest usec. Note that this will overflow for larger values.
  */
 static inline unsigned long omap_32k_ticks_to_usecs(unsigned long ticks_32k)
 {
 	return (ticks_32k * 5*5*5*5*5*5) >> 9;
 }
 
+/*
+ * Rounds down to nearest nsec.
+ */
+static inline unsigned long long
+omap_32k_ticks_to_nsecs(unsigned long ticks_32k)
+{
+	return (unsigned long long) ticks_32k * 1000 * 5*5*5*5*5*5 >> 9;
+}
+
 static unsigned long omap_32k_last_tick = 0;
 
 /*
@@ -314,6 +323,15 @@ static unsigned long omap_32k_timer_gettimeoffset(void)
 	return omap_32k_ticks_to_usecs(now - omap_32k_last_tick);
 }
 
+/*
+ * Returns current time from boot in nsecs. It's OK for this to wrap
+ * around for now, as it's just a relative time stamp.
+ */
+unsigned long long sched_clock(void)
+{
+	return omap_32k_ticks_to_nsecs(omap_32k_sync_timer_read());
+}
+
 /*
  * Timer interrupt for 32KHz timer. When dynamic tick is enabled, this
  * function is also called from other interrupts to remove latency