[U-Boot] [PATCH 2/4] ep93xx timer: Fix resolution of get_ticks()

Matthias Kaehlcke matthias at kaehlcke.net
Tue Mar 9 22:13:33 CET 2010


ep93xx timer: Make get_ticks() return a value in CONFIG_SYS_HZ resolution,
as announced by get_tbclk()

Signed-off-by: Matthias Kaehlcke <matthias at kaehlcke.net>
---
 cpu/arm920t/ep93xx/timer.c |   15 +++++++++------
 1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/cpu/arm920t/ep93xx/timer.c b/cpu/arm920t/ep93xx/timer.c
index bc4ec8f..31304b7 100644
--- a/cpu/arm920t/ep93xx/timer.c
+++ b/cpu/arm920t/ep93xx/timer.c
@@ -69,7 +69,7 @@ static inline unsigned long read_timer(void)
 }
 
 /*
- * timer without interrupts
+ * Get the number of ticks (in CONFIG_SYS_HZ resolution)
  */
 unsigned long long get_ticks(void)
 {
@@ -83,12 +83,12 @@ unsigned long long get_ticks(void)
 
 	timer.last_update = now;
 
-	return timer.ticks;
+	return clk_to_systicks(timer.ticks);
 }
 
 unsigned long get_timer_masked(void)
 {
-	return clk_to_systicks(get_ticks());
+	return get_ticks();
 }
 
 unsigned long get_timer(unsigned long base)
@@ -109,10 +109,13 @@ void reset_timer(void)
 
 void __udelay(unsigned long usec)
 {
-	const unsigned long target = get_ticks() + usecs_to_ticks(usec);
+	/* read the timer and update timer.ticks */
+	get_ticks();
 
-	while (get_ticks() < target)
-		/* noop */;
+	const unsigned long long target = timer.ticks + usecs_to_ticks(usec);
+
+	while (timer.ticks < target)
+		get_ticks();
 }
 
 int timer_init(void)
-- 
1.6.5



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