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

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

[Matthias Kaehlcke]

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

Signed-off-by: Matthias Kaehlcke <matthias@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

[U-Boot] [PATCH 3/4] ep93xx timer: Rename struct timer_reg pointers

[Matthias Kaehlcke]

ep93xx timer: Renamed pointers to struct timer_regs from name 'timer' to
'timer_regs' in order to avoid confusion with the global variable 'timer'

Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
---
 cpu/arm920t/ep93xx/timer.c |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/cpu/arm920t/ep93xx/timer.c b/cpu/arm920t/ep93xx/timer.c
index 31304b7..943f193 100644
--- a/cpu/arm920t/ep93xx/timer.c
+++ b/cpu/arm920t/ep93xx/timer.c
@@ -63,9 +63,9 @@ static inline unsigned long long usecs_to_ticks(unsigned long usecs)
 
 static inline unsigned long read_timer(void)
 {
-	struct timer_regs *timer = (struct timer_regs *)TIMER_BASE;
+	struct timer_regs *timer_regs = (struct timer_regs *)TIMER_BASE;
 
-	return TIMER_MAX_VAL - readl(&timer->timer3.value);
+	return TIMER_MAX_VAL - readl(&timer_regs->timer3.value);
 }
 
 /*
@@ -120,17 +120,17 @@ void __udelay(unsigned long usec)
 
 int timer_init(void)
 {
-	struct timer_regs *timer = (struct timer_regs *)TIMER_BASE;
+	struct timer_regs *timer_regs = (struct timer_regs *)TIMER_BASE;
 
 	/* use timer 3 with 508KHz and free running */
-	writel(TIMER_CLKSEL, &timer->timer3.control);
+	writel(TIMER_CLKSEL, &timer_regs->timer3.control);
 
 	/* set initial timer value 3 */
-	writel(TIMER_MAX_VAL, &timer->timer3.load);
+	writel(TIMER_MAX_VAL, &timer_regs->timer3.load);
 
 	/* Enable the timer */
 	writel(TIMER_ENABLE | TIMER_CLKSEL,
-		&timer->timer3.control);
+		&timer_regs->timer3.control);
 
 	reset_timer_masked();
 
-- 
1.6.5

[U-Boot] [PATCH 4/4] ep93xx timer: refactoring

[Matthias Kaehlcke]

ep93xx timer: Simplified the timer code by eliminating clk_to_systicks() and
performing (almost) all manipulation of the timer structure in read_timer()

Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
---
 cpu/arm920t/ep93xx/timer.c |   52 ++++++++++++++++++++-----------------------
 1 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/cpu/arm920t/ep93xx/timer.c b/cpu/arm920t/ep93xx/timer.c
index 943f193..4a0ce4d 100644
--- a/cpu/arm920t/ep93xx/timer.c
+++ b/cpu/arm920t/ep93xx/timer.c
@@ -1,8 +1,7 @@
 /*
  * Cirrus Logic EP93xx timer support.
  *
- * Copyright (C) 2009, 2010
- * Matthias Kaehlcke <matthias@kaehlcke.net>
+ * Copyright (C) 2009, 2010 Matthias Kaehlcke <matthias@kaehlcke.net>
  *
  * Copyright (C) 2004, 2005
  * Cory T. Tusar, Videon Central, Inc., <ctusar@videon-central.com>
@@ -42,17 +41,9 @@
 static struct ep93xx_timer
 {
 	unsigned long long ticks;
-	unsigned long last_update;
+	unsigned long last_read;
 } timer;
 
-static inline unsigned long clk_to_systicks(unsigned long long clk_ticks)
-{
-	unsigned long long sys_ticks = (clk_ticks * CONFIG_SYS_HZ);
-	do_div(sys_ticks, TIMER_FREQ);
-
-	return (unsigned long)sys_ticks;
-}
-
 static inline unsigned long long usecs_to_ticks(unsigned long usecs)
 {
 	unsigned long long ticks = (unsigned long long)usecs * TIMER_FREQ;
@@ -61,11 +52,18 @@ static inline unsigned long long usecs_to_ticks(unsigned long usecs)
 	return ticks;
 }
 
-static inline unsigned long read_timer(void)
+static inline void read_timer(void)
 {
 	struct timer_regs *timer_regs = (struct timer_regs *)TIMER_BASE;
+	const unsigned long now = TIMER_MAX_VAL - readl(&timer_regs->timer3.value);
+
+	if (now >= timer.last_read)
+		timer.ticks += now - timer.last_read;
+	else
+		/* an overflow occurred */
+		timer.ticks += TIMER_MAX_VAL - timer.last_read + now;
 
-	return TIMER_MAX_VAL - readl(&timer_regs->timer3.value);
+	timer.last_read = now;
 }
 
 /*
@@ -73,17 +71,14 @@ static inline unsigned long read_timer(void)
  */
 unsigned long long get_ticks(void)
 {
-	const unsigned long now = read_timer();
+	unsigned long long sys_ticks;
 
-	if (now >= timer.last_update)
-		timer.ticks += now - timer.last_update;
-	else
-		/* an overflow occurred */
-		timer.ticks += TIMER_MAX_VAL - timer.last_update + now;
+	read_timer();
 
-	timer.last_update = now;
+	sys_ticks = timer.ticks * CONFIG_SYS_HZ;
+	do_div(sys_ticks, TIMER_FREQ);
 
-	return clk_to_systicks(timer.ticks);
+	return sys_ticks;
 }
 
 unsigned long get_timer_masked(void)
@@ -98,7 +93,7 @@ unsigned long get_timer(unsigned long base)
 
 void reset_timer_masked(void)
 {
-	timer.last_update = read_timer();
+	read_timer();
 	timer.ticks = 0;
 }
 
@@ -109,23 +104,24 @@ void reset_timer(void)
 
 void __udelay(unsigned long usec)
 {
-	/* read the timer and update timer.ticks */
-	get_ticks();
+	unsigned long long target;
+
+	read_timer();
 
-	const unsigned long long target = timer.ticks + usecs_to_ticks(usec);
+	target = timer.ticks + usecs_to_ticks(usec);
 
 	while (timer.ticks < target)
-		get_ticks();
+		read_timer();
 }
 
 int timer_init(void)
 {
 	struct timer_regs *timer_regs = (struct timer_regs *)TIMER_BASE;
 
-	/* use timer 3 with 508KHz and free running */
+	/* use timer 3 with 508KHz and free running, not enabled now */
 	writel(TIMER_CLKSEL, &timer_regs->timer3.control);
 
-	/* set initial timer value 3 */
+	/* set initial timer value */
 	writel(TIMER_MAX_VAL, &timer_regs->timer3.load);
 
 	/* Enable the timer */
-- 
1.6.5

[U-Boot] [PATCH 4/4] ep93xx timer: refactoring

[Tom]

Matthias Kaehlcke wrote:
> ep93xx timer: Simplified the timer code by eliminating clk_to_systicks() and
> performing (almost) all manipulation of the timer structure in read_timer()
> 
> Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
> ---
>  cpu/arm920t/ep93xx/timer.c |   52 ++++++++++++++++++++-----------------------
>  1 files changed, 24 insertions(+), 28 deletions(-)
> 
Applied this patchset.
Thanks,
Tom