[PATCH] arm/spear600: fix one-shot timer

[PATCH] arm/spear600: fix one-shot timer

[Gilles Chanteperdrix]

Currently, the "clockevent_next_event" function only works correctly
if the timer is not running when this function is called, which is
not always the case when running with CONFIG_HIGH_RES_TIMERS.

Fix this by stopping the timer at the beginning of this function.

Signed-off-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
---
 arch/arm/plat-spear/time.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/arch/arm/plat-spear/time.c b/arch/arm/plat-spear/time.c
index 0c77e42..ac15ff3 100644
--- a/arch/arm/plat-spear/time.c
+++ b/arch/arm/plat-spear/time.c
@@ -147,9 +147,12 @@ static int clockevent_next_event(unsigned long cycles,
 {
 	u16 val;
 
+	val = readw(gpt_base + CR(CLKEVT));
+	if ((val & CTRL_ENABLE))
+		writew(val & ~CTRL_ENABLE, gpt_base + CR(CLKEVT));
+
 	writew(cycles, gpt_base + LOAD(CLKEVT));
 
-	val = readw(gpt_base + CR(CLKEVT));
 	val |= CTRL_ENABLE | CTRL_INT_ENABLE;
 	writew(val, gpt_base + CR(CLKEVT));
 
-- 
1.7.2.5

[PATCH] arm/spear600: fix one-shot timer

[Viresh Kumar]

On 2/22/2012 3:49 AM, Gilles Chanteperdrix wrote:
> diff --git a/arch/arm/plat-spear/time.c b/arch/arm/plat-spear/time.c
> index 0c77e42..ac15ff3 100644
> --- a/arch/arm/plat-spear/time.c
> +++ b/arch/arm/plat-spear/time.c
> @@ -147,9 +147,12 @@ static int clockevent_next_event(unsigned long cycles,
>  {
>  	u16 val;
>  
> +	val = readw(gpt_base + CR(CLKEVT));

can merge above three lines now.

> +	if ((val & CTRL_ENABLE))

no need of extra (). Did you run checkpatch? I believe checkpatch
reports such issues.

> +		writew(val & ~CTRL_ENABLE, gpt_base + CR(CLKEVT));
> +
>  	writew(cycles, gpt_base + LOAD(CLKEVT));
>  
> -	val = readw(gpt_base + CR(CLKEVT));
>  	val |= CTRL_ENABLE | CTRL_INT_ENABLE;
>  	writew(val, gpt_base + CR(CLKEVT));

Otherwise,

Acked-by: Viresh Kumar <viresh.kumar@st.com>

-- 
viresh

[PATCH v2] arm/spear600: fix one-shot timer

[Gilles Chanteperdrix]

Currently, the "clockevent_next_event" function only works correctly
if the timer is not running when this function is called, which is
not always the case when running with CONFIG_HIGH_RES_TIMERS.

Fix this by stopping the timer at the beginning of this function.

Acked-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
---
 arch/arm/plat-spear/time.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/plat-spear/time.c b/arch/arm/plat-spear/time.c
index 0c77e42..abb5bde 100644
--- a/arch/arm/plat-spear/time.c
+++ b/arch/arm/plat-spear/time.c
@@ -145,11 +145,13 @@ static void clockevent_set_mode(enum clock_event_mode mode,
 static int clockevent_next_event(unsigned long cycles,
 				 struct clock_event_device *clk_event_dev)
 {
-	u16 val;
+	u16 val = readw(gpt_base + CR(CLKEVT));
+
+	if (val & CTRL_ENABLE)
+		writew(val & ~CTRL_ENABLE, gpt_base + CR(CLKEVT));
 
 	writew(cycles, gpt_base + LOAD(CLKEVT));
 
-	val = readw(gpt_base + CR(CLKEVT));
 	val |= CTRL_ENABLE | CTRL_INT_ENABLE;
 	writew(val, gpt_base + CR(CLKEVT));
 
-- 
1.7.2.5

[PATCH v2] arm/spear600: fix one-shot timer

[Stefan Roese]

On Wednesday 22 February 2012 11:18:12 Gilles Chanteperdrix wrote:
> Currently, the "clockevent_next_event" function only works correctly
> if the timer is not running when this function is called, which is
> not always the case when running with CONFIG_HIGH_RES_TIMERS.
> 
> Fix this by stopping the timer at the beginning of this function.
> 
> Acked-by: Viresh Kumar <viresh.kumar@st.com>
> Signed-off-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>

Acked-by: Stefan Roese <sr@denx.de>

Thanks,
Stefan