[PATCH 1/2] ARM: mxc: Add dummy_get_cycles to avoid access before init is done

[PATCH 1/2] ARM: mxc: Add dummy_get_cycles to avoid access before init is done

[Jan Weitzel]

this is needed to use get_cycles with sched_clock. Accessing timer
without enabled clk will result in crash

Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
---
 arch/arm/plat-mxc/time.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/arch/arm/plat-mxc/time.c b/arch/arm/plat-mxc/time.c
index 9f0c261..0142e4b 100644
--- a/arch/arm/plat-mxc/time.c
+++ b/arch/arm/plat-mxc/time.c
@@ -105,6 +105,11 @@ static void gpt_irq_acknowledge(void)
 		__raw_writel(V2_TSTAT_OF1, timer_base + V2_TSTAT);
 }
 
+static cycle_t dummy_get_cycles(struct clocksource *cs)
+{
+	return 0;
+}
+
 static cycle_t mx1_2_get_cycles(struct clocksource *cs)
 {
 	return __raw_readl(timer_base + MX1_2_TCN);
@@ -118,7 +123,7 @@ static cycle_t v2_get_cycles(struct clocksource *cs)
 static struct clocksource clocksource_mxc = {
 	.name 		= "mxc_timer1",
 	.rating		= 200,
-	.read		= mx1_2_get_cycles,
+	.read		= dummy_get_cycles,
 	.mask		= CLOCKSOURCE_MASK(32),
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
@@ -129,6 +134,8 @@ static int __init mxc_clocksource_init(struct clk *timer_clk)
 
 	if (timer_is_v2())
 		clocksource_mxc.read = v2_get_cycles;
+	else
+		clocksource_mxc.read = mx1_2_get_cycles;
 
 	clocksource_register_hz(&clocksource_mxc, c);
 
-- 
1.7.0.4

[PATCH 2/2] ARM: mxc: Add sched_clock to mxc platform

[Jan Weitzel]

Add sched_clock using cyc_to_sched_clock and update_sched_clock
with HAVE_SCHED_CLOCK
tested on iMX27 and iMX35

Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
---
 arch/arm/Kconfig         |    1 +
 arch/arm/plat-mxc/time.c |   16 ++++++++++++++++
 2 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 26d45e5..076e307 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -356,6 +356,7 @@ config ARCH_MXC
 	select GENERIC_CLOCKEVENTS
 	select ARCH_REQUIRE_GPIOLIB
 	select CLKDEV_LOOKUP
+	select HAVE_SCHED_CLOCK
 	help
 	  Support for Freescale MXC/iMX-based family of processors
 
diff --git a/arch/arm/plat-mxc/time.c b/arch/arm/plat-mxc/time.c
index 0142e4b..2237ff8 100644
--- a/arch/arm/plat-mxc/time.c
+++ b/arch/arm/plat-mxc/time.c
@@ -27,6 +27,7 @@
 #include <linux/clk.h>
 
 #include <mach/hardware.h>
+#include <asm/sched_clock.h>
 #include <asm/mach/time.h>
 #include <mach/common.h>
 
@@ -128,6 +129,20 @@ static struct clocksource clocksource_mxc = {
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
+static DEFINE_CLOCK_DATA(cd);
+unsigned long long notrace sched_clock(void)
+{
+	cycle_t cyc = clocksource_mxc.read(&clocksource_mxc);
+
+	return cyc_to_sched_clock(&cd, cyc, (u32)~0);
+}
+
+static void notrace mxc_update_sched_clock(void)
+{
+	cycle_t cyc = clocksource_mxc.read(&clocksource_mxc);
+	update_sched_clock(&cd, cyc, (u32)~0);
+}
+
 static int __init mxc_clocksource_init(struct clk *timer_clk)
 {
 	unsigned int c = clk_get_rate(timer_clk);
@@ -137,6 +152,7 @@ static int __init mxc_clocksource_init(struct clk *timer_clk)
 	else
 		clocksource_mxc.read = mx1_2_get_cycles;
 
+	init_sched_clock(&cd, mxc_update_sched_clock, 32, c);
 	clocksource_register_hz(&clocksource_mxc, c);
 
 	return 0;
-- 
1.7.0.4

[PATCH 2/2] ARM: mxc: Add sched_clock to mxc platform

[Uwe Kleine-König]

On Thu, Mar 17, 2011 at 01:44:30PM +0100, Jan Weitzel wrote:
> Add sched_clock using cyc_to_sched_clock and update_sched_clock
> with HAVE_SCHED_CLOCK
> tested on iMX27 and iMX35
> 
> Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
> ---
>  arch/arm/Kconfig         |    1 +
>  arch/arm/plat-mxc/time.c |   16 ++++++++++++++++
>  2 files changed, 17 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 26d45e5..076e307 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -356,6 +356,7 @@ config ARCH_MXC
>  	select GENERIC_CLOCKEVENTS
>  	select ARCH_REQUIRE_GPIOLIB
>  	select CLKDEV_LOOKUP
> +	select HAVE_SCHED_CLOCK
>  	help
>  	  Support for Freescale MXC/iMX-based family of processors
>  
> diff --git a/arch/arm/plat-mxc/time.c b/arch/arm/plat-mxc/time.c
> index 0142e4b..2237ff8 100644
> --- a/arch/arm/plat-mxc/time.c
> +++ b/arch/arm/plat-mxc/time.c
> @@ -27,6 +27,7 @@
>  #include <linux/clk.h>
>  
>  #include <mach/hardware.h>
> +#include <asm/sched_clock.h>
>  #include <asm/mach/time.h>
>  #include <mach/common.h>
>  
> @@ -128,6 +129,20 @@ static struct clocksource clocksource_mxc = {
>  	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
>  };
>  
> +static DEFINE_CLOCK_DATA(cd);
> +unsigned long long notrace sched_clock(void)
> +{
> +	cycle_t cyc = clocksource_mxc.read(&clocksource_mxc);
> +
> +	return cyc_to_sched_clock(&cd, cyc, (u32)~0);
This cast to u32 isn't needed. The third argument to cyc_to_sched_clock
(and update_sched_clock below) is a u32 anyhow. I would support 

	~(u32)0

though.

Best regards
Uwe

> +}
> +
> +static void notrace mxc_update_sched_clock(void)
> +{
> +	cycle_t cyc = clocksource_mxc.read(&clocksource_mxc);
> +	update_sched_clock(&cd, cyc, (u32)~0);
> +}
> +
>  static int __init mxc_clocksource_init(struct clk *timer_clk)
>  {
>  	unsigned int c = clk_get_rate(timer_clk);
> @@ -137,6 +152,7 @@ static int __init mxc_clocksource_init(struct clk *timer_clk)
>  	else
>  		clocksource_mxc.read = mx1_2_get_cycles;
>  
> +	init_sched_clock(&cd, mxc_update_sched_clock, 32, c);
>  	clocksource_register_hz(&clocksource_mxc, c);
>  
>  	return 0;

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |