[patch 2.6.20-rc6-rt6 0/6] ARM clockevent patches

[patch 2.6.20-rc6-rt6 0/6] ARM clockevent patches

[Kevin Hilman]

Thomas, Ingo,

Here are some updates to get a couple ARM platforms working
with the latest -rt.  The platforms tested are OMAP 
and XScale IXP4xx.

Patches against 2.6.20-rc6-rt6

Kevin

[patch 2.6.20-rc6-rt6 1/6] ARM build fixups

[Kevin Hilman]

[-- Attachment #1: arm-build-fixups.patch --]
[-- Type: text/plain, Size: 331 bytes --]

Index: linux-2.6/kernel/time/tick-sched.c
===================================================================
--- linux-2.6.orig/kernel/time/tick-sched.c
+++ linux-2.6/kernel/time/tick-sched.c
@@ -21,6 +21,8 @@
 #include <linux/sched.h>
 #include <linux/tick.h>
 
+#include <asm/irq_regs.h>
+
 #include "tick-internal.h"
 
 /*

--

[patch 2.6.20-rc6-rt6 2/6] ARM NO_HZ idle loop fixup

[Kevin Hilman]

[-- Attachment #1: arm-nohz-idle.patch --]
[-- Type: text/plain, Size: 805 bytes --]

Index: linux-2.6/arch/arm/kernel/process.c
===================================================================
--- linux-2.6.orig/arch/arm/kernel/process.c
+++ linux-2.6/arch/arm/kernel/process.c
@@ -28,6 +28,7 @@
 #include <linux/cpu.h>
 #include <linux/elfcore.h>
 #include <linux/pm.h>
+#include <linux/tick.h>
 
 #include <asm/leds.h>
 #include <asm/processor.h>
@@ -154,12 +155,12 @@ void cpu_idle(void)
 		if (!idle)
 			idle = default_idle;
 		leds_event(led_idle_start);
-		hrtimer_stop_sched_tick();
+		tick_nohz_stop_sched_tick();
 		while (!need_resched() && !need_resched_delayed())
 			idle();
 		leds_event(led_idle_end);
-		hrtimer_restart_sched_tick();
 		local_irq_disable();
+		tick_nohz_restart_sched_tick();
 		__preempt_enable_no_resched();
 		__schedule();
 		preempt_disable();

--

[patch 2.6.20-rc6-rt6 3/6] ARM Kconfig support for GENERIC_CLOCKEVENTS

[Kevin Hilman]

[-- Attachment #1: arm-kconfig-clockevents.patch --]
[-- Type: text/plain, Size: 320 bytes --]

Index: linux-2.6/arch/arm/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/Kconfig
+++ linux-2.6/arch/arm/Kconfig
@@ -25,6 +25,10 @@ config GENERIC_CLOCKEVENTS
 	bool
 	default n
 
+config GENERIC_CLOCKEVENTS
+	bool
+	default n
+
 config MMU
 	bool
 	default y

--

[patch 2.6.20-rc6-rt6 4/6] ARM: LEDS_TIMER hackery for clockevents

[Kevin Hilman]

[-- Attachment #1: arm-leds-timer.patch --]
[-- Type: text/plain, Size: 999 bytes --]

The clockevent layer now handles everything done by the ARM 
timer_tick() call, except the LED stuff.  Here we add an
arch_tick_leds() to handle LED toggling which is called by 
do_timer().

Index: linux-2.6/arch/arm/kernel/time.c
===================================================================
--- linux-2.6.orig/arch/arm/kernel/time.c
+++ linux-2.6/arch/arm/kernel/time.c
@@ -244,6 +244,13 @@ static inline void do_leds(void)
 #define	do_leds()
 #endif
 
+void arch_tick_leds(void)
+{
+#ifdef CONFIG_LEDS_TIMER
+	do_leds();
+#endif
+}
+
 #ifndef CONFIG_GENERIC_TIME
 void do_gettimeofday(struct timeval *tv)
 {
Index: linux-2.6/kernel/timer.c
===================================================================
--- linux-2.6.orig/kernel/timer.c
+++ linux-2.6/kernel/timer.c
@@ -1471,6 +1471,9 @@ static void run_timer_softirq(struct sof
 void do_timer(unsigned long ticks)
 {
 	jiffies_64 += ticks;
+#ifdef CONFIG_LEDS_TIMER
+ 	arch_tick_leds();
+#endif
 }
 
 #ifdef __ARCH_WANT_SYS_ALARM

--

[patch 2.6.20-rc6-rt6 5/6] ARM: clockevent support for ixp4xx platform

[Kevin Hilman]

[-- Attachment #1: arm-ixp4xx-clockevents.patch --]
[-- Type: text/plain, Size: 4533 bytes --]

Index: linux-2.6/arch/arm/mach-ixp4xx/common.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-ixp4xx/common.c
+++ linux-2.6/arch/arm/mach-ixp4xx/common.c
@@ -27,6 +27,7 @@
 #include <linux/time.h>
 #include <linux/timex.h>
 #include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/arch/udc.h>
 #include <asm/hardware.h>
@@ -41,6 +42,8 @@
 #include <asm/mach/time.h>
 
 static int __init ixp4xx_clocksource_init(void);
+static int __init ixp4xx_clockevent_init(void);
+static struct clock_event_device clockevent_ixp4xx;
 
 /*************************************************************************
  * IXP4xx chipset I/O mapping
@@ -239,52 +242,40 @@ void __init ixp4xx_init_irq(void)
  * counter as a source of real clock ticks to account for missed jiffies.
  *************************************************************************/
 
-static unsigned volatile last_jiffy_time;
-
-#define CLOCK_TICKS_PER_USEC	((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
-
 static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
+	struct clock_event_device *evt = &clockevent_ixp4xx;
 
 	/* Clear Pending Interrupt by writing '1' to it */
 	*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 
-	/*
-	 * Catch up with the real idea of time
-	 */
-	while ((signed long)(*IXP4XX_OSTS - last_jiffy_time) >= LATCH) {
-		timer_tick();
-		last_jiffy_time += LATCH;
-	}
-
-	write_sequnlock(&xtime_lock);
+	evt->event_handler(evt);
 
 	return IRQ_HANDLED;
 }
 
 static struct irqaction ixp4xx_timer_irq = {
-	.name		= "IXP4xx Timer Tick",
+	.name		= "timer1",
 	.flags		= IRQF_DISABLED | IRQF_TIMER,
 	.handler	= ixp4xx_timer_interrupt,
 };
 
 static void __init ixp4xx_timer_init(void)
 {
+	/* Reset/disable counter */
+	*IXP4XX_OSRT1 = 0;
+
 	/* Clear Pending Interrupt by writing '1' to it */
 	*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 
-	/* Setup the Timer counter value */
-	*IXP4XX_OSRT1 = (LATCH & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE;
-
 	/* Reset time-stamp counter */
 	*IXP4XX_OSTS = 0;
-	last_jiffy_time = 0;
 
 	/* Connect the interrupt handler and enable the interrupt */
 	setup_irq(IRQ_IXP4XX_TIMER1, &ixp4xx_timer_irq);
 
 	ixp4xx_clocksource_init();
+	ixp4xx_clockevent_init();
 }
 
 struct sys_timer ixp4xx_timer = {
@@ -384,6 +375,9 @@ void __init ixp4xx_sys_init(void)
 			ixp4xx_exp_bus_size >> 20);
 }
 
+/*
+ * clocksource
+ */
 cycle_t ixp4xx_get_cycles(void)
 {
 	return *IXP4XX_OSTS;
@@ -408,3 +402,64 @@ static int __init ixp4xx_clocksource_ini
 
 	return 0;
 }
+
+/*
+ * clockevents
+ */
+static int ixp4xx_set_next_event(unsigned long evt,
+				 struct clock_event_device *unused)
+{
+	unsigned long opts = *IXP4XX_OSRT1 & IXP4XX_OST_RELOAD_MASK;
+
+	*IXP4XX_OSRT1 = (evt & ~IXP4XX_OST_RELOAD_MASK) | opts;
+
+	return 0;
+}
+
+static void ixp4xx_set_mode(enum clock_event_mode mode,
+			    struct clock_event_device *evt)
+{
+	unsigned long opts, osrt = *IXP4XX_OSRT1 & ~IXP4XX_OST_RELOAD_MASK;
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		osrt = LATCH & ~IXP4XX_OST_RELOAD_MASK;
+ 		opts = IXP4XX_OST_ENABLE;
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		/* period set by 'set next_event' */
+		osrt = 0;
+		opts = IXP4XX_OST_ENABLE | IXP4XX_OST_ONE_SHOT;
+		break;
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_UNUSED:
+	default:
+		osrt = opts = 0;
+		break;
+	}
+
+	*IXP4XX_OSRT1 = osrt | opts;
+}
+
+static struct clock_event_device clockevent_ixp4xx = {
+	.name		= "ixp4xx timer1",
+	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.rating         = 200,
+	.shift		= 24,
+	.set_mode	= ixp4xx_set_mode,
+	.set_next_event	= ixp4xx_set_next_event,
+};
+
+static int __init ixp4xx_clockevent_init(void)
+{
+	clockevent_ixp4xx.mult = div_sc(FREQ, NSEC_PER_SEC,
+					clockevent_ixp4xx.shift);
+	clockevent_ixp4xx.max_delta_ns =
+		clockevent_delta2ns(0xfffffffe, &clockevent_ixp4xx);
+	clockevent_ixp4xx.min_delta_ns =
+		clockevent_delta2ns(0xf, &clockevent_ixp4xx);
+	clockevent_ixp4xx.cpumask = cpumask_of_cpu(0);
+
+	clockevents_register_device(&clockevent_ixp4xx);
+	return 0;
+}
Index: linux-2.6/arch/arm/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/Kconfig
+++ linux-2.6/arch/arm/Kconfig
@@ -255,6 +255,7 @@ config ARCH_IXP4XX
 	bool "IXP4xx-based"
 	depends on MMU
 	select GENERIC_TIME
+	select GENERIC_CLOCKEVENTS
 	help
 	  Support for Intel's IXP4XX (XScale) family of processors.
 

--

[patch 2.6.20-rc6-rt6 6/6] ARM: clockevent support for OMAP1 platform

[Kevin Hilman]

[-- Attachment #1: arm-omap-clockevent-fixups.patch --]
[-- Type: text/plain, Size: 5428 bytes --]

These are minor fixups to the clockevent support which is
already in 2.6.20-rc6-rt6 for OMAP.

Index: linux-2.6/arch/arm/plat-omap/common.c
===================================================================
--- linux-2.6.orig/arch/arm/plat-omap/common.c
+++ linux-2.6/arch/arm/plat-omap/common.c
@@ -186,7 +186,7 @@ static struct clocksource clocksource_32
 	.read		= omap_32k_read,
 	.mask		= CLOCKSOURCE_MASK(32),
 	.shift		= 10,
-	.is_continuous	= 1,
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
 static int __init omap_init_clocksource_32k(void)
Index: linux-2.6/arch/arm/plat-omap/timer32k.c
===================================================================
--- linux-2.6.orig/arch/arm/plat-omap/timer32k.c
+++ linux-2.6/arch/arm/plat-omap/timer32k.c
@@ -144,35 +144,16 @@ static inline void omap_32k_timer_ack_ir
 
 #endif
 
-static void omap_32k_timer_set_next_event(unsigned long cycles,
-				    struct clock_event_device *evt)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	omap_32k_timer_stop();
-	omap_32k_timer_start(cycles);
-	local_irq_restore(flags);
-}
-
 static void omap_32k_timer_set_mode(enum clock_event_mode mode,
-			      struct clock_event_device *evt)
+				    struct clock_event_device *evt)
 {
-	static int periodic_requests = 0;
-
 	switch (mode) {
-	case CLOCK_EVT_ONESHOT:
-		/* 32k timer does not have one-shot support in hardware.
-		 * instead, wet just to a stop in the next_event hook,
-		 * and dont support PERIODIC */
+	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_PERIODIC:
+		omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
 		break;
-	case CLOCK_EVT_PERIODIC:
-		if (periodic_requests)
-			printk(KERN_ERR "32k-timer: CLOCK_EVT_PERIODIC "
-			       "is not supported.\n");
-		periodic_requests++;
-		break;
-	case CLOCK_EVT_SHUTDOWN:
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
 		omap_32k_timer_stop();
 		break;
 	}
@@ -180,10 +161,8 @@ static void omap_32k_timer_set_mode(enum
 
 static struct clock_event_device clockevent_32k_timer = {
 	.name		= "32k-timer",
-	.capabilities	= CLOCK_CAP_NEXTEVT | CLOCK_CAP_TICK |
-			  CLOCK_CAP_UPDATE,
+	.features       = CLOCK_EVT_FEAT_PERIODIC,
 	.shift		= 32,
-	.set_next_event	= omap_32k_timer_set_next_event,
 	.set_mode	= omap_32k_timer_set_mode,
 };
 
@@ -226,9 +205,10 @@ unsigned long long sched_clock(void)
 
 static irqreturn_t omap_32k_timer_interrupt(int irq, void *dev_id)
 {
+	struct clock_event_device *evt = &clockevent_32k_timer;
 	omap_32k_timer_ack_irq();
 
-	clockevent_32k_timer.event_handler();
+	evt->event_handler(evt);
 
 	return IRQ_HANDLED;
 }
@@ -259,8 +239,6 @@ static __init void omap_init_32k_timer(v
 	}
 #endif
 
-	omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
-
 	clockevent_32k_timer.mult = div_sc(OMAP_32K_TICKS_PER_SEC,
 					   NSEC_PER_SEC,
 					   clockevent_32k_timer.shift);
@@ -269,7 +247,8 @@ static __init void omap_init_32k_timer(v
 	clockevent_32k_timer.min_delta_ns =
 		clockevent_delta2ns(1, &clockevent_32k_timer);
 
-	register_global_clockevent(&clockevent_32k_timer);
+	clockevent_32k_timer.cpumask = cpumask_of_cpu(0);
+	clockevents_register_device(&clockevent_32k_timer);
 }
 
 /*
Index: linux-2.6/arch/arm/mach-omap1/time.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-omap1/time.c
+++ linux-2.6/arch/arm/mach-omap1/time.c
@@ -137,31 +137,32 @@ static inline void omap_mpu_timer_start(
  * MPU timer 1 ... count down to zero, interrupt, reload
  * ---------------------------------------------------------------------------
  */
-static void omap_mpu_set_next_event(unsigned long cycles,
+static int omap_mpu_set_next_event(unsigned long cycles,
 				    struct clock_event_device *evt)
 {
 	omap_mpu_timer_start(0, cycles, 0);
+	return 0;
 }
 
 static void omap_mpu_set_mode(enum clock_event_mode mode,
 			      struct clock_event_device *evt)
 {
 	switch (mode) {
-	case CLOCK_EVT_PERIODIC:
+	case CLOCK_EVT_MODE_PERIODIC:
 		omap_mpu_set_autoreset(0);
 		break;
-	case CLOCK_EVT_ONESHOT:
+	case CLOCK_EVT_MODE_ONESHOT:
 		omap_mpu_remove_autoreset(0);
 		break;
-	case CLOCK_EVT_SHUTDOWN:
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
 		break;
 	}
 }
 
 static struct clock_event_device clockevent_mpu_timer1 = {
 	.name		= "mpu_timer1",
-	.capabilities	= CLOCK_CAP_NEXTEVT | CLOCK_CAP_TICK |
-			  CLOCK_CAP_UPDATE,
+	.features       = CLOCK_EVT_FEAT_PERIODIC, CLOCK_EVT_FEAT_ONESHOT,
 	.shift		= 32,
 	.set_next_event	= omap_mpu_set_next_event,
 	.set_mode	= omap_mpu_set_mode,
@@ -169,7 +170,9 @@ static struct clock_event_device clockev
 
 static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id)
 {
-	clockevent_mpu_timer1.event_handler();
+	struct clock_event_device *evt = &clockevent_mpu_timer1;
+
+	evt->event_handler(evt);
 
 	return IRQ_HANDLED;
 }
@@ -194,7 +197,8 @@ static __init void omap_init_mpu_timer(u
 	clockevent_mpu_timer1.min_delta_ns =
 		clockevent_delta2ns(1, &clockevent_mpu_timer1);
 
-        register_global_clockevent(&clockevent_mpu_timer1);
+	clockevent_mpu_timer1.cpumask = cpumask_of_cpu(0);
+	clockevents_register_device(&clockevent_mpu_timer1);
 }
 
 
@@ -229,7 +233,7 @@ static struct clocksource clocksource_mp
 	.read		= mpu_read,
 	.mask		= CLOCKSOURCE_MASK(32),
 	.shift		= 24,
-	.is_continuous	= 1,
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
 static void __init omap_init_clocksource(unsigned long rate)

--

Re: [patch 2.6.20-rc6-rt6 0/6] ARM clockevent patches

[Ingo Molnar]

* Kevin Hilman <khilman@mvista.com> wrote:

> Thomas, Ingo,
> 
> Here are some updates to get a couple ARM platforms working with the 
> latest -rt.  The platforms tested are OMAP and XScale IXP4xx.
> 
> Patches against 2.6.20-rc6-rt6

thanks, i've applied all of them, they'll show up in -rc7-rt1.

	Ingo

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