[RFC, PATCH 0/7] ARM support for hrtimers, dyntick

[RFC, PATCH 0/7] ARM support for hrtimers, dyntick

[Kevin Hilman]

Here is support for hrtimers and dyntick on a few ARM platforms:
ixp4xx, versatile and OMAP.  Patches are against today's Linus git
tree.

For the time being, LED support is missing as the ARM-specific
do_leds() is no longer used.  Based on feedback from my previous RFC,
I think the right thing to do is to migrate any LED drivers to the new
drivers/led framework.

Kevin

[RFC, PATCH 1/7] ARM: build fixups for hrtimers

[Kevin Hilman]

[-- Attachment #1: arm-build-fixups.patch --]
[-- Type: text/plain, Size: 381 bytes --]

Signed-off-by: Kevin Hilman <khilman@mvista.com>

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"
 
 /*

--

[RFC, PATCH 2/7] ARM: Kconfig support for GENERIC_CLOCKEVENTS

[Kevin Hilman]

[-- Attachment #1: arm-kconfig-clockevents.patch --]
[-- Type: text/plain, Size: 822 bytes --]

Signed-off-by: Kevin Hilman <khilman@mvista.com>

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_TIME
 	bool
 	default n
 
+config GENERIC_CLOCKEVENTS
+	bool
+	default n
+
 config MMU
 	bool
 	default y
@@ -480,6 +484,8 @@ endmenu
 
 menu "Kernel Features"
 
+source "kernel/time/Kconfig"
+
 config SMP
 	bool "Symmetric Multi-Processing (EXPERIMENTAL)"
 	depends on EXPERIMENTAL && REALVIEW_MPCORE
@@ -539,6 +545,7 @@ config PREEMPT
 
 config NO_IDLE_HZ
 	bool "Dynamic tick timer"
+	depends on !GENERIC_CLOCKEVENTS
 	help
 	  Select this option if you want to disable continuous timer ticks
 	  and have them programmed to occur as required. This option saves

--

[RFC, PATCH 3/7] ARM: dynamic tick support in idle loop

[Kevin Hilman]

[-- Attachment #1: arm-nohz-idle.patch --]
[-- Type: text/plain, Size: 736 bytes --]

Signed-off-by: Kevin Hilman <khilman@mvista.com>

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>
@@ -154,9 +155,11 @@ void cpu_idle(void)
 		if (!idle)
 			idle = default_idle;
 		leds_event(led_idle_start);
+		tick_nohz_stop_sched_tick();
 		while (!need_resched())
 			idle();
 		leds_event(led_idle_end);
+		tick_nohz_restart_sched_tick();
 		preempt_enable_no_resched();
 		schedule();
 		preempt_disable();

--

[RFC, PATCH 4/7] ARM: clockevent support for ixp4xx platform

[Kevin Hilman]

[-- Attachment #1: arm-ixp4xx-clockevents.patch --]
[-- Type: text/plain, Size: 4583 bytes --]

Signed-off-by: Kevin Hilman <khilman@mvista.com>

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.
 

--

[RFC, PATCH 5/7] ARM: clocksource support for Versatile platform

[Kevin Hilman]

[-- Attachment #1: arm-versatile-clocksource.patch --]
[-- Type: text/plain, Size: 3412 bytes --]

Signed-off-by: Kevin Hilman <khilman@mvista.com>

Index: linux-2.6/arch/arm/mach-versatile/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-versatile/core.c
+++ linux-2.6/arch/arm/mach-versatile/core.c
@@ -26,6 +26,7 @@
 #include <linux/interrupt.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/clcd.h>
+#include <linux/clocksource.h>
 
 #include <asm/cnt32_to_63.h>
 #include <asm/system.h>
@@ -829,46 +830,6 @@ void __init versatile_init(void)
 #endif
 
 /*
- * Returns number of ms since last clock interrupt.  Note that interrupts
- * will have been disabled by do_gettimeoffset()
- */
-static unsigned long versatile_gettimeoffset(void)
-{
-	unsigned long ticks1, ticks2, status;
-
-	/*
-	 * Get the current number of ticks.  Note that there is a race
-	 * condition between us reading the timer and checking for
-	 * an interrupt.  We get around this by ensuring that the
-	 * counter has not reloaded between our two reads.
-	 */
-	ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;
-	do {
-		ticks1 = ticks2;
-		status = __raw_readl(VA_IC_BASE + VIC_RAW_STATUS);
-		ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;
-	} while (ticks2 > ticks1);
-
-	/*
-	 * Number of ticks since last interrupt.
-	 */
-	ticks1 = TIMER_RELOAD - ticks2;
-
-	/*
-	 * Interrupt pending?  If so, we've reloaded once already.
-	 *
-	 * FIXME: Need to check this is effectively timer 0 that expires
-	 */
-	if (status & IRQMASK_TIMERINT0_1)
-		ticks1 += TIMER_RELOAD;
-
-	/*
-	 * Convert the ticks to usecs
-	 */
-	return TICKS2USECS(ticks1);
-}
-
-/*
  * IRQ handler for the timer
  */
 static irqreturn_t versatile_timer_interrupt(int irq, void *dev_id)
@@ -891,6 +852,36 @@ static struct irqaction versatile_timer_
 	.handler	= versatile_timer_interrupt,
 };
 
+static cycle_t versatile_get_cycles(void)
+{
+	return ~readl(TIMER3_VA_BASE + TIMER_VALUE);
+}
+
+static struct clocksource clocksource_versatile = {
+	.name 		= "timer3",
+ 	.rating		= 200,
+ 	.read		= versatile_get_cycles,
+	.mask		= CLOCKSOURCE_MASK(32),
+ 	.shift 		= 20,
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init versatile_clocksource_init(void)
+{
+	/* setup timer3 as free-running clocksource */
+	writel(0, TIMER3_VA_BASE + TIMER_CTRL);
+	writel(0xffffffff, TIMER3_VA_BASE + TIMER_LOAD);
+	writel(0xffffffff, TIMER3_VA_BASE + TIMER_VALUE);
+	writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
+	       TIMER3_VA_BASE + TIMER_CTRL);
+
+ 	clocksource_versatile.mult =
+ 		clocksource_khz2mult(1000, clocksource_versatile.shift);
+ 	clocksource_register(&clocksource_versatile);
+
+ 	return 0;
+}
+
 /*
  * Set up timer interrupt, and return the current time in seconds.
  */
@@ -927,9 +918,11 @@ static void __init versatile_timer_init(
 	 * Make irqs happen for the system timer
 	 */
 	setup_irq(IRQ_TIMERINT0_1, &versatile_timer_irq);
+
+	versatile_clocksource_init();
 }
 
 struct sys_timer versatile_timer = {
 	.init		= versatile_timer_init,
-	.offset		= versatile_gettimeoffset,
 };
+
Index: linux-2.6/arch/arm/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/Kconfig
+++ linux-2.6/arch/arm/Kconfig
@@ -162,6 +162,7 @@ config ARCH_VERSATILE
 	select ARM_AMBA
 	select ARM_VIC
 	select ICST307
+	select GENERIC_TIME
 	help
 	  This enables support for ARM Ltd Versatile board.
 

--

[RFC, PATCH 6/7] ARM: clockevent support for Versatile platform

[Kevin Hilman]

[-- Attachment #1: arm-versatile-clockevents.patch --]
[-- Type: text/plain, Size: 3414 bytes --]

Signed-off-by: Kevin Hilman <khilman@mvista.com>

Index: linux-2.6/arch/arm/mach-versatile/core.c
===================================================================
--- linux-2.6.orig/arch/arm/mach-versatile/core.c
+++ linux-2.6/arch/arm/mach-versatile/core.c
@@ -27,6 +27,7 @@
 #include <linux/amba/bus.h>
 #include <linux/amba/clcd.h>
 #include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/cnt32_to_63.h>
 #include <asm/system.h>
@@ -829,19 +830,61 @@ void __init versatile_init(void)
 #define TICKS2USECS(x)	((x) / TICKS_PER_uSEC)
 #endif
 
+static void timer_set_mode(enum clock_event_mode mode,
+			   struct clock_event_device *clk)
+{
+	unsigned long ctrl;
+
+	switch(mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD);
+
+		ctrl = TIMER_CTRL_PERIODIC;
+		ctrl |= TIMER_CTRL_32BIT | TIMER_CTRL_IE | TIMER_CTRL_ENABLE;
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		/* period set, and timer enabled in 'next_event' hook */
+		ctrl = TIMER_CTRL_ONESHOT;
+		ctrl |= TIMER_CTRL_32BIT | TIMER_CTRL_IE;
+		break;
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	default:
+		ctrl = 0;
+	}
+
+	writel(ctrl, TIMER0_VA_BASE + TIMER_CTRL);
+}
+
+static int timer_set_next_event(unsigned long evt,
+				struct clock_event_device *unused)
+{
+	unsigned long ctrl = readl(TIMER0_VA_BASE + TIMER_CTRL);
+
+	writel(evt, TIMER0_VA_BASE + TIMER_LOAD);
+	writel(ctrl | TIMER_CTRL_ENABLE, TIMER0_VA_BASE + TIMER_CTRL);
+
+	return 0;
+}
+
+static struct clock_event_device timer0_clockevent =	 {
+	.name		= "timer0",
+	.shift		= 32,
+	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.set_mode	= timer_set_mode,
+	.set_next_event	= timer_set_next_event,
+};
+
 /*
  * IRQ handler for the timer
  */
 static irqreturn_t versatile_timer_interrupt(int irq, void *dev_id)
 {
-	write_seqlock(&xtime_lock);
+	struct clock_event_device *evt = &timer0_clockevent;
 
-	// ...clear the interrupt
 	writel(1, TIMER0_VA_BASE + TIMER_INTCLR);
 
-	timer_tick();
-
-	write_sequnlock(&xtime_lock);
+	evt->event_handler(evt);
 
 	return IRQ_HANDLED;
 }
@@ -909,17 +952,22 @@ static void __init versatile_timer_init(
 	writel(0, TIMER2_VA_BASE + TIMER_CTRL);
 	writel(0, TIMER3_VA_BASE + TIMER_CTRL);
 
-	writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD);
-	writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_VALUE);
-	writel(TIMER_DIVISOR | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC |
-	       TIMER_CTRL_IE, TIMER0_VA_BASE + TIMER_CTRL);
-
 	/* 
 	 * Make irqs happen for the system timer
 	 */
 	setup_irq(IRQ_TIMERINT0_1, &versatile_timer_irq);
 
 	versatile_clocksource_init();
+
+	timer0_clockevent.mult =
+		div_sc(1000000, NSEC_PER_SEC, timer0_clockevent.shift);
+	timer0_clockevent.max_delta_ns =
+		clockevent_delta2ns(0xffffffff, &timer0_clockevent);
+	timer0_clockevent.min_delta_ns =
+		clockevent_delta2ns(0xf, &timer0_clockevent);
+
+	timer0_clockevent.cpumask = cpumask_of_cpu(0);
+	clockevents_register_device(&timer0_clockevent);
 }
 
 struct sys_timer versatile_timer = {
Index: linux-2.6/arch/arm/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/Kconfig
+++ linux-2.6/arch/arm/Kconfig
@@ -163,6 +163,7 @@ config ARCH_VERSATILE
 	select ARM_VIC
 	select ICST307
 	select GENERIC_TIME
+	select GENERIC_CLOCKEVENTS
 	help
 	  This enables support for ARM Ltd Versatile board.
 

--

[RFC, PATCH 7/7] ARM: OMAP: clocksource and clockevent support

[Kevin Hilman]

[-- Attachment #1: arm-omap-clocksource-clockevent.patch --]
[-- Type: text/plain, Size: 17223 bytes --]

Signed-off-by: Kevin Hilman <khilman@mvista.com>

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
@@ -39,6 +39,10 @@
 #include <linux/interrupt.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/system.h>
 #include <asm/hardware.h>
@@ -48,13 +52,7 @@
 #include <asm/mach/irq.h>
 #include <asm/mach/time.h>
 
-struct sys_timer omap_timer;
 
-/*
- * ---------------------------------------------------------------------------
- * MPU timer
- * ---------------------------------------------------------------------------
- */
 #define OMAP_MPU_TIMER_BASE		OMAP_MPU_TIMER1_BASE
 #define OMAP_MPU_TIMER_OFFSET		0x100
 
@@ -88,21 +86,6 @@ static inline unsigned long long cycles_
 	return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
 }
 
-/*
- * MPU_TICKS_PER_SEC must be an even number, otherwise machinecycles_to_usecs
- * will break. On P2, the timer count rate is 6.5 MHz after programming PTV
- * with 0. This divides the 13MHz input by 2, and is undocumented.
- */
-#if defined(CONFIG_MACH_OMAP_PERSEUS2) || defined(CONFIG_MACH_OMAP_FSAMPLE)
-/* REVISIT: This ifdef construct should be replaced by a query to clock
- * framework to see if timer base frequency is 12.0, 13.0 or 19.2 MHz.
- */
-#define MPU_TICKS_PER_SEC		(13000000 / 2)
-#else
-#define MPU_TICKS_PER_SEC		(12000000 / 2)
-#endif
-
-#define MPU_TIMER_TICK_PERIOD		((MPU_TICKS_PER_SEC / HZ) - 1)
 
 typedef struct {
 	u32 cntl;			/* CNTL_TIMER, R/W */
@@ -120,98 +103,164 @@ static inline unsigned long omap_mpu_tim
 	return timer->read_tim;
 }
 
-static inline void omap_mpu_timer_start(int nr, unsigned long load_val)
+static inline void omap_mpu_set_autoreset(int nr)
+{
+	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+
+	timer->cntl = timer->cntl | MPU_TIMER_AR;
+}
+
+static inline void omap_mpu_remove_autoreset(int nr)
+{
+	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+
+	timer->cntl = timer->cntl & ~MPU_TIMER_AR;
+}
+
+static inline void omap_mpu_timer_start(int nr, unsigned long load_val,
+					int autoreset)
 {
 	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+	unsigned int timerflags = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST);
+
+	if (autoreset) timerflags |= MPU_TIMER_AR;
 
 	timer->cntl = MPU_TIMER_CLOCK_ENABLE;
 	udelay(1);
 	timer->load_tim = load_val;
         udelay(1);
-	timer->cntl = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_AR | MPU_TIMER_ST);
+	timer->cntl = timerflags;
+}
+
+/*
+ * ---------------------------------------------------------------------------
+ * MPU timer 1 ... count down to zero, interrupt, reload
+ * ---------------------------------------------------------------------------
+ */
+static int omap_mpu_set_next_event(unsigned long cycles,
+				    struct clock_event_device *evt)
+{
+	omap_mpu_timer_start(0, cycles, 0);
+	return 0;
 }
 
-unsigned long omap_mpu_timer_ticks_to_usecs(unsigned long nr_ticks)
+static void omap_mpu_set_mode(enum clock_event_mode mode,
+			      struct clock_event_device *evt)
+{
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		omap_mpu_set_autoreset(0);
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		omap_mpu_remove_autoreset(0);
+		break;
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		break;
+	}
+}
+
+static struct clock_event_device clockevent_mpu_timer1 = {
+	.name		= "mpu_timer1",
+	.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,
+};
+
+static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id)
 {
-	unsigned long long nsec;
+	struct clock_event_device *evt = &clockevent_mpu_timer1;
+
+	evt->event_handler(evt);
 
-	nsec = cycles_2_ns((unsigned long long)nr_ticks);
-	return (unsigned long)nsec / 1000;
+	return IRQ_HANDLED;
 }
 
-/*
- * Last processed system timer interrupt
- */
-static unsigned long omap_mpu_timer_last = 0;
+static struct irqaction omap_mpu_timer1_irq = {
+	.name		= "mpu_timer1",
+	.flags		= IRQF_DISABLED | IRQF_TIMER,
+	.handler	= omap_mpu_timer1_interrupt,
+};
 
-/*
- * Returns elapsed usecs since last system timer interrupt
- */
-static unsigned long omap_mpu_timer_gettimeoffset(void)
+static __init void omap_init_mpu_timer(unsigned long rate)
 {
-	unsigned long now = 0 - omap_mpu_timer_read(0);
-	unsigned long elapsed = now - omap_mpu_timer_last;
+	set_cyc2ns_scale(rate / 1000);
+
+	setup_irq(INT_TIMER1, &omap_mpu_timer1_irq);
+	omap_mpu_timer_start(0, (rate / HZ) - 1, 1);
+
+	clockevent_mpu_timer1.mult = div_sc(rate, NSEC_PER_SEC,
+					    clockevent_mpu_timer1.shift);
+	clockevent_mpu_timer1.max_delta_ns =
+		clockevent_delta2ns(-1, &clockevent_mpu_timer1);
+	clockevent_mpu_timer1.min_delta_ns =
+		clockevent_delta2ns(1, &clockevent_mpu_timer1);
 
-	return omap_mpu_timer_ticks_to_usecs(elapsed);
+	clockevent_mpu_timer1.cpumask = cpumask_of_cpu(0);
+	clockevents_register_device(&clockevent_mpu_timer1);
 }
 
+
 /*
- * Elapsed time between interrupts is calculated using timer0.
- * Latency during the interrupt is calculated using timer1.
- * Both timer0 and timer1 are counting at 6MHz (P2 6.5MHz).
+ * ---------------------------------------------------------------------------
+ * MPU timer 2 ... free running 32-bit clock source and scheduler clock
+ * ---------------------------------------------------------------------------
  */
-static irqreturn_t omap_mpu_timer_interrupt(int irq, void *dev_id)
-{
-	unsigned long now, latency;
 
-	write_seqlock(&xtime_lock);
-	now = 0 - omap_mpu_timer_read(0);
-	latency = MPU_TICKS_PER_SEC / HZ - omap_mpu_timer_read(1);
-	omap_mpu_timer_last = now - latency;
-	timer_tick();
-	write_sequnlock(&xtime_lock);
+static unsigned long omap_mpu_timer2_overflows;
 
+static irqreturn_t omap_mpu_timer2_interrupt(int irq, void *dev_id)
+{
+	omap_mpu_timer2_overflows++;
 	return IRQ_HANDLED;
 }
 
-static struct irqaction omap_mpu_timer_irq = {
-	.name		= "mpu timer",
-	.flags		= IRQF_DISABLED | IRQF_TIMER,
-	.handler	= omap_mpu_timer_interrupt,
+static struct irqaction omap_mpu_timer2_irq = {
+	.name		= "mpu_timer2",
+	.flags		= IRQF_DISABLED,
+	.handler	= omap_mpu_timer2_interrupt,
 };
 
-static unsigned long omap_mpu_timer1_overflows;
-static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id)
+static cycle_t mpu_read(void)
 {
-	omap_mpu_timer1_overflows++;
-	return IRQ_HANDLED;
+	return ~omap_mpu_timer_read(1);
 }
 
-static struct irqaction omap_mpu_timer1_irq = {
-	.name		= "mpu timer1 overflow",
-	.flags		= IRQF_DISABLED,
-	.handler	= omap_mpu_timer1_interrupt,
+static struct clocksource clocksource_mpu = {
+	.name		= "mpu_timer2",
+	.rating		= 300,
+	.read		= mpu_read,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.shift		= 24,
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-static __init void omap_init_mpu_timer(void)
+static void __init omap_init_clocksource(unsigned long rate)
 {
-	set_cyc2ns_scale(MPU_TICKS_PER_SEC / 1000);
-	omap_timer.offset = omap_mpu_timer_gettimeoffset;
-	setup_irq(INT_TIMER1, &omap_mpu_timer1_irq);
-	setup_irq(INT_TIMER2, &omap_mpu_timer_irq);
-	omap_mpu_timer_start(0, 0xffffffff);
-	omap_mpu_timer_start(1, MPU_TIMER_TICK_PERIOD);
+	static char err[] __initdata = KERN_ERR
+			"%s: can't register clocksource!\n";
+
+	clocksource_mpu.mult
+		= clocksource_khz2mult(rate/1000, clocksource_mpu.shift);
+
+	setup_irq(INT_TIMER2, &omap_mpu_timer2_irq);
+	omap_mpu_timer_start(1, ~0, 1);
+
+	if (clocksource_register(&clocksource_mpu))
+		printk(err, clocksource_mpu.name);
 }
 
+
 /*
  * Scheduler clock - returns current time in nanosec units.
  */
 unsigned long long sched_clock(void)
 {
-	unsigned long ticks = 0 - omap_mpu_timer_read(0);
+	unsigned long ticks = 0 - omap_mpu_timer_read(1);
 	unsigned long long ticks64;
 
-	ticks64 = omap_mpu_timer1_overflows;
+	ticks64 = omap_mpu_timer2_overflows;
 	ticks64 <<= 32;
 	ticks64 |= ticks;
 
@@ -225,10 +274,21 @@ unsigned long long sched_clock(void)
  */
 static void __init omap_timer_init(void)
 {
-	omap_init_mpu_timer();
+	struct clk	*ck_ref = clk_get(NULL, "ck_ref");
+	unsigned long	rate;
+
+	BUG_ON(IS_ERR(ck_ref));
+
+	rate = clk_get_rate(ck_ref);
+	clk_put(ck_ref);
+
+	/* PTV = 0 */
+	rate /= 2;
+
+	omap_init_mpu_timer(rate);
+	omap_init_clocksource(rate);
 }
 
 struct sys_timer omap_timer = {
 	.init		= omap_timer_init,
-	.offset		= NULL,		/* Initialized later */
 };
Index: linux-2.6/arch/arm/plat-omap/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/plat-omap/Kconfig
+++ linux-2.6/arch/arm/plat-omap/Kconfig
@@ -11,6 +11,7 @@ choice
 
 config ARCH_OMAP1
 	bool "TI OMAP1"
+	select GENERIC_CLOCKEVENTS
 
 config ARCH_OMAP2
 	bool "TI OMAP2"
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
@@ -156,3 +156,53 @@ static int __init omap_add_serial_consol
 	return add_preferred_console("ttyS", line, opt);
 }
 console_initcall(omap_add_serial_console);
+
+
+/*
+ * 32KHz clocksource ... always available, on pretty most chips except
+ * OMAP 730 and 1510.  Other timers could be used as clocksources, with
+ * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
+ * but systems won't necessarily want to spend resources that way.
+ */
+
+#if defined(CONFIG_ARCH_OMAP16XX)
+#define TIMER_32K_SYNCHRONIZED		0xfffbc410
+#elif defined(CONFIG_ARCH_OMAP24XX)
+#define TIMER_32K_SYNCHRONIZED		0x48004010
+#endif
+
+#ifdef	TIMER_32K_SYNCHRONIZED
+
+#include <linux/clocksource.h>
+
+static cycle_t omap_32k_read(void)
+{
+	return omap_readl(TIMER_32K_SYNCHRONIZED);
+}
+
+static struct clocksource clocksource_32k = {
+	.name		= "32k_counter",
+	.rating		= 250,
+	.read		= omap_32k_read,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.shift		= 10,
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init omap_init_clocksource_32k(void)
+{
+	static char err[] __initdata = KERN_ERR
+			"%s: can't register clocksource!\n";
+
+	if (cpu_is_omap16xx() || cpu_is_omap24xx()) {
+		clocksource_32k.mult = clocksource_hz2mult(32768,
+					    clocksource_32k.shift);
+
+		if (clocksource_register(&clocksource_32k))
+			printk(err, clocksource_32k.name);
+	}
+	return 0;
+}
+arch_initcall(omap_init_clocksource_32k);
+
+#endif	/* TIMER_32K_SYNCHRONIZED */
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
@@ -42,6 +42,8 @@
 #include <linux/spinlock.h>
 #include <linux/err.h>
 #include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/system.h>
 #include <asm/hardware.h>
@@ -80,13 +82,13 @@ struct sys_timer omap_timer;
 #define OMAP1_32K_TIMER_TVR		0x00
 #define OMAP1_32K_TIMER_TCR		0x04
 
-#define OMAP_32K_TICKS_PER_HZ		(32768 / HZ)
+#define OMAP_32K_TICKS_PER_SEC		(32768)
 
 /*
  * TRM says 1 / HZ = ( TVR + 1) / 32768, so TRV = (32768 / HZ) - 1
  * so with HZ = 128, TVR = 255.
  */
-#define OMAP_32K_TIMER_TICK_PERIOD	((32768 / HZ) - 1)
+#define OMAP_32K_TIMER_TICK_PERIOD	((OMAP_32K_TICKS_PER_SEC / HZ) - 1)
 
 #define JIFFIES_TO_HW_TICKS(nr_jiffies, clock_rate)			\
 				(((nr_jiffies) * (clock_rate)) / HZ)
@@ -142,6 +144,28 @@ static inline void omap_32k_timer_ack_ir
 
 #endif
 
+static void omap_32k_timer_set_mode(enum clock_event_mode mode,
+				    struct clock_event_device *evt)
+{
+	switch (mode) {
+	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_PERIODIC:
+		omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
+		break;
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		omap_32k_timer_stop();
+		break;
+	}
+}
+
+static struct clock_event_device clockevent_32k_timer = {
+	.name		= "32k-timer",
+	.features       = CLOCK_EVT_FEAT_PERIODIC,
+	.shift		= 32,
+	.set_mode	= omap_32k_timer_set_mode,
+};
+
 /*
  * The 32KHz synchronized timer is an additional timer on 16xx.
  * It is always running.
@@ -171,15 +195,6 @@ omap_32k_ticks_to_nsecs(unsigned long ti
 static unsigned long omap_32k_last_tick = 0;
 
 /*
- * Returns elapsed usecs since last 32k timer interrupt
- */
-static unsigned long omap_32k_timer_gettimeoffset(void)
-{
-	unsigned long now = omap_32k_sync_timer_read();
-	return omap_32k_ticks_to_usecs(now - omap_32k_last_tick);
-}
-
-/*
  * Returns current time from boot in nsecs. It's OK for this to wrap
  * around for now, as it's just a relative time stamp.
  */
@@ -188,95 +203,16 @@ unsigned long long sched_clock(void)
 	return omap_32k_ticks_to_nsecs(omap_32k_sync_timer_read());
 }
 
-/*
- * Timer interrupt for 32KHz timer. When dynamic tick is enabled, this
- * function is also called from other interrupts to remove latency
- * issues with dynamic tick. In the dynamic tick case, we need to lock
- * with irqsave.
- */
-static inline irqreturn_t _omap_32k_timer_interrupt(int irq, void *dev_id)
-{
-	unsigned long now;
-
-	omap_32k_timer_ack_irq();
-	now = omap_32k_sync_timer_read();
-
-	while ((signed long)(now - omap_32k_last_tick)
-						>= OMAP_32K_TICKS_PER_HZ) {
-		omap_32k_last_tick += OMAP_32K_TICKS_PER_HZ;
-		timer_tick();
-	}
-
-	/* Restart timer so we don't drift off due to modulo or dynamic tick.
-	 * By default we program the next timer to be continuous to avoid
-	 * latencies during high system load. During dynamic tick operation the
-	 * continuous timer can be overridden from pm_idle to be longer.
-	 */
-	omap_32k_timer_start(omap_32k_last_tick + OMAP_32K_TICKS_PER_HZ - now);
-
-	return IRQ_HANDLED;
-}
-
-static irqreturn_t omap_32k_timer_handler(int irq, void *dev_id)
-{
-	return _omap_32k_timer_interrupt(irq, dev_id);
-}
-
 static irqreturn_t omap_32k_timer_interrupt(int irq, void *dev_id)
 {
-	unsigned long flags;
+	struct clock_event_device *evt = &clockevent_32k_timer;
+	omap_32k_timer_ack_irq();
 
-	write_seqlock_irqsave(&xtime_lock, flags);
-	_omap_32k_timer_interrupt(irq, dev_id);
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	evt->event_handler(evt);
 
 	return IRQ_HANDLED;
 }
 
-#ifdef CONFIG_NO_IDLE_HZ
-/*
- * Programs the next timer interrupt needed. Called when dynamic tick is
- * enabled, and to reprogram the ticks to skip from pm_idle. Note that
- * we can keep the timer continuous, and don't need to set it to run in
- * one-shot mode. This is because the timer will get reprogrammed again
- * after next interrupt.
- */
-void omap_32k_timer_reprogram(unsigned long next_tick)
-{
-	unsigned long ticks = JIFFIES_TO_HW_TICKS(next_tick, 32768) + 1;
-	unsigned long now = omap_32k_sync_timer_read();
-	unsigned long idled = now - omap_32k_last_tick;
-
-	if (idled + 1 < ticks)
-		ticks -= idled;
-	else
-		ticks = 1;
-	omap_32k_timer_start(ticks);
-}
-
-static struct irqaction omap_32k_timer_irq;
-extern struct timer_update_handler timer_update;
-
-static int omap_32k_timer_enable_dyn_tick(void)
-{
-	/* No need to reprogram timer, just use the next interrupt */
-	return 0;
-}
-
-static int omap_32k_timer_disable_dyn_tick(void)
-{
-	omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
-	return 0;
-}
-
-static struct dyn_tick_timer omap_dyn_tick_timer = {
-	.enable		= omap_32k_timer_enable_dyn_tick,
-	.disable	= omap_32k_timer_disable_dyn_tick,
-	.reprogram	= omap_32k_timer_reprogram,
-	.handler	= omap_32k_timer_handler,
-};
-#endif	/* CONFIG_NO_IDLE_HZ */
-
 static struct irqaction omap_32k_timer_irq = {
 	.name		= "32KHz timer",
 	.flags		= IRQF_DISABLED | IRQF_TIMER,
@@ -285,13 +221,8 @@ static struct irqaction omap_32k_timer_i
 
 static __init void omap_init_32k_timer(void)
 {
-#ifdef CONFIG_NO_IDLE_HZ
-	omap_timer.dyn_tick = &omap_dyn_tick_timer;
-#endif
-
 	if (cpu_class_is_omap1())
 		setup_irq(INT_OS_TIMER, &omap_32k_timer_irq);
-	omap_timer.offset  = omap_32k_timer_gettimeoffset;
 	omap_32k_last_tick = omap_32k_sync_timer_read();
 
 #ifdef CONFIG_ARCH_OMAP2
@@ -308,7 +239,16 @@ 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);
+	clockevent_32k_timer.max_delta_ns =
+		clockevent_delta2ns(0xfffffffe, &clockevent_32k_timer);
+	clockevent_32k_timer.min_delta_ns =
+		clockevent_delta2ns(1, &clockevent_32k_timer);
+
+	clockevent_32k_timer.cpumask = cpumask_of_cpu(0);
+	clockevents_register_device(&clockevent_32k_timer);
 }
 
 /*
@@ -326,5 +266,4 @@ static void __init omap_timer_init(void)
 
 struct sys_timer omap_timer = {
 	.init		= omap_timer_init,
-	.offset		= NULL,		/* Initialized later */
 };
Index: linux-2.6/arch/arm/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/Kconfig
+++ linux-2.6/arch/arm/Kconfig
@@ -346,6 +346,7 @@ config ARCH_LH7A40X
 
 config ARCH_OMAP
 	bool "TI OMAP"
+	select GENERIC_TIME
 	help
 	  Support for TI's OMAP platform (OMAP1 and OMAP2).
 

--

Re: [RFC, PATCH 1/7] ARM: build fixups for hrtimers

[Thomas Gleixner]

On Mon, 2007-02-19 at 13:47 -0800, Kevin Hilman wrote:
> Signed-off-by: Kevin Hilman <khilman@mvista.com>
> 
> 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"

Went in already via 9e203bcc1051cac2a8b15c3ee9db4c0d05794abe

	tglx



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Re: [RFC, PATCH 2/7] ARM: Kconfig support for GENERIC_CLOCKEVENTS

[Thomas Gleixner]

On Mon, 2007-02-19 at 13:47 -0800, Kevin Hilman wrote:
> plain text document attachment (arm-kconfig-clockevents.patch)
> Signed-off-by: Kevin Hilman <khilman@mvista.com>

Acked-by: Thomas Gleixner <tglx@linutronix.de>



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