Commit 075192ae authored by Kevin Hilman's avatar Kevin Hilman Committed by Russell King
Browse files

[ARM] 4262/1: OMAP: clocksource and clockevent support 



Update OMAP1 to enable support for hrtimers and dynticks by using new clocksource and clockevent infrastructure.

Signed-off-by: default avatarKevin Hilman <khilman@mvista.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 89df1272

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -370,6 +370,7 @@ config ARCH_LH7A40X 
config ARCH_OMAP

	bool "TI OMAP"

	select GENERIC_GPIO

	select GENERIC_TIME

	help

	  Support for TI's OMAP platform (OMAP1 and OMAP2).

arch/arm/mach-omap1/time.c

+133 −73
Original line number Diff line number Diff line
@@ -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_2_ns(unsigned long long cyc) 
	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_timer_read(int nr) 
	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 = 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 = timer->cntl | MPU_TIMER_AR;

}



unsigned long omap_mpu_timer_ticks_to_usecs(unsigned long nr_ticks)

static inline void omap_mpu_remove_autoreset(int nr)

{

	unsigned long long nsec;

	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);



	nsec = cycles_2_ns((unsigned long long)nr_ticks);

	return (unsigned long)nsec / 1000;

	timer->cntl = timer->cntl & ~MPU_TIMER_AR;

}



/*

 * Last processed system timer interrupt

 */

static unsigned long omap_mpu_timer_last = 0;

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 = timerflags;

}



/*

 * Returns elapsed usecs since last system timer interrupt

 * ---------------------------------------------------------------------------

 * MPU timer 1 ... count down to zero, interrupt, reload

 * ---------------------------------------------------------------------------

 */

static unsigned long omap_mpu_timer_gettimeoffset(void)

static int omap_mpu_set_next_event(unsigned long cycles,

				    struct clock_event_device *evt)

{

	unsigned long now = 0 - omap_mpu_timer_read(0);

	unsigned long elapsed = now - omap_mpu_timer_last;

	omap_mpu_timer_start(0, cycles, 0);

	return 0;

}



	return omap_mpu_timer_ticks_to_usecs(elapsed);

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;

	}

}



/*

 * 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).

 */

static irqreturn_t omap_mpu_timer_interrupt(int irq, void *dev_id)

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 now, latency;

	struct clock_event_device *evt = &clockevent_mpu_timer1;



	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);

	evt->event_handler(evt);



	return IRQ_HANDLED;

}



static struct irqaction omap_mpu_timer_irq = {

	.name		= "mpu timer",

static struct irqaction omap_mpu_timer1_irq = {

	.name		= "mpu_timer1",

	.flags		= IRQF_DISABLED | IRQF_TIMER,

	.handler	= omap_mpu_timer_interrupt,

	.handler	= omap_mpu_timer1_interrupt,

};



static unsigned long omap_mpu_timer1_overflows;

static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id)

static __init void omap_init_mpu_timer(unsigned long rate)

{

	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);



	clockevent_mpu_timer1.cpumask = cpumask_of_cpu(0);

	clockevents_register_device(&clockevent_mpu_timer1);

}





/*

 * ---------------------------------------------------------------------------

 * MPU timer 2 ... free running 32-bit clock source and scheduler clock

 * ---------------------------------------------------------------------------

 */



static unsigned long omap_mpu_timer2_overflows;



static irqreturn_t omap_mpu_timer2_interrupt(int irq, void *dev_id)

{

	omap_mpu_timer1_overflows++;

	omap_mpu_timer2_overflows++;

	return IRQ_HANDLED;

}



static struct irqaction omap_mpu_timer1_irq = {

	.name		= "mpu timer1 overflow",

static struct irqaction omap_mpu_timer2_irq = {

	.name		= "mpu_timer2",

	.flags		= IRQF_DISABLED,

	.handler	= omap_mpu_timer1_interrupt,

	.handler	= omap_mpu_timer2_interrupt,

};



static __init void omap_init_mpu_timer(void)

static cycle_t mpu_read(void)

{

	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);

	return ~omap_mpu_timer_read(1);

}



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 void __init omap_init_clocksource(unsigned long rate)

{

	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 */

};

arch/arm/plat-omap/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ choice 


config ARCH_OMAP1

	bool "TI OMAP1"

	select GENERIC_CLOCKEVENTS



config ARCH_OMAP2

	bool "TI OMAP2"

arch/arm/plat-omap/common.c

+50 −0
Original line number Diff line number Diff line
@@ -156,3 +156,53 @@ static int __init omap_add_serial_console(void) 
	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 */

arch/arm/plat-omap/timer32k.c

+39 −100
Original line number Diff line number Diff line
@@ -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_irq(void) 


#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.
@@ -170,15 +194,6 @@ omap_32k_ticks_to_nsecs(unsigned long ticks_32k) 


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_irq = { 


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(void) 
	}

#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 */

};

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