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[ARM] 4259/1: clockevent support for ixp4xx platform

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Update ixp4xx timer support to use new clockevent infrastructure.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Kevin Hilman 2007-03-08 20:23:59 +01:00 committed by Russell King
parent 9e4559ddff
commit e32f1502be
2 changed files with 75 additions and 19 deletions
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1
arch/arm/Kconfig
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@ -266,6 +266,7 @@ 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.

93
arch/arm/mach-ixp4xx/common.c
View File

@ -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_init(void)
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;
}