Commit 3e238be2 authored by Russell King's avatar Russell King Committed by Russell King

[ARM] sa1100: add clock event support

d142b6e7 added clock source support,
now it's time for the clock event support.
Tested-by: default avatarThomas Kunze <thommycheck@gmx.de>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent b43a9e60
......@@ -425,6 +425,8 @@ config ARCH_SA1100
select ARCH_MTD_XIP
select GENERIC_GPIO
select GENERIC_TIME
select GENERIC_CLOCKEVENTS
select TICK_ONESHOT
select HAVE_IDE
select HAVE_GPIO_LIB
help
......
......@@ -13,67 +13,69 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/timex.h>
#include <linux/signal.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <asm/mach/time.h>
#include <asm/hardware.h>
#define RTC_DEF_DIVIDER (32768 - 1)
#define RTC_DEF_TRIM 0
#define MIN_OSCR_DELTA 2
static int sa1100_set_rtc(void)
static irqreturn_t sa1100_ost0_interrupt(int irq, void *dev_id)
{
unsigned long current_time = xtime.tv_sec;
struct clock_event_device *c = dev_id;
if (RTSR & RTSR_ALE) {
/* make sure not to forward the clock over an alarm */
unsigned long alarm = RTAR;
if (current_time >= alarm && alarm >= RCNR)
return -ERESTARTSYS;
}
RCNR = current_time;
return 0;
}
/* Disarm the compare/match, signal the event. */
OIER &= ~OIER_E0;
OSSR = OSSR_M0;
c->event_handler(c);
#ifdef CONFIG_NO_IDLE_HZ
static unsigned long initial_match;
static int match_posponed;
#endif
return IRQ_HANDLED;
}
static irqreturn_t
sa1100_timer_interrupt(int irq, void *dev_id)
static int
sa1100_osmr0_set_next_event(unsigned long delta, struct clock_event_device *c)
{
unsigned int next_match;
unsigned long flags, next, oscr;
#ifdef CONFIG_NO_IDLE_HZ
if (match_posponed) {
match_posponed = 0;
OSMR0 = initial_match;
}
#endif
raw_local_irq_save(flags);
OIER |= OIER_E0;
next = OSCR + delta;
OSMR0 = next;
oscr = OSCR;
raw_local_irq_restore(flags);
/*
* Loop until we get ahead of the free running timer.
* This ensures an exact clock tick count and time accuracy.
* Since IRQs are disabled at this point, coherence between
* lost_ticks(updated in do_timer()) and the match reg value is
* ensured, hence we can use do_gettimeofday() from interrupt
* handlers.
*/
do {
timer_tick();
OSSR = OSSR_M0; /* Clear match on timer 0 */
next_match = (OSMR0 += LATCH);
} while ((signed long)(next_match - OSCR) <= 0);
return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0;
}
return IRQ_HANDLED;
static void
sa1100_osmr0_set_mode(enum clock_event_mode mode, struct clock_event_device *c)
{
unsigned long flags;
switch (mode) {
case CLOCK_EVT_MODE_ONESHOT:
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
raw_local_irq_save(flags);
OIER &= ~OIER_E0;
OSSR = OSSR_M0;
raw_local_irq_restore(flags);
break;
case CLOCK_EVT_MODE_RESUME:
case CLOCK_EVT_MODE_PERIODIC:
break;
}
}
static struct irqaction sa1100_timer_irq = {
.name = "SA11xx Timer Tick",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = sa1100_timer_interrupt,
static struct clock_event_device ckevt_sa1100_osmr0 = {
.name = "osmr0",
.features = CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.rating = 200,
.cpumask = CPU_MASK_CPU0,
.set_next_event = sa1100_osmr0_set_next_event,
.set_mode = sa1100_osmr0_set_mode,
};
static cycle_t sa1100_read_oscr(void)
......@@ -90,62 +92,34 @@ static struct clocksource cksrc_sa1100_oscr = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static struct irqaction sa1100_timer_irq = {
.name = "ost0",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = sa1100_ost0_interrupt,
.dev_id = &ckevt_sa1100_osmr0,
};
static void __init sa1100_timer_init(void)
{
unsigned long flags;
set_rtc = sa1100_set_rtc;
OIER = 0; /* disable any timer interrupts */
OSSR = 0xf; /* clear status on all timers */
setup_irq(IRQ_OST0, &sa1100_timer_irq);
local_irq_save(flags);
OIER = OIER_E0; /* enable match on timer 0 to cause interrupts */
OSMR0 = OSCR + LATCH; /* set initial match */
local_irq_restore(flags);
ckevt_sa1100_osmr0.mult =
div_sc(3686400, NSEC_PER_SEC, ckevt_sa1100_osmr0.shift);
ckevt_sa1100_osmr0.max_delta_ns =
clockevent_delta2ns(0x7fffffff, &ckevt_sa1100_osmr0);
ckevt_sa1100_osmr0.min_delta_ns =
clockevent_delta2ns(MIN_OSCR_DELTA * 2, &ckevt_sa1100_osmr0) + 1;
cksrc_sa1100_oscr.mult =
clocksource_hz2mult(CLOCK_TICK_RATE, cksrc_sa1100_oscr.shift);
clocksource_register(&cksrc_sa1100_oscr);
}
#ifdef CONFIG_NO_IDLE_HZ
static int sa1100_dyn_tick_enable_disable(void)
{
/* nothing to do */
return 0;
}
static void sa1100_dyn_tick_reprogram(unsigned long ticks)
{
if (ticks > 1) {
initial_match = OSMR0;
OSMR0 = initial_match + ticks * LATCH;
match_posponed = 1;
}
}
setup_irq(IRQ_OST0, &sa1100_timer_irq);
static irqreturn_t
sa1100_dyn_tick_handler(int irq, void *dev_id)
{
if (match_posponed) {
match_posponed = 0;
OSMR0 = initial_match;
if ((signed long)(initial_match - OSCR) <= 0)
return sa1100_timer_interrupt(irq, dev_id);
}
return IRQ_NONE;
clocksource_register(&cksrc_sa1100_oscr);
clockevents_register_device(&ckevt_sa1100_osmr0);
}
static struct dyn_tick_timer sa1100_dyn_tick = {
.enable = sa1100_dyn_tick_enable_disable,
.disable = sa1100_dyn_tick_enable_disable,
.reprogram = sa1100_dyn_tick_reprogram,
.handler = sa1100_dyn_tick_handler,
};
#endif
#ifdef CONFIG_PM
unsigned long osmr[4], oier;
......@@ -181,7 +155,4 @@ struct sys_timer sa1100_timer = {
.init = sa1100_timer_init,
.suspend = sa1100_timer_suspend,
.resume = sa1100_timer_resume,
#ifdef CONFIG_NO_IDLE_HZ
.dyn_tick = &sa1100_dyn_tick,
#endif
};
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment