[ARM] sa1100: add clock event support
d142b6e77d394a4fcc0a42381b03852bd9c4e263 added clock source support,
now it's time for the clock event support.
Tested-by: Thomas Kunze <thommycheck@gmx.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 1f7c728..63cc733 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -425,6 +425,8 @@
select ARCH_MTD_XIP
select GENERIC_GPIO
select GENERIC_TIME
+ select GENERIC_CLOCKEVENTS
+ select TICK_ONESHOT
select HAVE_IDE
select HAVE_GPIO_LIB
help
diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c
index c2677368..a9799cb 100644
--- a/arch/arm/mach-sa1100/time.c
+++ b/arch/arm/mach-sa1100/time.c
@@ -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;
-}
-
-#ifdef CONFIG_NO_IDLE_HZ
-static unsigned long initial_match;
-static int match_posponed;
-#endif
-
-static irqreturn_t
-sa1100_timer_interrupt(int irq, void *dev_id)
-{
- unsigned int next_match;
-
-#ifdef CONFIG_NO_IDLE_HZ
- if (match_posponed) {
- match_posponed = 0;
- OSMR0 = initial_match;
- }
-#endif
-
- /*
- * 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);
+ /* Disarm the compare/match, signal the event. */
+ OIER &= ~OIER_E0;
+ OSSR = OSSR_M0;
+ c->event_handler(c);
return IRQ_HANDLED;
}
-static struct irqaction sa1100_timer_irq = {
- .name = "SA11xx Timer Tick",
- .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
- .handler = sa1100_timer_interrupt,
+static int
+sa1100_osmr0_set_next_event(unsigned long delta, struct clock_event_device *c)
+{
+ unsigned long flags, next, oscr;
+
+ raw_local_irq_save(flags);
+ OIER |= OIER_E0;
+ next = OSCR + delta;
+ OSMR0 = next;
+ oscr = OSCR;
+ raw_local_irq_restore(flags);
+
+ return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0;
+}
+
+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 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 @@
.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);
+ setup_irq(IRQ_OST0, &sa1100_timer_irq);
+
clocksource_register(&cksrc_sa1100_oscr);
+ clockevents_register_device(&ckevt_sa1100_osmr0);
}
-#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;
- }
-}
-
-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;
-}
-
-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 @@
.init = sa1100_timer_init,
.suspend = sa1100_timer_suspend,
.resume = sa1100_timer_resume,
-#ifdef CONFIG_NO_IDLE_HZ
- .dyn_tick = &sa1100_dyn_tick,
-#endif
};