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-rw-r--r--arch/arm/mach-sa1100/time.c216
1 files changed, 84 insertions, 132 deletions
diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c
index c2677368d6a..1dea6cfafb3 100644
--- a/arch/arm/mach-sa1100/time.c
+++ b/arch/arm/mach-sa1100/time.c
@@ -2,186 +2,138 @@
* linux/arch/arm/mach-sa1100/time.c
*
* Copyright (C) 1998 Deborah Wallach.
- * Twiddles (C) 1999 Hugo Fiennes <hugo@empeg.com>
- *
- * 2000/03/29 (C) Nicolas Pitre <nico@cam.org>
+ * Twiddles (C) 1999 Hugo Fiennes <hugo@empeg.com>
+ *
+ * 2000/03/29 (C) Nicolas Pitre <nico@fluxnic.net>
* Rewritten: big cleanup, much simpler, better HZ accuracy.
*
*/
#include <linux/init.h>
+#include <linux/kernel.h>
#include <linux/errno.h>
#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 <linux/sched_clock.h>
#include <asm/mach/time.h>
-#include <asm/hardware.h>
+#include <mach/hardware.h>
+#include <mach/irqs.h>
-#define RTC_DEF_DIVIDER (32768 - 1)
-#define RTC_DEF_TRIM 0
+#define SA1100_CLOCK_FREQ 3686400
+#define SA1100_LATCH DIV_ROUND_CLOSEST(SA1100_CLOCK_FREQ, HZ)
-static int sa1100_set_rtc(void)
+static u64 notrace sa1100_read_sched_clock(void)
{
- unsigned long current_time = xtime.tv_sec;
-
- 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;
+ return readl_relaxed(OSCR);
}
-#ifdef CONFIG_NO_IDLE_HZ
-static unsigned long initial_match;
-static int match_posponed;
-#endif
+#define MIN_OSCR_DELTA 2
-static irqreturn_t
-sa1100_timer_interrupt(int irq, void *dev_id)
+static irqreturn_t sa1100_ost0_interrupt(int irq, void *dev_id)
{
- unsigned int next_match;
+ struct clock_event_device *c = dev_id;
-#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. */
+ writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER);
+ writel_relaxed(OSSR_M0, OSSR);
+ 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 cycle_t sa1100_read_oscr(void)
-{
- return OSCR;
-}
-
-static struct clocksource cksrc_sa1100_oscr = {
- .name = "oscr",
- .rating = 200,
- .read = sa1100_read_oscr,
- .mask = CLOCKSOURCE_MASK(32),
- .shift = 20,
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-static void __init sa1100_timer_init(void)
+static int
+sa1100_osmr0_set_next_event(unsigned long delta, struct clock_event_device *c)
{
- 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);
-
- cksrc_sa1100_oscr.mult =
- clocksource_hz2mult(CLOCK_TICK_RATE, cksrc_sa1100_oscr.shift);
+ unsigned long next, oscr;
- clocksource_register(&cksrc_sa1100_oscr);
-}
-
-#ifdef CONFIG_NO_IDLE_HZ
-static int sa1100_dyn_tick_enable_disable(void)
-{
- /* nothing to do */
- return 0;
-}
+ writel_relaxed(readl_relaxed(OIER) | OIER_E0, OIER);
+ next = readl_relaxed(OSCR) + delta;
+ writel_relaxed(next, OSMR0);
+ oscr = readl_relaxed(OSCR);
-static void sa1100_dyn_tick_reprogram(unsigned long ticks)
-{
- if (ticks > 1) {
- initial_match = OSMR0;
- OSMR0 = initial_match + ticks * LATCH;
- match_posponed = 1;
- }
+ return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0;
}
-static irqreturn_t
-sa1100_dyn_tick_handler(int irq, void *dev_id)
+static void
+sa1100_osmr0_set_mode(enum clock_event_mode mode, struct clock_event_device *c)
{
- if (match_posponed) {
- match_posponed = 0;
- OSMR0 = initial_match;
- if ((signed long)(initial_match - OSCR) <= 0)
- return sa1100_timer_interrupt(irq, dev_id);
+ switch (mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER);
+ writel_relaxed(OSSR_M0, OSSR);
+ break;
+
+ case CLOCK_EVT_MODE_RESUME:
+ case CLOCK_EVT_MODE_PERIODIC:
+ break;
}
- 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;
-static void sa1100_timer_suspend(void)
+static void sa1100_timer_suspend(struct clock_event_device *cedev)
{
- osmr[0] = OSMR0;
- osmr[1] = OSMR1;
- osmr[2] = OSMR2;
- osmr[3] = OSMR3;
- oier = OIER;
+ osmr[0] = readl_relaxed(OSMR0);
+ osmr[1] = readl_relaxed(OSMR1);
+ osmr[2] = readl_relaxed(OSMR2);
+ osmr[3] = readl_relaxed(OSMR3);
+ oier = readl_relaxed(OIER);
}
-static void sa1100_timer_resume(void)
+static void sa1100_timer_resume(struct clock_event_device *cedev)
{
- OSSR = 0x0f;
- OSMR0 = osmr[0];
- OSMR1 = osmr[1];
- OSMR2 = osmr[2];
- OSMR3 = osmr[3];
- OIER = oier;
+ writel_relaxed(0x0f, OSSR);
+ writel_relaxed(osmr[0], OSMR0);
+ writel_relaxed(osmr[1], OSMR1);
+ writel_relaxed(osmr[2], OSMR2);
+ writel_relaxed(osmr[3], OSMR3);
+ writel_relaxed(oier, OIER);
/*
* OSMR0 is the system timer: make sure OSCR is sufficiently behind
*/
- OSCR = OSMR0 - LATCH;
+ writel_relaxed(OSMR0 - SA1100_LATCH, OSCR);
}
#else
#define sa1100_timer_suspend NULL
#define sa1100_timer_resume NULL
#endif
-struct sys_timer sa1100_timer = {
- .init = sa1100_timer_init,
+static struct clock_event_device ckevt_sa1100_osmr0 = {
+ .name = "osmr0",
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 200,
+ .set_next_event = sa1100_osmr0_set_next_event,
+ .set_mode = sa1100_osmr0_set_mode,
.suspend = sa1100_timer_suspend,
.resume = sa1100_timer_resume,
-#ifdef CONFIG_NO_IDLE_HZ
- .dyn_tick = &sa1100_dyn_tick,
-#endif
};
+
+static struct irqaction sa1100_timer_irq = {
+ .name = "ost0",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = sa1100_ost0_interrupt,
+ .dev_id = &ckevt_sa1100_osmr0,
+};
+
+void __init sa1100_timer_init(void)
+{
+ writel_relaxed(0, OIER);
+ writel_relaxed(OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3, OSSR);
+
+ sched_clock_register(sa1100_read_sched_clock, 32, 3686400);
+
+ ckevt_sa1100_osmr0.cpumask = cpumask_of(0);
+
+ setup_irq(IRQ_OST0, &sa1100_timer_irq);
+
+ clocksource_mmio_init(OSCR, "oscr", SA1100_CLOCK_FREQ, 200, 32,
+ clocksource_mmio_readl_up);
+ clockevents_config_and_register(&ckevt_sa1100_osmr0, 3686400,
+ MIN_OSCR_DELTA * 2, 0x7fffffff);
+}
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