Merge branch 'upstream' of git://lost.foo-projects.org/~ahkok/git/netdev-2.6 into...

[pandora-kernel.git] / arch / arm / mach-sa1100 / time.c

diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c
index 0eeb361..49ae716 100644 (file)
--- a/arch/arm/mach-sa1100/time.c
+++ b/arch/arm/mach-sa1100/time.c
@@ -11,6 +11,7 @@
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/timex.h>
 #include <linux/signal.h>
 
@@ -70,15 +71,11 @@ static unsigned long sa1100_gettimeoffset (void)
        return usec;
 }
 
-/*
- * We will be entered with IRQs enabled.
- *
- * Loop until we get ahead of the free running timer.
- * This ensures an exact clock tick count and time accuracy.
- * IRQs are disabled inside the loop to ensure coherence between
- * lost_ticks (updated in do_timer()) and the match reg value, so we
- * can use do_gettimeofday() from interrupt handlers.
- */
+#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, struct pt_regs *regs)
 {
@@ -86,6 +83,21 @@ sa1100_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 
        write_seqlock(&xtime_lock);
 
+#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(regs);
                OSSR = OSSR_M0;  /* Clear match on timer 0 */
@@ -99,7 +111,7 @@ sa1100_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 
 static struct irqaction sa1100_timer_irq = {
        .name           = "SA11xx Timer Tick",
-       .flags          = SA_INTERRUPT | SA_TIMER,
+       .flags          = IRQF_DISABLED | IRQF_TIMER,
        .handler        = sa1100_timer_interrupt,
 };
 
@@ -113,13 +125,51 @@ static void __init sa1100_timer_init(void)
        tv.tv_sec = sa1100_get_rtc_time();
        do_settimeofday(&tv);
 
-       OSMR0 = 0;              /* set initial match at 0 */
+       OIER = 0;               /* disable any timer interrupts */
+       OSCR = LATCH*2;         /* push OSCR out of the way */
+       OSMR0 = LATCH;          /* set initial match */
        OSSR = 0xf;             /* clear status on all timers */
        setup_irq(IRQ_OST0, &sa1100_timer_irq);
-       OIER |= OIER_E0;        /* enable match on timer 0 to cause interrupts */
-       OSCR = 0;               /* initialize free-running timer, force first match */
+       OIER = OIER_E0;         /* enable match on timer 0 to cause interrupts */
+       OSCR = 0;               /* initialize free-running timer */
+}
+
+#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, struct pt_regs *regs)
+{
+       if (match_posponed) {
+               match_posponed = 0;
+               OSMR0 = initial_match;
+               if ((signed long)(initial_match - OSCR) <= 0)
+                       return sa1100_timer_interrupt(irq, dev_id, regs);
+       }
+       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;
 
@@ -156,4 +206,7 @@ struct sys_timer sa1100_timer = {
        .suspend        = sa1100_timer_suspend,
        .resume         = sa1100_timer_resume,
        .offset         = sa1100_gettimeoffset,
+#ifdef CONFIG_NO_IDLE_HZ
+       .dyn_tick       = &sa1100_dyn_tick,
+#endif
 };