X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Farm%2Fmach-pxa%2Ftime.c;h=b9b2057349ebe9a1738fd327ab668bd11decb4e7;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=473fb6173f7210a3ac7561983f05a437c8b8f910;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c
index 473fb6173..b9b205734 100644
--- a/arch/arm/mach-pxa/time.c
+++ b/arch/arm/mach-pxa/time.c
@@ -70,6 +70,11 @@ static unsigned long pxa_gettimeoffset (void)
 	return usec;
 }
 
+#ifdef CONFIG_NO_IDLE_HZ
+static unsigned long initial_match;
+static int match_posponed;
+#endif
+
 static irqreturn_t
 pxa_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
@@ -77,11 +82,19 @@ pxa_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.
-	 * 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.
+	 * 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.
 	 *
 	 * HACK ALERT: it seems that the PXA timer regs aren't updated right
 	 * away in all cases when a write occurs.  We therefore compare with
@@ -105,8 +118,8 @@ pxa_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 
 static struct irqaction pxa_timer_irq = {
 	.name		= "PXA Timer Tick",
-	.flags		= SA_INTERRUPT,
-	.handler	= pxa_timer_interrupt
+	.flags		= SA_INTERRUPT | SA_TIMER,
+	.handler	= pxa_timer_interrupt,
 };
 
 static void __init pxa_timer_init(void)
@@ -119,13 +132,51 @@ static void __init pxa_timer_init(void)
 	tv.tv_sec = pxa_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, &pxa_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 pxa_dyn_tick_enable_disable(void)
+{
+	/* nothing to do */
+	return 0;
+}
+
+static void pxa_dyn_tick_reprogram(unsigned long ticks)
+{
+	if (ticks > 1) {
+		initial_match = OSMR0;
+		OSMR0 = initial_match + ticks * LATCH;
+		match_posponed = 1;
+	}
 }
 
+static irqreturn_t
+pxa_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) <= 8 )
+			return pxa_timer_interrupt(irq, dev_id, regs);
+	}
+	return IRQ_NONE;
+}
+
+static struct dyn_tick_timer pxa_dyn_tick = {
+	.enable		= pxa_dyn_tick_enable_disable,
+	.disable	= pxa_dyn_tick_enable_disable,
+	.reprogram	= pxa_dyn_tick_reprogram,
+	.handler	= pxa_dyn_tick_handler,
+};
+#endif
+
 #ifdef CONFIG_PM
 static unsigned long osmr[4], oier;
 
@@ -161,4 +212,7 @@ struct sys_timer pxa_timer = {
 	.suspend	= pxa_timer_suspend,
 	.resume		= pxa_timer_resume,
 	.offset		= pxa_gettimeoffset,
+#ifdef CONFIG_NO_IDLE_HZ
+	.dyn_tick	= &pxa_dyn_tick,
+#endif
 };