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Diffstat (limited to 'arch/arm/cpu/ixp/timer.c')
-rw-r--r--arch/arm/cpu/ixp/timer.c124
1 files changed, 58 insertions, 66 deletions
diff --git a/arch/arm/cpu/ixp/timer.c b/arch/arm/cpu/ixp/timer.c
index edf341f..9f3ea42 100644
--- a/arch/arm/cpu/ixp/timer.c
+++ b/arch/arm/cpu/ixp/timer.c
@@ -1,4 +1,7 @@
/*
+ * (C) Copyright 2010
+ * Michael Schwingen, michael@schwingen.org
+ *
* (C) Copyright 2006
* Stefan Roese, DENX Software Engineering, sr@denx.de.
*
@@ -31,105 +34,94 @@
#include <common.h>
#include <asm/arch/ixp425.h>
+#include <asm/io.h>
+#include <div64.h>
-#ifdef CONFIG_TIMER_IRQ
-
-#define FREQ 66666666
-#define CLOCK_TICK_RATE (((FREQ / CONFIG_SYS_HZ & ~IXP425_OST_RELOAD_MASK) + 1) * CONFIG_SYS_HZ)
-#define LATCH ((CLOCK_TICK_RATE + CONFIG_SYS_HZ/2) / CONFIG_SYS_HZ) /* For divider */
+DECLARE_GLOBAL_DATA_PTR;
/*
- * When interrupts are enabled, use timer 2 for time/delay generation...
+ * The IXP42x time-stamp timer runs at 2*OSC_IN (66.666MHz when using a
+ * 33.333MHz crystal).
*/
-
-static volatile ulong timestamp;
-
-static void timer_isr(void *data)
+static inline unsigned long long tick_to_time(unsigned long long tick)
{
- unsigned int *pTime = (unsigned int *)data;
-
- (*pTime)++;
-
- /*
- * Reset IRQ source
- */
- *IXP425_OSST = IXP425_OSST_TIMER_2_PEND;
+ tick *= CONFIG_SYS_HZ;
+ do_div(tick, CONFIG_IXP425_TIMER_CLK);
+ return tick;
}
-ulong get_timer (ulong base)
+static inline unsigned long long time_to_tick(unsigned long long time)
{
- return timestamp - base;
+ time *= CONFIG_IXP425_TIMER_CLK;
+ do_div(time, CONFIG_SYS_HZ);
+ return time;
}
-void reset_timer (void)
+static inline unsigned long long us_to_tick(unsigned long long us)
{
- timestamp = 0;
+ us = us * CONFIG_IXP425_TIMER_CLK + 999999;
+ do_div(us, 1000000);
+ return us;
}
-int timer_init (void)
+unsigned long long get_ticks(void)
{
- /* install interrupt handler for timer */
- irq_install_handler(IXP425_TIMER_2_IRQ, timer_isr, (void *)&timestamp);
-
- /* setup the Timer counter value */
- *IXP425_OSRT2 = (LATCH & ~IXP425_OST_RELOAD_MASK) | IXP425_OST_ENABLE;
+ ulong now = readl(IXP425_OSTS_B);
+
+ if (readl(IXP425_OSST) & IXP425_OSST_TIMER_TS_PEND) {
+ /* rollover of timestamp timer register */
+ gd->timestamp += (0xFFFFFFFF - gd->lastinc) + now + 1;
+ writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST);
+ } else {
+ /* move stamp forward with absolut diff ticks */
+ gd->timestamp += (now - gd->lastinc);
+ }
+ gd->lastinc = now;
+ return gd->timestamp;
+}
- /* enable timer irq */
- *IXP425_ICMR = (1 << IXP425_TIMER_2_IRQ);
- return 0;
-}
-#else
-ulong get_timer (ulong base)
+void reset_timer_masked(void)
{
- return get_timer_masked () - base;
+ /* capture current timestamp counter */
+ gd->lastinc = readl(IXP425_OSTS_B);
+ /* start "advancing" time stamp from 0 */
+ gd->timestamp = 0;
}
-void ixp425_udelay(unsigned long usec)
+void reset_timer(void)
{
- /*
- * This function has a max usec, but since it is called from udelay
- * we should not have to worry... be happy
- */
- unsigned long usecs = CONFIG_SYS_HZ/1000000L & ~IXP425_OST_RELOAD_MASK;
-
- *IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
- usecs |= IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
- *IXP425_OSRT1 = usecs;
- while (!(*IXP425_OSST & IXP425_OSST_TIMER_1_PEND));
+ reset_timer_masked();
}
-void __udelay (unsigned long usec)
+ulong get_timer_masked(void)
{
- while (usec--) ixp425_udelay(1);
+ return tick_to_time(get_ticks());
}
-static ulong reload_constant = 0xfffffff0;
-
-void reset_timer_masked (void)
+ulong get_timer(ulong base)
{
- ulong reload = reload_constant | IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
+ return get_timer_masked() - base;
+}
- *IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
- *IXP425_OSRT1 = reload;
+void set_timer(ulong t)
+{
+ gd->timestamp = time_to_tick(t);
}
-ulong get_timer_masked (void)
+/* delay x useconds AND preserve advance timestamp value */
+void __udelay(unsigned long usec)
{
- /*
- * Note that it is possible for this to wrap!
- * In this case we return max.
- */
- ulong current = *IXP425_OST1;
- if (*IXP425_OSST & IXP425_OSST_TIMER_1_PEND)
- {
- return reload_constant;
- }
- return (reload_constant - current);
+ unsigned long long tmp;
+
+ tmp = get_ticks() + us_to_tick(usec);
+
+ while (get_ticks() < tmp)
+ ;
}
int timer_init(void)
{
+ writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST);
return 0;
}
-#endif