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Diffstat (limited to 'cpu/arm926ejs/interrupts.c')
-rw-r--r--cpu/arm926ejs/interrupts.c107
1 files changed, 61 insertions, 46 deletions
diff --git a/cpu/arm926ejs/interrupts.c b/cpu/arm926ejs/interrupts.c
index 3985217..4d6efeb 100644
--- a/cpu/arm926ejs/interrupts.c
+++ b/cpu/arm926ejs/interrupts.c
@@ -1,4 +1,7 @@
/*
+ * (C) Copyright 2003
+ * Texas Instruments <www.ti.com>
+ *
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
@@ -31,7 +34,6 @@
#include <common.h>
#include <arm925t.h>
-#include <configs/omap1510.h>
#include <asm/proc-armv/ptrace.h>
@@ -47,12 +49,14 @@ void enable_interrupts (void)
{
unsigned long temp;
__asm__ __volatile__("mrs %0, cpsr\n"
- "bic %0, %0, #0x80\n"
- "msr cpsr_c, %0"
- : "=r" (temp)
- : "memory");
+ "bic %0, %0, #0x80\n"
+ "msr cpsr_c, %0"
+ : "=r" (temp)
+ :
+ : "memory");
}
+
/*
* disable IRQ/FIQ interrupts
* returns true if interrupts had been enabled before we disabled them
@@ -61,10 +65,11 @@ int disable_interrupts (void)
{
unsigned long old,temp;
__asm__ __volatile__("mrs %0, cpsr\n"
- "orr %1, %0, #0xc0\n"
- "msr cpsr_c, %1"
- : "=r" (old), "=r" (temp)
- : "memory");
+ "orr %1, %0, #0xc0\n"
+ "msr cpsr_c, %1"
+ : "=r" (old), "=r" (temp)
+ :
+ : "memory");
return (old & 0x80) == 0;
}
#else
@@ -179,10 +184,14 @@ int interrupt_init (void)
{
int32_t val;
+ /* Start the decrementer ticking down from 0xffffffff */
*((int32_t *) (CFG_TIMERBASE + LOAD_TIM)) = TIMER_LOAD_VAL;
- val = MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE |
- (CFG_PVT << MPUTIM_PTV_BIT);
+ val = MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE | (CFG_PVT << MPUTIM_PTV_BIT);
*((int32_t *) (CFG_TIMERBASE + CNTL_TIMER)) = val;
+
+ /* init the timestamp and lastdec value */
+ reset_timer_masked();
+
return (0);
}
@@ -205,44 +214,50 @@ void set_timer (ulong t)
timestamp = t;
}
-/* very rough timer... */
+/* delay x useconds AND perserve advance timstamp value */
void udelay (unsigned long usec)
{
-#ifdef CONFIG_INNOVATOROMAP1610
-#define LOOPS_PER_MSEC 100 /* tuned on omap1610 */
- volatile int i, time_remaining = LOOPS_PER_MSEC * usec;
-
- for (i = time_remaining; i > 0; i--) {
+ ulong tmo, tmp;
+
+ if(usec >= 1000){ /* if "big" number, spread normalization to seconds */
+ tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
+ tmo *= CFG_HZ; /* find number of "ticks" to wait to achieve target */
+ tmo /= 1000; /* finish normalize. */
+ }else{ /* else small number, don't kill it prior to HZ multiply */
+ tmo = usec * CFG_HZ;
+ tmo /= (1000*1000);
}
-#else
- ulong tmo;
- tmo = usec / 1000;
- tmo *= CFG_HZ;
- tmo /= 1000;
- tmo += get_timer (0);
- while (get_timer_masked () < tmo)
+ tmp = get_timer (0); /* get current timestamp */
+ if( (tmo + tmp) < tmp ) /* if setting this fordward will roll time stamp */
+ reset_timer_masked (); /* reset "advancing" timestamp to 0, set lastdec value */
+ else
+ tmo += tmp; /* else, set advancing stamp wake up time */
+
+ while (get_timer_masked () < tmo)/* loop till event */
/*NOP*/;
-#endif
}
void reset_timer_masked (void)
{
/* reset time */
- lastdec = READ_TIMER;
- timestamp = 0;
+ lastdec = READ_TIMER; /* capure current decrementer value time */
+ timestamp = 0; /* start "advancing" time stamp from 0 */
}
ulong get_timer_masked (void)
{
ulong now = READ_TIMER; /* current tick value */
- if (lastdec >= now) { /* did I roll (rem decrementer) */
+ if (lastdec >= now) { /* normal mode (non roll) */
/* normal mode */
- /* record amount of time since last check */
- timestamp += lastdec - now;
- } else {
- /* we have an overflow ... */
+ timestamp += lastdec - now; /* move stamp fordward with absoulte diff ticks */
+ } else { /* we have overflow of the count down timer */
+ /* nts = ts + ld + (TLV - now)
+ * ts=old stamp, ld=time that passed before passing through -1
+ * (TLV-now) amount of time after passing though -1
+ * nts = new "advancing time stamp"...it could also roll and cause problems.
+ */
timestamp += lastdec + TIMER_LOAD_VAL - now;
}
lastdec = now;
@@ -250,25 +265,24 @@ ulong get_timer_masked (void)
return timestamp;
}
+/* waits specified delay value and resets timestamp */
void udelay_masked (unsigned long usec)
{
-#ifdef CONFIG_INNOVATOROMAP1610
- #define LOOPS_PER_MSEC 100 /* tuned on omap1610 */
- volatile int i, time_remaining = LOOPS_PER_MSEC*usec;
- for (i=time_remaining; i>0; i--) { }
-#else
-
- ulong tmo;
+ ulong tmo, tmp;
+
+ if(usec >= 1000){ /* if "big" number, spread normalization to seconds */
+ tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
+ tmo *= CFG_HZ; /* find number of "ticks" to wait to achieve target */
+ tmo /= 1000; /* finish normalize. */
+ }else{ /* else small number, don't kill it prior to HZ multiply */
+ tmo = usec * CFG_HZ;
+ tmo /= (1000*1000);
+ }
- tmo = usec / 1000;
- tmo *= CFG_HZ;
- tmo /= 1000;
+ reset_timer_masked (); /* set "advancing" timestamp to 0, set lastdec vaule */
- reset_timer_masked ();
-
- while (get_timer_masked () < tmo)
+ while (get_timer_masked () < tmo) /* wait for time stamp to overtake tick number.*/
/*NOP*/;
-#endif
}
/*
@@ -287,6 +301,7 @@ unsigned long long get_ticks(void)
ulong get_tbclk (void)
{
ulong tbclk;
+
tbclk = CFG_HZ;
return tbclk;
}