diff options
Diffstat (limited to 'cpu/arm926ejs/interrupts.c')
| -rw-r--r-- | cpu/arm926ejs/interrupts.c | 107 |
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; } |