diff options
Diffstat (limited to 'cpu/arm925t/interrupts.c')
| -rw-r--r-- | cpu/arm925t/interrupts.c | 88 |
1 files changed, 24 insertions, 64 deletions
diff --git a/cpu/arm925t/interrupts.c b/cpu/arm925t/interrupts.c index e5c77f7..ec2a978 100644 --- a/cpu/arm925t/interrupts.c +++ b/cpu/arm925t/interrupts.c @@ -1,4 +1,7 @@ /* + * (C) Copyright 2009 + * 2N Telekomunikace, <www.2n.cz> + * * (C) Copyright 2003 * Texas Instruments, <www.ti.com> * @@ -37,7 +40,8 @@ #include <configs/omap1510.h> #include <asm/io.h> -#define TIMER_LOAD_VAL 0xffffffff +#define TIMER_LOAD_VAL 0xffffffff +#define TIMER_CLOCK (CONFIG_SYS_CLK_FREQ / (2 << CONFIG_SYS_PTV)) static uint32_t timestamp; static uint32_t lastdec; @@ -79,85 +83,41 @@ void set_timer (ulong t) /* delay x useconds AND preserve advance timestamp value */ void udelay (unsigned long usec) { - 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 *= CONFIG_SYS_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 * CONFIG_SYS_HZ; - tmo /= (1000*1000); + int32_t tmo = usec * (TIMER_CLOCK / 1000) / 1000; + uint32_t now, last = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM); + + while (tmo > 0) { + now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM); + if (last < now) /* count down timer underflow */ + tmo -= TIMER_LOAD_VAL - now + last; + else + tmo -= last - now; + last = now; } - - tmp = get_timer (0); /* get current timestamp */ - if ((tmo + tmp + 1) < 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*/; } void reset_timer_masked (void) { /* reset time */ - lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM); + lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) / + (TIMER_CLOCK / CONFIG_SYS_HZ); timestamp = 0; /* start "advancing" time stamp from 0 */ } ulong get_timer_masked (void) { - uint32_t now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM); - - if (lastdec >= now) { /* normal mode (non roll) */ - /* normal mode */ - 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; - } + uint32_t now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) / + (TIMER_CLOCK / CONFIG_SYS_HZ); + if (lastdec < now) /* count down timer underflow */ + timestamp += TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ) - + now + lastdec; + else + timestamp += lastdec - now; lastdec = now; return timestamp; } -/* waits specified delay value and resets timestamp */ -void udelay_masked (unsigned long usec) -{ -#ifdef CONFIG_INNOVATOROMAP1510 - #define LOOPS_PER_MSEC 60 /* tuned on omap1510 */ - volatile int i, time_remaining = LOOPS_PER_MSEC*usec; - for (i=time_remaining; i>0; i--) { } -#else - - ulong tmo; - ulong endtime; - signed long diff; - - if (usec >= 1000) { /* if "big" number, spread normalization to seconds */ - tmo = usec / 1000; /* start to normalize for usec to ticks per sec */ - tmo *= CONFIG_SYS_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 * CONFIG_SYS_HZ; - tmo /= (1000*1000); - } - - endtime = get_timer_masked () + tmo; - - do { - ulong now = get_timer_masked (); - diff = endtime - now; - } while (diff >= 0); -#endif -} - /* * This function is derived from PowerPC code (read timebase as long long). * On ARM it just returns the timer value. |