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Coldfire: New timer handling on CPU frequency change, adjusting the prescaler on the fly, for both tick and user timer. Precondition is that the higher frequencies are integer multiples of the base: now NORMAL is 45 MHz and MAX is 124 MHz. Removes the need for applications with longer timer periods (>= 10 ms) to boost the CPU all the time, e.g. the grayscale lib. Timer counts are now always based on the base frequency (CPU_FREQ). * Adjusted the RAM refresh timers to the new frequencies (all frequencies for H100) * All: Fixed the tick timer count being off by one.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7576 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2005-10-03 09:24:36 +00:00
parent 7190cf2ed9
commit cfb073c452
10 changed files with 98 additions and 59 deletions
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32
firmware/timer.c
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@ -28,7 +28,9 @@
static int timer_prio = -1;
static void (*pfn_timer)(void) = NULL; /* timer callback */
static void (*pfn_unregister)(void) = NULL; /* unregister callback */
#ifdef CPU_COLDFIRE
static int base_prescale;
#endif
/* interrupt handler */
#if CONFIG_CPU == SH7034
@ -93,16 +95,19 @@ static bool timer_set(long cycles, bool start)
and_b(~0x01, &TSR4); /* clear an eventual interrupt */
#elif defined CPU_COLDFIRE
if (prescale > 4096)
if (prescale > 4096/CPUFREQ_MAX_MULT)
return false;
if (prescale > 256)
if (prescale > 256/CPUFREQ_MAX_MULT)
{
phi = 0x05; /* prescale sysclk/16, timer enabled */
prescale >>= 4;
}
else
phi = 0x03; /* prescale sysclk, timer enabled */
base_prescale = prescale;
prescale *= (cpu_frequency / CPU_FREQ);
if (start)
{
@ -125,7 +130,26 @@ static bool timer_set(long cycles, bool start)
return true;
}
/* Register a user timer, called every <count> CPU cycles */
#ifdef CPU_COLDFIRE
void timers_adjust_prescale(int multiplier, bool enable_irq)
{
/* tick timer */
TMR0 = (TMR0 & 0x00ef)
| ((unsigned short)(multiplier - 1) << 8)
| (enable_irq ? 0x10 : 0);
if (pfn_timer)
{
/* user timer */
int prescale = base_prescale * multiplier;
TMR1 = (TMR1 & 0x00ef)
| ((unsigned short)(prescale - 1) << 8)
| (enable_irq ? 0x10 : 0);
}
}
#endif
/* Register a user timer, called every <cycles> CPU_FREQ cycles */
bool timer_register(int reg_prio, void (*unregister_callback)(void),
long cycles, int int_prio, void (*timer_callback)(void))
{