void gfxMutexEnter(gfxMutex *pmutex) {
INTERRUPTS_OFF();
while (pmutex[0]) {
INTERRUPTS_ON();
gfxYield();
INTERRUPTS_OFF();
}
pmutex[0] = 1;
INTERRUPTS_ON();
}
void gfxSleepMicroseconds(delaytime_t ms) {
systemticks_t starttm, delay;
// Safety first
switch (ms) {
case TIME_IMMEDIATE:
return;
case TIME_INFINITE:
while(1)
gfxYield();
return;
}
// Convert our delay to ticks
delay = gfxMillisecondsToTicks(ms/1000);
starttm = gfxSystemTicks();
do {
gfxYield();
} while (gfxSystemTicks() - starttm < delay);
}
bool_t gfxSemWait(gfxSem *psem, delaytime_t ms) {
systemticks_t starttm, delay;
// Convert our delay to ticks
starttm = 0;
switch (ms) {
case TIME_IMMEDIATE:
delay = TIME_IMMEDIATE;
break;
case TIME_INFINITE:
delay = TIME_INFINITE;
break;
default:
delay = gfxMillisecondsToTicks(ms);
if (!delay) delay = 1;
starttm = gfxSystemTicks();
}
INTERRUPTS_OFF();
while (psem->cnt <= 0) {
INTERRUPTS_ON();
// Check if we have exceeded the defined delay
switch (delay) {
case TIME_IMMEDIATE:
return FALSE;
case TIME_INFINITE:
break;
default:
if (gfxSystemTicks() - starttm >= delay)
return FALSE;
break;
}
gfxYield();
INTERRUPTS_OFF();
}
psem->cnt--;
INTERRUPTS_ON();
return TRUE;
}
static void _ltdc_reload(void) {
LTDC->SRCR |= LTDC_SRCR_IMR;
while (LTDC->SRCR & (LTDC_SRCR_IMR | LTDC_SRCR_VBR))
gfxYield();
}
static DECLARE_THREAD_FUNCTION(GTimerThreadHandler, arg) {
GTimer *pt;
systemticks_t tm;
systemticks_t nxtTimeout;
systemticks_t lastTime;
GTimerFunction fn;
void *param;
(void) arg;
nxtTimeout = TIME_INFINITE;
lastTime = 0;
while(1) {
/* Wait for work to do. */
gfxYield(); // Give someone else a go no matter how busy we are
gfxSemWait(&waitsem, nxtTimeout);
restartTimerChecks:
// Our reference time
tm = gfxSystemTicks();
nxtTimeout = TIME_INFINITE;
/* We need to obtain the mutex */
gfxMutexEnter(&mutex);
if (pTimerHead) {
pt = pTimerHead;
do {
// Do we have something to do for this timer?
if ((pt->flags & GTIMER_FLG_JABBED) || (!(pt->flags & GTIMER_FLG_INFINITE) && TimeIsWithin(pt->when, lastTime, tm))) {
// Is this timer periodic?
if ((pt->flags & GTIMER_FLG_PERIODIC) && pt->period != TIME_IMMEDIATE) {
// Yes - Update ready for the next period
if (!(pt->flags & GTIMER_FLG_INFINITE)) {
// We may have skipped a period.
// We use this complicated formulae rather than a loop
// because the gcc compiler stuffs up the loop so that it
// either loops forever or doesn't get executed at all.
pt->when += ((tm + pt->period - pt->when) / pt->period) * pt->period;
}
// We are definitely no longer jabbed
pt->flags &= ~GTIMER_FLG_JABBED;
} else {
// No - get us off the timers list
if (pt->next == pt)
pTimerHead = 0;
else {
pt->next->prev = pt->prev;
pt->prev->next = pt->next;
if (pTimerHead == pt)
pTimerHead = pt->next;
}
pt->flags = 0;
}
// Call the callback function
fn = pt->fn;
param = pt->param;
gfxMutexExit(&mutex);
fn(param);
// We no longer hold the mutex, the callback function may have taken a while
// and our list may have been altered so start again!
goto restartTimerChecks;
}
// Find when we next need to wake up
if (!(pt->flags & GTIMER_FLG_INFINITE) && pt->when - tm < nxtTimeout)
nxtTimeout = (pt->when - tm)/ticks2ms;
pt = pt->next;
} while(pt != pTimerHead);
}
// Ready for the next loop
lastTime = tm;
gfxMutexExit(&mutex);
}
THREAD_RETURN(0);
}
