int sam_freerun_counter(struct sam_freerun_s *freerun, struct timespec *ts)
{
uint64_t usec;
uint32_t counter;
uint32_t verify;
uint32_t sr;
uint32_t overflow;
uint32_t sec;
irqstate_t flags;
DEBUGASSERT(freerun && freerun->tch && ts);
/* Temporarily disable the overflow counter. NOTE that we have to be careful
* here because sam_tc_getpending() will reset the pending interrupt status.
* If we do not handle the overflow here then, it will be lost.
*/
flags = enter_critical_section();
overflow = freerun->overflow;
counter = sam_tc_getcounter(freerun->tch);
sr = sam_tc_getpending(freerun->tch);
verify = sam_tc_getcounter(freerun->tch);
/* If an interrupt was pending before we re-enabled interrupts,
* then the overflow needs to be incremented.
*/
if ((sr & TC_INT_COVFS) != 0)
{
/* Increment the overflow count and use the value of the
* guaranteed to be AFTER the overflow occurred.
*/
overflow++;
counter = verify;
/* Update freerun overflow counter. */
freerun->overflow = overflow;
}
leave_critical_section(flags);
tmrinfo("counter=%lu (%lu) overflow=%lu, sr=%08lx\n",
(unsigned long)counter, (unsigned long)verify,
(unsigned long)overflow, (unsigned long)sr);
/* Convert the whole thing to units of microseconds.
*
* frequency = ticks / second
* seconds = ticks * frequency
* usecs = (ticks * USEC_PER_SEC) / frequency;
*/
usec = ((((uint64_t)overflow << 16) + (uint64_t)counter) * USEC_PER_SEC) /
sam_tc_divfreq(freerun->tch);
/* And return the value of the timer */
sec = (uint32_t)(usec / USEC_PER_SEC);
ts->tv_sec = sec;
ts->tv_nsec = (usec - (sec * USEC_PER_SEC)) * NSEC_PER_USEC;
tmrinfo("usec=%llu ts=(%lu, %lu)\n",
usec, (unsigned long)ts->tv_sec, (unsigned long)ts->tv_nsec);
return OK;
}
int sam_freerun_counter(struct sam_freerun_s *freerun, struct timespec *ts)
{
uint64_t usec;
uint32_t counter;
uint32_t verify;
uint32_t sr;
uint32_t overflow;
uint32_t sec;
irqstate_t flags;
DEBUGASSERT(freerun && freerun->tch && ts);
/* Temporarily disable the overflow counter */
flags = irqsave();
overflow = freerun->overflow;
counter = sam_tc_getcounter(freerun->tch);
sr = sam_tc_getpending(freerun->tch);
verify = sam_tc_getcounter(freerun->tch);
irqrestore(flags);
tcvdbg("counter=%lu (%lu) overflow=%lu, sr=%08lx\n",
(unsigned long)counter, (unsigned long)verify,
(unsigned long)overflow, (unsigned long)sr);
/* If an interrupt was pending before we re-enabled interrupts,
* then our value of overflow needs to be incremented.
*/
if ((sr & TC_INT_COVFS) != 0)
{
/* Increment the overflow count and use the value of the
* guaranteed to be AFTER the overflow occurred.
*/
overflow++;
counter = verify;
tcvdbg("counter=%lu overflow=%lu\n",
(unsigned long)counter, (unsigned long)overflow);
}
/* Convert the whole thing to units of microseconds.
*
* frequency = ticks / second
* seconds = ticks * frequency
* usecs = (ticks * USEC_PER_SEC) / frequency;
*/
usec = ((((uint64_t)overflow << 32) + (uint64_t)counter) * USEC_PER_SEC) /
sam_tc_divfreq(freerun->tch);
/* And return the value of the timer */
sec = (uint32_t)(usec / USEC_PER_SEC);
ts->tv_sec = sec;
ts->tv_nsec = (usec - (sec * USEC_PER_SEC)) * NSEC_PER_USEC;
tcvdbg("usec=%llu ts=(%lu, %lu)\n",
usec, (unsigned long)ts->tv_sec, (unsigned long)ts->tv_nsec);
return OK;
}
