void us_ticker_set_interrupt(timestamp_t timestamp)
{
/* We get here absolute interrupt time which takes into account counter overflow.
* Since we use additional count-down timer to generate interrupt we need to calculate
* load value based on time-stamp.
*/
const uint32_t now_ticks = us_ticker_read();
uint32_t delta_ticks =
timestamp >= now_ticks ? timestamp - now_ticks : (uint32_t)((uint64_t) timestamp + 0xFFFFFFFF - now_ticks);
if (delta_ticks == 0) {
/* The requested delay is less than the minimum resolution of this counter. */
delta_ticks = 1;
}
us_ticker_int_counter = (uint32_t)(delta_ticks >> 16);
us_ticker_int_remainder = (uint16_t)(0xFFFF & delta_ticks);
TPM_StopTimer(TPM2);
TPM2->CNT = 0;
if (us_ticker_int_counter > 0) {
TPM2->MOD = 0xFFFF;
us_ticker_int_counter--;
} else {
TPM2->MOD = us_ticker_int_remainder;
us_ticker_int_remainder = 0;
}
/* Clear the count and set match value */
TPM_ClearStatusFlags(TPM2, kTPM_TimeOverflowFlag);
TPM_EnableInterrupts(TPM2, kTPM_TimeOverflowInterruptEnable);
TPM_StartTimer(TPM2, kTPM_SystemClock);
}
void StackTimer_Disable(void)
{
#if FSL_FEATURE_SOC_FTM_COUNT
FTM_StopTimer(mFtmBase[gStackTimerInstance_c]);
#else
TPM_StopTimer(mTpmBase[gStackTimerInstance_c]);
#endif
}
static void tpm_isr(void)
{
// Clear the TPM timer overflow flag
TPM_ClearStatusFlags(TPM2, kTPM_TimeOverflowFlag);
TPM_StopTimer(TPM2);
if (us_ticker_int_counter > 0) {
TPM2->MOD = 0xFFFF;
TPM_StartTimer(TPM2, kTPM_SystemClock);
us_ticker_int_counter--;
} else {
if (us_ticker_int_remainder > 0) {
TPM2->MOD = us_ticker_int_remainder;
TPM_StartTimer(TPM2, kTPM_SystemClock);
us_ticker_int_remainder = 0;
} else {
// This function is going to disable the interrupts if there are
// no other events in the queue
us_ticker_irq_handler();
}
}
}
/************************************************************************************
*************************************************************************************
* Public functions
*************************************************************************************
************************************************************************************/
void StackTimer_Init(void (*cb)(void))
{
IRQn_Type irqId;
#if FSL_FEATURE_SOC_FTM_COUNT
FTM_Type *ftmBaseAddr = (FTM_Type*)mFtmBase[gStackTimerInstance_c];
FTM_Init(ftmBaseAddr, &mFtmConfig);
FTM_StopTimer(ftmBaseAddr);
ftmBaseAddr->MOD = 0xFFFF;
/* Configure channel to Software compare; output pin not used */
FTM_SetupOutputCompare(ftmBaseAddr, (ftm_chnl_t)gStackTimerChannel_c, kFTM_NoOutputSignal, 0x01);
/* Install ISR */
irqId = mFtmIrqId[gStackTimerInstance_c];
FTM_EnableInterrupts(ftmBaseAddr, kFTM_TimeOverflowInterruptEnable | (1 << gStackTimerChannel_c));
#else
TPM_Type *tpmBaseAddr = (TPM_Type*)mTpmBase[gStackTimerInstance_c];
TPM_Init(tpmBaseAddr, &mTpmConfig);
TPM_StopTimer(tpmBaseAddr);
/* Set the timer to be in free-running mode */
tpmBaseAddr->MOD = 0xFFFF;
/* Configure channel to Software compare; output pin not used */
TPM_SetupOutputCompare(tpmBaseAddr, (tpm_chnl_t)gStackTimerChannel_c, kTPM_NoOutputSignal, 0x01);
/* Install ISR */
irqId = mTpmIrqId[gStackTimerInstance_c];
TPM_EnableInterrupts(tpmBaseAddr, kTPM_TimeOverflowInterruptEnable | (1 << gStackTimerChannel_c));
#endif
/* Overwrite old ISR */
OSA_InstallIntHandler(irqId, cb);
/* set interrupt priority */
NVIC_SetPriority(irqId, gStackTimer_IsrPrio_c >> (8 - __NVIC_PRIO_BITS));
NVIC_ClearPendingIRQ(irqId);
NVIC_EnableIRQ(irqId);
}
