rtc: support periodic ticks at intervals from 1 to 128 Hz

This commit is contained in:
Joey Castillo
2021-09-28 15:13:09 -04:00
parent 39a17c99b9
commit 9da9dfb7b2
3 changed files with 96 additions and 22 deletions

View File

@@ -24,7 +24,7 @@
#include "watch_rtc.h"
ext_irq_cb_t tick_callback;
ext_irq_cb_t tick_callbacks[8];
ext_irq_cb_t alarm_callback;
ext_irq_cb_t btn_alarm_callback;
ext_irq_cb_t a2_callback;
@@ -70,15 +70,40 @@ watch_date_time watch_rtc_get_date_time() {
return retval;
}
void watch_register_tick_callback(ext_irq_cb_t callback) {
tick_callback = callback;
NVIC_ClearPendingIRQ(RTC_IRQn);
NVIC_EnableIRQ(RTC_IRQn);
RTC->MODE2.INTENSET.reg = RTC_MODE2_INTENSET_PER7;
void watch_rtc_register_1Hz_callback(ext_irq_cb_t callback) {
watch_rtc_register_tick_callback(callback, 1);
}
void watch_disable_tick_callback() {
RTC->MODE2.INTENCLR.reg = RTC_MODE2_INTENCLR_PER7;
void watch_rtc_disable_1Hz_callback() {
watch_rtc_disable_tick_callback(1);
}
void watch_rtc_register_tick_callback(ext_irq_cb_t callback, uint8_t period) {
// we told them, it has to be a power of 2.
if (__builtin_popcount(period) != 1) return;
// this left-justifies the period in a 32-bit integer.
uint32_t tmp = period << 24;
// now we can count the leading zeroes to get the value we need.
// 0x01 (1 Hz) will have 7 leading zeros for PER7. 0xF0 (128 Hz) will have no leading zeroes for PER0.
uint8_t per_n = __builtin_clz(tmp);
// this also maps nicely to an index for our list of tick callbacks.
tick_callbacks[per_n] = callback;
NVIC_ClearPendingIRQ(RTC_IRQn);
NVIC_EnableIRQ(RTC_IRQn);
RTC->MODE2.INTENSET.reg = 1 << per_n;
}
void watch_rtc_disable_tick_callback(uint8_t period) {
if (__builtin_popcount(period) != 1) return;
uint8_t per_n = __builtin_clz(period << 24);
RTC->MODE2.INTENCLR.reg = 1 << per_n;
}
void watch_rtc_disable_all_tick_callbacks() {
RTC->MODE2.INTENCLR.reg = 0xFF;
}
void watch_rtc_register_alarm_callback(ext_irq_cb_t callback, watch_date_time alarm_time, watch_rtc_alarm_match mask) {
@@ -99,17 +124,20 @@ void RTC_Handler(void) {
uint16_t interrupt_status = RTC->MODE2.INTFLAG.reg;
uint16_t interrupt_enabled = RTC->MODE2.INTENSET.reg;
if ((interrupt_status & interrupt_enabled) & RTC_MODE2_INTFLAG_ALARM0) {
if (alarm_callback != NULL) {
alarm_callback();
if ((interrupt_status & interrupt_enabled) & RTC_MODE2_INTFLAG_PER_Msk) {
// handle the tick callback first, it's what we do the most.
// start from PER7, the 1 Hz tick.
for(int8_t i = 7; i >= 0; i--) {
if ((interrupt_status & interrupt_enabled) & (1 << i)) {
if (tick_callbacks[i] != NULL) {
tick_callbacks[i]();
}
RTC->MODE2.INTFLAG.reg = 1 << i;
break;
}
}
RTC->MODE2.INTFLAG.reg = RTC_MODE2_INTFLAG_ALARM0;
} else if ((interrupt_status & interrupt_enabled) & RTC_MODE2_INTFLAG_PER7) {
if (tick_callback != NULL) {
tick_callback();
}
RTC->MODE2.INTFLAG.reg = RTC_MODE2_INTFLAG_PER7;
} else if ((interrupt_status & interrupt_enabled) & RTC_MODE2_INTFLAG_TAMPER) {
// handle the extwake interrupts next.
uint8_t reason = RTC->MODE2.TAMPID.reg;
if (reason & RTC_TAMPID_TAMPID2) {
if (btn_alarm_callback != NULL) btn_alarm_callback();
@@ -120,6 +148,12 @@ void RTC_Handler(void) {
}
RTC->MODE2.TAMPID.reg = reason;
RTC->MODE2.INTFLAG.reg = RTC_MODE2_INTFLAG_TAMPER;
} else if ((interrupt_status & interrupt_enabled) & RTC_MODE2_INTFLAG_ALARM0) {
// finally handle the alarm.
if (alarm_callback != NULL) {
alarm_callback();
}
RTC->MODE2.INTFLAG.reg = RTC_MODE2_INTFLAG_ALARM0;
}
}
@@ -152,3 +186,10 @@ void watch_get_date_time(struct calendar_date_time *date_time) {
date_time->date.month = val.bit.MONTH;
date_time->date.year = val.bit.YEAR + WATCH_RTC_REFERENCE_YEAR;
}
void watch_register_tick_callback(ext_irq_cb_t callback) {
tick_callbacks[7] = callback;
NVIC_ClearPendingIRQ(RTC_IRQn);
NVIC_EnableIRQ(RTC_IRQn);
RTC->MODE2.INTENSET.reg = RTC_MODE2_INTENSET_PER7;
}