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/*
* MIT License
*
* Copyright (c) 2020 Joey Castillo
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "watch_rtc.h"
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;
ext_irq_cb_t a4_callback;
bool _watch_rtc_is_enabled(void) {
return RTC->MODE2.CTRLA.bit.ENABLE;
}
static void _sync_rtc(void) {
while (RTC->MODE2.SYNCBUSY.reg);
}
void _watch_rtc_init(void) {
MCLK->APBAMASK.reg |= MCLK_APBAMASK_RTC;
if (_watch_rtc_is_enabled()) return; // don't reset the RTC if it's already set up.
RTC->MODE2.CTRLA.bit.ENABLE = 0;
_sync_rtc();
RTC->MODE2.CTRLA.bit.SWRST = 1;
_sync_rtc();
RTC->MODE2.CTRLA.bit.MODE = RTC_MODE2_CTRLA_MODE_CLOCK_Val;
RTC->MODE2.CTRLA.bit.PRESCALER = RTC_MODE2_CTRLA_PRESCALER_DIV1024_Val;
RTC->MODE2.CTRLA.bit.CLOCKSYNC = 1;
RTC->MODE2.CTRLA.bit.ENABLE = 1;
_sync_rtc();
}
void watch_rtc_set_date_time(watch_date_time date_time) {
RTC->MODE2.CLOCK.reg = date_time.reg;
_sync_rtc();
}
watch_date_time watch_rtc_get_date_time(void) {
watch_date_time retval;
_sync_rtc();
retval.reg = RTC->MODE2.CLOCK.reg;
return retval;
}
void watch_rtc_register_tick_callback(ext_irq_cb_t callback) {
watch_rtc_register_periodic_callback(callback, 1);
}
void watch_rtc_disable_tick_callback(void) {
watch_rtc_disable_periodic_callback(1);
}
void watch_rtc_register_periodic_callback(ext_irq_cb_t callback, uint8_t frequency) {
// we told them, it has to be a power of 2.
if (__builtin_popcount(frequency) != 1) return;
// this left-justifies the period in a 32-bit integer.
uint32_t tmp = frequency << 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_periodic_callback(uint8_t frequency) {
if (__builtin_popcount(frequency) != 1) return;
uint8_t per_n = __builtin_clz(frequency << 24);
RTC->MODE2.INTENCLR.reg = 1 << per_n;
}
void watch_rtc_disable_all_periodic_callbacks(void) {
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) {
RTC->MODE2.Mode2Alarm[0].ALARM.reg = alarm_time.reg;
RTC->MODE2.Mode2Alarm[0].MASK.reg = mask;
RTC->MODE2.INTENSET.reg = RTC_MODE2_INTENSET_ALARM0;
alarm_callback = callback;
NVIC_ClearPendingIRQ(RTC_IRQn);
NVIC_EnableIRQ(RTC_IRQn);
RTC->MODE2.INTENSET.reg = RTC_MODE2_INTENSET_ALARM0;
}
void watch_rtc_disable_alarm_callback(void) {
RTC->MODE2.INTENCLR.reg = RTC_MODE2_INTENCLR_ALARM0;
}
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_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;
}
}
} 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();
} else if (reason & RTC_TAMPID_TAMPID1) {
if (a2_callback != NULL) a2_callback();
} else if (reason & RTC_TAMPID_TAMPID0) {
if (a4_callback != NULL) a4_callback();
}
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;
}
}
///////////////////////
// Deprecated functions
void watch_set_date_time(struct calendar_date_time date_time) {
RTC_MODE2_CLOCK_Type val;
val.bit.SECOND = date_time.time.sec;
val.bit.MINUTE = date_time.time.min;
val.bit.HOUR = date_time.time.hour;
val.bit.DAY = date_time.date.day;
val.bit.MONTH = date_time.date.month;
val.bit.YEAR = (uint8_t)(date_time.date.year - WATCH_RTC_REFERENCE_YEAR);
RTC->MODE2.CLOCK.reg = val.reg;
_sync_rtc();
}
void watch_get_date_time(struct calendar_date_time *date_time) {
_sync_rtc();
RTC_MODE2_CLOCK_Type val = RTC->MODE2.CLOCK;
date_time->time.sec = val.bit.SECOND;
date_time->time.min = val.bit.MINUTE;
date_time->time.hour = val.bit.HOUR;
date_time->date.day = val.bit.DAY;
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;
}
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