Yash Kuntavalli / WakeUpLib

WakeUpLib

Dependencies:   LPC1114_WakeInterruptIn

Fork of WakeUp by Erik -

Device/WakeUp_STM_RTC.cpp@22:49ca85e8822f, 2015-11-11 (annotated)

Committer:
root@developer-sjc-cyan-compiler.local.mbed.org
Date:
Wed Nov 11 20:20:27 2015 +0000
Revision:
22:49ca85e8822f
Parent:
20:68f2ee917691 
Added tag test for changeset 30845899cca2

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 9:29bdf5fed21a 1 #ifdef TARGET_STM
Sissors 9:29bdf5fed21a 2
Sissors 9:29bdf5fed21a 3 #include "WakeUp.h"
Sissors 9:29bdf5fed21a 4 #include "rtc_api.h"
Sissors 9:29bdf5fed21a 5
Sissors 9:29bdf5fed21a 6 #define BYTE2BCD(byte) ((byte % 10) | ((byte / 10) << 4))
Sissors 9:29bdf5fed21a 7
Sissors 9:29bdf5fed21a 8 //Most things are pretty similar between the different STM targets.
Sissors 9:29bdf5fed21a 9 //Only the IRQ number the alarm is connected to differs. Any errors
Sissors 9:29bdf5fed21a 10 //with RTC_IRQn/RTC_Alarm_IRQn in them are related to this
Sissors 15:b2a710aca356 11 #if defined(TARGET_M4) || defined(TARGET_M3)
Sissors 9:29bdf5fed21a 12 #define RTC_IRQ RTC_Alarm_IRQn
Sissors 9:29bdf5fed21a 13 #else
Sissors 9:29bdf5fed21a 14 #define RTC_IRQ RTC_IRQn
Sissors 9:29bdf5fed21a 15 #endif
Sissors 9:29bdf5fed21a 16
Sissors 20:68f2ee917691 17 // Some things to handle Disco L476VG (and similar ones)
Sissors 20:68f2ee917691 18 #if defined(TARGET_STM32L4)
Sissors 20:68f2ee917691 19 #define IMR IMR1
Sissors 20:68f2ee917691 20 #define EMR EMR1
Sissors 20:68f2ee917691 21 #define RTSR RTSR1
Sissors 20:68f2ee917691 22 #define FTSR FTSR2
Sissors 20:68f2ee917691 23 #define PR PR1
Sissors 20:68f2ee917691 24 #endif
Sissors 20:68f2ee917691 25
Sissors 17:49d9e3a3e904 26 //Disabling the Backup Powerdomain does not seem to work nicely anymore if you want to use other RTC functions afterwards.
Sissors 17:49d9e3a3e904 27 //For now I have disabled it in code, if you find WakeUp increases your powerconsumption, try enabling it again (code is still there, just commented)
Sissors 17:49d9e3a3e904 28
Sissors 9:29bdf5fed21a 29 FunctionPointer WakeUp::callback;
Sissors 9:29bdf5fed21a 30
Sissors 9:29bdf5fed21a 31 void WakeUp::set_ms(uint32_t ms)
Sissors 9:29bdf5fed21a 32 {
Sissors 9:29bdf5fed21a 33 if (!rtc_isenabled()) { //Make sure RTC is running
Sissors 9:29bdf5fed21a 34 rtc_init();
Sissors 9:29bdf5fed21a 35 wait_us(250); //The f401 seems to want a delay after init
Sissors 9:29bdf5fed21a 36 }
Sissors 9:29bdf5fed21a 37
Sissors 17:49d9e3a3e904 38 //PWR->CR |= PWR_CR_DBP; //Enable power domain
Sissors 9:29bdf5fed21a 39 RTC->WPR = 0xCA; //Disable RTC write protection
Sissors 9:29bdf5fed21a 40 RTC->WPR = 0x53;
Sissors 9:29bdf5fed21a 41
Sissors 9:29bdf5fed21a 42 //Alarm must be disabled to change anything
Sissors 9:29bdf5fed21a 43 RTC->CR &= ~RTC_CR_ALRAE;
Sissors 9:29bdf5fed21a 44 while(!(RTC->ISR & RTC_ISR_ALRAWF));
Sissors 9:29bdf5fed21a 45
Sissors 9:29bdf5fed21a 46 if (ms == 0) { //Just disable alarm
Sissors 17:49d9e3a3e904 47 //PWR->CR &= ~PWR_CR_DBP; //Disable power domain
Sissors 9:29bdf5fed21a 48 RTC->WPR = 0xFF; //Enable RTC write protection
Sissors 9:29bdf5fed21a 49 return;
Sissors 9:29bdf5fed21a 50 }
Sissors 9:29bdf5fed21a 51
Sissors 9:29bdf5fed21a 52 //RTC prescaler + calculate how many sub-seconds should be added
Sissors 9:29bdf5fed21a 53 uint32_t prescaler = (RTC->PRER & 0x7FFF) + 1;
Sissors 9:29bdf5fed21a 54 uint32_t subsecsadd = ((ms % 1000) * prescaler) / 1000;
Sissors 9:29bdf5fed21a 55
Sissors 9:29bdf5fed21a 56 if ((ms < 1000) && (subsecsadd < 2))
Sissors 9:29bdf5fed21a 57 subsecsadd = 2; //At least 2 subsecs delay to be sure interrupt is called
Sissors 9:29bdf5fed21a 58
Sissors 9:29bdf5fed21a 59 __disable_irq(); //At this point we don't want IRQs anymore
Sissors 9:29bdf5fed21a 60
Sissors 9:29bdf5fed21a 61 //Get current time
Sissors 9:29bdf5fed21a 62 uint32_t subsecs = RTC->SSR;
Sissors 9:29bdf5fed21a 63 time_t secs = rtc_read();
Sissors 9:29bdf5fed21a 64
Sissors 9:29bdf5fed21a 65 //Calculate alarm values
Sissors 9:29bdf5fed21a 66 //Subseconds is countdown, so substract the 'added' sub-seconds and prevent underflow
Sissors 9:29bdf5fed21a 67 if (subsecs < subsecsadd) {
Sissors 9:29bdf5fed21a 68 subsecs += prescaler;
Sissors 9:29bdf5fed21a 69 secs++;
Sissors 9:29bdf5fed21a 70 }
Sissors 9:29bdf5fed21a 71 subsecs -= subsecsadd;
Sissors 9:29bdf5fed21a 72
Sissors 9:29bdf5fed21a 73 //Set seconds correctly
Sissors 9:29bdf5fed21a 74 secs += ms / 1000;
Sissors 9:29bdf5fed21a 75 struct tm *timeinfo = localtime(&secs);
Sissors 9:29bdf5fed21a 76
Sissors 9:29bdf5fed21a 77 //Enable rising edge EXTI interrupt of the RTC
Sissors 20:68f2ee917691 78 EXTI->IMR |= RTC_EXTI_LINE_ALARM_EVENT;
Sissors 20:68f2ee917691 79 EXTI->EMR &= ~RTC_EXTI_LINE_ALARM_EVENT;
Sissors 20:68f2ee917691 80 EXTI->RTSR |= RTC_EXTI_LINE_ALARM_EVENT;
Sissors 20:68f2ee917691 81 EXTI->FTSR &= ~RTC_EXTI_LINE_ALARM_EVENT;
Sissors 9:29bdf5fed21a 82
Sissors 9:29bdf5fed21a 83 //Calculate alarm register values
Sissors 9:29bdf5fed21a 84 uint32_t alarmreg = 0;
Sissors 9:29bdf5fed21a 85 alarmreg |= BYTE2BCD(timeinfo->tm_sec) << 0;
Sissors 9:29bdf5fed21a 86 alarmreg |= BYTE2BCD(timeinfo->tm_min) << 8;
Sissors 9:29bdf5fed21a 87 alarmreg |= BYTE2BCD(timeinfo->tm_hour) << 16;
Sissors 9:29bdf5fed21a 88 alarmreg |= BYTE2BCD(timeinfo->tm_mday) << 24;
Sissors 9:29bdf5fed21a 89
Sissors 9:29bdf5fed21a 90 //Enable RTC interrupt
Sissors 9:29bdf5fed21a 91 RTC->ALRMAR = alarmreg;
Sissors 9:29bdf5fed21a 92 RTC->ALRMASSR = subsecs | RTC_ALRMASSR_MASKSS; //Mask no subseconds
Sissors 9:29bdf5fed21a 93 RTC->CR |= RTC_CR_ALRAE | RTC_CR_ALRAIE; //Enable Alarm
Sissors 9:29bdf5fed21a 94
Sissors 9:29bdf5fed21a 95 RTC->WPR = 0xFF; //Enable RTC write protection
Sissors 17:49d9e3a3e904 96 //PWR->CR &= ~PWR_CR_DBP; //Disable power domain
Sissors 9:29bdf5fed21a 97
Sissors 9:29bdf5fed21a 98 __enable_irq(); //Alarm is set, so irqs can be enabled again
Sissors 9:29bdf5fed21a 99
Sissors 9:29bdf5fed21a 100 //Enable everything else
Sissors 9:29bdf5fed21a 101 NVIC_SetVector(RTC_IRQ, (uint32_t)WakeUp::irq_handler);
Sissors 9:29bdf5fed21a 102 NVIC_EnableIRQ(RTC_IRQ);
Sissors 9:29bdf5fed21a 103 }
Sissors 9:29bdf5fed21a 104
Sissors 9:29bdf5fed21a 105
Sissors 9:29bdf5fed21a 106 void WakeUp::irq_handler(void)
Sissors 9:29bdf5fed21a 107 {
Sissors 9:29bdf5fed21a 108 //Clear RTC + EXTI interrupt flags
Sissors 17:49d9e3a3e904 109 //PWR->CR |= PWR_CR_DBP; //Enable power domain
Sissors 9:29bdf5fed21a 110 RTC->ISR &= ~RTC_ISR_ALRAF;
Sissors 17:49d9e3a3e904 111 RTC->WPR = 0xCA; //Disable RTC write protection
Sissors 17:49d9e3a3e904 112 RTC->WPR = 0x53;
Sissors 17:49d9e3a3e904 113 RTC->CR &= ~RTC_CR_ALRAE;
Sissors 17:49d9e3a3e904 114 RTC->WPR = 0xFF; //Enable RTC write protection
Sissors 20:68f2ee917691 115 EXTI->PR = RTC_EXTI_LINE_ALARM_EVENT;
Sissors 17:49d9e3a3e904 116 //PWR->CR &= ~PWR_CR_DBP; //Disable power domain
Sissors 9:29bdf5fed21a 117 callback.call();
Sissors 9:29bdf5fed21a 118 }
Sissors 9:29bdf5fed21a 119
Sissors 9:29bdf5fed21a 120 void WakeUp::calibrate(void)
Sissors 9:29bdf5fed21a 121 {
Sissors 9:29bdf5fed21a 122 //RTC, we assume it is accurate enough without calibration
Sissors 9:29bdf5fed21a 123 }
Sissors 9:29bdf5fed21a 124
Sissors 9:29bdf5fed21a 125
Sissors 9:29bdf5fed21a 126 #endif