/* ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010, 2011 Giovanni Di Sirio. This file is part of ChibiOS/RT. ChibiOS/RT is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. ChibiOS/RT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /* Concepts and parts of this file have been contributed by Uladzimir Pylinsky aka barthess. */ /** * @file STM32/RTCv1/rtc_lld.c * @brief STM32 RTC subsystem low level driver header. * * @addtogroup RTC * @{ */ #include "ch.h" #include "hal.h" #if HAL_USE_RTC || defined(__DOXYGEN__) /*===========================================================================*/ /* Driver exported variables. */ /*===========================================================================*/ /** * @brief RTC driver identifier. */ RTCDriver RTCD1; /*===========================================================================*/ /* Driver local variables. */ /*===========================================================================*/ /*===========================================================================*/ /* Driver local functions. */ /*===========================================================================*/ /** * @brief Shared IRQ handler. * * @param[in] rtcp pointer to a @p RTCDriver object * * @notapi */ static void rtc_lld_serve_interrupt(RTCDriver *rtcp) { chSysLockFromIsr(); if ((RTC->CRH & RTC_CRH_SECIE) && (RTC->CRL & RTC_CRL_SECF)) { rtcp->callback(rtcp, RTC_EVENT_SECOND); RTC->CRL &= ~RTC_CRL_SECF; } if ((RTC->CRH & RTC_CRH_ALRIE) && (RTC->CRL & RTC_CRL_ALRF)) { rtcp->callback(rtcp, RTC_EVENT_ALARM); RTC->CRL &= ~RTC_CRL_ALRF; } if ((RTC->CRH & RTC_CRH_OWIE) && (RTC->CRL & RTC_CRL_OWF)) { rtcp->callback(rtcp, RTC_EVENT_OVERFLOW); RTC->CRL &= ~RTC_CRL_OWF; } chSysUnlockFromIsr(); } /** * @brief Acquire atomic write access to RTC registers. * * @notapi */ static void rtc_lld_acquire(void) { /* Waits registers write completion.*/ BEGIN: while ((RTC->CRL & RTC_CRL_RTOFF) == 0) ; chSysLock(); if ((RTC->CRL & RTC_CRL_RTOFF) == 0){ chSysUnlock(); goto BEGIN; } } /** * @brief Release atomic write access to RTC registers. * * @notapi */ #define rtc_lld_release() {chSysUnlock();} /*===========================================================================*/ /* Driver interrupt handlers. */ /*===========================================================================*/ /** * @brief RTC interrupt handler. * * @isr */ CH_IRQ_HANDLER(RTC_IRQHandler) { CH_IRQ_PROLOGUE(); rtc_lld_serve_interrupt(&RTCD1); CH_IRQ_EPILOGUE(); } /*===========================================================================*/ /* Driver exported functions. */ /*===========================================================================*/ /** * @brief Enable access to registers and initialize RTC if BKP domain * was previously reseted. * @note: Cold start time of LSE oscillator on STM32 platform * takes about 3 seconds. * * @notapi */ void rtc_lld_init(void){ /* Ensure that RTC_CNT and RTC_DIV contain actual values after enabling clocking on APB1, because these values only update when APB1 functioning.*/ RTC->CRL = 0; while (!(RTC->CRL & RTC_CRL_RSF)) ; /* Write preload register only if its value is not equal to desired value.*/ if (STM32_RTCCLK != (((uint32_t)(RTC->PRLH)) << 16) + ((uint32_t)RTC->PRLL) + 1) { /* Enters configuration mode and writes PRLx registers then leaves the configuration mode.*/ rtc_lld_acquire(); RTC->CRL |= RTC_CRL_CNF; RTC->PRLH = (uint16_t)((STM32_RTCCLK - 1) >> 16); RTC->PRLL = (uint16_t)((STM32_RTCCLK - 1) & 0xFFFF); RTC->CRL &= ~RTC_CRL_CNF; rtc_lld_release(); } /* All interrupts initially disabled.*/ if (RTC->CRH != 0){ rtc_lld_acquire(); RTC->CRH = 0; rtc_lld_release(); } /* Callback initially disabled.*/ RTCD1.callback = NULL; } /** * @brief Set current time. * @note Fractional part will be silently ignored. There is no possibility * to change it on STM32F1xx platform. * * @param[in] rtcp pointer to RTC driver structure * @param[in] timespec pointer to a @p RTCTime structure * * @notapi */ void rtc_lld_set_time(RTCDriver *rtcp, const RTCTime *timespec) { (void)rtcp; rtc_lld_acquire(); RTC->CRL |= RTC_CRL_CNF; RTC->CNTH = (uint16_t)(timespec->tv_sec >> 16); RTC->CNTL = (uint16_t)(timespec->tv_sec & 0xFFFF); RTC->CRL &= ~RTC_CRL_CNF; rtc_lld_release(); } /** * @brief Get current time. * * @param[in] rtcp pointer to RTC driver structure * @param[in] timespec pointer to a @p RTCTime structure * * @notapi */ void rtc_lld_get_time(RTCDriver *rtcp, RTCTime *timespec) { (void)rtcp; uint32_t time_frac; /* The read is repeated until we are able to do it twice and obtain the same result.*/ do { timespec->tv_sec = ((uint32_t)(RTC->CNTH) << 16) + RTC->CNTL; time_frac = (((uint32_t)RTC->DIVH) << 16) + (uint32_t)RTC->DIVL; } while ((timespec->tv_sec) != (((uint32_t)(RTC->CNTH) << 16) + RTC->CNTL)); timespec->tv_msec = (uint16_t)(((STM32_RTCCLK - 1 - time_frac) * 1000) / STM32_RTCCLK); } /** * @brief Set alarm time. * * @note Default value after BKP domain reset is 0xFFFFFFFF * * @param[in] rtcp pointer to RTC driver structure * @param[in] alarm alarm identifier * @param[in] alarmspec pointer to a @p RTCAlarm structure * * @notapi */ void rtc_lld_set_alarm(RTCDriver *rtcp, rtcalarm_t alarm, const RTCAlarm *alarmspec) { (void)rtcp; (void)alarm; /* Enters configuration mode and writes ALRHx registers then leaves the configuration mode.*/ rtc_lld_acquire(); RTC->CRL |= RTC_CRL_CNF; if (alarmspec != NULL) { RTC->ALRH = (uint16_t)(alarmspec->tv_sec >> 16); RTC->ALRL = (uint16_t)(alarmspec->tv_sec & 0xFFFF); } else { RTC->ALRH = 0; RTC->ALRL = 0; } RTC->CRL &= ~RTC_CRL_CNF; rtc_lld_release(); } /** * @brief Get current alarm. * @note If an alarm has not been set then the returned alarm specification * is not meaningful. * * @note Default value after BKP domain reset is 0xFFFFFFFF. * * @param[in] rtcp pointer to RTC driver structure * @param[in] alarm alarm identifier * @param[out] alarmspec pointer to a @p RTCAlarm structure * * @notapi */ void rtc_lld_get_alarm(RTCDriver *rtcp, rtcalarm_t alarm, RTCAlarm *alarmspec) { (void)rtcp; (void)alarm; alarmspec->tv_sec = ((RTC->ALRH << 16) + RTC->ALRL); } /** * @brief Enables or disables RTC callbacks. * @details This function enables or disables callbacks, use a @p NULL pointer * in order to disable a callback. * * @param[in] rtcp pointer to RTC driver structure * @param[in] callback callback function pointer or @p NULL * * @notapi */ void rtc_lld_set_callback(RTCDriver *rtcp, rtccb_t callback) { rtc_lld_acquire(); if (callback != NULL) { rtcp->callback = callback; /* Interrupts are enabled only after setting up the callback, this way there is no need to check for the NULL callback pointer inside the IRQ handler.*/ RTC->CRL &= ~(RTC_CRL_OWF | RTC_CRL_ALRF | RTC_CRL_SECF); nvicEnableVector(RTC_IRQn, CORTEX_PRIORITY_MASK(STM32_RTC_IRQ_PRIORITY)); RTC->CRH |= RTC_CRH_OWIE | RTC_CRH_ALRIE | RTC_CRH_SECIE; } else { nvicDisableVector(RTC_IRQn); RTC->CRL &= ~(RTC_CRL_OWF | RTC_CRL_ALRF | RTC_CRL_SECF); RTC->CRH &= ~(RTC_CRH_OWIE | RTC_CRH_ALRIE | RTC_CRH_SECIE); } rtc_lld_release(); } #endif /* HAL_USE_RTC */ /** @} */