mbed library sources
Fork of mbed-src by
targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/rtc_api.c
- Committer:
- moirans2
- Date:
- 2015-01-14
- Revision:
- 445:9a3ffe6cfa19
- Parent:
- 402:09075a3b15e3
File content as of revision 445:9a3ffe6cfa19:
/* mbed Microcontroller Library ******************************************************************************* * Copyright (c) 2014, STMicroelectronics * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of STMicroelectronics nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ******************************************************************************* */ #include "rtc_api.h" #if DEVICE_RTC #include "wait_api.h" #define LSE_STARTUP_TIMEOUT ((uint16_t)700) // delay in ms static int rtc_inited = 0; void rtc_init(void) { uint32_t StartUpCounter = 0; uint32_t LSEStatus = 0; uint32_t rtc_freq = 0; RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE); // Enable PWR and Backup clock PWR_BackupAccessCmd(ENABLE); // Allow access to Backup Domain BKP_DeInit(); // Reset Backup Domain // Enable LSE clock RCC_LSEConfig(RCC_LSE_ON); // Wait till LSE is ready do { LSEStatus = RCC_GetFlagStatus(RCC_FLAG_LSERDY); wait_ms(1); StartUpCounter++; } while ((LSEStatus == 0) && (StartUpCounter <= LSE_STARTUP_TIMEOUT)); if (StartUpCounter > LSE_STARTUP_TIMEOUT) { // The LSE has not started, use LSI instead. // The RTC Clock may vary due to LSI frequency dispersion. RCC_LSEConfig(RCC_LSE_OFF); RCC_LSICmd(ENABLE); // Enable LSI while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET) {} // Wait until ready RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI); // Select the RTC Clock Source rtc_freq = 40000; // [TODO] To be measured precisely using a timer input capture } else { // The LSE has correctly started RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE); // Select the RTC Clock Source rtc_freq = LSE_VALUE; } RCC_RTCCLKCmd(ENABLE); // Enable RTC Clock RTC_WaitForSynchro(); // Wait for RTC registers synchronization RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished // Set RTC period to 1 sec RTC_SetPrescaler(rtc_freq - 1); RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished rtc_inited = 1; } void rtc_free(void) { // Disable RTC, LSE and LSI clocks PWR_BackupAccessCmd(ENABLE); // Allow access to Backup Domain RCC_RTCCLKCmd(DISABLE); RCC_LSEConfig(RCC_LSE_OFF); RCC_LSICmd(DISABLE); rtc_inited = 0; } int rtc_isenabled(void) { return rtc_inited; } time_t rtc_read(void) { return (time_t)RTC_GetCounter(); } void rtc_write(time_t t) { RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished RTC_SetCounter(t); // Change the current time RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished } #endif