shao ziyang / mbed-src-kl05

mbed library sources

Dependents:   frdm_kl05z_gpio_test

Fork of mbed-src by mbed official

targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/rtc_api.c@323:9e901b0a5aa1, 2014-09-13 (annotated)

Committer:
shaoziyang
Date:
Sat Sep 13 14:25:46 2014 +0000
Revision:
323:9e901b0a5aa1
Parent:
215:83cf97a28428 
test with CLOCK_SETUP = 0

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 60:142c6c6f5949 1 /* mbed Microcontroller Library
mbed_official 70:c1fbde68b492 2 *******************************************************************************
mbed_official 70:c1fbde68b492 3 * Copyright (c) 2014, STMicroelectronics
mbed_official 70:c1fbde68b492 4 * All rights reserved.
mbed_official 60:142c6c6f5949 5 *
mbed_official 70:c1fbde68b492 6 * Redistribution and use in source and binary forms, with or without
mbed_official 70:c1fbde68b492 7 * modification, are permitted provided that the following conditions are met:
mbed_official 60:142c6c6f5949 8 *
mbed_official 70:c1fbde68b492 9 * 1. Redistributions of source code must retain the above copyright notice,
mbed_official 70:c1fbde68b492 10 * this list of conditions and the following disclaimer.
mbed_official 70:c1fbde68b492 11 * 2. Redistributions in binary form must reproduce the above copyright notice,
mbed_official 70:c1fbde68b492 12 * this list of conditions and the following disclaimer in the documentation
mbed_official 70:c1fbde68b492 13 * and/or other materials provided with the distribution.
mbed_official 70:c1fbde68b492 14 * 3. Neither the name of STMicroelectronics nor the names of its contributors
mbed_official 70:c1fbde68b492 15 * may be used to endorse or promote products derived from this software
mbed_official 70:c1fbde68b492 16 * without specific prior written permission.
mbed_official 60:142c6c6f5949 17 *
mbed_official 70:c1fbde68b492 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
mbed_official 70:c1fbde68b492 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
mbed_official 70:c1fbde68b492 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
mbed_official 70:c1fbde68b492 21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
mbed_official 70:c1fbde68b492 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
mbed_official 70:c1fbde68b492 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
mbed_official 70:c1fbde68b492 24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 70:c1fbde68b492 25 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
mbed_official 70:c1fbde68b492 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
mbed_official 70:c1fbde68b492 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
mbed_official 70:c1fbde68b492 28 *******************************************************************************
mbed_official 60:142c6c6f5949 29 */
mbed_official 60:142c6c6f5949 30 #include "rtc_api.h"
mbed_official 60:142c6c6f5949 31
mbed_official 174:8bb9f3a33240 32 #if DEVICE_RTC
mbed_official 174:8bb9f3a33240 33
mbed_official 174:8bb9f3a33240 34 #include "wait_api.h"
mbed_official 174:8bb9f3a33240 35
mbed_official 174:8bb9f3a33240 36 #define LSE_STARTUP_TIMEOUT ((uint16_t)700) // delay in ms
mbed_official 174:8bb9f3a33240 37
mbed_official 60:142c6c6f5949 38 static int rtc_inited = 0;
mbed_official 60:142c6c6f5949 39
mbed_official 60:142c6c6f5949 40 void rtc_init(void) {
mbed_official 174:8bb9f3a33240 41 uint32_t StartUpCounter = 0;
mbed_official 174:8bb9f3a33240 42 uint32_t LSEStatus = 0;
mbed_official 174:8bb9f3a33240 43 uint32_t rtc_freq = 0;
mbed_official 174:8bb9f3a33240 44
mbed_official 60:142c6c6f5949 45 RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE); // Enable PWR and Backup clock
mbed_official 60:142c6c6f5949 46
mbed_official 60:142c6c6f5949 47 PWR_BackupAccessCmd(ENABLE); // Allow access to Backup Domain
mbed_official 174:8bb9f3a33240 48
mbed_official 60:142c6c6f5949 49 BKP_DeInit(); // Reset Backup Domain
mbed_official 174:8bb9f3a33240 50
mbed_official 174:8bb9f3a33240 51 // Enable LSE clock
mbed_official 174:8bb9f3a33240 52 RCC_LSEConfig(RCC_LSE_ON);
mbed_official 174:8bb9f3a33240 53
mbed_official 174:8bb9f3a33240 54 // Wait till LSE is ready
mbed_official 174:8bb9f3a33240 55 do {
mbed_official 174:8bb9f3a33240 56 LSEStatus = RCC_GetFlagStatus(RCC_FLAG_LSERDY);
mbed_official 174:8bb9f3a33240 57 wait_ms(1);
mbed_official 174:8bb9f3a33240 58 StartUpCounter++;
mbed_official 174:8bb9f3a33240 59 } while ((LSEStatus == 0) && (StartUpCounter <= LSE_STARTUP_TIMEOUT));
mbed_official 174:8bb9f3a33240 60
mbed_official 174:8bb9f3a33240 61 if (StartUpCounter > LSE_STARTUP_TIMEOUT) {
mbed_official 174:8bb9f3a33240 62 // The LSE has not started, use LSI instead.
mbed_official 174:8bb9f3a33240 63 // The RTC Clock may vary due to LSI frequency dispersion.
mbed_official 174:8bb9f3a33240 64 RCC_LSEConfig(RCC_LSE_OFF);
mbed_official 174:8bb9f3a33240 65 RCC_LSICmd(ENABLE); // Enable LSI
mbed_official 174:8bb9f3a33240 66 while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET) {} // Wait until ready
mbed_official 174:8bb9f3a33240 67 RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI); // Select the RTC Clock Source
mbed_official 174:8bb9f3a33240 68 rtc_freq = 40000; // [TODO] To be measured precisely using a timer input capture
mbed_official 174:8bb9f3a33240 69 } else {
mbed_official 174:8bb9f3a33240 70 // The LSE has correctly started
mbed_official 174:8bb9f3a33240 71 RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE); // Select the RTC Clock Source
mbed_official 174:8bb9f3a33240 72 rtc_freq = LSE_VALUE;
mbed_official 174:8bb9f3a33240 73 }
mbed_official 174:8bb9f3a33240 74
mbed_official 174:8bb9f3a33240 75 RCC_RTCCLKCmd(ENABLE); // Enable RTC Clock
mbed_official 174:8bb9f3a33240 76
mbed_official 60:142c6c6f5949 77 RTC_WaitForSynchro(); // Wait for RTC registers synchronization
mbed_official 174:8bb9f3a33240 78
mbed_official 60:142c6c6f5949 79 RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished
mbed_official 60:142c6c6f5949 80
mbed_official 60:142c6c6f5949 81 // Set RTC period to 1 sec
mbed_official 174:8bb9f3a33240 82 RTC_SetPrescaler(rtc_freq - 1);
mbed_official 174:8bb9f3a33240 83
mbed_official 60:142c6c6f5949 84 RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished
mbed_official 174:8bb9f3a33240 85
mbed_official 60:142c6c6f5949 86 rtc_inited = 1;
mbed_official 60:142c6c6f5949 87 }
mbed_official 60:142c6c6f5949 88
mbed_official 60:142c6c6f5949 89 void rtc_free(void) {
mbed_official 215:83cf97a28428 90 // Disable RTC, LSE and LSI clocks
mbed_official 215:83cf97a28428 91 PWR_BackupAccessCmd(ENABLE); // Allow access to Backup Domain
mbed_official 215:83cf97a28428 92 RCC_RTCCLKCmd(DISABLE);
mbed_official 215:83cf97a28428 93 RCC_LSEConfig(RCC_LSE_OFF);
mbed_official 215:83cf97a28428 94 RCC_LSICmd(DISABLE);
mbed_official 215:83cf97a28428 95
mbed_official 60:142c6c6f5949 96 rtc_inited = 0;
mbed_official 60:142c6c6f5949 97 }
mbed_official 60:142c6c6f5949 98
mbed_official 60:142c6c6f5949 99 int rtc_isenabled(void) {
mbed_official 60:142c6c6f5949 100 return rtc_inited;
mbed_official 60:142c6c6f5949 101 }
mbed_official 60:142c6c6f5949 102
mbed_official 60:142c6c6f5949 103 time_t rtc_read(void) {
mbed_official 60:142c6c6f5949 104 return (time_t)RTC_GetCounter();
mbed_official 60:142c6c6f5949 105 }
mbed_official 60:142c6c6f5949 106
mbed_official 60:142c6c6f5949 107 void rtc_write(time_t t) {
mbed_official 60:142c6c6f5949 108 RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished
mbed_official 60:142c6c6f5949 109 RTC_SetCounter(t); // Change the current time
mbed_official 60:142c6c6f5949 110 RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished
mbed_official 60:142c6c6f5949 111 }
mbed_official 174:8bb9f3a33240 112
mbed_official 174:8bb9f3a33240 113 #endif