flight/pios/stm32f0x/pios_rtc.c

   1 /**
   2  ******************************************************************************
   3  * @addtogroup PIOS PIOS Core hardware abstraction layer
   4  * @{
   5  * @addtogroup   PIOS_PWM PWM Input Functions
   6  * @brief       Code to measure with PWM input
   7  * @{
   8  *
   9  * @file       pios_pwm.c
  10  * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
  11  * @brief      PWM Input functions (STM32 dependent)
  12  * @see        The GNU Public License (GPL) Version 3
  13  *
  14  *****************************************************************************/
  15 /*
  16  * This program is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License as published by
  18  * the Free Software Foundation; either version 3 of the License, or
  19  * (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful, but
  22  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  23  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  24  * for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License along
  27  * with this program; if not, write to the Free Software Foundation, Inc.,
  28  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  29  */
  30
  31 #include "pios.h"
  32
  33 #ifdef PIOS_INCLUDE_RTC
  34
  35 #include <pios_rtc_priv.h>
  36
  37 #ifndef PIOS_RTC_PRESCALER
  38 #define PIOS_RTC_PRESCALER 100
  39 #endif
  40
  41 struct rtc_callback_entry {
  42     void     (*fn)(uint32_t);
  43     uint32_t data;
  44 };
  45
  46 #define PIOS_RTC_MAX_CALLBACKS 3
  47 struct rtc_callback_entry rtc_callback_list[PIOS_RTC_MAX_CALLBACKS];
  48 static uint8_t rtc_callback_next = 0;
  49
  50 void PIOS_RTC_Init(const struct pios_rtc_cfg *cfg)
  51 {
  52     RCC_BackupResetCmd(ENABLE);
  53     RCC_BackupResetCmd(DISABLE);
  54     RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
  55     PWR_BackupAccessCmd(ENABLE);
  56     // Divide external 8 MHz clock to 1 MHz
  57     RCC_RTCCLKConfig(cfg->clksrc);
  58     RCC_RTCCLKCmd(ENABLE);
  59
  60     RTC_WakeUpCmd(DISABLE);
  61     // Divide 1 Mhz clock by 16 -> 62.5 khz
  62     RTC_WakeUpClockConfig(RTC_WakeUpClock_RTCCLK_Div16);
  63     // Divide 62.5 khz by 200 to get 625 Hz
  64     RTC_SetWakeUpCounter(cfg->prescaler); // cfg->prescaler);
  65     RTC_WakeUpCmd(ENABLE);
  66
  67     /* Configure and enable the RTC Second interrupt */
  68     EXTI_InitTypeDef ExtiInit = {
  69         .EXTI_Line    = EXTI_Line22, // matches above GPIO pin
  70         .EXTI_Mode    = EXTI_Mode_Interrupt,
  71         .EXTI_Trigger = EXTI_Trigger_Rising,
  72         .EXTI_LineCmd = ENABLE,
  73     };
  74     EXTI_Init(&ExtiInit);
  75     NVIC_Init(&cfg->irq.init);
  76     RTC_ITConfig(RTC_IT_WUT, ENABLE);
  77
  78     RTC_ClearFlag(RTC_FLAG_WUTF);
  79 }
  80
  81 uint32_t PIOS_RTC_Counter()
  82 {
  83     return RTC_GetWakeUpCounter();
  84 }
  85
  86 /* FIXME: This shouldn't use hard-coded clock rates, dividers or prescalers.
  87  *        Should get these from the cfg struct passed to init.
  88  */
  89 float PIOS_RTC_Rate()
  90 {
  91     return (float)(8e6f / 128.0f) / (1 + PIOS_RTC_PRESCALER);
  92 }
  93
  94 float PIOS_RTC_MsPerTick()
  95 {
  96     return 1000.0f / PIOS_RTC_Rate();
  97 }
  98
  99 /* TODO: This needs a mutex around rtc_callbacks[] */
 100 bool PIOS_RTC_RegisterTickCallback(void (*fn)(uint32_t id), uint32_t data)
 101 {
 102     struct rtc_callback_entry *cb;
 103
 104     if (rtc_callback_next >= PIOS_RTC_MAX_CALLBACKS) {
 105         return false;
 106     }
 107
 108     cb       = &rtc_callback_list[rtc_callback_next++];
 109
 110     cb->fn   = fn;
 111     cb->data = data;
 112     return true;
 113 }
 114
 115 void PIOS_RTC_irq_handler(void)
 116 {
 117     if (RTC_GetITStatus(RTC_IT_WUT)) {
 118         /* Call all registered callbacks */
 119         for (uint8_t i = 0; i < rtc_callback_next; i++) {
 120             struct rtc_callback_entry *cb = &rtc_callback_list[i];
 121             if (cb->fn) {
 122                 (cb->fn)(cb->data);
 123             }
 124         }
 125
 126         /* Clear the RTC Second interrupt */
 127         RTC_ClearITPendingBit(RTC_IT_WUT);
 128     }
 129
 130     if (EXTI_GetITStatus(EXTI_Line22) != RESET) {
 131         EXTI_ClearITPendingBit(EXTI_Line22);
 132     }
 133 }
 134
 135 #endif /* PIOS_INCLUDE_RTC */
 136
 137 /**
 138  * @}
 139  * @}
 140  */