/**
 ******************************************************************************
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 * @addtogroup   PIOS_PWM PWM Input Functions
 * @brief		Code to measure with PWM input
 * @{
 *
 * @file       pios_pwm.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      PWM Input functions (STM32 dependent)
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * This program 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.
 *
 * This program 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, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "pios.h"

#ifdef PIOS_INCLUDE_RTC

#include <pios_rtc_priv.h>

#ifndef PIOS_RTC_PRESCALER
#define PIOS_RTC_PRESCALER 100
#endif

struct rtc_callback_entry {
    void     (*fn)(uint32_t);
    uint32_t data;
};

#define PIOS_RTC_MAX_CALLBACKS 3
struct rtc_callback_entry rtc_callback_list[PIOS_RTC_MAX_CALLBACKS];
static uint8_t rtc_callback_next = 0;

void PIOS_RTC_Init(const struct pios_rtc_cfg *cfg)
{
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_BKP | RCC_APB1Periph_PWR,
                           ENABLE);
    PWR_BackupAccessCmd(ENABLE);

    RCC_RTCCLKConfig(cfg->clksrc);
    RCC_RTCCLKCmd(ENABLE);
    RTC_WaitForLastTask();
    RTC_WaitForSynchro();
    RTC_WaitForLastTask();

    /* Configure and enable the RTC Second interrupt */
    NVIC_Init(&cfg->irq.init);
    RTC_ITConfig(RTC_IT_SEC, ENABLE);
    RTC_WaitForLastTask();

    RTC_SetPrescaler(cfg->prescaler);
    RTC_WaitForLastTask();
    RTC_SetCounter(0);
    RTC_WaitForLastTask();
}

uint32_t PIOS_RTC_Counter()
{
    return RTC_GetCounter();
}

/* FIXME: This shouldn't use hard-coded clock rates, dividers or prescalers.
 *        Should get these from the cfg struct passed to init.
 */
float PIOS_RTC_Rate()
{
    return (float)(8e6f / 128.0f) / (1 + PIOS_RTC_PRESCALER);
}

float PIOS_RTC_MsPerTick()
{
    return 1000.0f / PIOS_RTC_Rate();
}

/* TODO: This needs a mutex around rtc_callbacks[] */
bool PIOS_RTC_RegisterTickCallback(void (*fn)(uint32_t id), uint32_t data)
{
    struct rtc_callback_entry *cb;

    if (rtc_callback_next >= PIOS_RTC_MAX_CALLBACKS) {
        return false;
    }

    cb       = &rtc_callback_list[rtc_callback_next++];

    cb->fn   = fn;
    cb->data = data;
    return true;
}

void PIOS_RTC_irq_handler(void)
{
    if (RTC_GetITStatus(RTC_IT_SEC)) {
        /* Call all registered callbacks */
        for (uint8_t i = 0; i < rtc_callback_next; i++) {
            struct rtc_callback_entry *cb = &rtc_callback_list[i];
            if (cb->fn) {
                (cb->fn)(cb->data);
            }
        }

        /* Wait until last write operation on RTC registers has finished */
        RTC_WaitForLastTask();
        /* Clear the RTC Second interrupt */
        RTC_ClearITPendingBit(RTC_IT_SEC);
    }
}

#endif /* PIOS_INCLUDE_RTC */

/**
 * @}
 * @}
 */