/*
 * Copyright 2008-2010, Freie Universitaet Berlin (FUB). All rights reserved.
 * Copyright 2014 INRIA
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

 /**
  * @ingroup     cpu_lpc23xx
  * @ingroup     drivers_periph_rtc
  * @{
  *
  * @file
  * @brief       Peripheral UART driver implementation
  *
  * @author      Kaspar Schleiser <kaspar@schleiser.de>
  *
  * @}
  */

#include <sys/time.h>
#include <stdint.h>
#include <string.h>

/* cpu */
#include "periph/rtc.h"
#include "VIC.h"
#include "lpc23xx.h"
#include "timex.h"

#define ENABLE_DEBUG 0
#include "debug.h"

/* Alarm callback */
static rtc_alarm_cb_t _cb;

/* Argument to alarm callback */
static void *_cb_arg;

void RTC_IRQHandler(void) __attribute__((interrupt("IRQ")));

void rtc_init(void)
{
    PCONP   |= BIT9;
    RTC_AMR  = 0xff;        /* disable alarm irq */
    RTC_CIIR = 0;           /* disable increase irq */
    RTC_CISS = 0;           /* disable subsecond irq */

    INTWAKE |= BIT15;       /* rtc irq wakes up mcu from power down */

    RTC_CCR  = CCR_CLKSRC;  /* Clock from external 32 kHz Osc. */

    /* Initialize clock to a a sane and predictable default
     * after cold boot or external reset.
     */
    if ((RSIR == RSIR_POR) || (RSIR == (RSIR_POR | RSIR_EXTR))) {
        struct tm localt = { .tm_year = RIOT_EPOCH - 1900 };
        rtc_set_time(&localt);
    }

    rtc_poweron();

    DEBUG("%2lu.%2lu.%4lu  %2lu:%2lu:%2lu\n",
          RTC_DOM, RTC_MONTH, RTC_YEAR, RTC_HOUR, RTC_MIN, RTC_SEC);
}

/**
 * @brief   Sets the current time in broken down format directly from to RTC
 * @param[in]   localt      Pointer to structure with time to set
 */
int rtc_set_time(struct tm *localt)
{
    if (localt == NULL) {
        return -1;
    }

    /* normalize input */
    rtc_tm_normalize(localt);

    /* set clock */
    RTC_SEC   = localt->tm_sec;
    RTC_MIN   = localt->tm_min;
    RTC_HOUR  = localt->tm_hour;
    RTC_DOM   = localt->tm_mday;
    RTC_DOW   = localt->tm_wday;
    RTC_DOY   = localt->tm_yday;
    RTC_MONTH = localt->tm_mon + 1;
    RTC_YEAR  = localt->tm_year;

    return 0;
}

int rtc_get_time(struct tm *localt)
{
    if (localt == NULL) {
        return -1;
    }

    localt->tm_sec   = RTC_SEC;
    localt->tm_min   = RTC_MIN;
    localt->tm_hour  = RTC_HOUR;
    localt->tm_mday  = RTC_DOM;
    localt->tm_wday  = RTC_DOW;
    localt->tm_yday  = RTC_DOY;
    localt->tm_mon   = RTC_MONTH - 1;
    localt->tm_year  = RTC_YEAR;
    localt->tm_isdst = -1; /* not available */

    return 0;
}

int rtc_get_time_ms(struct tm *time, uint16_t *ms)
{
    uint16_t ccr_before, ccr_after;

    /* loop in case of overflow */
    do {
        ccr_before = RTC_CCR >> 1;
        rtc_get_time(time);
        ccr_after = RTC_CCR >> 1;
    } while (ccr_before > ccr_after);

    /* CCR is 15-bit counter, increments second with each overflow */
    *ms = (ccr_after * MS_PER_SEC) >> 15;

    return 0;
}

int rtc_set_alarm(struct tm *localt, rtc_alarm_cb_t cb, void *arg)
{
    if (localt != NULL) {

        /* normalize input */
        rtc_tm_normalize(localt);

        RTC_ALSEC  = localt->tm_sec;
        RTC_ALMIN  = localt->tm_min;
        RTC_ALHOUR = localt->tm_hour;
        RTC_ALDOM  = localt->tm_mday;
        RTC_ALDOW  = localt->tm_wday;
        RTC_ALDOY  = localt->tm_yday;
        RTC_ALMON  = localt->tm_mon + 1;
        RTC_ALYEAR = localt->tm_year;
        RTC_AMR    = 0;                 /* set which alarm fields to check */
        DEBUG("alarm set %2lu.%2lu.%4lu  %2lu:%2lu:%2lu\n",
              RTC_ALDOM, RTC_ALMON, RTC_ALYEAR, RTC_ALHOUR, RTC_ALMIN, RTC_ALSEC);
    }

    if (cb) {
        _cb = cb;
        _cb_arg = arg;
    }

    return 0;
}

int rtc_get_alarm(struct tm *localt)
{
    if (localt == NULL) {
        return -1;
    }

    localt->tm_sec   = RTC_ALSEC;
    localt->tm_min   = RTC_ALMIN;
    localt->tm_hour  = RTC_ALHOUR;
    localt->tm_mday  = RTC_ALDOM;
    localt->tm_wday  = RTC_ALDOW;
    localt->tm_yday  = RTC_ALDOY;
    localt->tm_mon   = RTC_ALMON - 1;
    localt->tm_year  = RTC_ALYEAR;
    localt->tm_isdst = -1; /* not available */

    return 0;
}

void rtc_clear_alarm(void)
{
    RTC_AMR = 0xff;
}

void rtc_poweron(void)
{
    PCONP   |= BIT9;
    RTC_ILR  = (ILR_RTSSF | ILR_RTCCIF | ILR_RTCALF);    /* clear interrupt flags */
    RTC_CCR |= CCR_CLKEN;                               /* enable clock */
    install_irq(RTC_INT, &RTC_IRQHandler, IRQP_RTC);    /* install interrupt handler */
}

void rtc_poweroff(void)
{
    RTC_CCR &= ~CCR_CLKEN;  /* disable clock */
    install_irq(RTC_INT, NULL, 0);
    PCONP &= ~BIT9;
}

void RTC_IRQHandler(void)
{
    if (RTC_ILR & ILR_RTCALF) {
        RTC_ILR = ILR_RTCALF;
        RTC_AMR = 0xff;                     /* disable alarm irq */
        if (_cb) {
            _cb(_cb_arg);
        }
        DEBUG("Ring\n");
    }

    VICVectAddr = 0;                        /* Acknowledge Interrupt */
}