/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2008 by Maurus Cuelenaere
 *
 * 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 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
 
/*
 * Jz OnChip Real Time Clock interface for Linux
 *
 */

#include "config.h"
#include "jz4740.h"
#include "rtc.h"
#include "timefuncs.h"

static unsigned int epoch = 1900;
static const unsigned char days_in_mo[] = {
    0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

static const unsigned int yearday[5] = {0, 366, 366+365, 366+365*2, 366+365*3};
static const unsigned int sweekday = 6;
static const unsigned int sum_monthday[13] = {
    0,
    31,
    31+28,
    31+28+31,
    31+28+31+30,
    31+28+31+30+31,
    31+28+31+30+31+30,
    31+28+31+30+31+30+31,
    31+28+31+30+31+30+31+31,
    31+28+31+30+31+30+31+31+30,
    31+28+31+30+31+30+31+31+30+31,
    31+28+31+30+31+30+31+31+30+31+30,
    365
};

static unsigned int jz_mktime(int year, int mon, int day, int hour, int min, int sec)
{
    unsigned int seccounter;

    if (year < 2000)
        year = 2000;
    year -= 2000;
    seccounter = (year/4)*(365*3+366);
    seccounter += yearday[year%4];
    if (year%4)
        seccounter += sum_monthday[mon-1];
    else
        if (mon >= 3)
            seccounter += sum_monthday[mon-1]+1;
        else
            seccounter += sum_monthday[mon-1];
    seccounter += day-1;
    seccounter *= 24;
    seccounter += hour;
    seccounter *= 60;
    seccounter += min;
    seccounter *= 60;
    seccounter += sec;

    return seccounter;
}

static void jz_gettime(unsigned int rtc, int *year, int *mon, int *day, int *hour,
         int *min, int *sec, int *weekday)
{
    unsigned int tday, tsec, i, tmp;

    tday = rtc/(24*3600);
    *weekday = ((tday % 7) + sweekday) % 7;
    *year = (tday/(366+365*3)) * 4;
    tday = tday%(366+365*3);
    for (i=0;i<5;i++)
    {
        if (tday<yearday[i])
        {
            *year += i-1;
            tday -= yearday[i-1];
            break;
        }
    }
    for (i=0;i<13;i++)
    {
        tmp = sum_monthday[i];
        if (((*year%4) == 0) && (i>=2))
            tmp += 1;
        if (tday<tmp)
        {
            *mon = i;
            tmp = sum_monthday[i-1];
            if (((*year%4) == 0) && ((i-1)>=2))
                tmp += 1;
            *day = tday - tmp + 1;
            break;
        }
    }
    tsec = rtc % (24 * 3600);
    *hour = tsec / 3600;
    *min = (tsec / 60) % 60;
    *sec = tsec - *hour*3600 - *min*60;
    *year += 2000;
}

int rtc_read_datetime(unsigned char* buf)
{
    struct tm rtc_tm;
    unsigned int sec,mon,mday,wday,year,hour,min;
    
    /*
     * Only the values that we read from the RTC are set. We leave
     * tm_wday, tm_yday and tm_isdst untouched. Even though the
     * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
     * by the RTC when initially set to a non-zero value.
     */
    jz_gettime(REG_RTC_RSR, &year, &mon, &mday, &hour, &min, &sec, &wday);

    year -= 2000;

    rtc_tm.tm_sec = sec;
    rtc_tm.tm_min = min;
    rtc_tm.tm_hour = hour;
    rtc_tm.tm_mday = mday;
    rtc_tm.tm_wday = wday;
    /* Don't use centry, but start from year 1970 */
    rtc_tm.tm_mon = mon;
    if ((year += (epoch - 1900)) <= 69)
        year += 100;
    rtc_tm.tm_year = year + 1900;
    
    rtc_tm.tm_yday = 0; /* Not implemented for now */
    rtc_tm.tm_isdst = -1; /* Not implemented for now */
    
    (*((struct tm*)buf)) = rtc_tm;
    return 1;
}

#if 0
void get_rtc_alm_time(struct rtc_time *alm_tm)
{ 
    unsigned int sec,mon,mday,wday,year,hour,min;
    unsigned int lval;
    unsigned long flags;
    /*
     * Only the values that we read from the RTC are set. That
     * means only tm_hour, tm_min, and tm_sec.
     */
    lval = REG_RTC_RSAR;
    jz_gettime(lval, &year, &mon, &mday, &hour, &min, &sec, &wday);

    alm_tm->tm_sec = sec;
    alm_tm->tm_min = min;
    alm_tm->tm_hour = hour;
}


int rtc_ioctl(unsigned int cmd,struct rtc_time *val,unsigned int epo)
{
    struct rtc_time wtime; 
    switch (cmd) {
    case RTC_ALM_READ:    /* Read the present alarm time */
        /*
         * This returns a struct rtc_time. Reading >= 0xc0
         * means "don't care" or "match all". Only the tm_hour,
         * tm_min, and tm_sec values are filled in.
         */
        get_rtc_alm_time(val);
        break; 
    case RTC_ALM_SET:    /* Store a time into the alarm */
    {
        unsigned char ahrs, amin, asec;
        unsigned int sec,mon,mday,wday,year,hour,min;
        unsigned int lval;
        unsigned long flags;
        struct rtc_time alm_tm;

        alm_tm = *val;
        ahrs = alm_tm.tm_hour;
        amin = alm_tm.tm_min;
        asec = alm_tm.tm_sec;

    

        if (ahrs >= 24)
            return -1;

        if (amin >= 60)
            return -1;

        if (asec >= 60)
            return -1;

        flags = spin_lock_irqsave();
        lval = REG_RTC_RSR;
        jz_gettime(lval, &year, &mon, &mday, &hour, &min, &sec, &wday);
        hour = ahrs;
        min = amin;
        sec = asec;
        lval = jz_mktime(year, mon, mday, hour, min, sec);
        REG_RTC_RSAR = lval;
        spin_unlock_irqrestore(flags);
        break;
    }
    case RTC_RD_TIME:    /* Read the time/date from RTC    */
        get_rtc_time(val);
        break;
    case RTC_SET_TIME:    /* Set the RTC */
    {
        struct rtc_time rtc_tm;
        unsigned int mon, day, hrs, min, sec, leap_yr, date;
        unsigned int yrs;
        unsigned int lval;
        unsigned long flags;

        rtc_tm = *val;
        yrs = rtc_tm.tm_year;// + 1900;
        mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
        day = rtc_tm.tm_wday;
        date = rtc_tm.tm_mday;
        hrs = rtc_tm.tm_hour;
        min = rtc_tm.tm_min;
        sec = rtc_tm.tm_sec;


        if (yrs < 1970)
            return -EINVAL;
        leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));

        if ((mon > 12) || (date == 0))
            return -EINVAL;

        if (date > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
            return -EINVAL;

        if ((hrs >= 24) || (min >= 60) || (sec >= 60))
            return -EINVAL;

        if ((yrs -= epoch) > 255)    /* They are unsigned */
            return -EINVAL;

        flags = spin_lock_irqsave();
        /* These limits and adjustments are independant of
         * whether the chip is in binary mode or not.
         */

        if (yrs > 169) {
            spin_unlock_irqrestore(flags);
            return -EINVAL;
        }

        yrs += epoch;
        lval = jz_mktime(yrs, mon, date, hrs, min, sec);
        REG_RTC_RSR = lval;
        /* FIXME: maybe we need to write alarm register here. */
        spin_unlock_irqrestore(flags);

        return 0;
    }
    break;
    case RTC_EPOCH_READ:    /* Read the epoch.    */
        epo = epoch;
        return 0;
    case RTC_EPOCH_SET:    /* Set the epoch.    */
        /* 
         * There were no RTC clocks before 1900.
         */
        if (epo < 1900)
            return -EINVAL;

        epoch = epo;
        return 0;
    default:
        return -EINVAL;
    }
    return -EINVAL;
}
#endif

void rtc_init(void)
{
    REG_RTC_RCR = RTC_RCR_RTCE;
    udelay(70);
    while( !(REG_RTC_RCR & RTC_RCR_WRDY) );
    REG_RTC_RGR = (0x7fff | RTC_RGR_LOCK); 
    udelay(70);
}
