/*
 * (C) Copyright 2007
 * Stefan Roese, DENX Software Engineering, sr@denx.de.
 *
 * based on a the Linux rtc-x1207.c driver which is:
 *      Copyright 2004 Karen Spearel
 *      Copyright 2005 Alessandro Zummo
 *
 * Information and datasheet:
 * http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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 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
 */

/*
 * Date & Time support for Xicor/Intersil X1205 RTC
 */

/* #define      DEBUG   */

#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>

#if defined(CONFIG_CMD_DATE)

#define CCR_SEC                 0
#define CCR_MIN                 1
#define CCR_HOUR                2
#define CCR_MDAY                3
#define CCR_MONTH               4
#define CCR_YEAR                5
#define CCR_WDAY                6
#define CCR_Y2K                 7

#define X1205_REG_SR            0x3F    /* status register */
#define X1205_REG_Y2K           0x37
#define X1205_REG_DW            0x36
#define X1205_REG_YR            0x35
#define X1205_REG_MO            0x34
#define X1205_REG_DT            0x33
#define X1205_REG_HR            0x32
#define X1205_REG_MN            0x31
#define X1205_REG_SC            0x30
#define X1205_REG_DTR           0x13
#define X1205_REG_ATR           0x12
#define X1205_REG_INT           0x11
#define X1205_REG_0             0x10
#define X1205_REG_Y2K1          0x0F
#define X1205_REG_DWA1          0x0E
#define X1205_REG_YRA1          0x0D
#define X1205_REG_MOA1          0x0C
#define X1205_REG_DTA1          0x0B
#define X1205_REG_HRA1          0x0A
#define X1205_REG_MNA1          0x09
#define X1205_REG_SCA1          0x08
#define X1205_REG_Y2K0          0x07
#define X1205_REG_DWA0          0x06
#define X1205_REG_YRA0          0x05
#define X1205_REG_MOA0          0x04
#define X1205_REG_DTA0          0x03
#define X1205_REG_HRA0          0x02
#define X1205_REG_MNA0          0x01
#define X1205_REG_SCA0          0x00

#define X1205_CCR_BASE          0x30    /* Base address of CCR */
#define X1205_ALM0_BASE         0x00    /* Base address of ALARM0 */

#define X1205_SR_RTCF           0x01    /* Clock failure */
#define X1205_SR_WEL            0x02    /* Write Enable Latch */
#define X1205_SR_RWEL           0x04    /* Register Write Enable */

#define X1205_DTR_DTR0          0x01
#define X1205_DTR_DTR1          0x02
#define X1205_DTR_DTR2          0x04

#define X1205_HR_MIL            0x80    /* Set in ccr.hour for 24 hr mode */

static void rtc_write(int reg, u8 val)
{
        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, reg, 2, &val, 1);
}

/*
 * In the routines that deal directly with the x1205 hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
 * Epoch is initialized as 2000. Time is set to UTC.
 */
int rtc_get(struct rtc_time *tm)
{
        u8 buf[8];

        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, X1205_CCR_BASE, 2, buf, 8);

        debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
              "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
              __FUNCTION__,
              buf[0], buf[1], buf[2], buf[3],
              buf[4], buf[5], buf[6], buf[7]);

        tm->tm_sec = bcd2bin(buf[CCR_SEC]);
        tm->tm_min = bcd2bin(buf[CCR_MIN]);
        tm->tm_hour = bcd2bin(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
        tm->tm_mday = bcd2bin(buf[CCR_MDAY]);
        tm->tm_mon = bcd2bin(buf[CCR_MONTH]); /* mon is 0-11 */
        tm->tm_year = bcd2bin(buf[CCR_YEAR])
                + (bcd2bin(buf[CCR_Y2K]) * 100);
        tm->tm_wday = buf[CCR_WDAY];

        debug("%s: tm is secs=%d, mins=%d, hours=%d, "
              "mday=%d, mon=%d, year=%d, wday=%d\n",
              __FUNCTION__,
              tm->tm_sec, tm->tm_min, tm->tm_hour,
              tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

        return 0;
}

int rtc_set(struct rtc_time *tm)
{
        int i;
        u8 buf[8];

        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
              tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
              tm->tm_hour, tm->tm_min, tm->tm_sec);

        buf[CCR_SEC] = bin2bcd(tm->tm_sec);
        buf[CCR_MIN] = bin2bcd(tm->tm_min);

        /* set hour and 24hr bit */
        buf[CCR_HOUR] = bin2bcd(tm->tm_hour) | X1205_HR_MIL;

        buf[CCR_MDAY] = bin2bcd(tm->tm_mday);

        /* month, 1 - 12 */
        buf[CCR_MONTH] = bin2bcd(tm->tm_mon);

        /* year, since the rtc epoch*/
        buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100);
        buf[CCR_WDAY] = tm->tm_wday & 0x07;
        buf[CCR_Y2K] = bin2bcd(tm->tm_year / 100);

        /* this sequence is required to unlock the chip */
        rtc_write(X1205_REG_SR, X1205_SR_WEL);
        rtc_write(X1205_REG_SR, X1205_SR_WEL | X1205_SR_RWEL);

        /* write register's data */
        for (i = 0; i < 8; i++)
                rtc_write(X1205_CCR_BASE + i, buf[i]);

        rtc_write(X1205_REG_SR, 0);

        return 0;
}

void rtc_reset(void)
{
        /*
         * Nothing to do
         */
}

#endif