LXR uboot/drivers/rtc/max6900.c

   1/*
   2 * (C) Copyright 2004
   3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4 *
   5 * See file CREDITS for list of people who contributed to this
   6 * project.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of
  11 * the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21 * MA 02111-1307 USA
  22 */
  23
  24/*
  25 * Date & Time support for MAXIM MAX6900 RTC
  26 */
  27
  28/* #define      DEBUG   */
  29
  30#include <common.h>
  31#include <command.h>
  32#include <rtc.h>
  33#include <i2c.h>
  34
  35#if defined(CONFIG_CMD_DATE)
  36
  37#ifndef CONFIG_SYS_I2C_RTC_ADDR
  38#define CONFIG_SYS_I2C_RTC_ADDR 0x50
  39#endif
  40
  41/* ------------------------------------------------------------------------- */
  42
  43static uchar rtc_read (uchar reg)
  44{
  45        return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
  46}
  47
  48static void rtc_write (uchar reg, uchar val)
  49{
  50        i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
  51        udelay(2500);
  52}
  53
  54/* ------------------------------------------------------------------------- */
  55
  56int rtc_get (struct rtc_time *tmp)
  57{
  58        uchar sec, min, hour, mday, wday, mon, cent, year;
  59        int retry = 1;
  60
  61        do {
  62                sec     = rtc_read (0x80);
  63                min     = rtc_read (0x82);
  64                hour    = rtc_read (0x84);
  65                mday    = rtc_read (0x86);
  66                mon     = rtc_read (0x88);
  67                wday    = rtc_read (0x8a);
  68                year    = rtc_read (0x8c);
  69                cent    = rtc_read (0x92);
  70                /*
  71                 * Check for seconds rollover
  72                 */
  73                if ((sec != 59) || (rtc_read(0x80) == sec)){
  74                        retry = 0;
  75                }
  76        } while (retry);
  77
  78        debug ( "Get RTC year: %02x mon: %02x cent: %02x mday: %02x wday: %02x "
  79                "hr: %02x min: %02x sec: %02x\n",
  80                year, mon, cent, mday, wday,
  81                hour, min, sec );
  82
  83        tmp->tm_sec  = bcd2bin (sec  & 0x7F);
  84        tmp->tm_min  = bcd2bin (min  & 0x7F);
  85        tmp->tm_hour = bcd2bin (hour & 0x3F);
  86        tmp->tm_mday = bcd2bin (mday & 0x3F);
  87        tmp->tm_mon  = bcd2bin (mon & 0x1F);
  88        tmp->tm_year = bcd2bin (year) + bcd2bin(cent) * 100;
  89        tmp->tm_wday = bcd2bin (wday & 0x07);
  90        tmp->tm_yday = 0;
  91        tmp->tm_isdst= 0;
  92
  93        debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  94                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  95                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  96
  97        return 0;
  98}
  99
 100int rtc_set (struct rtc_time *tmp)
 101{
 102
 103        debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 104                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 105                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 106
 107        rtc_write (0x9E, 0x00);
 108        rtc_write (0x80, 0);    /* Clear seconds to ensure no rollover */
 109        rtc_write (0x92, bin2bcd(tmp->tm_year / 100));
 110        rtc_write (0x8c, bin2bcd(tmp->tm_year % 100));
 111        rtc_write (0x8a, bin2bcd(tmp->tm_wday));
 112        rtc_write (0x88, bin2bcd(tmp->tm_mon));
 113        rtc_write (0x86, bin2bcd(tmp->tm_mday));
 114        rtc_write (0x84, bin2bcd(tmp->tm_hour));
 115        rtc_write (0x82, bin2bcd(tmp->tm_min ));
 116        rtc_write (0x80, bin2bcd(tmp->tm_sec ));
 117
 118        return 0;
 119}
 120
 121void rtc_reset (void)
 122{
 123}
 124
 125#endif
 126