LXR uboot/drivers/rtc/ds1337.c

   1/*
   2 * (C) Copyright 2001-2008
   3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4 * Keith Outwater, keith_outwater@mvis.com`
   5 *
   6 * See file CREDITS for list of people who contributed to this
   7 * project.
   8 *
   9 * This program is free software; you can redistribute it and/or
  10 * modify it under the terms of the GNU General Public License as
  11 * published by the Free Software Foundation; either version 2 of
  12 * the License, or (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22 * MA 02111-1307 USA
  23 */
  24
  25/*
  26 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
  27 * DS1337 Real Time Clock (RTC).
  28 */
  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/*
  38 * RTC register addresses
  39 */
  40#if defined CONFIG_RTC_DS1337
  41#define RTC_SEC_REG_ADDR        0x0
  42#define RTC_MIN_REG_ADDR        0x1
  43#define RTC_HR_REG_ADDR         0x2
  44#define RTC_DAY_REG_ADDR        0x3
  45#define RTC_DATE_REG_ADDR       0x4
  46#define RTC_MON_REG_ADDR        0x5
  47#define RTC_YR_REG_ADDR         0x6
  48#define RTC_CTL_REG_ADDR        0x0e
  49#define RTC_STAT_REG_ADDR       0x0f
  50#define RTC_TC_REG_ADDR         0x10
  51#elif defined CONFIG_RTC_DS1388
  52#define RTC_SEC_REG_ADDR        0x1
  53#define RTC_MIN_REG_ADDR        0x2
  54#define RTC_HR_REG_ADDR         0x3
  55#define RTC_DAY_REG_ADDR        0x4
  56#define RTC_DATE_REG_ADDR       0x5
  57#define RTC_MON_REG_ADDR        0x6
  58#define RTC_YR_REG_ADDR         0x7
  59#define RTC_CTL_REG_ADDR        0x0c
  60#define RTC_STAT_REG_ADDR       0x0b
  61#define RTC_TC_REG_ADDR         0x0a
  62#endif
  63
  64/*
  65 * RTC control register bits
  66 */
  67#define RTC_CTL_BIT_A1IE        0x1     /* Alarm 1 interrupt enable     */
  68#define RTC_CTL_BIT_A2IE        0x2     /* Alarm 2 interrupt enable     */
  69#define RTC_CTL_BIT_INTCN       0x4     /* Interrupt control            */
  70#define RTC_CTL_BIT_RS1         0x8     /* Rate select 1                */
  71#define RTC_CTL_BIT_RS2         0x10    /* Rate select 2                */
  72#define RTC_CTL_BIT_DOSC        0x80    /* Disable Oscillator           */
  73
  74/*
  75 * RTC status register bits
  76 */
  77#define RTC_STAT_BIT_A1F        0x1     /* Alarm 1 flag                 */
  78#define RTC_STAT_BIT_A2F        0x2     /* Alarm 2 flag                 */
  79#define RTC_STAT_BIT_OSF        0x80    /* Oscillator stop flag         */
  80
  81
  82static uchar rtc_read (uchar reg);
  83static void rtc_write (uchar reg, uchar val);
  84
  85/*
  86 * Get the current time from the RTC
  87 */
  88int rtc_get (struct rtc_time *tmp)
  89{
  90        int rel = 0;
  91        uchar sec, min, hour, mday, wday, mon_cent, year, control, status;
  92
  93        control = rtc_read (RTC_CTL_REG_ADDR);
  94        status = rtc_read (RTC_STAT_REG_ADDR);
  95        sec = rtc_read (RTC_SEC_REG_ADDR);
  96        min = rtc_read (RTC_MIN_REG_ADDR);
  97        hour = rtc_read (RTC_HR_REG_ADDR);
  98        wday = rtc_read (RTC_DAY_REG_ADDR);
  99        mday = rtc_read (RTC_DATE_REG_ADDR);
 100        mon_cent = rtc_read (RTC_MON_REG_ADDR);
 101        year = rtc_read (RTC_YR_REG_ADDR);
 102
 103        /* No century bit, assume year 2000 */
 104#ifdef CONFIG_RTC_DS1388
 105        mon_cent |= 0x80;
 106#endif
 107
 108        debug("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
 109                "hr: %02x min: %02x sec: %02x control: %02x status: %02x\n",
 110                year, mon_cent, mday, wday, hour, min, sec, control, status);
 111
 112        if (status & RTC_STAT_BIT_OSF) {
 113                printf ("### Warning: RTC oscillator has stopped\n");
 114                /* clear the OSF flag */
 115                rtc_write (RTC_STAT_REG_ADDR,
 116                           rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF);
 117                rel = -1;
 118        }
 119
 120        tmp->tm_sec  = bcd2bin (sec & 0x7F);
 121        tmp->tm_min  = bcd2bin (min & 0x7F);
 122        tmp->tm_hour = bcd2bin (hour & 0x3F);
 123        tmp->tm_mday = bcd2bin (mday & 0x3F);
 124        tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
 125        tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
 126        tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
 127        tmp->tm_yday = 0;
 128        tmp->tm_isdst= 0;
 129
 130        debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 131                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 132                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 133
 134        return rel;
 135}
 136
 137
 138/*
 139 * Set the RTC
 140 */
 141int rtc_set (struct rtc_time *tmp)
 142{
 143        uchar century;
 144
 145        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 146                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 147                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 148
 149        rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
 150
 151        century = (tmp->tm_year >= 2000) ? 0x80 : 0;
 152        rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century);
 153
 154        rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
 155        rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
 156        rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
 157        rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
 158        rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
 159
 160        return 0;
 161}
 162
 163
 164/*
 165 * Reset the RTC.  We also enable the oscillator output on the
 166 * SQW/INTB* pin and program it for 32,768 Hz output. Note that
 167 * according to the datasheet, turning on the square wave output
 168 * increases the current drain on the backup battery from about
 169 * 600 nA to 2uA. Define CONFIG_SYS_RTC_DS1337_NOOSC if you wish to turn
 170 * off the OSC output.
 171 */
 172
 173#ifdef CONFIG_SYS_RTC_DS1337_NOOSC
 174 #define RTC_DS1337_RESET_VAL \
 175        (RTC_CTL_BIT_INTCN | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2)
 176#else
 177 #define RTC_DS1337_RESET_VAL (RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2)
 178#endif
 179void rtc_reset (void)
 180{
 181#ifdef CONFIG_SYS_RTC_DS1337
 182        rtc_write (RTC_CTL_REG_ADDR, RTC_DS1337_RESET_VAL);
 183#elif defined CONFIG_SYS_RTC_DS1388
 184        rtc_write(RTC_CTL_REG_ADDR, 0x0); /* hw default */
 185#endif
 186#ifdef CONFIG_SYS_DS1339_TCR_VAL
 187        rtc_write (RTC_TC_REG_ADDR, CONFIG_SYS_DS1339_TCR_VAL);
 188#endif
 189#ifdef CONFIG_SYS_DS1388_TCR_VAL
 190        rtc_write(RTC_TC_REG_ADDR, CONFIG_SYS_DS1388_TCR_VAL);
 191#endif
 192}
 193
 194
 195/*
 196 * Helper functions
 197 */
 198
 199static
 200uchar rtc_read (uchar reg)
 201{
 202        return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
 203}
 204
 205
 206static void rtc_write (uchar reg, uchar val)
 207{
 208        i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 209}
 210
 211#endif
 212