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
  82 static uchar rtc_read (uchar reg);
  83 static void rtc_write (uchar reg, uchar val);
  84
  85 /*
  86  * Get the current time from the RTC
  87  */
  88 int 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  */
 141 int 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
 179 void 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
 199 static
 200 uchar rtc_read (uchar reg)
 201 {
 202         return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
 203 }
 204
 205
 206 static void rtc_write (uchar reg, uchar val)
 207 {
 208         i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 209 }
 210
 211 #endif