LXR uboot/drivers/rtc/ds1374.c

   1/*
   2 * (C) Copyright 2001, 2002, 2003
   3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4 * Keith Outwater, keith_outwater@mvis.com`
   5 * Steven Scholz, steven.scholz@imc-berlin.de
   6 *
   7 * See file CREDITS for list of people who contributed to this
   8 * project.
   9 *
  10 * This program is free software; you can redistribute it and/or
  11 * modify it under the terms of the GNU General Public License as
  12 * published by the Free Software Foundation; either version 2 of
  13 * the License, or (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  23 * MA 02111-1307 USA
  24 */
  25
  26/*
  27 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
  28 * DS1374 Real Time Clock (RTC).
  29 *
  30 * based on ds1337.c
  31 */
  32
  33#include <common.h>
  34#include <command.h>
  35#include <rtc.h>
  36#include <i2c.h>
  37
  38#if defined(CONFIG_CMD_DATE)
  39
  40/*---------------------------------------------------------------------*/
  41#undef DEBUG_RTC
  42#define DEBUG_RTC
  43
  44#ifdef DEBUG_RTC
  45#define DEBUGR(fmt,args...) printf(fmt ,##args)
  46#else
  47#define DEBUGR(fmt,args...)
  48#endif
  49/*---------------------------------------------------------------------*/
  50
  51#ifndef CONFIG_SYS_I2C_RTC_ADDR
  52# define CONFIG_SYS_I2C_RTC_ADDR        0x68
  53#endif
  54
  55#if defined(CONFIG_RTC_DS1374) && (CONFIG_SYS_I2C_SPEED > 400000)
  56# error The DS1374 is specified up to 400kHz in fast mode!
  57#endif
  58
  59/*
  60 * RTC register addresses
  61 */
  62#define RTC_TOD_CNT_BYTE0_ADDR          0x00 /* TimeOfDay */
  63#define RTC_TOD_CNT_BYTE1_ADDR          0x01
  64#define RTC_TOD_CNT_BYTE2_ADDR          0x02
  65#define RTC_TOD_CNT_BYTE3_ADDR          0x03
  66
  67#define RTC_WD_ALM_CNT_BYTE0_ADDR       0x04
  68#define RTC_WD_ALM_CNT_BYTE1_ADDR       0x05
  69#define RTC_WD_ALM_CNT_BYTE2_ADDR       0x06
  70
  71#define RTC_CTL_ADDR                    0x07 /* RTC-CoNTrol-register */
  72#define RTC_SR_ADDR                     0x08 /* RTC-StatusRegister */
  73#define RTC_TCS_DS_ADDR                 0x09 /* RTC-TrickleChargeSelect DiodeSelect-register */
  74
  75#define RTC_CTL_BIT_AIE                 (1<<0) /* Bit 0 - Alarm Interrupt enable */
  76#define RTC_CTL_BIT_RS1                 (1<<1) /* Bit 1/2 - Rate Select square wave output */
  77#define RTC_CTL_BIT_RS2                 (1<<2) /* Bit 2/2 - Rate Select square wave output */
  78#define RTC_CTL_BIT_WDSTR               (1<<3) /* Bit 3 - Watchdog Reset Steering */
  79#define RTC_CTL_BIT_BBSQW               (1<<4) /* Bit 4 - Battery-Backed Square-Wave */
  80#define RTC_CTL_BIT_WD_ALM              (1<<5) /* Bit 5 - Watchdoc/Alarm Counter Select */
  81#define RTC_CTL_BIT_WACE                (1<<6) /* Bit 6 - Watchdog/Alarm Counter Enable WACE*/
  82#define RTC_CTL_BIT_EN_OSC              (1<<7) /* Bit 7 - Enable Oscilator */
  83
  84#define RTC_SR_BIT_AF                   0x01 /* Bit 0 = Alarm Flag */
  85#define RTC_SR_BIT_OSF                  0x80 /* Bit 7 - Osc Stop Flag */
  86
  87typedef unsigned char boolean_t;
  88
  89#ifndef TRUE
  90#define TRUE ((boolean_t)(0==0))
  91#endif
  92#ifndef FALSE
  93#define FALSE (!TRUE)
  94#endif
  95
  96const char RtcTodAddr[] = {
  97        RTC_TOD_CNT_BYTE0_ADDR,
  98        RTC_TOD_CNT_BYTE1_ADDR,
  99        RTC_TOD_CNT_BYTE2_ADDR,
 100        RTC_TOD_CNT_BYTE3_ADDR
 101};
 102
 103static uchar rtc_read (uchar reg);
 104static void rtc_write (uchar reg, uchar val, boolean_t set);
 105static void rtc_write_raw (uchar reg, uchar val);
 106
 107/*
 108 * Get the current time from the RTC
 109 */
 110int rtc_get (struct rtc_time *tm){
 111        int rel = 0;
 112        unsigned long time1, time2;
 113        unsigned int limit;
 114        unsigned char tmp;
 115        unsigned int i;
 116
 117        /*
 118         * Since the reads are being performed one byte at a time,
 119         * there is a chance that a carry will occur during the read.
 120         * To detect this, 2 reads are performed and compared.
 121         */
 122        limit = 10;
 123        do {
 124                i = 4;
 125                time1 = 0;
 126                while (i--) {
 127                        tmp = rtc_read(RtcTodAddr[i]);
 128                        time1 = (time1 << 8) | (tmp & 0xff);
 129                }
 130
 131                i = 4;
 132                time2 = 0;
 133                while (i--) {
 134                        tmp = rtc_read(RtcTodAddr[i]);
 135                        time2 = (time2 << 8) | (tmp & 0xff);
 136                }
 137        } while ((time1 != time2) && limit--);
 138
 139        if (time1 != time2) {
 140                printf("can't get consistent time from rtc chip\n");
 141                rel = -1;
 142        }
 143
 144        DEBUGR ("Get RTC s since 1.1.1970: %ld\n", time1);
 145
 146        to_tm(time1, tm); /* To Gregorian Date */
 147
 148        if (rtc_read(RTC_SR_ADDR) & RTC_SR_BIT_OSF) {
 149                printf ("### Warning: RTC oscillator has stopped\n");
 150                rel = -1;
 151        }
 152
 153        DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 154                tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
 155                tm->tm_hour, tm->tm_min, tm->tm_sec);
 156
 157        return rel;
 158}
 159
 160/*
 161 * Set the RTC
 162 */
 163int rtc_set (struct rtc_time *tmp){
 164
 165        unsigned long time;
 166        unsigned i;
 167
 168        DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 169                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 170                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 171
 172        if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
 173                printf("WARNING: year should be between 1970 and 2069!\n");
 174
 175        time = mktime(tmp->tm_year, tmp->tm_mon,
 176                        tmp->tm_mday, tmp->tm_hour,
 177                        tmp->tm_min, tmp->tm_sec);
 178
 179        DEBUGR ("Set RTC s since 1.1.1970: %ld (0x%02lx)\n", time, time);
 180
 181        /* write to RTC_TOD_CNT_BYTEn_ADDR */
 182        for (i = 0; i <= 3; i++) {
 183                rtc_write_raw(RtcTodAddr[i], (unsigned char)(time & 0xff));
 184                time = time >> 8;
 185        }
 186
 187        /* Start clock */
 188        rtc_write(RTC_CTL_ADDR, RTC_CTL_BIT_EN_OSC, FALSE);
 189
 190        return 0;
 191}
 192
 193/*
 194 * Reset the RTC. We setting the date back to 1970-01-01.
 195 * We also enable the oscillator output on the SQW/OUT pin and program
 196 * it for 32,768 Hz output. Note that according to the datasheet, turning
 197 * on the square wave output increases the current drain on the backup
 198 * battery to something between 480nA and 800nA.
 199 */
 200void rtc_reset (void){
 201
 202        struct rtc_time tmp;
 203
 204        /* clear status flags */
 205        rtc_write (RTC_SR_ADDR, (RTC_SR_BIT_AF|RTC_SR_BIT_OSF), FALSE); /* clearing OSF and AF */
 206
 207        /* Initialise DS1374 oriented to MPC8349E-ADS */
 208        rtc_write (RTC_CTL_ADDR, (RTC_CTL_BIT_EN_OSC
 209                                 |RTC_CTL_BIT_WACE
 210                                 |RTC_CTL_BIT_AIE), FALSE);/* start osc, disable WACE, clear AIE
 211                                                              - set to 0 */
 212        rtc_write (RTC_CTL_ADDR, (RTC_CTL_BIT_WD_ALM
 213                                |RTC_CTL_BIT_WDSTR
 214                                |RTC_CTL_BIT_RS1
 215                                |RTC_CTL_BIT_RS2
 216                                |RTC_CTL_BIT_BBSQW), TRUE);/* disable WD/ALM, WDSTR set to INT-pin,
 217                                                              set BBSQW and SQW to 32k
 218                                                              - set to 1 */
 219        tmp.tm_year = 1970;
 220        tmp.tm_mon = 1;
 221        tmp.tm_mday= 1;
 222        tmp.tm_hour = 0;
 223        tmp.tm_min = 0;
 224        tmp.tm_sec = 0;
 225
 226        rtc_set(&tmp);
 227
 228        printf("RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
 229                tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
 230                tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
 231
 232        rtc_write(RTC_WD_ALM_CNT_BYTE2_ADDR,0xAC, TRUE);
 233        rtc_write(RTC_WD_ALM_CNT_BYTE1_ADDR,0xDE, TRUE);
 234        rtc_write(RTC_WD_ALM_CNT_BYTE2_ADDR,0xAD, TRUE);
 235}
 236
 237/*
 238 * Helper functions
 239 */
 240static uchar rtc_read (uchar reg)
 241{
 242        return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
 243}
 244
 245static void rtc_write (uchar reg, uchar val, boolean_t set)
 246{
 247        if (set == TRUE) {
 248                val |= i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg);
 249                i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 250        } else {
 251                val = i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg) & ~val;
 252                i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 253        }
 254}
 255
 256static void rtc_write_raw (uchar reg, uchar val)
 257{
 258                i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 259}
 260#endif
 261