LXR uboot/drivers/rtc/isl1208.c

   1/*
   2 * (C) Copyright 2008
   3 * Tor Krill, Excito Elektronik i Skåne , tor@excito.com
   4 *
   5 * Modelled after the ds1337 driver
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License as
   9 * published by the Free Software Foundation; either version 2 of
  10 * the License, or (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20 * MA 02111-1307 USA
  21 */
  22
  23/*
  24 * Date & Time support (no alarms) for Intersil
  25 * ISL1208 Real Time Clock (RTC).
  26 */
  27
  28#include <common.h>
  29#include <command.h>
  30#include <rtc.h>
  31#include <i2c.h>
  32
  33/*---------------------------------------------------------------------*/
  34#ifdef DEBUG_RTC
  35#define DEBUGR(fmt,args...) printf(fmt ,##args)
  36#else
  37#define DEBUGR(fmt,args...)
  38#endif
  39/*---------------------------------------------------------------------*/
  40
  41/*
  42 * RTC register addresses
  43 */
  44
  45#define RTC_SEC_REG_ADDR        0x0
  46#define RTC_MIN_REG_ADDR        0x1
  47#define RTC_HR_REG_ADDR         0x2
  48#define RTC_DATE_REG_ADDR       0x3
  49#define RTC_MON_REG_ADDR        0x4
  50#define RTC_YR_REG_ADDR         0x5
  51#define RTC_DAY_REG_ADDR        0x6
  52#define RTC_STAT_REG_ADDR       0x7
  53/*
  54 * RTC control register bits
  55 */
  56
  57/*
  58 * RTC status register bits
  59 */
  60#define RTC_STAT_BIT_ARST       0x80    /* AUTO RESET ENABLE BIT */
  61#define RTC_STAT_BIT_XTOSCB     0x40    /* CRYSTAL OSCILLATOR ENABLE BIT */
  62#define RTC_STAT_BIT_WRTC       0x10    /* WRITE RTC ENABLE BIT */
  63#define RTC_STAT_BIT_ALM        0x04    /* ALARM BIT */
  64#define RTC_STAT_BIT_BAT        0x02    /* BATTERY BIT */
  65#define RTC_STAT_BIT_RTCF       0x01    /* REAL TIME CLOCK FAIL BIT */
  66
  67static uchar rtc_read (uchar reg);
  68static void rtc_write (uchar reg, uchar val);
  69
  70/*
  71 * Get the current time from the RTC
  72 */
  73
  74int rtc_get (struct rtc_time *tmp)
  75{
  76        int rel = 0;
  77        uchar sec, min, hour, mday, wday, mon, year, status;
  78
  79        status = rtc_read (RTC_STAT_REG_ADDR);
  80        sec = rtc_read (RTC_SEC_REG_ADDR);
  81        min = rtc_read (RTC_MIN_REG_ADDR);
  82        hour = rtc_read (RTC_HR_REG_ADDR);
  83        wday = rtc_read (RTC_DAY_REG_ADDR);
  84        mday = rtc_read (RTC_DATE_REG_ADDR);
  85        mon = rtc_read (RTC_MON_REG_ADDR);
  86        year = rtc_read (RTC_YR_REG_ADDR);
  87
  88        DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  89                "hr: %02x min: %02x sec: %02x status: %02x\n",
  90                year, mon, mday, wday, hour, min, sec, status);
  91
  92        if (status & RTC_STAT_BIT_RTCF) {
  93                printf ("### Warning: RTC oscillator has stopped\n");
  94                rtc_write(RTC_STAT_REG_ADDR,
  95                        rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF));
  96                rel = -1;
  97        }
  98
  99        tmp->tm_sec  = bcd2bin (sec & 0x7F);
 100        tmp->tm_min  = bcd2bin (min & 0x7F);
 101        tmp->tm_hour = bcd2bin (hour & 0x3F);
 102        tmp->tm_mday = bcd2bin (mday & 0x3F);
 103        tmp->tm_mon  = bcd2bin (mon & 0x1F);
 104        tmp->tm_year = bcd2bin (year)+2000;
 105        tmp->tm_wday = bcd2bin (wday & 0x07);
 106        tmp->tm_yday = 0;
 107        tmp->tm_isdst= 0;
 108
 109        DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 110                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 111                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 112
 113        return rel;
 114}
 115
 116/*
 117 * Set the RTC
 118 */
 119int rtc_set (struct rtc_time *tmp)
 120{
 121        DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 122                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 123                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 124
 125        /* enable write */
 126        rtc_write(RTC_STAT_REG_ADDR,
 127                rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC);
 128
 129        rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
 130        rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
 131        rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
 132        rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
 133        rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour) | 0x80 ); /* 24h clock */
 134        rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
 135        rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
 136
 137        /* disable write */
 138        rtc_write(RTC_STAT_REG_ADDR,
 139                rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC);
 140
 141        return 0;
 142}
 143
 144void rtc_reset (void)
 145{
 146}
 147
 148/*
 149 * Helper functions
 150 */
 151
 152static uchar rtc_read (uchar reg)
 153{
 154        return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
 155}
 156
 157static void rtc_write (uchar reg, uchar val)
 158{
 159        i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 160}
 161