LXR uboot/drivers/rtc/m41t62.c

   1/*
   2 * (C) Copyright 2008
   3 * Stefan Roese, DENX Software Engineering, sr@denx.de.
   4 *
   5 * based on a the Linux rtc-m41t80.c driver which is:
   6 *   Alexander Bigga <ab@mycable.de>, 2006 (c) mycable GmbH
   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 STMicroelectronics M41T62
  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#define M41T62_REG_SSEC 0
  38#define M41T62_REG_SEC  1
  39#define M41T62_REG_MIN  2
  40#define M41T62_REG_HOUR 3
  41#define M41T62_REG_WDAY 4
  42#define M41T62_REG_DAY  5
  43#define M41T62_REG_MON  6
  44#define M41T62_REG_YEAR 7
  45#define M41T62_REG_ALARM_MON    0xa
  46#define M41T62_REG_ALARM_DAY    0xb
  47#define M41T62_REG_ALARM_HOUR   0xc
  48#define M41T62_REG_ALARM_MIN    0xd
  49#define M41T62_REG_ALARM_SEC    0xe
  50#define M41T62_REG_FLAGS        0xf
  51
  52#define M41T62_DATETIME_REG_SIZE        (M41T62_REG_YEAR + 1)
  53#define M41T62_ALARM_REG_SIZE   \
  54        (M41T62_REG_ALARM_SEC + 1 - M41T62_REG_ALARM_MON)
  55
  56#define M41T62_SEC_ST           (1 << 7)        /* ST: Stop Bit */
  57#define M41T62_ALMON_AFE        (1 << 7)        /* AFE: AF Enable Bit */
  58#define M41T62_ALMON_SQWE       (1 << 6)        /* SQWE: SQW Enable Bit */
  59#define M41T62_ALHOUR_HT        (1 << 6)        /* HT: Halt Update Bit */
  60#define M41T62_FLAGS_AF         (1 << 6)        /* AF: Alarm Flag Bit */
  61#define M41T62_FLAGS_BATT_LOW   (1 << 4)        /* BL: Battery Low Bit */
  62
  63#define M41T62_FEATURE_HT       (1 << 0)
  64#define M41T62_FEATURE_BL       (1 << 1)
  65
  66#define M41T80_ALHOUR_HT        (1 << 6)        /* HT: Halt Update Bit */
  67
  68int rtc_get(struct rtc_time *tm)
  69{
  70        u8 buf[M41T62_DATETIME_REG_SIZE];
  71
  72        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
  73
  74        debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
  75              "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
  76              __FUNCTION__,
  77              buf[0], buf[1], buf[2], buf[3],
  78              buf[4], buf[5], buf[6], buf[7]);
  79
  80        tm->tm_sec = bcd2bin(buf[M41T62_REG_SEC] & 0x7f);
  81        tm->tm_min = bcd2bin(buf[M41T62_REG_MIN] & 0x7f);
  82        tm->tm_hour = bcd2bin(buf[M41T62_REG_HOUR] & 0x3f);
  83        tm->tm_mday = bcd2bin(buf[M41T62_REG_DAY] & 0x3f);
  84        tm->tm_wday = buf[M41T62_REG_WDAY] & 0x07;
  85        tm->tm_mon = bcd2bin(buf[M41T62_REG_MON] & 0x1f);
  86
  87        /* assume 20YY not 19YY, and ignore the Century Bit */
  88        /* U-Boot needs to add 1900 here */
  89        tm->tm_year = bcd2bin(buf[M41T62_REG_YEAR]) + 100 + 1900;
  90
  91        debug("%s: tm is secs=%d, mins=%d, hours=%d, "
  92              "mday=%d, mon=%d, year=%d, wday=%d\n",
  93              __FUNCTION__,
  94              tm->tm_sec, tm->tm_min, tm->tm_hour,
  95              tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
  96
  97        return 0;
  98}
  99
 100int rtc_set(struct rtc_time *tm)
 101{
 102        u8 buf[M41T62_DATETIME_REG_SIZE];
 103
 104        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 105              tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
 106              tm->tm_hour, tm->tm_min, tm->tm_sec);
 107
 108        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
 109
 110        /* Merge time-data and register flags into buf[0..7] */
 111        buf[M41T62_REG_SSEC] = 0;
 112        buf[M41T62_REG_SEC] =
 113                bin2bcd(tm->tm_sec) | (buf[M41T62_REG_SEC] & ~0x7f);
 114        buf[M41T62_REG_MIN] =
 115                bin2bcd(tm->tm_min) | (buf[M41T62_REG_MIN] & ~0x7f);
 116        buf[M41T62_REG_HOUR] =
 117                bin2bcd(tm->tm_hour) | (buf[M41T62_REG_HOUR] & ~0x3f) ;
 118        buf[M41T62_REG_WDAY] =
 119                (tm->tm_wday & 0x07) | (buf[M41T62_REG_WDAY] & ~0x07);
 120        buf[M41T62_REG_DAY] =
 121                bin2bcd(tm->tm_mday) | (buf[M41T62_REG_DAY] & ~0x3f);
 122        buf[M41T62_REG_MON] =
 123                bin2bcd(tm->tm_mon) | (buf[M41T62_REG_MON] & ~0x1f);
 124        /* assume 20YY not 19YY */
 125        buf[M41T62_REG_YEAR] = bin2bcd(tm->tm_year % 100);
 126
 127        if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE)) {
 128                printf("I2C write failed in %s()\n", __func__);
 129                return -1;
 130        }
 131
 132        return 0;
 133}
 134
 135void rtc_reset(void)
 136{
 137        u8 val;
 138
 139        /*
 140         * M41T82: Make sure HT (Halt Update) bit is cleared.
 141         * This bit is 0 in M41T62 so its save to clear it always.
 142         */
 143        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
 144        val &= ~M41T80_ALHOUR_HT;
 145        i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
 146}
 147
 148#endif
 149