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#include <bcd.h>
  35
  36#if defined(CONFIG_CMD_DATE)
  37
  38#define M41T62_REG_SSEC 0
  39#define M41T62_REG_SEC  1
  40#define M41T62_REG_MIN  2
  41#define M41T62_REG_HOUR 3
  42#define M41T62_REG_WDAY 4
  43#define M41T62_REG_DAY  5
  44#define M41T62_REG_MON  6
  45#define M41T62_REG_YEAR 7
  46#define M41T62_REG_ALARM_MON    0xa
  47#define M41T62_REG_ALARM_DAY    0xb
  48#define M41T62_REG_ALARM_HOUR   0xc
  49#define M41T62_REG_ALARM_MIN    0xd
  50#define M41T62_REG_ALARM_SEC    0xe
  51#define M41T62_REG_FLAGS        0xf
  52
  53#define M41T62_DATETIME_REG_SIZE        (M41T62_REG_YEAR + 1)
  54#define M41T62_ALARM_REG_SIZE   \
  55        (M41T62_REG_ALARM_SEC + 1 - M41T62_REG_ALARM_MON)
  56
  57#define M41T62_SEC_ST           (1 << 7)        /* ST: Stop Bit */
  58#define M41T62_ALMON_AFE        (1 << 7)        /* AFE: AF Enable Bit */
  59#define M41T62_ALMON_SQWE       (1 << 6)        /* SQWE: SQW Enable Bit */
  60#define M41T62_ALHOUR_HT        (1 << 6)        /* HT: Halt Update Bit */
  61#define M41T62_FLAGS_AF         (1 << 6)        /* AF: Alarm Flag Bit */
  62#define M41T62_FLAGS_BATT_LOW   (1 << 4)        /* BL: Battery Low Bit */
  63
  64#define M41T62_FEATURE_HT       (1 << 0)
  65#define M41T62_FEATURE_BL       (1 << 1)
  66
  67int rtc_get(struct rtc_time *tm)
  68{
  69        u8 buf[M41T62_DATETIME_REG_SIZE];
  70
  71        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
  72
  73        debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
  74              "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
  75              __FUNCTION__,
  76              buf[0], buf[1], buf[2], buf[3],
  77              buf[4], buf[5], buf[6], buf[7]);
  78
  79        tm->tm_sec = BCD2BIN(buf[M41T62_REG_SEC] & 0x7f);
  80        tm->tm_min = BCD2BIN(buf[M41T62_REG_MIN] & 0x7f);
  81        tm->tm_hour = BCD2BIN(buf[M41T62_REG_HOUR] & 0x3f);
  82        tm->tm_mday = BCD2BIN(buf[M41T62_REG_DAY] & 0x3f);
  83        tm->tm_wday = buf[M41T62_REG_WDAY] & 0x07;
  84        tm->tm_mon = BCD2BIN(buf[M41T62_REG_MON] & 0x1f);
  85
  86        /* assume 20YY not 19YY, and ignore the Century Bit */
  87        /* U-Boot needs to add 1900 here */
  88        tm->tm_year = BCD2BIN(buf[M41T62_REG_YEAR]) + 100 + 1900;
  89
  90        debug("%s: tm is secs=%d, mins=%d, hours=%d, "
  91              "mday=%d, mon=%d, year=%d, wday=%d\n",
  92              __FUNCTION__,
  93              tm->tm_sec, tm->tm_min, tm->tm_hour,
  94              tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
  95
  96        return 0;
  97}
  98
  99int rtc_set(struct rtc_time *tm)
 100{
 101        u8 buf[M41T62_DATETIME_REG_SIZE];
 102
 103        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 104              tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
 105              tm->tm_hour, tm->tm_min, tm->tm_sec);
 106
 107        i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
 108
 109        /* Merge time-data and register flags into buf[0..7] */
 110        buf[M41T62_REG_SSEC] = 0;
 111        buf[M41T62_REG_SEC] =
 112                BIN2BCD(tm->tm_sec) | (buf[M41T62_REG_SEC] & ~0x7f);
 113        buf[M41T62_REG_MIN] =
 114                BIN2BCD(tm->tm_min) | (buf[M41T62_REG_MIN] & ~0x7f);
 115        buf[M41T62_REG_HOUR] =
 116                BIN2BCD(tm->tm_hour) | (buf[M41T62_REG_HOUR] & ~0x3f) ;
 117        buf[M41T62_REG_WDAY] =
 118                (tm->tm_wday & 0x07) | (buf[M41T62_REG_WDAY] & ~0x07);
 119        buf[M41T62_REG_DAY] =
 120                BIN2BCD(tm->tm_mday) | (buf[M41T62_REG_DAY] & ~0x3f);
 121        buf[M41T62_REG_MON] =
 122                BIN2BCD(tm->tm_mon) | (buf[M41T62_REG_MON] & ~0x1f);
 123        /* assume 20YY not 19YY */
 124        buf[M41T62_REG_YEAR] = BIN2BCD(tm->tm_year % 100);
 125
 126        if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE)) {
 127                printf("I2C write failed in %s()\n", __func__);
 128                return -1;
 129        }
 130
 131        return 0;
 132}
 133
 134void rtc_reset(void)
 135{
 136        /*
 137         * Nothing to do
 138         */
 139}
 140
 141#endif
 142