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  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 /*
  12  * Date & Time support for STMicroelectronics M41T62
  13  */
  14
  15 /* #define      DEBUG   */
  16
  17 #include <common.h>
  18 #include <command.h>
  19 #include <rtc.h>
  20 #include <i2c.h>
  21
  22 #if defined(CONFIG_CMD_DATE)
  23
  24 #define M41T62_REG_SSEC 0
  25 #define M41T62_REG_SEC  1
  26 #define M41T62_REG_MIN  2
  27 #define M41T62_REG_HOUR 3
  28 #define M41T62_REG_WDAY 4
  29 #define M41T62_REG_DAY  5
  30 #define M41T62_REG_MON  6
  31 #define M41T62_REG_YEAR 7
  32 #define M41T62_REG_ALARM_MON    0xa
  33 #define M41T62_REG_ALARM_DAY    0xb
  34 #define M41T62_REG_ALARM_HOUR   0xc
  35 #define M41T62_REG_ALARM_MIN    0xd
  36 #define M41T62_REG_ALARM_SEC    0xe
  37 #define M41T62_REG_FLAGS        0xf
  38
  39 #define M41T62_DATETIME_REG_SIZE        (M41T62_REG_YEAR + 1)
  40 #define M41T62_ALARM_REG_SIZE   \
  41         (M41T62_REG_ALARM_SEC + 1 - M41T62_REG_ALARM_MON)
  42
  43 #define M41T62_SEC_ST           (1 << 7)        /* ST: Stop Bit */
  44 #define M41T62_ALMON_AFE        (1 << 7)        /* AFE: AF Enable Bit */
  45 #define M41T62_ALMON_SQWE       (1 << 6)        /* SQWE: SQW Enable Bit */
  46 #define M41T62_ALHOUR_HT        (1 << 6)        /* HT: Halt Update Bit */
  47 #define M41T62_FLAGS_AF         (1 << 6)        /* AF: Alarm Flag Bit */
  48 #define M41T62_FLAGS_BATT_LOW   (1 << 4)        /* BL: Battery Low Bit */
  49
  50 #define M41T62_FEATURE_HT       (1 << 0)
  51 #define M41T62_FEATURE_BL       (1 << 1)
  52
  53 #define M41T80_ALHOUR_HT        (1 << 6)        /* HT: Halt Update Bit */
  54
  55 int rtc_get(struct rtc_time *tm)
  56 {
  57         u8 buf[M41T62_DATETIME_REG_SIZE];
  58
  59         i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
  60
  61         debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
  62               "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
  63               __FUNCTION__,
  64               buf[0], buf[1], buf[2], buf[3],
  65               buf[4], buf[5], buf[6], buf[7]);
  66
  67         tm->tm_sec = bcd2bin(buf[M41T62_REG_SEC] & 0x7f);
  68         tm->tm_min = bcd2bin(buf[M41T62_REG_MIN] & 0x7f);
  69         tm->tm_hour = bcd2bin(buf[M41T62_REG_HOUR] & 0x3f);
  70         tm->tm_mday = bcd2bin(buf[M41T62_REG_DAY] & 0x3f);
  71         tm->tm_wday = buf[M41T62_REG_WDAY] & 0x07;
  72         tm->tm_mon = bcd2bin(buf[M41T62_REG_MON] & 0x1f);
  73
  74         /* assume 20YY not 19YY, and ignore the Century Bit */
  75         /* U-Boot needs to add 1900 here */
  76         tm->tm_year = bcd2bin(buf[M41T62_REG_YEAR]) + 100 + 1900;
  77
  78         debug("%s: tm is secs=%d, mins=%d, hours=%d, "
  79               "mday=%d, mon=%d, year=%d, wday=%d\n",
  80               __FUNCTION__,
  81               tm->tm_sec, tm->tm_min, tm->tm_hour,
  82               tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
  83
  84         return 0;
  85 }
  86
  87 int rtc_set(struct rtc_time *tm)
  88 {
  89         u8 buf[M41T62_DATETIME_REG_SIZE];
  90
  91         debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  92               tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  93               tm->tm_hour, tm->tm_min, tm->tm_sec);
  94
  95         i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
  96
  97         /* Merge time-data and register flags into buf[0..7] */
  98         buf[M41T62_REG_SSEC] = 0;
  99         buf[M41T62_REG_SEC] =
 100                 bin2bcd(tm->tm_sec) | (buf[M41T62_REG_SEC] & ~0x7f);
 101         buf[M41T62_REG_MIN] =
 102                 bin2bcd(tm->tm_min) | (buf[M41T62_REG_MIN] & ~0x7f);
 103         buf[M41T62_REG_HOUR] =
 104                 bin2bcd(tm->tm_hour) | (buf[M41T62_REG_HOUR] & ~0x3f) ;
 105         buf[M41T62_REG_WDAY] =
 106                 (tm->tm_wday & 0x07) | (buf[M41T62_REG_WDAY] & ~0x07);
 107         buf[M41T62_REG_DAY] =
 108                 bin2bcd(tm->tm_mday) | (buf[M41T62_REG_DAY] & ~0x3f);
 109         buf[M41T62_REG_MON] =
 110                 bin2bcd(tm->tm_mon) | (buf[M41T62_REG_MON] & ~0x1f);
 111         /* assume 20YY not 19YY */
 112         buf[M41T62_REG_YEAR] = bin2bcd(tm->tm_year % 100);
 113
 114         if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE)) {
 115                 printf("I2C write failed in %s()\n", __func__);
 116                 return -1;
 117         }
 118
 119         return 0;
 120 }
 121
 122 void rtc_reset(void)
 123 {
 124         u8 val;
 125
 126         /*
 127          * M41T82: Make sure HT (Halt Update) bit is cleared.
 128          * This bit is 0 in M41T62 so its save to clear it always.
 129          */
 130         i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
 131         val &= ~M41T80_ALHOUR_HT;
 132         i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
 133 }
 134
 135 #endif