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 * 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
  55int 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
  87int 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
 122void 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
 136