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 136