1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2008 4 * Stefan Roese, DENX Software Engineering, sr@denx.de. 5 * 6 * based on a the Linux rtc-m41t80.c driver which is: 7 * Alexander Bigga <ab@mycable.de>, 2006 (c) mycable GmbH 8 */ 9 10 /* 11 * Date & Time support for STMicroelectronics M41T62 12 */ 13 14 /* #define DEBUG */ 15 16 #include <common.h> 17 #include <command.h> 18 #include <rtc.h> 19 #include <i2c.h> 20 21 #define M41T62_REG_SSEC 0 22 #define M41T62_REG_SEC 1 23 #define M41T62_REG_MIN 2 24 #define M41T62_REG_HOUR 3 25 #define M41T62_REG_WDAY 4 26 #define M41T62_REG_DAY 5 27 #define M41T62_REG_MON 6 28 #define M41T62_REG_YEAR 7 29 #define M41T62_REG_ALARM_MON 0xa 30 #define M41T62_REG_ALARM_DAY 0xb 31 #define M41T62_REG_ALARM_HOUR 0xc 32 #define M41T62_REG_ALARM_MIN 0xd 33 #define M41T62_REG_ALARM_SEC 0xe 34 #define M41T62_REG_FLAGS 0xf 35 36 #define M41T62_DATETIME_REG_SIZE (M41T62_REG_YEAR + 1) 37 #define M41T62_ALARM_REG_SIZE \ 38 (M41T62_REG_ALARM_SEC + 1 - M41T62_REG_ALARM_MON) 39 40 #define M41T62_SEC_ST (1 << 7) /* ST: Stop Bit */ 41 #define M41T62_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */ 42 #define M41T62_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */ 43 #define M41T62_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */ 44 #define M41T62_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */ 45 #define M41T62_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */ 46 47 #define M41T62_FEATURE_HT (1 << 0) 48 #define M41T62_FEATURE_BL (1 << 1) 49 50 #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */ 51 52 int rtc_get(struct rtc_time *tm) 53 { 54 u8 buf[M41T62_DATETIME_REG_SIZE]; 55 56 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE); 57 58 debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, " 59 "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n", 60 __FUNCTION__, 61 buf[0], buf[1], buf[2], buf[3], 62 buf[4], buf[5], buf[6], buf[7]); 63 64 tm->tm_sec = bcd2bin(buf[M41T62_REG_SEC] & 0x7f); 65 tm->tm_min = bcd2bin(buf[M41T62_REG_MIN] & 0x7f); 66 tm->tm_hour = bcd2bin(buf[M41T62_REG_HOUR] & 0x3f); 67 tm->tm_mday = bcd2bin(buf[M41T62_REG_DAY] & 0x3f); 68 tm->tm_wday = buf[M41T62_REG_WDAY] & 0x07; 69 tm->tm_mon = bcd2bin(buf[M41T62_REG_MON] & 0x1f); 70 71 /* assume 20YY not 19YY, and ignore the Century Bit */ 72 /* U-Boot needs to add 1900 here */ 73 tm->tm_year = bcd2bin(buf[M41T62_REG_YEAR]) + 100 + 1900; 74 75 debug("%s: tm is secs=%d, mins=%d, hours=%d, " 76 "mday=%d, mon=%d, year=%d, wday=%d\n", 77 __FUNCTION__, 78 tm->tm_sec, tm->tm_min, tm->tm_hour, 79 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 80 81 return 0; 82 } 83 84 int rtc_set(struct rtc_time *tm) 85 { 86 u8 buf[M41T62_DATETIME_REG_SIZE]; 87 88 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 89 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, 90 tm->tm_hour, tm->tm_min, tm->tm_sec); 91 92 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE); 93 94 /* Merge time-data and register flags into buf[0..7] */ 95 buf[M41T62_REG_SSEC] = 0; 96 buf[M41T62_REG_SEC] = 97 bin2bcd(tm->tm_sec) | (buf[M41T62_REG_SEC] & ~0x7f); 98 buf[M41T62_REG_MIN] = 99 bin2bcd(tm->tm_min) | (buf[M41T62_REG_MIN] & ~0x7f); 100 buf[M41T62_REG_HOUR] = 101 bin2bcd(tm->tm_hour) | (buf[M41T62_REG_HOUR] & ~0x3f) ; 102 buf[M41T62_REG_WDAY] = 103 (tm->tm_wday & 0x07) | (buf[M41T62_REG_WDAY] & ~0x07); 104 buf[M41T62_REG_DAY] = 105 bin2bcd(tm->tm_mday) | (buf[M41T62_REG_DAY] & ~0x3f); 106 buf[M41T62_REG_MON] = 107 bin2bcd(tm->tm_mon) | (buf[M41T62_REG_MON] & ~0x1f); 108 /* assume 20YY not 19YY */ 109 buf[M41T62_REG_YEAR] = bin2bcd(tm->tm_year % 100); 110 111 if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE)) { 112 printf("I2C write failed in %s()\n", __func__); 113 return -1; 114 } 115 116 return 0; 117 } 118 119 void rtc_reset(void) 120 { 121 u8 val; 122 123 /* 124 * M41T82: Make sure HT (Halt Update) bit is cleared. 125 * This bit is 0 in M41T62 so its save to clear it always. 126 */ 127 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1); 128 val &= ~M41T80_ALHOUR_HT; 129 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1); 130 } 131