1 /* 2 * (C) Copyright 2008 3 * Tor Krill, Excito Elektronik i Skåne , tor@excito.com 4 * 5 * Modelled after the ds1337 driver 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 /* 11 * Date & Time support (no alarms) for Intersil 12 * ISL1208 Real Time Clock (RTC). 13 */ 14 15 #include <common.h> 16 #include <command.h> 17 #include <rtc.h> 18 #include <i2c.h> 19 20 /*---------------------------------------------------------------------*/ 21 #ifdef DEBUG_RTC 22 #define DEBUGR(fmt,args...) printf(fmt ,##args) 23 #else 24 #define DEBUGR(fmt,args...) 25 #endif 26 /*---------------------------------------------------------------------*/ 27 28 /* 29 * RTC register addresses 30 */ 31 32 #define RTC_SEC_REG_ADDR 0x0 33 #define RTC_MIN_REG_ADDR 0x1 34 #define RTC_HR_REG_ADDR 0x2 35 #define RTC_DATE_REG_ADDR 0x3 36 #define RTC_MON_REG_ADDR 0x4 37 #define RTC_YR_REG_ADDR 0x5 38 #define RTC_DAY_REG_ADDR 0x6 39 #define RTC_STAT_REG_ADDR 0x7 40 /* 41 * RTC control register bits 42 */ 43 44 /* 45 * RTC status register bits 46 */ 47 #define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */ 48 #define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */ 49 #define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */ 50 #define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */ 51 #define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */ 52 #define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */ 53 54 static uchar rtc_read (uchar reg); 55 static void rtc_write (uchar reg, uchar val); 56 57 /* 58 * Get the current time from the RTC 59 */ 60 61 int rtc_get (struct rtc_time *tmp) 62 { 63 int rel = 0; 64 uchar sec, min, hour, mday, wday, mon, year, status; 65 66 status = rtc_read (RTC_STAT_REG_ADDR); 67 sec = rtc_read (RTC_SEC_REG_ADDR); 68 min = rtc_read (RTC_MIN_REG_ADDR); 69 hour = rtc_read (RTC_HR_REG_ADDR); 70 wday = rtc_read (RTC_DAY_REG_ADDR); 71 mday = rtc_read (RTC_DATE_REG_ADDR); 72 mon = rtc_read (RTC_MON_REG_ADDR); 73 year = rtc_read (RTC_YR_REG_ADDR); 74 75 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 76 "hr: %02x min: %02x sec: %02x status: %02x\n", 77 year, mon, mday, wday, hour, min, sec, status); 78 79 if (status & RTC_STAT_BIT_RTCF) { 80 printf ("### Warning: RTC oscillator has stopped\n"); 81 rtc_write(RTC_STAT_REG_ADDR, 82 rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF)); 83 rel = -1; 84 } 85 86 tmp->tm_sec = bcd2bin (sec & 0x7F); 87 tmp->tm_min = bcd2bin (min & 0x7F); 88 tmp->tm_hour = bcd2bin (hour & 0x3F); 89 tmp->tm_mday = bcd2bin (mday & 0x3F); 90 tmp->tm_mon = bcd2bin (mon & 0x1F); 91 tmp->tm_year = bcd2bin (year)+2000; 92 tmp->tm_wday = bcd2bin (wday & 0x07); 93 tmp->tm_yday = 0; 94 tmp->tm_isdst= 0; 95 96 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 97 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 98 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 99 100 return rel; 101 } 102 103 /* 104 * Set the RTC 105 */ 106 int rtc_set (struct rtc_time *tmp) 107 { 108 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 109 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 110 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 111 112 /* enable write */ 113 rtc_write(RTC_STAT_REG_ADDR, 114 rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC); 115 116 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 117 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 118 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday)); 119 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 120 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour) | 0x80 ); /* 24h clock */ 121 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 122 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 123 124 /* disable write */ 125 rtc_write(RTC_STAT_REG_ADDR, 126 rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC); 127 128 return 0; 129 } 130 131 void rtc_reset (void) 132 { 133 } 134 135 /* 136 * Helper functions 137 */ 138 139 static uchar rtc_read (uchar reg) 140 { 141 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 142 } 143 144 static void rtc_write (uchar reg, uchar val) 145 { 146 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 147 } 148