1 /* 2 * (C) Copyright 2008 3 * Tor Krill, Excito Elektronik i Skåne , tor@excito.com 4 * 5 * Modelled after the ds1337 driver 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License as 9 * published by the Free Software Foundation; either version 2 of 10 * the License, or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 20 * MA 02111-1307 USA 21 */ 22 23 /* 24 * Date & Time support (no alarms) for Intersil 25 * ISL1208 Real Time Clock (RTC). 26 */ 27 28 #include <common.h> 29 #include <command.h> 30 #include <rtc.h> 31 #include <i2c.h> 32 33 /*---------------------------------------------------------------------*/ 34 #ifdef DEBUG_RTC 35 #define DEBUGR(fmt,args...) printf(fmt ,##args) 36 #else 37 #define DEBUGR(fmt,args...) 38 #endif 39 /*---------------------------------------------------------------------*/ 40 41 /* 42 * RTC register addresses 43 */ 44 45 #define RTC_SEC_REG_ADDR 0x0 46 #define RTC_MIN_REG_ADDR 0x1 47 #define RTC_HR_REG_ADDR 0x2 48 #define RTC_DATE_REG_ADDR 0x3 49 #define RTC_MON_REG_ADDR 0x4 50 #define RTC_YR_REG_ADDR 0x5 51 #define RTC_DAY_REG_ADDR 0x6 52 #define RTC_STAT_REG_ADDR 0x7 53 /* 54 * RTC control register bits 55 */ 56 57 /* 58 * RTC status register bits 59 */ 60 #define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */ 61 #define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */ 62 #define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */ 63 #define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */ 64 #define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */ 65 #define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */ 66 67 static uchar rtc_read (uchar reg); 68 static void rtc_write (uchar reg, uchar val); 69 70 /* 71 * Get the current time from the RTC 72 */ 73 74 int rtc_get (struct rtc_time *tmp) 75 { 76 int rel = 0; 77 uchar sec, min, hour, mday, wday, mon, year, status; 78 79 status = rtc_read (RTC_STAT_REG_ADDR); 80 sec = rtc_read (RTC_SEC_REG_ADDR); 81 min = rtc_read (RTC_MIN_REG_ADDR); 82 hour = rtc_read (RTC_HR_REG_ADDR); 83 wday = rtc_read (RTC_DAY_REG_ADDR); 84 mday = rtc_read (RTC_DATE_REG_ADDR); 85 mon = rtc_read (RTC_MON_REG_ADDR); 86 year = rtc_read (RTC_YR_REG_ADDR); 87 88 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 89 "hr: %02x min: %02x sec: %02x status: %02x\n", 90 year, mon, mday, wday, hour, min, sec, status); 91 92 if (status & RTC_STAT_BIT_RTCF) { 93 printf ("### Warning: RTC oscillator has stopped\n"); 94 rtc_write(RTC_STAT_REG_ADDR, 95 rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF)); 96 rel = -1; 97 } 98 99 tmp->tm_sec = bcd2bin (sec & 0x7F); 100 tmp->tm_min = bcd2bin (min & 0x7F); 101 tmp->tm_hour = bcd2bin (hour & 0x3F); 102 tmp->tm_mday = bcd2bin (mday & 0x3F); 103 tmp->tm_mon = bcd2bin (mon & 0x1F); 104 tmp->tm_year = bcd2bin (year)+2000; 105 tmp->tm_wday = bcd2bin (wday & 0x07); 106 tmp->tm_yday = 0; 107 tmp->tm_isdst= 0; 108 109 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 110 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 111 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 112 113 return rel; 114 } 115 116 /* 117 * Set the RTC 118 */ 119 int rtc_set (struct rtc_time *tmp) 120 { 121 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 122 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 123 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 124 125 /* enable write */ 126 rtc_write(RTC_STAT_REG_ADDR, 127 rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC); 128 129 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 130 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 131 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday)); 132 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 133 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour) | 0x80 ); /* 24h clock */ 134 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 135 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 136 137 /* disable write */ 138 rtc_write(RTC_STAT_REG_ADDR, 139 rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC); 140 141 return 0; 142 } 143 144 void rtc_reset (void) 145 { 146 } 147 148 /* 149 * Helper functions 150 */ 151 152 static uchar rtc_read (uchar reg) 153 { 154 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 155 } 156 157 static void rtc_write (uchar reg, uchar val) 158 { 159 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 160 } 161