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 static uchar bin2bcd (unsigned int n); 70 static unsigned bcd2bin (uchar c); 71 72 /* 73 * Get the current time from the RTC 74 */ 75 76 int rtc_get (struct rtc_time *tmp) 77 { 78 int rel = 0; 79 uchar sec, min, hour, mday, wday, mon, year, status; 80 81 status = rtc_read (RTC_STAT_REG_ADDR); 82 sec = rtc_read (RTC_SEC_REG_ADDR); 83 min = rtc_read (RTC_MIN_REG_ADDR); 84 hour = rtc_read (RTC_HR_REG_ADDR); 85 wday = rtc_read (RTC_DAY_REG_ADDR); 86 mday = rtc_read (RTC_DATE_REG_ADDR); 87 mon = rtc_read (RTC_MON_REG_ADDR); 88 year = rtc_read (RTC_YR_REG_ADDR); 89 90 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 91 "hr: %02x min: %02x sec: %02x status: %02x\n", 92 year, mon, mday, wday, hour, min, sec, status); 93 94 if (status & RTC_STAT_BIT_RTCF) { 95 printf ("### Warning: RTC oscillator has stopped\n"); 96 rtc_write(RTC_STAT_REG_ADDR, 97 rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF)); 98 rel = -1; 99 } 100 101 tmp->tm_sec = bcd2bin (sec & 0x7F); 102 tmp->tm_min = bcd2bin (min & 0x7F); 103 tmp->tm_hour = bcd2bin (hour & 0x3F); 104 tmp->tm_mday = bcd2bin (mday & 0x3F); 105 tmp->tm_mon = bcd2bin (mon & 0x1F); 106 tmp->tm_year = bcd2bin (year)+2000; 107 tmp->tm_wday = bcd2bin (wday & 0x07); 108 tmp->tm_yday = 0; 109 tmp->tm_isdst= 0; 110 111 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 112 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 113 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 114 115 return rel; 116 } 117 118 /* 119 * Set the RTC 120 */ 121 int rtc_set (struct rtc_time *tmp) 122 { 123 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 124 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 125 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 126 127 /* enable write */ 128 rtc_write(RTC_STAT_REG_ADDR, 129 rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC); 130 131 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 132 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 133 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday)); 134 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 135 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour) | 0x80 ); /* 24h clock */ 136 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 137 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 138 139 /* disable write */ 140 rtc_write(RTC_STAT_REG_ADDR, 141 rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC); 142 143 return 0; 144 } 145 146 void rtc_reset (void) 147 { 148 } 149 150 /* 151 * Helper functions 152 */ 153 154 static uchar rtc_read (uchar reg) 155 { 156 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 157 } 158 159 static void rtc_write (uchar reg, uchar val) 160 { 161 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 162 } 163 164 static unsigned bcd2bin (uchar n) 165 { 166 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F)); 167 } 168 169 static unsigned char bin2bcd (unsigned int n) 170 { 171 return (((n / 10) << 4) | (n % 10)); 172 } 173