1 /* 2 * (C) Copyright 2004 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21 * MA 02111-1307 USA 22 */ 23 24 /* 25 * Date & Time support for MAXIM MAX6900 RTC 26 */ 27 28 /* #define DEBUG */ 29 30 #include <common.h> 31 #include <command.h> 32 #include <rtc.h> 33 #include <i2c.h> 34 35 #if defined(CONFIG_RTC_MAX6900) && defined(CONFIG_CMD_DATE) 36 37 #ifndef CFG_I2C_RTC_ADDR 38 #define CFG_I2C_RTC_ADDR 0x50 39 #endif 40 41 /* ------------------------------------------------------------------------- */ 42 43 static uchar rtc_read (uchar reg) 44 { 45 return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg)); 46 } 47 48 static void rtc_write (uchar reg, uchar val) 49 { 50 i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val); 51 udelay(2500); 52 } 53 54 static unsigned bcd2bin (uchar n) 55 { 56 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F)); 57 } 58 59 static unsigned char bin2bcd (unsigned int n) 60 { 61 return (((n / 10) << 4) | (n % 10)); 62 } 63 64 /* ------------------------------------------------------------------------- */ 65 66 int rtc_get (struct rtc_time *tmp) 67 { 68 uchar sec, min, hour, mday, wday, mon, cent, year; 69 int retry = 1; 70 71 do { 72 sec = rtc_read (0x80); 73 min = rtc_read (0x82); 74 hour = rtc_read (0x84); 75 mday = rtc_read (0x86); 76 mon = rtc_read (0x88); 77 wday = rtc_read (0x8a); 78 year = rtc_read (0x8c); 79 cent = rtc_read (0x92); 80 /* 81 * Check for seconds rollover 82 */ 83 if ((sec != 59) || (rtc_read(0x80) == sec)){ 84 retry = 0; 85 } 86 } while (retry); 87 88 debug ( "Get RTC year: %02x mon: %02x cent: %02x mday: %02x wday: %02x " 89 "hr: %02x min: %02x sec: %02x\n", 90 year, mon, cent, mday, wday, 91 hour, min, sec ); 92 93 tmp->tm_sec = bcd2bin (sec & 0x7F); 94 tmp->tm_min = bcd2bin (min & 0x7F); 95 tmp->tm_hour = bcd2bin (hour & 0x3F); 96 tmp->tm_mday = bcd2bin (mday & 0x3F); 97 tmp->tm_mon = bcd2bin (mon & 0x1F); 98 tmp->tm_year = bcd2bin (year) + bcd2bin(cent) * 100; 99 tmp->tm_wday = bcd2bin (wday & 0x07); 100 tmp->tm_yday = 0; 101 tmp->tm_isdst= 0; 102 103 debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 104 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 105 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 106 107 return 0; 108 } 109 110 void rtc_set (struct rtc_time *tmp) 111 { 112 113 debug ( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 114 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 115 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 116 117 rtc_write (0x9E, 0x00); 118 rtc_write (0x80, 0); /* Clear seconds to ensure no rollover */ 119 rtc_write (0x92, bin2bcd(tmp->tm_year / 100)); 120 rtc_write (0x8c, bin2bcd(tmp->tm_year % 100)); 121 rtc_write (0x8a, bin2bcd(tmp->tm_wday)); 122 rtc_write (0x88, bin2bcd(tmp->tm_mon)); 123 rtc_write (0x86, bin2bcd(tmp->tm_mday)); 124 rtc_write (0x84, bin2bcd(tmp->tm_hour)); 125 rtc_write (0x82, bin2bcd(tmp->tm_min )); 126 rtc_write (0x80, bin2bcd(tmp->tm_sec )); 127 } 128 129 void rtc_reset (void) 130 { 131 } 132 133 #endif 134