1 /* 2 * (C) Copyright 2001, 2002, 2003 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * Keith Outwater, keith_outwater@mvis.com` 5 * Steven Scholz, steven.scholz@imc-berlin.de 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 /* 11 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim) 12 * DS1374 Real Time Clock (RTC). 13 * 14 * based on ds1337.c 15 */ 16 17 #include <common.h> 18 #include <command.h> 19 #include <rtc.h> 20 #include <i2c.h> 21 22 #if defined(CONFIG_CMD_DATE) 23 24 /*---------------------------------------------------------------------*/ 25 #undef DEBUG_RTC 26 #define DEBUG_RTC 27 28 #ifdef DEBUG_RTC 29 #define DEBUGR(fmt,args...) printf(fmt ,##args) 30 #else 31 #define DEBUGR(fmt,args...) 32 #endif 33 /*---------------------------------------------------------------------*/ 34 35 #ifndef CONFIG_SYS_I2C_RTC_ADDR 36 # define CONFIG_SYS_I2C_RTC_ADDR 0x68 37 #endif 38 39 #if defined(CONFIG_RTC_DS1374) && (CONFIG_SYS_I2C_SPEED > 400000) 40 # error The DS1374 is specified up to 400kHz in fast mode! 41 #endif 42 43 /* 44 * RTC register addresses 45 */ 46 #define RTC_TOD_CNT_BYTE0_ADDR 0x00 /* TimeOfDay */ 47 #define RTC_TOD_CNT_BYTE1_ADDR 0x01 48 #define RTC_TOD_CNT_BYTE2_ADDR 0x02 49 #define RTC_TOD_CNT_BYTE3_ADDR 0x03 50 51 #define RTC_WD_ALM_CNT_BYTE0_ADDR 0x04 52 #define RTC_WD_ALM_CNT_BYTE1_ADDR 0x05 53 #define RTC_WD_ALM_CNT_BYTE2_ADDR 0x06 54 55 #define RTC_CTL_ADDR 0x07 /* RTC-CoNTrol-register */ 56 #define RTC_SR_ADDR 0x08 /* RTC-StatusRegister */ 57 #define RTC_TCS_DS_ADDR 0x09 /* RTC-TrickleChargeSelect DiodeSelect-register */ 58 59 #define RTC_CTL_BIT_AIE (1<<0) /* Bit 0 - Alarm Interrupt enable */ 60 #define RTC_CTL_BIT_RS1 (1<<1) /* Bit 1/2 - Rate Select square wave output */ 61 #define RTC_CTL_BIT_RS2 (1<<2) /* Bit 2/2 - Rate Select square wave output */ 62 #define RTC_CTL_BIT_WDSTR (1<<3) /* Bit 3 - Watchdog Reset Steering */ 63 #define RTC_CTL_BIT_BBSQW (1<<4) /* Bit 4 - Battery-Backed Square-Wave */ 64 #define RTC_CTL_BIT_WD_ALM (1<<5) /* Bit 5 - Watchdoc/Alarm Counter Select */ 65 #define RTC_CTL_BIT_WACE (1<<6) /* Bit 6 - Watchdog/Alarm Counter Enable WACE*/ 66 #define RTC_CTL_BIT_EN_OSC (1<<7) /* Bit 7 - Enable Oscilator */ 67 68 #define RTC_SR_BIT_AF 0x01 /* Bit 0 = Alarm Flag */ 69 #define RTC_SR_BIT_OSF 0x80 /* Bit 7 - Osc Stop Flag */ 70 71 const char RtcTodAddr[] = { 72 RTC_TOD_CNT_BYTE0_ADDR, 73 RTC_TOD_CNT_BYTE1_ADDR, 74 RTC_TOD_CNT_BYTE2_ADDR, 75 RTC_TOD_CNT_BYTE3_ADDR 76 }; 77 78 static uchar rtc_read (uchar reg); 79 static void rtc_write(uchar reg, uchar val, bool set); 80 static void rtc_write_raw (uchar reg, uchar val); 81 82 /* 83 * Get the current time from the RTC 84 */ 85 int rtc_get (struct rtc_time *tm){ 86 int rel = 0; 87 unsigned long time1, time2; 88 unsigned int limit; 89 unsigned char tmp; 90 unsigned int i; 91 92 /* 93 * Since the reads are being performed one byte at a time, 94 * there is a chance that a carry will occur during the read. 95 * To detect this, 2 reads are performed and compared. 96 */ 97 limit = 10; 98 do { 99 i = 4; 100 time1 = 0; 101 while (i--) { 102 tmp = rtc_read(RtcTodAddr[i]); 103 time1 = (time1 << 8) | (tmp & 0xff); 104 } 105 106 i = 4; 107 time2 = 0; 108 while (i--) { 109 tmp = rtc_read(RtcTodAddr[i]); 110 time2 = (time2 << 8) | (tmp & 0xff); 111 } 112 } while ((time1 != time2) && limit--); 113 114 if (time1 != time2) { 115 printf("can't get consistent time from rtc chip\n"); 116 rel = -1; 117 } 118 119 DEBUGR ("Get RTC s since 1.1.1970: %ld\n", time1); 120 121 rtc_to_tm(time1, tm); /* To Gregorian Date */ 122 123 if (rtc_read(RTC_SR_ADDR) & RTC_SR_BIT_OSF) { 124 printf ("### Warning: RTC oscillator has stopped\n"); 125 rel = -1; 126 } 127 128 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 129 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, 130 tm->tm_hour, tm->tm_min, tm->tm_sec); 131 132 return rel; 133 } 134 135 /* 136 * Set the RTC 137 */ 138 int rtc_set (struct rtc_time *tmp){ 139 140 unsigned long time; 141 unsigned i; 142 143 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 144 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 145 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 146 147 if (tmp->tm_year < 1970 || tmp->tm_year > 2069) 148 printf("WARNING: year should be between 1970 and 2069!\n"); 149 150 time = rtc_mktime(tmp); 151 152 DEBUGR ("Set RTC s since 1.1.1970: %ld (0x%02lx)\n", time, time); 153 154 /* write to RTC_TOD_CNT_BYTEn_ADDR */ 155 for (i = 0; i <= 3; i++) { 156 rtc_write_raw(RtcTodAddr[i], (unsigned char)(time & 0xff)); 157 time = time >> 8; 158 } 159 160 /* Start clock */ 161 rtc_write(RTC_CTL_ADDR, RTC_CTL_BIT_EN_OSC, false); 162 163 return 0; 164 } 165 166 /* 167 * Reset the RTC. We setting the date back to 1970-01-01. 168 * We also enable the oscillator output on the SQW/OUT pin and program 169 * it for 32,768 Hz output. Note that according to the datasheet, turning 170 * on the square wave output increases the current drain on the backup 171 * battery to something between 480nA and 800nA. 172 */ 173 void rtc_reset (void){ 174 175 struct rtc_time tmp; 176 177 /* clear status flags */ 178 rtc_write(RTC_SR_ADDR, (RTC_SR_BIT_AF|RTC_SR_BIT_OSF), false); /* clearing OSF and AF */ 179 180 /* Initialise DS1374 oriented to MPC8349E-ADS */ 181 rtc_write (RTC_CTL_ADDR, (RTC_CTL_BIT_EN_OSC 182 |RTC_CTL_BIT_WACE 183 |RTC_CTL_BIT_AIE), false);/* start osc, disable WACE, clear AIE 184 - set to 0 */ 185 rtc_write (RTC_CTL_ADDR, (RTC_CTL_BIT_WD_ALM 186 |RTC_CTL_BIT_WDSTR 187 |RTC_CTL_BIT_RS1 188 |RTC_CTL_BIT_RS2 189 |RTC_CTL_BIT_BBSQW), true);/* disable WD/ALM, WDSTR set to INT-pin, 190 set BBSQW and SQW to 32k 191 - set to 1 */ 192 tmp.tm_year = 1970; 193 tmp.tm_mon = 1; 194 tmp.tm_mday= 1; 195 tmp.tm_hour = 0; 196 tmp.tm_min = 0; 197 tmp.tm_sec = 0; 198 199 rtc_set(&tmp); 200 201 printf("RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n", 202 tmp.tm_year, tmp.tm_mon, tmp.tm_mday, 203 tmp.tm_hour, tmp.tm_min, tmp.tm_sec); 204 205 rtc_write(RTC_WD_ALM_CNT_BYTE2_ADDR, 0xAC, true); 206 rtc_write(RTC_WD_ALM_CNT_BYTE1_ADDR, 0xDE, true); 207 rtc_write(RTC_WD_ALM_CNT_BYTE2_ADDR, 0xAD, true); 208 } 209 210 /* 211 * Helper functions 212 */ 213 static uchar rtc_read (uchar reg) 214 { 215 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 216 } 217 218 static void rtc_write(uchar reg, uchar val, bool set) 219 { 220 if (set == true) { 221 val |= i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg); 222 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 223 } else { 224 val = i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg) & ~val; 225 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 226 } 227 } 228 229 static void rtc_write_raw (uchar reg, uchar val) 230 { 231 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 232 } 233 #endif 234