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