1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2007 4 * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com. 5 */ 6 7 /* 8 * Epson RX8025 RTC driver. 9 */ 10 11 #include <common.h> 12 #include <command.h> 13 #include <rtc.h> 14 #include <i2c.h> 15 16 /*---------------------------------------------------------------------*/ 17 #undef DEBUG_RTC 18 19 #ifdef DEBUG_RTC 20 #define DEBUGR(fmt,args...) printf(fmt ,##args) 21 #else 22 #define DEBUGR(fmt,args...) 23 #endif 24 /*---------------------------------------------------------------------*/ 25 26 #ifndef CONFIG_SYS_I2C_RTC_ADDR 27 # define CONFIG_SYS_I2C_RTC_ADDR 0x32 28 #endif 29 30 /* 31 * RTC register addresses 32 */ 33 #define RTC_SEC_REG_ADDR 0x00 34 #define RTC_MIN_REG_ADDR 0x01 35 #define RTC_HR_REG_ADDR 0x02 36 #define RTC_DAY_REG_ADDR 0x03 37 #define RTC_DATE_REG_ADDR 0x04 38 #define RTC_MON_REG_ADDR 0x05 39 #define RTC_YR_REG_ADDR 0x06 40 41 #define RTC_CTL1_REG_ADDR 0x0e 42 #define RTC_CTL2_REG_ADDR 0x0f 43 44 /* 45 * Control register 1 bits 46 */ 47 #define RTC_CTL1_BIT_2412 0x20 48 49 /* 50 * Control register 2 bits 51 */ 52 #define RTC_CTL2_BIT_PON 0x10 53 #define RTC_CTL2_BIT_VDET 0x40 54 #define RTC_CTL2_BIT_XST 0x20 55 #define RTC_CTL2_BIT_VDSL 0x80 56 57 /* 58 * Note: the RX8025 I2C RTC requires register 59 * reads and write to consist of a single bus 60 * cycle. It is not allowed to write the register 61 * address in a first cycle that is terminated by 62 * a STOP condition. The chips needs a 'restart' 63 * sequence (start sequence without a prior stop). 64 * This driver has been written for a 4xx board. 65 * U-Boot's 4xx i2c driver is currently not capable 66 * to generate such cycles to some work arounds 67 * are used. 68 */ 69 70 /* static uchar rtc_read (uchar reg); */ 71 #define rtc_read(reg) buf[((reg) + 1) & 0xf] 72 73 static void rtc_write (uchar reg, uchar val); 74 75 /* 76 * Get the current time from the RTC 77 */ 78 int rtc_get (struct rtc_time *tmp) 79 { 80 int rel = 0; 81 uchar sec, min, hour, mday, wday, mon, year, ctl2; 82 uchar buf[16]; 83 84 if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 16)) 85 printf("Error reading from RTC\n"); 86 87 sec = rtc_read(RTC_SEC_REG_ADDR); 88 min = rtc_read(RTC_MIN_REG_ADDR); 89 hour = rtc_read(RTC_HR_REG_ADDR); 90 wday = rtc_read(RTC_DAY_REG_ADDR); 91 mday = rtc_read(RTC_DATE_REG_ADDR); 92 mon = rtc_read(RTC_MON_REG_ADDR); 93 year = rtc_read(RTC_YR_REG_ADDR); 94 95 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 96 "hr: %02x min: %02x sec: %02x\n", 97 year, mon, mday, wday, hour, min, sec); 98 99 /* dump status */ 100 ctl2 = rtc_read(RTC_CTL2_REG_ADDR); 101 if (ctl2 & RTC_CTL2_BIT_PON) { 102 printf("RTC: power-on detected\n"); 103 rel = -1; 104 } 105 106 if (ctl2 & RTC_CTL2_BIT_VDET) { 107 printf("RTC: voltage drop detected\n"); 108 rel = -1; 109 } 110 111 if (!(ctl2 & RTC_CTL2_BIT_XST)) { 112 printf("RTC: oscillator stop detected\n"); 113 rel = -1; 114 } 115 116 tmp->tm_sec = bcd2bin (sec & 0x7F); 117 tmp->tm_min = bcd2bin (min & 0x7F); 118 if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412) 119 tmp->tm_hour = bcd2bin (hour & 0x3F); 120 else 121 tmp->tm_hour = bcd2bin (hour & 0x1F) % 12 + 122 ((hour & 0x20) ? 12 : 0); 123 tmp->tm_mday = bcd2bin (mday & 0x3F); 124 tmp->tm_mon = bcd2bin (mon & 0x1F); 125 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); 126 tmp->tm_wday = bcd2bin (wday & 0x07); 127 tmp->tm_yday = 0; 128 tmp->tm_isdst= 0; 129 130 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 131 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 132 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 133 134 return rel; 135 } 136 137 /* 138 * Set the RTC 139 */ 140 int rtc_set (struct rtc_time *tmp) 141 { 142 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 143 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 144 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 145 146 if (tmp->tm_year < 1970 || tmp->tm_year > 2069) 147 printf("WARNING: year should be between 1970 and 2069!\n"); 148 149 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 150 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 151 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday)); 152 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 153 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 154 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 155 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 156 157 rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412); 158 159 return 0; 160 } 161 162 /* 163 * Reset the RTC 164 */ 165 void rtc_reset (void) 166 { 167 uchar buf[16]; 168 uchar ctl2; 169 170 if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 16)) 171 printf("Error reading from RTC\n"); 172 173 ctl2 = rtc_read(RTC_CTL2_REG_ADDR); 174 ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET); 175 ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL; 176 rtc_write (RTC_CTL2_REG_ADDR, ctl2); 177 } 178 179 /* 180 * Helper functions 181 */ 182 static void rtc_write (uchar reg, uchar val) 183 { 184 uchar buf[2]; 185 buf[0] = reg << 4; 186 buf[1] = val; 187 if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 2) != 0) 188 printf("Error writing to RTC\n"); 189 190 } 191