1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2008 4 * Tor Krill, Excito Elektronik i Skåne , tor@excito.com 5 * 6 * Modelled after the ds1337 driver 7 */ 8 9 /* 10 * Date & Time support (no alarms) for Intersil 11 * ISL1208 Real Time Clock (RTC). 12 */ 13 14 #include <common.h> 15 #include <command.h> 16 #include <dm.h> 17 #include <rtc.h> 18 #include <i2c.h> 19 20 /*---------------------------------------------------------------------*/ 21 #ifdef DEBUG_RTC 22 #define DEBUGR(fmt,args...) printf(fmt ,##args) 23 #else 24 #define DEBUGR(fmt,args...) 25 #endif 26 /*---------------------------------------------------------------------*/ 27 28 /* 29 * RTC register addresses 30 */ 31 32 #define RTC_SEC_REG_ADDR 0x0 33 #define RTC_MIN_REG_ADDR 0x1 34 #define RTC_HR_REG_ADDR 0x2 35 #define RTC_DATE_REG_ADDR 0x3 36 #define RTC_MON_REG_ADDR 0x4 37 #define RTC_YR_REG_ADDR 0x5 38 #define RTC_DAY_REG_ADDR 0x6 39 #define RTC_STAT_REG_ADDR 0x7 40 /* 41 * RTC control register bits 42 */ 43 44 /* 45 * RTC status register bits 46 */ 47 #define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */ 48 #define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */ 49 #define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */ 50 #define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */ 51 #define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */ 52 #define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */ 53 54 /* 55 * Get the current time from the RTC 56 */ 57 58 static int isl1208_rtc_get(struct udevice *dev, struct rtc_time *tmp) 59 { 60 int ret; 61 uchar buf[8], val; 62 63 ret = dm_i2c_read(dev, 0, buf, sizeof(buf)); 64 if (ret < 0) 65 return ret; 66 67 if (buf[RTC_STAT_REG_ADDR] & RTC_STAT_BIT_RTCF) { 68 printf ("### Warning: RTC oscillator has stopped\n"); 69 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 70 if (ret < 0) 71 return ret; 72 73 val = val & ~(RTC_STAT_BIT_BAT | RTC_STAT_BIT_RTCF); 74 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 75 if (ret < 0) 76 return ret; 77 } 78 79 tmp->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F); 80 tmp->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F); 81 tmp->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F); 82 tmp->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F); 83 tmp->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F); 84 tmp->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000; 85 tmp->tm_wday = bcd2bin(buf[RTC_DAY_REG_ADDR] & 0x07); 86 tmp->tm_yday = 0; 87 tmp->tm_isdst= 0; 88 89 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 90 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 91 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 92 93 return 0; 94 } 95 96 /* 97 * Set the RTC 98 */ 99 static int isl1208_rtc_set(struct udevice *dev, const struct rtc_time *tmp) 100 { 101 int ret; 102 uchar val, buf[7]; 103 104 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 105 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 106 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 107 108 if (tmp->tm_year < 2000 || tmp->tm_year > 2099) 109 printf("WARNING: year should be between 2000 and 2099!\n"); 110 111 /* enable write */ 112 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 113 if (ret < 0) 114 return ret; 115 116 val = val | RTC_STAT_BIT_WRTC; 117 118 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 119 if (ret < 0) 120 return ret; 121 122 buf[RTC_YR_REG_ADDR] = bin2bcd(tmp->tm_year % 100); 123 buf[RTC_MON_REG_ADDR] = bin2bcd(tmp->tm_mon); 124 buf[RTC_DAY_REG_ADDR] = bin2bcd(tmp->tm_wday); 125 buf[RTC_DATE_REG_ADDR] = bin2bcd(tmp->tm_mday); 126 buf[RTC_HR_REG_ADDR] = bin2bcd(tmp->tm_hour) | 0x80; /* 24h clock */ 127 buf[RTC_MIN_REG_ADDR] = bin2bcd(tmp->tm_min); 128 buf[RTC_SEC_REG_ADDR] = bin2bcd(tmp->tm_sec); 129 130 ret = dm_i2c_write(dev, 0, buf, sizeof(buf)); 131 if (ret < 0) 132 return ret; 133 134 /* disable write */ 135 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 136 if (ret < 0) 137 return ret; 138 139 val = val & ~RTC_STAT_BIT_WRTC; 140 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 141 if (ret < 0) 142 return ret; 143 144 return 0; 145 } 146 147 static int isl1208_rtc_reset(struct udevice *dev) 148 { 149 return 0; 150 } 151 152 static int isl1208_probe(struct udevice *dev) 153 { 154 i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS | 155 DM_I2C_CHIP_WR_ADDRESS); 156 157 return 0; 158 } 159 160 static const struct rtc_ops isl1208_rtc_ops = { 161 .get = isl1208_rtc_get, 162 .set = isl1208_rtc_set, 163 .reset = isl1208_rtc_reset, 164 }; 165 166 static const struct udevice_id isl1208_rtc_ids[] = { 167 { .compatible = "isil,isl1208" }, 168 { } 169 }; 170 171 U_BOOT_DRIVER(rtc_isl1208) = { 172 .name = "rtc-isl1208", 173 .id = UCLASS_RTC, 174 .probe = isl1208_probe, 175 .of_match = isl1208_rtc_ids, 176 .ops = &isl1208_rtc_ops, 177 }; 178