1 /* 2 * (C) Copyright 2008 3 * Tor Krill, Excito Elektronik i Skåne , tor@excito.com 4 * 5 * Modelled after the ds1337 driver 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 /* 11 * Date & Time support (no alarms) for Intersil 12 * ISL1208 Real Time Clock (RTC). 13 */ 14 15 #include <common.h> 16 #include <command.h> 17 #include <dm.h> 18 #include <rtc.h> 19 #include <i2c.h> 20 21 /*---------------------------------------------------------------------*/ 22 #ifdef DEBUG_RTC 23 #define DEBUGR(fmt,args...) printf(fmt ,##args) 24 #else 25 #define DEBUGR(fmt,args...) 26 #endif 27 /*---------------------------------------------------------------------*/ 28 29 /* 30 * RTC register addresses 31 */ 32 33 #define RTC_SEC_REG_ADDR 0x0 34 #define RTC_MIN_REG_ADDR 0x1 35 #define RTC_HR_REG_ADDR 0x2 36 #define RTC_DATE_REG_ADDR 0x3 37 #define RTC_MON_REG_ADDR 0x4 38 #define RTC_YR_REG_ADDR 0x5 39 #define RTC_DAY_REG_ADDR 0x6 40 #define RTC_STAT_REG_ADDR 0x7 41 /* 42 * RTC control register bits 43 */ 44 45 /* 46 * RTC status register bits 47 */ 48 #define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */ 49 #define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */ 50 #define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */ 51 #define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */ 52 #define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */ 53 #define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */ 54 55 /* 56 * Get the current time from the RTC 57 */ 58 59 static int isl1208_rtc_get(struct udevice *dev, struct rtc_time *tmp) 60 { 61 int ret; 62 uchar buf[8], val; 63 64 ret = dm_i2c_read(dev, 0, buf, sizeof(buf)); 65 if (ret < 0) 66 return ret; 67 68 if (buf[RTC_STAT_REG_ADDR] & RTC_STAT_BIT_RTCF) { 69 printf ("### Warning: RTC oscillator has stopped\n"); 70 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 71 if (ret < 0) 72 return ret; 73 74 val = val & ~(RTC_STAT_BIT_BAT | RTC_STAT_BIT_RTCF); 75 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 76 if (ret < 0) 77 return ret; 78 } 79 80 tmp->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F); 81 tmp->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F); 82 tmp->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F); 83 tmp->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F); 84 tmp->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F); 85 tmp->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000; 86 tmp->tm_wday = bcd2bin(buf[RTC_DAY_REG_ADDR] & 0x07); 87 tmp->tm_yday = 0; 88 tmp->tm_isdst= 0; 89 90 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 91 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 92 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 93 94 return 0; 95 } 96 97 /* 98 * Set the RTC 99 */ 100 static int isl1208_rtc_set(struct udevice *dev, const struct rtc_time *tmp) 101 { 102 int ret; 103 uchar val, buf[7]; 104 105 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 106 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 107 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 108 109 if (tmp->tm_year < 2000 || tmp->tm_year > 2099) 110 printf("WARNING: year should be between 2000 and 2099!\n"); 111 112 /* enable write */ 113 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 114 if (ret < 0) 115 return ret; 116 117 val = val | RTC_STAT_BIT_WRTC; 118 119 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 120 if (ret < 0) 121 return ret; 122 123 buf[RTC_YR_REG_ADDR] = bin2bcd(tmp->tm_year % 100); 124 buf[RTC_MON_REG_ADDR] = bin2bcd(tmp->tm_mon); 125 buf[RTC_DAY_REG_ADDR] = bin2bcd(tmp->tm_wday); 126 buf[RTC_DATE_REG_ADDR] = bin2bcd(tmp->tm_mday); 127 buf[RTC_HR_REG_ADDR] = bin2bcd(tmp->tm_hour) | 0x80; /* 24h clock */ 128 buf[RTC_MIN_REG_ADDR] = bin2bcd(tmp->tm_min); 129 buf[RTC_SEC_REG_ADDR] = bin2bcd(tmp->tm_sec); 130 131 ret = dm_i2c_write(dev, 0, buf, sizeof(buf)); 132 if (ret < 0) 133 return ret; 134 135 /* disable write */ 136 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 137 if (ret < 0) 138 return ret; 139 140 val = val & ~RTC_STAT_BIT_WRTC; 141 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val)); 142 if (ret < 0) 143 return ret; 144 145 return 0; 146 } 147 148 static int isl1208_rtc_reset(struct udevice *dev) 149 { 150 return 0; 151 } 152 153 static int isl1208_probe(struct udevice *dev) 154 { 155 i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS | 156 DM_I2C_CHIP_WR_ADDRESS); 157 158 return 0; 159 } 160 161 static const struct rtc_ops isl1208_rtc_ops = { 162 .get = isl1208_rtc_get, 163 .set = isl1208_rtc_set, 164 .reset = isl1208_rtc_reset, 165 }; 166 167 static const struct udevice_id isl1208_rtc_ids[] = { 168 { .compatible = "isil,isl1208" }, 169 { } 170 }; 171 172 U_BOOT_DRIVER(rtc_isl1208) = { 173 .name = "rtc-isl1208", 174 .id = UCLASS_RTC, 175 .probe = isl1208_probe, 176 .of_match = isl1208_rtc_ids, 177 .ops = &isl1208_rtc_ops, 178 }; 179