drivers/rtc/isl1208.c

   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 };