drivers/rtc/isl1208.c

   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  * Read an RTC register
  56  */
  57
  58 static int isl1208_rtc_read8(struct udevice *dev, unsigned int reg)
  59 {
  60         return dm_i2c_reg_read(dev, reg);
  61 }
  62
  63 /*
  64  * Write an RTC register
  65  */
  66
  67 static int isl1208_rtc_write8(struct udevice *dev, unsigned int reg, int val)
  68 {
  69         return dm_i2c_reg_write(dev, reg, val);
  70 }
  71
  72 /*
  73  * Get the current time from the RTC
  74  */
  75
  76 static int isl1208_rtc_get(struct udevice *dev, struct rtc_time *tmp)
  77 {
  78         int ret;
  79         uchar buf[8], val;
  80
  81         ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
  82         if (ret < 0)
  83                 return ret;
  84
  85         if (buf[RTC_STAT_REG_ADDR] & RTC_STAT_BIT_RTCF) {
  86                 printf ("### Warning: RTC oscillator has stopped\n");
  87                 ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
  88                 if (ret < 0)
  89                         return ret;
  90
  91                 val = val & ~(RTC_STAT_BIT_BAT | RTC_STAT_BIT_RTCF);
  92                 ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
  93                 if (ret < 0)
  94                         return ret;
  95         }
  96
  97         tmp->tm_sec  = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
  98         tmp->tm_min  = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
  99         tmp->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
 100         tmp->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
 101         tmp->tm_mon  = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
 102         tmp->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000;
 103         tmp->tm_wday = bcd2bin(buf[RTC_DAY_REG_ADDR] & 0x07);
 104         tmp->tm_yday = 0;
 105         tmp->tm_isdst= 0;
 106
 107         DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 108                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 109                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 110
 111         return 0;
 112 }
 113
 114 /*
 115  * Set the RTC
 116  */
 117 static int isl1208_rtc_set(struct udevice *dev, const struct rtc_time *tmp)
 118 {
 119         int ret;
 120         uchar val, buf[7];
 121
 122         DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 123                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 124                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 125
 126         if (tmp->tm_year < 2000 || tmp->tm_year > 2099)
 127                 printf("WARNING: year should be between 2000 and 2099!\n");
 128
 129         /* enable write */
 130         ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
 131         if (ret < 0)
 132                 return ret;
 133
 134         val = val | RTC_STAT_BIT_WRTC;
 135
 136         ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
 137         if (ret < 0)
 138                 return ret;
 139
 140         buf[RTC_YR_REG_ADDR] = bin2bcd(tmp->tm_year % 100);
 141         buf[RTC_MON_REG_ADDR] = bin2bcd(tmp->tm_mon);
 142         buf[RTC_DAY_REG_ADDR] = bin2bcd(tmp->tm_wday);
 143         buf[RTC_DATE_REG_ADDR] = bin2bcd(tmp->tm_mday);
 144         buf[RTC_HR_REG_ADDR] = bin2bcd(tmp->tm_hour) | 0x80; /* 24h clock */
 145         buf[RTC_MIN_REG_ADDR] = bin2bcd(tmp->tm_min);
 146         buf[RTC_SEC_REG_ADDR] = bin2bcd(tmp->tm_sec);
 147
 148         ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
 149         if (ret < 0)
 150                 return ret;
 151
 152         /* disable write */
 153         ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
 154         if (ret < 0)
 155                 return ret;
 156
 157         val = val & ~RTC_STAT_BIT_WRTC;
 158         ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
 159         if (ret < 0)
 160                 return ret;
 161
 162         return 0;
 163 }
 164
 165 static int isl1208_rtc_reset(struct udevice *dev)
 166 {
 167         return 0;
 168 }
 169
 170 static int isl1208_probe(struct udevice *dev)
 171 {
 172         i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
 173                            DM_I2C_CHIP_WR_ADDRESS);
 174
 175         return 0;
 176 }
 177
 178 static const struct rtc_ops isl1208_rtc_ops = {
 179         .get = isl1208_rtc_get,
 180         .set = isl1208_rtc_set,
 181         .reset = isl1208_rtc_reset,
 182         .read8 = isl1208_rtc_read8,
 183         .write8 = isl1208_rtc_write8,
 184 };
 185
 186 static const struct udevice_id isl1208_rtc_ids[] = {
 187         { .compatible = "isil,isl1208" },
 188         { }
 189 };
 190
 191 U_BOOT_DRIVER(rtc_isl1208) = {
 192         .name   = "rtc-isl1208",
 193         .id     = UCLASS_RTC,
 194         .probe  = isl1208_probe,
 195         .of_match = isl1208_rtc_ids,
 196         .ops    = &isl1208_rtc_ops,
 197 };