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  * 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 };