drivers/rtc/rx8025.c

   1 /*
   2  * (C) Copyright 2007
   3  * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * Epson RX8025 RTC driver.
  10  */
  11
  12 #include <common.h>
  13 #include <command.h>
  14 #include <rtc.h>
  15 #include <i2c.h>
  16
  17 #if defined(CONFIG_CMD_DATE)
  18
  19 /*---------------------------------------------------------------------*/
  20 #undef DEBUG_RTC
  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 #ifndef CONFIG_SYS_I2C_RTC_ADDR
  30 # define CONFIG_SYS_I2C_RTC_ADDR        0x32
  31 #endif
  32
  33 /*
  34  * RTC register addresses
  35  */
  36 #define RTC_SEC_REG_ADDR        0x00
  37 #define RTC_MIN_REG_ADDR        0x01
  38 #define RTC_HR_REG_ADDR         0x02
  39 #define RTC_DAY_REG_ADDR        0x03
  40 #define RTC_DATE_REG_ADDR       0x04
  41 #define RTC_MON_REG_ADDR        0x05
  42 #define RTC_YR_REG_ADDR         0x06
  43
  44 #define RTC_CTL1_REG_ADDR       0x0e
  45 #define RTC_CTL2_REG_ADDR       0x0f
  46
  47 /*
  48  * Control register 1 bits
  49  */
  50 #define RTC_CTL1_BIT_2412       0x20
  51
  52 /*
  53  * Control register 2 bits
  54  */
  55 #define RTC_CTL2_BIT_PON        0x10
  56 #define RTC_CTL2_BIT_VDET       0x40
  57 #define RTC_CTL2_BIT_XST        0x20
  58 #define RTC_CTL2_BIT_VDSL       0x80
  59
  60 /*
  61  * Note: the RX8025 I2C RTC requires register
  62  * reads and write to consist of a single bus
  63  * cycle. It is not allowed to write the register
  64  * address in a first cycle that is terminated by
  65  * a STOP condition. The chips needs a 'restart'
  66  * sequence (start sequence without a prior stop).
  67  * This driver has been written for a 4xx board.
  68  * U-Boot's 4xx i2c driver is currently not capable
  69  * to generate such cycles to some work arounds
  70  * are used.
  71  */
  72
  73 /* static uchar rtc_read (uchar reg); */
  74 #define rtc_read(reg) buf[((reg) + 1) & 0xf]
  75
  76 static void rtc_write (uchar reg, uchar val);
  77
  78 /*
  79  * Get the current time from the RTC
  80  */
  81 int rtc_get (struct rtc_time *tmp)
  82 {
  83         int rel = 0;
  84         uchar sec, min, hour, mday, wday, mon, year, ctl2;
  85         uchar buf[16];
  86
  87         if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 16))
  88                 printf("Error reading from RTC\n");
  89
  90         sec = rtc_read(RTC_SEC_REG_ADDR);
  91         min = rtc_read(RTC_MIN_REG_ADDR);
  92         hour = rtc_read(RTC_HR_REG_ADDR);
  93         wday = rtc_read(RTC_DAY_REG_ADDR);
  94         mday = rtc_read(RTC_DATE_REG_ADDR);
  95         mon = rtc_read(RTC_MON_REG_ADDR);
  96         year = rtc_read(RTC_YR_REG_ADDR);
  97
  98         DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  99                 "hr: %02x min: %02x sec: %02x\n",
 100                 year, mon, mday, wday, hour, min, sec);
 101
 102         /* dump status */
 103         ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
 104         if (ctl2 & RTC_CTL2_BIT_PON) {
 105                 printf("RTC: power-on detected\n");
 106                 rel = -1;
 107         }
 108
 109         if (ctl2 & RTC_CTL2_BIT_VDET) {
 110                 printf("RTC: voltage drop detected\n");
 111                 rel = -1;
 112         }
 113
 114         if (!(ctl2 & RTC_CTL2_BIT_XST)) {
 115                 printf("RTC: oscillator stop detected\n");
 116                 rel = -1;
 117         }
 118
 119         tmp->tm_sec  = bcd2bin (sec & 0x7F);
 120         tmp->tm_min  = bcd2bin (min & 0x7F);
 121         if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412)
 122                 tmp->tm_hour = bcd2bin (hour & 0x3F);
 123         else
 124                 tmp->tm_hour = bcd2bin (hour & 0x1F) % 12 +
 125                                ((hour & 0x20) ? 12 : 0);
 126         tmp->tm_mday = bcd2bin (mday & 0x3F);
 127         tmp->tm_mon  = bcd2bin (mon & 0x1F);
 128         tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
 129         tmp->tm_wday = bcd2bin (wday & 0x07);
 130         tmp->tm_yday = 0;
 131         tmp->tm_isdst= 0;
 132
 133         DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 134                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 135                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 136
 137         return rel;
 138 }
 139
 140 /*
 141  * Set the RTC
 142  */
 143 int rtc_set (struct rtc_time *tmp)
 144 {
 145         DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 146                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 147                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 148
 149         if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
 150                 printf("WARNING: year should be between 1970 and 2069!\n");
 151
 152         rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
 153         rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
 154         rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
 155         rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
 156         rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
 157         rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
 158         rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
 159
 160         rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412);
 161
 162         return 0;
 163 }
 164
 165 /*
 166  * Reset the RTC. We setting the date back to 1970-01-01.
 167  */
 168 void rtc_reset (void)
 169 {
 170         struct rtc_time tmp;
 171         uchar buf[16];
 172         uchar ctl2;
 173
 174         if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0,    0,   buf, 16))
 175                 printf("Error reading from RTC\n");
 176
 177         ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
 178         ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
 179         ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL;
 180         rtc_write (RTC_CTL2_REG_ADDR, ctl2);
 181
 182         tmp.tm_year = 1970;
 183         tmp.tm_mon = 1;
 184         tmp.tm_mday= 1;
 185         tmp.tm_hour = 0;
 186         tmp.tm_min = 0;
 187         tmp.tm_sec = 0;
 188
 189         rtc_set(&tmp);
 190
 191         printf ( "RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
 192                 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
 193                 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
 194
 195         return;
 196 }
 197
 198 /*
 199  * Helper functions
 200  */
 201 static void rtc_write (uchar reg, uchar val)
 202 {
 203         uchar buf[2];
 204         buf[0] = reg << 4;
 205         buf[1] = val;
 206         if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 2) != 0)
 207                 printf("Error writing to RTC\n");
 208
 209 }
 210
 211 #endif /* CONFIG_RTC_RX8025 && CONFIG_CMD_DATE */