drivers/rtc/rx8025.c

   1 /*
   2  * (C) Copyright 2007
   3  * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 /*
  25  * Epson RX8025 RTC driver.
  26  */
  27
  28 #include <common.h>
  29 #include <command.h>
  30 #include <rtc.h>
  31 #include <i2c.h>
  32
  33 #if defined(CONFIG_RTC_RX8025) && defined(CONFIG_CMD_DATE)
  34
  35 /*---------------------------------------------------------------------*/
  36 #undef DEBUG_RTC
  37
  38 #ifdef DEBUG_RTC
  39 #define DEBUGR(fmt,args...) printf(fmt ,##args)
  40 #else
  41 #define DEBUGR(fmt,args...)
  42 #endif
  43 /*---------------------------------------------------------------------*/
  44
  45 #ifndef CFG_I2C_RTC_ADDR
  46 # define CFG_I2C_RTC_ADDR       0x32
  47 #endif
  48
  49 /*
  50  * RTC register addresses
  51  */
  52 #define RTC_SEC_REG_ADDR        0x00
  53 #define RTC_MIN_REG_ADDR        0x01
  54 #define RTC_HR_REG_ADDR         0x02
  55 #define RTC_DAY_REG_ADDR        0x03
  56 #define RTC_DATE_REG_ADDR       0x04
  57 #define RTC_MON_REG_ADDR        0x05
  58 #define RTC_YR_REG_ADDR         0x06
  59
  60 #define RTC_CTL1_REG_ADDR       0x0e
  61 #define RTC_CTL2_REG_ADDR       0x0f
  62
  63 /*
  64  * Control register 1 bits
  65  */
  66 #define RTC_CTL1_BIT_2412       0x20
  67
  68 /*
  69  * Control register 2 bits
  70  */
  71 #define RTC_CTL2_BIT_PON        0x10
  72 #define RTC_CTL2_BIT_VDET       0x40
  73 #define RTC_CTL2_BIT_XST        0x20
  74 #define RTC_CTL2_BIT_VDSL       0x80
  75
  76 /*
  77  * Note: the RX8025 I2C RTC requires register
  78  * reads and write to consist of a single bus
  79  * cycle. It is not allowed to write the register
  80  * address in a first cycle that is terminated by
  81  * a STOP condition. The chips needs a 'restart'
  82  * sequence (start sequence without a prior stop).
  83  * This driver has been written for a 4xx board.
  84  * U-Boot's 4xx i2c driver is currently not capable
  85  * to generate such cycles to some work arounds
  86  * are used.
  87  */
  88
  89 /* static uchar rtc_read (uchar reg); */
  90 #define rtc_read(reg) buf[((reg) + 1) & 0xf]
  91
  92 static void rtc_write (uchar reg, uchar val);
  93 static uchar bin2bcd (unsigned int n);
  94 static unsigned bcd2bin (uchar c);
  95
  96 /*
  97  * Get the current time from the RTC
  98  */
  99 void rtc_get (struct rtc_time *tmp)
 100 {
 101         uchar sec, min, hour, mday, wday, mon, year, ctl2;
 102         uchar buf[16];
 103
 104         if (i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 16))
 105                 printf("Error reading from RTC\n");
 106
 107         sec = rtc_read(RTC_SEC_REG_ADDR);
 108         min = rtc_read(RTC_MIN_REG_ADDR);
 109         hour = rtc_read(RTC_HR_REG_ADDR);
 110         wday = rtc_read(RTC_DAY_REG_ADDR);
 111         mday = rtc_read(RTC_DATE_REG_ADDR);
 112         mon = rtc_read(RTC_MON_REG_ADDR);
 113         year = rtc_read(RTC_YR_REG_ADDR);
 114
 115         DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
 116                 "hr: %02x min: %02x sec: %02x\n",
 117                 year, mon, mday, wday, hour, min, sec);
 118
 119         /* dump status */
 120         ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
 121         if (ctl2 & RTC_CTL2_BIT_PON)
 122                 printf("RTC: power-on detected\n");
 123
 124         if (ctl2 & RTC_CTL2_BIT_VDET)
 125                 printf("RTC: voltage drop detected\n");
 126
 127         if (!(ctl2 & RTC_CTL2_BIT_XST))
 128                 printf("RTC: oscillator stop detected\n");
 129
 130         tmp->tm_sec  = bcd2bin (sec & 0x7F);
 131         tmp->tm_min  = bcd2bin (min & 0x7F);
 132         tmp->tm_hour = bcd2bin (hour & 0x3F);
 133         tmp->tm_mday = bcd2bin (mday & 0x3F);
 134         tmp->tm_mon  = bcd2bin (mon & 0x1F);
 135         tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
 136         tmp->tm_wday = bcd2bin (wday & 0x07);
 137         tmp->tm_yday = 0;
 138         tmp->tm_isdst= 0;
 139
 140         DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 141                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 142                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 143 }
 144
 145 /*
 146  * Set the RTC
 147  */
 148 void rtc_set (struct rtc_time *tmp)
 149 {
 150         DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 151                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 152                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 153
 154         if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
 155                 printf("WARNING: year should be between 1970 and 2069!\n");
 156
 157         rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
 158         rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
 159         rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
 160         rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
 161         rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
 162         rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
 163         rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
 164
 165         rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412);
 166 }
 167
 168 /*
 169  * Reset the RTC. We setting the date back to 1970-01-01.
 170  */
 171 void rtc_reset (void)
 172 {
 173         struct rtc_time tmp;
 174         uchar buf[16];
 175         uchar ctl2;
 176
 177         if (i2c_read(CFG_I2C_RTC_ADDR, 0,    0,   buf, 16))
 178                 printf("Error reading from RTC\n");
 179
 180         ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
 181         ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
 182         ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL;
 183         rtc_write (RTC_CTL2_REG_ADDR, ctl2);
 184
 185         tmp.tm_year = 1970;
 186         tmp.tm_mon = 1;
 187         tmp.tm_mday= 1;
 188         tmp.tm_hour = 0;
 189         tmp.tm_min = 0;
 190         tmp.tm_sec = 0;
 191
 192         rtc_set(&tmp);
 193
 194         printf ( "RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
 195                 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
 196                 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
 197
 198         return;
 199 }
 200
 201 /*
 202  * Helper functions
 203  */
 204 static void rtc_write (uchar reg, uchar val)
 205 {
 206         uchar buf[2];
 207         buf[0] = reg << 4;
 208         buf[1] = val;
 209         if (i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, 2) != 0)
 210                 printf("Error writing to RTC\n");
 211
 212 }
 213
 214 static unsigned bcd2bin (uchar n)
 215 {
 216         return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
 217 }
 218
 219 static unsigned char bin2bcd (unsigned int n)
 220 {
 221         return (((n / 10) << 4) | (n % 10));
 222 }
 223
 224 #endif /* CONFIG_RTC_RX8025 && CONFIG_CMD_DATE */