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 int rtc_get (struct rtc_time *tmp)
 100 {
 101         int rel = 0;
 102         uchar sec, min, hour, mday, wday, mon, year, ctl2;
 103         uchar buf[16];
 104
 105         if (i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 16))
 106                 printf("Error reading from RTC\n");
 107
 108         sec = rtc_read(RTC_SEC_REG_ADDR);
 109         min = rtc_read(RTC_MIN_REG_ADDR);
 110         hour = rtc_read(RTC_HR_REG_ADDR);
 111         wday = rtc_read(RTC_DAY_REG_ADDR);
 112         mday = rtc_read(RTC_DATE_REG_ADDR);
 113         mon = rtc_read(RTC_MON_REG_ADDR);
 114         year = rtc_read(RTC_YR_REG_ADDR);
 115
 116         DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
 117                 "hr: %02x min: %02x sec: %02x\n",
 118                 year, mon, mday, wday, hour, min, sec);
 119
 120         /* dump status */
 121         ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
 122         if (ctl2 & RTC_CTL2_BIT_PON) {
 123                 printf("RTC: power-on detected\n");
 124                 rel = -1;
 125         }
 126
 127         if (ctl2 & RTC_CTL2_BIT_VDET) {
 128                 printf("RTC: voltage drop detected\n");
 129                 rel = -1;
 130         }
 131
 132         if (!(ctl2 & RTC_CTL2_BIT_XST)) {
 133                 printf("RTC: oscillator stop detected\n");
 134                 rel = -1;
 135         }
 136
 137         tmp->tm_sec  = bcd2bin (sec & 0x7F);
 138         tmp->tm_min  = bcd2bin (min & 0x7F);
 139         tmp->tm_hour = bcd2bin (hour & 0x3F);
 140         tmp->tm_mday = bcd2bin (mday & 0x3F);
 141         tmp->tm_mon  = bcd2bin (mon & 0x1F);
 142         tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
 143         tmp->tm_wday = bcd2bin (wday & 0x07);
 144         tmp->tm_yday = 0;
 145         tmp->tm_isdst= 0;
 146
 147         DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 148                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 149                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 150
 151         return rel;
 152 }
 153
 154 /*
 155  * Set the RTC
 156  */
 157 void rtc_set (struct rtc_time *tmp)
 158 {
 159         DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 160                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 161                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 162
 163         if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
 164                 printf("WARNING: year should be between 1970 and 2069!\n");
 165
 166         rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
 167         rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
 168         rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
 169         rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
 170         rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
 171         rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
 172         rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
 173
 174         rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412);
 175 }
 176
 177 /*
 178  * Reset the RTC. We setting the date back to 1970-01-01.
 179  */
 180 void rtc_reset (void)
 181 {
 182         struct rtc_time tmp;
 183         uchar buf[16];
 184         uchar ctl2;
 185
 186         if (i2c_read(CFG_I2C_RTC_ADDR, 0,    0,   buf, 16))
 187                 printf("Error reading from RTC\n");
 188
 189         ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
 190         ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
 191         ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL;
 192         rtc_write (RTC_CTL2_REG_ADDR, ctl2);
 193
 194         tmp.tm_year = 1970;
 195         tmp.tm_mon = 1;
 196         tmp.tm_mday= 1;
 197         tmp.tm_hour = 0;
 198         tmp.tm_min = 0;
 199         tmp.tm_sec = 0;
 200
 201         rtc_set(&tmp);
 202
 203         printf ( "RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
 204                 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
 205                 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
 206
 207         return;
 208 }
 209
 210 /*
 211  * Helper functions
 212  */
 213 static void rtc_write (uchar reg, uchar val)
 214 {
 215         uchar buf[2];
 216         buf[0] = reg << 4;
 217         buf[1] = val;
 218         if (i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, 2) != 0)
 219                 printf("Error writing to RTC\n");
 220
 221 }
 222
 223 static unsigned bcd2bin (uchar n)
 224 {
 225         return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
 226 }
 227
 228 static unsigned char bin2bcd (unsigned int n)
 229 {
 230         return (((n / 10) << 4) | (n % 10));
 231 }
 232
 233 #endif /* CONFIG_RTC_RX8025 && CONFIG_CMD_DATE */