drivers/rtc/rs5c372.c

   1 /*
   2  * rs5c372.c
   3  *
   4  * Device driver for Ricoh's Real Time Controller RS5C372A.
   5  *
   6  * Copyright (C) 2004 Gary Jennejohn garyj@denx.de
   7  *
   8  * Based in part in ds1307.c -
   9  * (C) Copyright 2001, 2002, 2003
  10  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  11  * Keith Outwater, keith_outwater@mvis.com`
  12  * Steven Scholz, steven.scholz@imc-berlin.de
  13  *
  14  * See file CREDITS for list of people who contributed to this
  15  * project.
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License version 2 as
  19  * published by the Free Software Foundation.
  20  */
  21
  22 #include <common.h>
  23 #include <command.h>
  24 #include <rtc.h>
  25 #include <i2c.h>
  26
  27 #if defined(CONFIG_CMD_DATE)
  28 /*
  29  * Reads are always done starting with register 15, which requires some
  30  * jumping-through-hoops to access the data correctly.
  31  *
  32  * Writes are always done starting with register 0.
  33  */
  34
  35 #define DEBUG 0
  36
  37 #if DEBUG
  38 static unsigned int rtc_debug = DEBUG;
  39 #else
  40 #define rtc_debug 0     /* gcc will remove all the debug code for us */
  41 #endif
  42
  43 #ifndef CONFIG_SYS_I2C_RTC_ADDR
  44 #define CONFIG_SYS_I2C_RTC_ADDR 0x32
  45 #endif
  46
  47 #define RS5C372_RAM_SIZE 0x10
  48 #define RATE_32000HZ    0x80    /* Rate Select 32.000KHz */
  49 #define RATE_32768HZ    0x00    /* Rate Select 32.768KHz */
  50
  51 #define STATUS_XPT  0x10    /* data invalid because voltage was 0 */
  52
  53 #define USE_24HOUR_MODE 0x20
  54 #define TWELVE_HOUR_MODE(n) ((((n) >> 5) & 1) == 0)
  55 #define HOURS_AP(n)     (((n) >> 5) & 1)
  56 #define HOURS_12(n)     bcd2bin((n) & 0x1F)
  57 #define HOURS_24(n)     bcd2bin((n) & 0x3F)
  58
  59
  60 static int setup_done = 0;
  61
  62 static int
  63 rs5c372_readram(unsigned char *buf, int len)
  64 {
  65         int ret;
  66
  67         ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, len);
  68         if (ret != 0) {
  69                 printf("%s: failed to read\n", __FUNCTION__);
  70                 return ret;
  71         }
  72
  73         if (buf[0] & STATUS_XPT)
  74                 printf("### Warning: RTC lost power\n");
  75
  76         return ret;
  77 }
  78
  79 static void
  80 rs5c372_enable(void)
  81 {
  82         unsigned char buf[RS5C372_RAM_SIZE + 1];
  83         int ret;
  84
  85         /* note that this returns reg. 15 in buf[1] */
  86         ret = rs5c372_readram(&buf[1], RS5C372_RAM_SIZE);
  87         if (ret != 0) {
  88                 printf("%s: failed\n", __FUNCTION__);
  89                 return;
  90         }
  91
  92         buf[0] = 0;
  93         /* we want to start writing at register 0 so we have to copy the */
  94         /* register contents up one slot */
  95         for (ret = 2; ret < 9; ret++)
  96                 buf[ret - 1] = buf[ret];
  97         /* registers 0 to 6 (time values) are not touched */
  98         buf[8] = RATE_32768HZ; /* reg. 7 */
  99         buf[9] = 0; /* reg. 8 */
 100         buf[10] = 0; /* reg. 9 */
 101         buf[11] = 0; /* reg. 10 */
 102         buf[12] = 0; /* reg. 11 */
 103         buf[13] = 0; /* reg. 12 */
 104         buf[14] = 0; /* reg. 13 */
 105         buf[15] = 0; /* reg. 14 */
 106         buf[16] = USE_24HOUR_MODE; /* reg. 15 */
 107         ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, RS5C372_RAM_SIZE+1);
 108         if (ret != 0) {
 109                 printf("%s: failed\n", __FUNCTION__);
 110                 return;
 111         }
 112         setup_done = 1;
 113
 114         return;
 115 }
 116
 117 static void
 118 rs5c372_convert_to_time(struct rtc_time *dt, unsigned char *buf)
 119 {
 120         /* buf[0] is register 15 */
 121         dt->tm_sec = bcd2bin(buf[1]);
 122         dt->tm_min = bcd2bin(buf[2]);
 123
 124         if (TWELVE_HOUR_MODE(buf[0])) {
 125                 dt->tm_hour = HOURS_12(buf[3]);
 126                 if (HOURS_AP(buf[3])) /* PM */
 127                         dt->tm_hour += 12;
 128         } else /* 24-hour-mode */
 129                 dt->tm_hour = HOURS_24(buf[3]);
 130
 131         dt->tm_mday = bcd2bin(buf[5]);
 132         dt->tm_mon = bcd2bin(buf[6]);
 133         dt->tm_year = bcd2bin(buf[7]);
 134         if (dt->tm_year >= 70)
 135                 dt->tm_year += 1900;
 136         else
 137                 dt->tm_year += 2000;
 138         /* 0 is Sunday */
 139         dt->tm_wday = bcd2bin(buf[4] & 0x07);
 140         dt->tm_yday = 0;
 141         dt->tm_isdst= 0;
 142
 143         if(rtc_debug > 2) {
 144                 printf("rs5c372_convert_to_time: year = %d\n", dt->tm_year);
 145                 printf("rs5c372_convert_to_time: mon  = %d\n", dt->tm_mon);
 146                 printf("rs5c372_convert_to_time: mday = %d\n", dt->tm_mday);
 147                 printf("rs5c372_convert_to_time: hour = %d\n", dt->tm_hour);
 148                 printf("rs5c372_convert_to_time: min  = %d\n", dt->tm_min);
 149                 printf("rs5c372_convert_to_time: sec  = %d\n", dt->tm_sec);
 150         }
 151 }
 152
 153 /*
 154  * Get the current time from the RTC
 155  */
 156 int
 157 rtc_get (struct rtc_time *tmp)
 158 {
 159         unsigned char buf[RS5C372_RAM_SIZE];
 160         int ret;
 161
 162         if (!setup_done)
 163                 rs5c372_enable();
 164
 165         if (!setup_done)
 166                 return -1;
 167
 168         memset(buf, 0, sizeof(buf));
 169
 170         /* note that this returns reg. 15 in buf[0] */
 171         ret = rs5c372_readram(buf, RS5C372_RAM_SIZE);
 172         if (ret != 0) {
 173                 printf("%s: failed\n", __FUNCTION__);
 174                 return -1;
 175         }
 176
 177         rs5c372_convert_to_time(tmp, buf);
 178
 179         return 0;
 180 }
 181
 182 /*
 183  * Set the RTC
 184  */
 185 int rtc_set (struct rtc_time *tmp)
 186 {
 187         unsigned char buf[8], reg15;
 188         int ret;
 189
 190         if (!setup_done)
 191                 rs5c372_enable();
 192
 193         if (!setup_done)
 194                 return -1;
 195
 196         if(rtc_debug > 2) {
 197                 printf("rtc_set: tm_year = %d\n", tmp->tm_year);
 198                 printf("rtc_set: tm_mon  = %d\n", tmp->tm_mon);
 199                 printf("rtc_set: tm_mday = %d\n", tmp->tm_mday);
 200                 printf("rtc_set: tm_hour = %d\n", tmp->tm_hour);
 201                 printf("rtc_set: tm_min  = %d\n", tmp->tm_min);
 202                 printf("rtc_set: tm_sec  = %d\n", tmp->tm_sec);
 203         }
 204
 205         memset(buf, 0, sizeof(buf));
 206
 207         /* only read register 15 */
 208         ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 1);
 209
 210         if (ret == 0) {
 211                 /* need to save register 15 */
 212                 reg15 = buf[0];
 213                 buf[0] = 0;     /* register address on RS5C372 */
 214                 buf[1] = bin2bcd(tmp->tm_sec);
 215                 buf[2] = bin2bcd(tmp->tm_min);
 216                 /* need to handle 12 hour mode */
 217                 if (TWELVE_HOUR_MODE(reg15)) {
 218                         if (tmp->tm_hour >= 12) { /* PM */
 219                                 /* 12 PM is a special case */
 220                                 if (tmp->tm_hour == 12)
 221                                         buf[3] = bin2bcd(tmp->tm_hour);
 222                                 else
 223                                         buf[3] = bin2bcd(tmp->tm_hour - 12);
 224                                 buf[3] |= 0x20;
 225                         }
 226                 } else {
 227                         buf[3] = bin2bcd(tmp->tm_hour);
 228                 }
 229
 230                 buf[4] = bin2bcd(tmp->tm_wday);
 231                 buf[5] = bin2bcd(tmp->tm_mday);
 232                 buf[6] = bin2bcd(tmp->tm_mon);
 233                 if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
 234                         printf("WARNING: year should be between 1970 and 2069!\n");
 235                 buf[7] = bin2bcd(tmp->tm_year % 100);
 236
 237                 ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 8);
 238                 if (ret != 0) {
 239                         printf("rs5c372_set_datetime(), i2c_master_send() returned %d\n",ret);
 240                         return -1;
 241                 }
 242         } else {
 243                 return -1;
 244         }
 245
 246         return 0;
 247 }
 248
 249 /*
 250  * Reset the RTC. We set the date back to 1970-01-01.
 251  */
 252 void
 253 rtc_reset (void)
 254 {
 255         struct rtc_time tmp;
 256
 257         if (!setup_done)
 258                 rs5c372_enable();
 259
 260         if (!setup_done)
 261                 return;
 262
 263         tmp.tm_year = 1970;
 264         tmp.tm_mon = 1;
 265         /* Jan. 1, 1970 was a Thursday */
 266         tmp.tm_wday= 4;
 267         tmp.tm_mday= 1;
 268         tmp.tm_hour = 0;
 269         tmp.tm_min = 0;
 270         tmp.tm_sec = 0;
 271
 272         rtc_set(&tmp);
 273
 274         printf ("RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
 275                 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
 276                 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
 277
 278         return;
 279 }
 280
 281 #endif