drivers/rtc/ds1307.c

   1 /*
   2  * (C) Copyright 2001, 2002, 2003
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  * Keith Outwater, keith_outwater@mvis.com`
   5  * Steven Scholz, steven.scholz@imc-berlin.de
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 /*
  11  * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
  12  * DS1307 and DS1338/9 Real Time Clock (RTC).
  13  *
  14  * based on ds1337.c
  15  */
  16
  17 #include <common.h>
  18 #include <command.h>
  19 #include <dm.h>
  20 #include <rtc.h>
  21 #include <i2c.h>
  22
  23 enum ds_type {
  24         ds_1307,
  25         ds_1337,
  26         ds_1340,
  27         mcp794xx,
  28 };
  29
  30 /*
  31  * RTC register addresses
  32  */
  33 #define RTC_SEC_REG_ADDR        0x00
  34 #define RTC_MIN_REG_ADDR        0x01
  35 #define RTC_HR_REG_ADDR         0x02
  36 #define RTC_DAY_REG_ADDR        0x03
  37 #define RTC_DATE_REG_ADDR       0x04
  38 #define RTC_MON_REG_ADDR        0x05
  39 #define RTC_YR_REG_ADDR         0x06
  40 #define RTC_CTL_REG_ADDR        0x07
  41
  42 #define RTC_SEC_BIT_CH          0x80    /* Clock Halt (in Register 0)   */
  43
  44 #define RTC_CTL_BIT_RS0         0x01    /* Rate select 0                */
  45 #define RTC_CTL_BIT_RS1         0x02    /* Rate select 1                */
  46 #define RTC_CTL_BIT_SQWE        0x10    /* Square Wave Enable           */
  47 #define RTC_CTL_BIT_OUT         0x80    /* Output Control               */
  48
  49 /* MCP7941X-specific bits */
  50 #define MCP7941X_BIT_ST         0x80
  51 #define MCP7941X_BIT_VBATEN     0x08
  52
  53 #ifndef CONFIG_DM_RTC
  54
  55 #if defined(CONFIG_CMD_DATE)
  56
  57 /*---------------------------------------------------------------------*/
  58 #undef DEBUG_RTC
  59
  60 #ifdef DEBUG_RTC
  61 #define DEBUGR(fmt, args...) printf(fmt, ##args)
  62 #else
  63 #define DEBUGR(fmt, args...)
  64 #endif
  65 /*---------------------------------------------------------------------*/
  66
  67 #ifndef CONFIG_SYS_I2C_RTC_ADDR
  68 # define CONFIG_SYS_I2C_RTC_ADDR        0x68
  69 #endif
  70
  71 #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
  72 # error The DS1307 is specified only up to 100kHz!
  73 #endif
  74
  75 static uchar rtc_read (uchar reg);
  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;
  85
  86 #ifdef CONFIG_RTC_MCP79411
  87 read_rtc:
  88 #endif
  89         sec = rtc_read (RTC_SEC_REG_ADDR);
  90         min = rtc_read (RTC_MIN_REG_ADDR);
  91         hour = rtc_read (RTC_HR_REG_ADDR);
  92         wday = rtc_read (RTC_DAY_REG_ADDR);
  93         mday = rtc_read (RTC_DATE_REG_ADDR);
  94         mon = rtc_read (RTC_MON_REG_ADDR);
  95         year = rtc_read (RTC_YR_REG_ADDR);
  96
  97         DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  98                 "hr: %02x min: %02x sec: %02x\n",
  99                 year, mon, mday, wday, hour, min, sec);
 100
 101 #ifdef CONFIG_RTC_DS1307
 102         if (sec & RTC_SEC_BIT_CH) {
 103                 printf ("### Warning: RTC oscillator has stopped\n");
 104                 /* clear the CH flag */
 105                 rtc_write (RTC_SEC_REG_ADDR,
 106                            rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
 107                 rel = -1;
 108         }
 109 #endif
 110
 111 #ifdef CONFIG_RTC_MCP79411
 112         /* make sure that the backup battery is enabled */
 113         if (!(wday & MCP7941X_BIT_VBATEN)) {
 114                 rtc_write(RTC_DAY_REG_ADDR,
 115                           wday | MCP7941X_BIT_VBATEN);
 116         }
 117
 118         /* clock halted?  turn it on, so clock can tick. */
 119         if (!(sec & MCP7941X_BIT_ST)) {
 120                 rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST);
 121                 printf("Started RTC\n");
 122                 goto read_rtc;
 123         }
 124 #endif
 125
 126
 127         tmp->tm_sec  = bcd2bin (sec & 0x7F);
 128         tmp->tm_min  = bcd2bin (min & 0x7F);
 129         tmp->tm_hour = bcd2bin (hour & 0x3F);
 130         tmp->tm_mday = bcd2bin (mday & 0x3F);
 131         tmp->tm_mon  = bcd2bin (mon & 0x1F);
 132         tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
 133         tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
 134         tmp->tm_yday = 0;
 135         tmp->tm_isdst= 0;
 136
 137         DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 138                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 139                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 140
 141         return rel;
 142 }
 143
 144
 145 /*
 146  * Set the RTC
 147  */
 148 int 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 #ifdef CONFIG_RTC_MCP79411
 160         rtc_write (RTC_DAY_REG_ADDR,
 161                    bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN);
 162 #else
 163         rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
 164 #endif
 165         rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
 166         rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
 167         rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
 168 #ifdef CONFIG_RTC_MCP79411
 169         rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST);
 170 #else
 171         rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
 172 #endif
 173
 174         return 0;
 175 }
 176
 177
 178 /*
 179  * Reset the RTC. We setting the date back to 1970-01-01.
 180  * We also enable the oscillator output on the SQW/OUT pin and program
 181  * it for 32,768 Hz output. Note that according to the datasheet, turning
 182  * on the square wave output increases the current drain on the backup
 183  * battery to something between 480nA and 800nA.
 184  */
 185 void rtc_reset (void)
 186 {
 187         struct rtc_time tmp;
 188
 189         rtc_write (RTC_SEC_REG_ADDR, 0x00);     /* clearing Clock Halt  */
 190         rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
 191
 192         tmp.tm_year = 1970;
 193         tmp.tm_mon = 1;
 194         tmp.tm_mday= 1;
 195         tmp.tm_hour = 0;
 196         tmp.tm_min = 0;
 197         tmp.tm_sec = 0;
 198
 199         rtc_set(&tmp);
 200
 201         printf ( "RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
 202                 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
 203                 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
 204
 205         return;
 206 }
 207
 208
 209 /*
 210  * Helper functions
 211  */
 212
 213 static
 214 uchar rtc_read (uchar reg)
 215 {
 216         return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
 217 }
 218
 219
 220 static void rtc_write (uchar reg, uchar val)
 221 {
 222         i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 223 }
 224
 225 #endif /* CONFIG_CMD_DATE*/
 226
 227 #endif /* !CONFIG_DM_RTC */
 228
 229 #ifdef CONFIG_DM_RTC
 230 static int ds1307_rtc_set(struct udevice *dev, const struct rtc_time *tm)
 231 {
 232         int ret;
 233         uchar buf[7];
 234         enum ds_type type = dev_get_driver_data(dev);
 235
 236         debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 237               tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
 238               tm->tm_hour, tm->tm_min, tm->tm_sec);
 239
 240         if (tm->tm_year < 1970 || tm->tm_year > 2069)
 241                 printf("WARNING: year should be between 1970 and 2069!\n");
 242
 243         buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
 244         buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
 245         buf[RTC_DAY_REG_ADDR] = bin2bcd(tm->tm_wday + 1);
 246         buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
 247         buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
 248         buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
 249         buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
 250
 251         if (type == mcp794xx) {
 252                 buf[RTC_DAY_REG_ADDR] |= MCP7941X_BIT_VBATEN;
 253                 buf[RTC_SEC_REG_ADDR] |= MCP7941X_BIT_ST;
 254         }
 255
 256         ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
 257         if (ret < 0)
 258                 return ret;
 259
 260         return 0;
 261 }
 262
 263 static int ds1307_rtc_get(struct udevice *dev, struct rtc_time *tm)
 264 {
 265         int ret;
 266         uchar buf[7];
 267         enum ds_type type = dev_get_driver_data(dev);
 268
 269 read_rtc:
 270         ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
 271         if (ret < 0)
 272                 return ret;
 273
 274         if (type == ds_1307) {
 275                 if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
 276                         printf("### Warning: RTC oscillator has stopped\n");
 277                         /* clear the CH flag */
 278                         buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
 279                         dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
 280                                          buf[RTC_SEC_REG_ADDR]);
 281                         return -1;
 282                 }
 283         }
 284
 285         if (type == mcp794xx) {
 286                 /* make sure that the backup battery is enabled */
 287                 if (!(buf[RTC_DAY_REG_ADDR] & MCP7941X_BIT_VBATEN)) {
 288                         dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR,
 289                                          buf[RTC_DAY_REG_ADDR] |
 290                                          MCP7941X_BIT_VBATEN);
 291                 }
 292
 293                 /* clock halted?  turn it on, so clock can tick. */
 294                 if (!(buf[RTC_SEC_REG_ADDR] & MCP7941X_BIT_ST)) {
 295                         dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
 296                                          MCP7941X_BIT_ST);
 297                         printf("Started RTC\n");
 298                         goto read_rtc;
 299                 }
 300         }
 301
 302         tm->tm_sec  = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
 303         tm->tm_min  = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
 304         tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
 305         tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
 306         tm->tm_mon  = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
 307         tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) +
 308                               (bcd2bin(buf[RTC_YR_REG_ADDR]) >= 70 ?
 309                                1900 : 2000);
 310         tm->tm_wday = bcd2bin((buf[RTC_DAY_REG_ADDR] - 1) & 0x07);
 311         tm->tm_yday = 0;
 312         tm->tm_isdst = 0;
 313
 314         debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 315               tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
 316               tm->tm_hour, tm->tm_min, tm->tm_sec);
 317
 318         return 0;
 319 }
 320
 321 static int ds1307_rtc_reset(struct udevice *dev)
 322 {
 323         int ret;
 324         struct rtc_time tmp = {
 325                 .tm_year = 1970,
 326                 .tm_mon = 1,
 327                 .tm_mday = 1,
 328                 .tm_hour = 0,
 329                 .tm_min = 0,
 330                 .tm_sec = 0,
 331         };
 332
 333         /* clear Clock Halt */
 334         ret = dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 0x00);
 335         if (ret < 0)
 336                 return ret;
 337         ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
 338                                RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 |
 339                                RTC_CTL_BIT_RS0);
 340         if (ret < 0)
 341                 return ret;
 342
 343         ret = ds1307_rtc_set(dev, &tmp);
 344         if (ret < 0)
 345                 return ret;
 346
 347         debug("RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
 348               tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
 349               tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
 350
 351         return 0;
 352 }
 353
 354 static int ds1307_probe(struct udevice *dev)
 355 {
 356         i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
 357                            DM_I2C_CHIP_WR_ADDRESS);
 358
 359         return 0;
 360 }
 361
 362 static const struct rtc_ops ds1307_rtc_ops = {
 363         .get = ds1307_rtc_get,
 364         .set = ds1307_rtc_set,
 365         .reset = ds1307_rtc_reset,
 366 };
 367
 368 static const struct udevice_id ds1307_rtc_ids[] = {
 369         { .compatible = "dallas,ds1307", .data = ds_1307 },
 370         { .compatible = "dallas,ds1337", .data = ds_1337 },
 371         { .compatible = "dallas,ds1340", .data = ds_1340 },
 372         { .compatible = "microchip,mcp7941x", .data = mcp794xx },
 373         { }
 374 };
 375
 376 U_BOOT_DRIVER(rtc_ds1307) = {
 377         .name   = "rtc-ds1307",
 378         .id     = UCLASS_RTC,
 379         .probe  = ds1307_probe,
 380         .of_match = ds1307_rtc_ids,
 381         .ops    = &ds1307_rtc_ops,
 382 };
 383 #endif /* CONFIG_DM_RTC */