drivers/rtc/ds1306.c

   1 /*
   2  * (C) Copyright 2002 SIXNET, dge@sixnetio.com.
   3  *
   4  * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
   5  * Stephan Linz <linz@li-pro.net>
   6  *
   7  * See file CREDITS for list of people who contributed to this
   8  * project.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of
  13  * the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  23  * MA 02111-1307 USA
  24  */
  25
  26 /*
  27  * Date & Time support for DS1306 RTC using SPI:
  28  *
  29  *    - SXNI855T:    it uses its own soft SPI here in this file
  30  *    - all other:   use the external spi_xfer() function
  31  *                   (see include/spi.h)
  32  */
  33
  34 #include <common.h>
  35 #include <command.h>
  36 #include <rtc.h>
  37 #include <spi.h>
  38
  39 #if defined(CONFIG_RTC_DS1306) && defined(CONFIG_CMD_DATE)
  40
  41 #define RTC_SECONDS             0x00
  42 #define RTC_MINUTES             0x01
  43 #define RTC_HOURS               0x02
  44 #define RTC_DAY_OF_WEEK         0x03
  45 #define RTC_DATE_OF_MONTH       0x04
  46 #define RTC_MONTH               0x05
  47 #define RTC_YEAR                0x06
  48
  49 #define RTC_SECONDS_ALARM0      0x07
  50 #define RTC_MINUTES_ALARM0      0x08
  51 #define RTC_HOURS_ALARM0        0x09
  52 #define RTC_DAY_OF_WEEK_ALARM0  0x0a
  53
  54 #define RTC_SECONDS_ALARM1      0x0b
  55 #define RTC_MINUTES_ALARM1      0x0c
  56 #define RTC_HOURS_ALARM1        0x0d
  57 #define RTC_DAY_OF_WEEK_ALARM1  0x0e
  58
  59 #define RTC_CONTROL             0x0f
  60 #define RTC_STATUS              0x10
  61 #define RTC_TRICKLE_CHARGER     0x11
  62
  63 #define RTC_USER_RAM_BASE       0x20
  64
  65 /*
  66  * External table of chip select functions (see the appropriate board
  67  * support for the actual definition of the table).
  68  */
  69 extern spi_chipsel_type spi_chipsel[];
  70 extern int spi_chipsel_cnt;
  71
  72 static unsigned int bin2bcd (unsigned int n);
  73 static unsigned char bcd2bin (unsigned char c);
  74
  75 /* ************************************************************************* */
  76 #ifdef CONFIG_SXNI855T          /* !!! SHOULD BE CHANGED TO NEW CODE !!! */
  77
  78 static void soft_spi_send (unsigned char n);
  79 static unsigned char soft_spi_read (void);
  80 static void init_spi (void);
  81
  82 /*-----------------------------------------------------------------------
  83  * Definitions
  84  */
  85
  86 #define PB_SPISCK       0x00000002      /* PB 30 */
  87 #define PB_SPIMOSI      0x00000004      /* PB 29 */
  88 #define PB_SPIMISO      0x00000008      /* PB 28 */
  89 #define PB_SPI_CE       0x00010000      /* PB 15 */
  90
  91 /* ------------------------------------------------------------------------- */
  92
  93 /* read clock time from DS1306 and return it in *tmp */
  94 int rtc_get (struct rtc_time *tmp)
  95 {
  96         volatile immap_t *immap = (immap_t *) CFG_IMMR;
  97         unsigned char spi_byte; /* Data Byte */
  98
  99         init_spi ();            /* set port B for software SPI */
 100
 101         /* Now we can enable the DS1306 RTC */
 102         immap->im_cpm.cp_pbdat |= PB_SPI_CE;
 103         udelay (10);
 104
 105         /* Shift out the address (0) of the time in the Clock Chip */
 106         soft_spi_send (0);
 107
 108         /* Put the clock readings into the rtc_time structure */
 109         tmp->tm_sec = bcd2bin (soft_spi_read ());       /* Read seconds */
 110         tmp->tm_min = bcd2bin (soft_spi_read ());       /* Read minutes */
 111
 112         /* Hours are trickier */
 113         spi_byte = soft_spi_read ();    /* Read Hours into temporary value */
 114         if (spi_byte & 0x40) {
 115                 /* 12 hour mode bit is set (time is in 1-12 format) */
 116                 if (spi_byte & 0x20) {
 117                         /* since PM we add 11 to get 0-23 for hours */
 118                         tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
 119                 } else {
 120                         /* since AM we subtract 1 to get 0-23 for hours */
 121                         tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
 122                 }
 123         } else {
 124                 /* Otherwise, 0-23 hour format */
 125                 tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
 126         }
 127
 128         soft_spi_read ();       /* Read and discard Day of week */
 129         tmp->tm_mday = bcd2bin (soft_spi_read ());      /* Read Day of the Month */
 130         tmp->tm_mon = bcd2bin (soft_spi_read ());       /* Read Month */
 131
 132         /* Read Year and convert to this century */
 133         tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;
 134
 135         /* Now we can disable the DS1306 RTC */
 136         immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 137         udelay (10);
 138
 139         GregorianDay (tmp);     /* Determine the day of week */
 140
 141         debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 142                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 143                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 144
 145         return 0;
 146 }
 147
 148 /* ------------------------------------------------------------------------- */
 149
 150 /* set clock time in DS1306 RTC and in MPC8xx RTC */
 151 void rtc_set (struct rtc_time *tmp)
 152 {
 153         volatile immap_t *immap = (immap_t *) CFG_IMMR;
 154
 155         init_spi ();            /* set port B for software SPI */
 156
 157         /* Now we can enable the DS1306 RTC */
 158         immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 159         udelay (10);
 160
 161         /* First disable write protect in the clock chip control register */
 162         soft_spi_send (0x8F);   /* send address of the control register */
 163         soft_spi_send (0x00);   /* send control register contents */
 164
 165         /* Now disable the DS1306 to terminate the write */
 166         immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
 167         udelay (10);
 168
 169         /* Now enable the DS1306 to initiate a new write */
 170         immap->im_cpm.cp_pbdat |= PB_SPI_CE;
 171         udelay (10);
 172
 173         /* Next, send the address of the clock time write registers */
 174         soft_spi_send (0x80);   /* send address of the first time register */
 175
 176         /* Use Burst Mode to send all of the time data to the clock */
 177         bin2bcd (tmp->tm_sec);
 178         soft_spi_send (bin2bcd (tmp->tm_sec));  /* Send Seconds */
 179         soft_spi_send (bin2bcd (tmp->tm_min));  /* Send Minutes */
 180         soft_spi_send (bin2bcd (tmp->tm_hour)); /* Send Hour */
 181         soft_spi_send (bin2bcd (tmp->tm_wday)); /* Send Day of the Week */
 182         soft_spi_send (bin2bcd (tmp->tm_mday)); /* Send Day of Month */
 183         soft_spi_send (bin2bcd (tmp->tm_mon));  /* Send Month */
 184         soft_spi_send (bin2bcd (tmp->tm_year - 2000));  /* Send Year */
 185
 186         /* Now we can disable the Clock chip to terminate the burst write */
 187         immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 188         udelay (10);
 189
 190         /* Now we can enable the Clock chip to initiate a new write */
 191         immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 192         udelay (10);
 193
 194         /* First we Enable write protect in the clock chip control register */
 195         soft_spi_send (0x8F);   /* send address of the control register */
 196         soft_spi_send (0x40);   /* send out Control Register contents */
 197
 198         /* Now disable the DS1306 */
 199         immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /*  Disable DS1306 Chip */
 200         udelay (10);
 201
 202         /* Set standard MPC8xx clock to the same time so Linux will
 203          * see the time even if it doesn't have a DS1306 clock driver.
 204          * This helps with experimenting with standard kernels.
 205          */
 206         {
 207                 ulong tim;
 208
 209                 tim = mktime (tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
 210                               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 211
 212                 immap->im_sitk.sitk_rtck = KAPWR_KEY;
 213                 immap->im_sit.sit_rtc = tim;
 214         }
 215
 216         debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 217                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 218                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 219 }
 220
 221 /* ------------------------------------------------------------------------- */
 222
 223 /* Initialize Port B for software SPI */
 224 static void init_spi (void)
 225 {
 226         volatile immap_t *immap = (immap_t *) CFG_IMMR;
 227
 228         /* Force output pins to begin at logic 0 */
 229         immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);
 230
 231         /* Set these 3 signals as outputs */
 232         immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
 233
 234         immap->im_cpm.cp_pbdir &= ~PB_SPIMISO;  /* Make MISO pin an input */
 235         udelay (10);
 236 }
 237
 238 /* ------------------------------------------------------------------------- */
 239
 240 /* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
 241 static void soft_spi_send (unsigned char n)
 242 {
 243         volatile immap_t *immap = (immap_t *) CFG_IMMR;
 244         unsigned char bitpos;   /* bit position to receive */
 245         unsigned char i;        /* Loop Control */
 246
 247         /* bit position to send, start with most significant bit */
 248         bitpos = 0x80;
 249
 250         /* Send 8 bits to software SPI */
 251         for (i = 0; i < 8; i++) {       /* Loop for 8 bits */
 252                 immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 253
 254                 if (n & bitpos)
 255                         immap->im_cpm.cp_pbdat |= PB_SPIMOSI;   /* Set MOSI to 1 */
 256                 else
 257                         immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI;  /* Set MOSI to 0 */
 258                 udelay (10);
 259
 260                 immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 261                 udelay (10);
 262
 263                 bitpos >>= 1;   /* Shift for next bit position */
 264         }
 265 }
 266
 267 /* ------------------------------------------------------------------------- */
 268
 269 /* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
 270 static unsigned char soft_spi_read (void)
 271 {
 272         volatile immap_t *immap = (immap_t *) CFG_IMMR;
 273
 274         unsigned char spi_byte = 0;     /* Return value, assume success */
 275         unsigned char bitpos;   /* bit position to receive */
 276         unsigned char i;        /* Loop Control */
 277
 278         /* bit position to receive, start with most significant bit */
 279         bitpos = 0x80;
 280
 281         /* Read 8 bits here */
 282         for (i = 0; i < 8; i++) {       /* Do 8 bits in loop */
 283                 immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 284                 udelay (10);
 285                 if (immap->im_cpm.cp_pbdat & PB_SPIMISO)        /* Get a bit of data */
 286                         spi_byte |= bitpos;     /* Set data accordingly */
 287                 immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 288                 udelay (10);
 289                 bitpos >>= 1;   /* Shift for next bit position */
 290         }
 291
 292         return spi_byte;        /* Return the byte read */
 293 }
 294
 295 /* ------------------------------------------------------------------------- */
 296
 297 void rtc_reset (void)
 298 {
 299         return;                 /* nothing to do */
 300 }
 301
 302 #else  /* not CONFIG_SXNI855T */
 303 /* ************************************************************************* */
 304
 305 static unsigned char rtc_read (unsigned char reg);
 306 static void rtc_write (unsigned char reg, unsigned char val);
 307
 308 /* read clock time from DS1306 and return it in *tmp */
 309 int rtc_get (struct rtc_time *tmp)
 310 {
 311         unsigned char sec, min, hour, mday, wday, mon, year;
 312
 313         sec = rtc_read (RTC_SECONDS);
 314         min = rtc_read (RTC_MINUTES);
 315         hour = rtc_read (RTC_HOURS);
 316         mday = rtc_read (RTC_DATE_OF_MONTH);
 317         wday = rtc_read (RTC_DAY_OF_WEEK);
 318         mon = rtc_read (RTC_MONTH);
 319         year = rtc_read (RTC_YEAR);
 320
 321         debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
 322                "hr: %02x min: %02x sec: %02x\n",
 323                year, mon, mday, wday, hour, min, sec);
 324         debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 325                rtc_read (RTC_DAY_OF_WEEK_ALARM0),
 326                rtc_read (RTC_HOURS_ALARM0),
 327                rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
 328         debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 329                rtc_read (RTC_DAY_OF_WEEK_ALARM1),
 330                rtc_read (RTC_HOURS_ALARM1),
 331                rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));
 332
 333         tmp->tm_sec = bcd2bin (sec & 0x7F);     /* convert Seconds */
 334         tmp->tm_min = bcd2bin (min & 0x7F);     /* convert Minutes */
 335
 336         /* convert Hours */
 337         tmp->tm_hour = (hour & 0x40)
 338                 ? ((hour & 0x20)        /* 12 hour mode */
 339                    ? bcd2bin (hour & 0x1F) + 11 /* PM */
 340                    : bcd2bin (hour & 0x1F) - 1  /* AM */
 341                 )
 342                 : bcd2bin (hour & 0x3F);        /* 24 hour mode */
 343
 344         tmp->tm_mday = bcd2bin (mday & 0x3F);   /* convert Day of the Month */
 345         tmp->tm_mon = bcd2bin (mon & 0x1F);     /* convert Month */
 346         tmp->tm_year = bcd2bin (year) + 2000;   /* convert Year */
 347         tmp->tm_wday = bcd2bin (wday & 0x07) - 1;       /* convert Day of the Week */
 348         tmp->tm_yday = 0;
 349         tmp->tm_isdst = 0;
 350
 351         debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 352                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 353                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 354
 355         return 0;
 356 }
 357
 358 /* ------------------------------------------------------------------------- */
 359
 360 /* set clock time from *tmp in DS1306 RTC */
 361 void rtc_set (struct rtc_time *tmp)
 362 {
 363         debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 364                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 365                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 366
 367         rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));
 368         rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
 369         rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
 370         rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
 371         rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
 372         rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
 373         rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));
 374 }
 375
 376 /* ------------------------------------------------------------------------- */
 377
 378 /* reset the DS1306 */
 379 void rtc_reset (void)
 380 {
 381         /* clear the control register */
 382         rtc_write (RTC_CONTROL, 0x00);  /* 1st step: reset WP */
 383         rtc_write (RTC_CONTROL, 0x00);  /* 2nd step: reset 1Hz, AIE1, AIE0 */
 384
 385         /* reset all alarms */
 386         rtc_write (RTC_SECONDS_ALARM0, 0x00);
 387         rtc_write (RTC_SECONDS_ALARM1, 0x00);
 388         rtc_write (RTC_MINUTES_ALARM0, 0x00);
 389         rtc_write (RTC_MINUTES_ALARM1, 0x00);
 390         rtc_write (RTC_HOURS_ALARM0, 0x00);
 391         rtc_write (RTC_HOURS_ALARM1, 0x00);
 392         rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
 393         rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);
 394 }
 395
 396 /* ------------------------------------------------------------------------- */
 397
 398 static unsigned char rtc_read (unsigned char reg)
 399 {
 400         unsigned char dout[2];  /* SPI Output Data Bytes */
 401         unsigned char din[2];   /* SPI Input Data Bytes */
 402
 403         dout[0] = reg;
 404
 405         if (spi_xfer (spi_chipsel[CFG_SPI_RTC_DEVID], 16, dout, din) != 0) {
 406                 return 0;
 407         } else {
 408                 return din[1];
 409         }
 410 }
 411
 412 /* ------------------------------------------------------------------------- */
 413
 414 static void rtc_write (unsigned char reg, unsigned char val)
 415 {
 416         unsigned char dout[2];  /* SPI Output Data Bytes */
 417         unsigned char din[2];   /* SPI Input Data Bytes */
 418
 419         dout[0] = 0x80 | reg;
 420         dout[1] = val;
 421
 422         spi_xfer (spi_chipsel[CFG_SPI_RTC_DEVID], 16, dout, din);
 423 }
 424
 425 #endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */
 426
 427 /* ------------------------------------------------------------------------- */
 428
 429 static unsigned char bcd2bin (unsigned char n)
 430 {
 431         return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
 432 }
 433
 434 /* ------------------------------------------------------------------------- */
 435
 436 static unsigned int bin2bcd (unsigned int n)
 437 {
 438         return (((n / 10) << 4) | (n % 10));
 439 }
 440 /* ------------------------------------------------------------------------- */
 441
 442 #endif