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_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 #ifdef CONFIG_SXNI855T          /* !!! SHOULD BE CHANGED TO NEW CODE !!! */
  67
  68 static void soft_spi_send (unsigned char n);
  69 static unsigned char soft_spi_read (void);
  70 static void init_spi (void);
  71
  72 /*-----------------------------------------------------------------------
  73  * Definitions
  74  */
  75
  76 #define PB_SPISCK       0x00000002      /* PB 30 */
  77 #define PB_SPIMOSI      0x00000004      /* PB 29 */
  78 #define PB_SPIMISO      0x00000008      /* PB 28 */
  79 #define PB_SPI_CE       0x00010000      /* PB 15 */
  80
  81 /* ------------------------------------------------------------------------- */
  82
  83 /* read clock time from DS1306 and return it in *tmp */
  84 int rtc_get (struct rtc_time *tmp)
  85 {
  86         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  87         unsigned char spi_byte; /* Data Byte */
  88
  89         init_spi ();            /* set port B for software SPI */
  90
  91         /* Now we can enable the DS1306 RTC */
  92         immap->im_cpm.cp_pbdat |= PB_SPI_CE;
  93         udelay (10);
  94
  95         /* Shift out the address (0) of the time in the Clock Chip */
  96         soft_spi_send (0);
  97
  98         /* Put the clock readings into the rtc_time structure */
  99         tmp->tm_sec = bcd2bin (soft_spi_read ());       /* Read seconds */
 100         tmp->tm_min = bcd2bin (soft_spi_read ());       /* Read minutes */
 101
 102         /* Hours are trickier */
 103         spi_byte = soft_spi_read ();    /* Read Hours into temporary value */
 104         if (spi_byte & 0x40) {
 105                 /* 12 hour mode bit is set (time is in 1-12 format) */
 106                 if (spi_byte & 0x20) {
 107                         /* since PM we add 11 to get 0-23 for hours */
 108                         tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
 109                 } else {
 110                         /* since AM we subtract 1 to get 0-23 for hours */
 111                         tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
 112                 }
 113         } else {
 114                 /* Otherwise, 0-23 hour format */
 115                 tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
 116         }
 117
 118         soft_spi_read ();       /* Read and discard Day of week */
 119         tmp->tm_mday = bcd2bin (soft_spi_read ());      /* Read Day of the Month */
 120         tmp->tm_mon = bcd2bin (soft_spi_read ());       /* Read Month */
 121
 122         /* Read Year and convert to this century */
 123         tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;
 124
 125         /* Now we can disable the DS1306 RTC */
 126         immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 127         udelay (10);
 128
 129         GregorianDay (tmp);     /* Determine the day of week */
 130
 131         debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 132                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 133                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 134
 135         return 0;
 136 }
 137
 138 /* ------------------------------------------------------------------------- */
 139
 140 /* set clock time in DS1306 RTC and in MPC8xx RTC */
 141 int rtc_set (struct rtc_time *tmp)
 142 {
 143         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 144
 145         init_spi ();            /* set port B for software SPI */
 146
 147         /* Now we can enable the DS1306 RTC */
 148         immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 149         udelay (10);
 150
 151         /* First disable write protect in the clock chip control register */
 152         soft_spi_send (0x8F);   /* send address of the control register */
 153         soft_spi_send (0x00);   /* send control register contents */
 154
 155         /* Now disable the DS1306 to terminate the write */
 156         immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
 157         udelay (10);
 158
 159         /* Now enable the DS1306 to initiate a new write */
 160         immap->im_cpm.cp_pbdat |= PB_SPI_CE;
 161         udelay (10);
 162
 163         /* Next, send the address of the clock time write registers */
 164         soft_spi_send (0x80);   /* send address of the first time register */
 165
 166         /* Use Burst Mode to send all of the time data to the clock */
 167         bin2bcd (tmp->tm_sec);
 168         soft_spi_send (bin2bcd (tmp->tm_sec));  /* Send Seconds */
 169         soft_spi_send (bin2bcd (tmp->tm_min));  /* Send Minutes */
 170         soft_spi_send (bin2bcd (tmp->tm_hour)); /* Send Hour */
 171         soft_spi_send (bin2bcd (tmp->tm_wday)); /* Send Day of the Week */
 172         soft_spi_send (bin2bcd (tmp->tm_mday)); /* Send Day of Month */
 173         soft_spi_send (bin2bcd (tmp->tm_mon));  /* Send Month */
 174         soft_spi_send (bin2bcd (tmp->tm_year - 2000));  /* Send Year */
 175
 176         /* Now we can disable the Clock chip to terminate the burst write */
 177         immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 178         udelay (10);
 179
 180         /* Now we can enable the Clock chip to initiate a new write */
 181         immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 182         udelay (10);
 183
 184         /* First we Enable write protect in the clock chip control register */
 185         soft_spi_send (0x8F);   /* send address of the control register */
 186         soft_spi_send (0x40);   /* send out Control Register contents */
 187
 188         /* Now disable the DS1306 */
 189         immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /*  Disable DS1306 Chip */
 190         udelay (10);
 191
 192         /* Set standard MPC8xx clock to the same time so Linux will
 193          * see the time even if it doesn't have a DS1306 clock driver.
 194          * This helps with experimenting with standard kernels.
 195          */
 196         {
 197                 ulong tim;
 198
 199                 tim = mktime (tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
 200                               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 201
 202                 immap->im_sitk.sitk_rtck = KAPWR_KEY;
 203                 immap->im_sit.sit_rtc = tim;
 204         }
 205
 206         debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 207                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 208                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 209
 210         return 0;
 211 }
 212
 213 /* ------------------------------------------------------------------------- */
 214
 215 /* Initialize Port B for software SPI */
 216 static void init_spi (void)
 217 {
 218         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 219
 220         /* Force output pins to begin at logic 0 */
 221         immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);
 222
 223         /* Set these 3 signals as outputs */
 224         immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
 225
 226         immap->im_cpm.cp_pbdir &= ~PB_SPIMISO;  /* Make MISO pin an input */
 227         udelay (10);
 228 }
 229
 230 /* ------------------------------------------------------------------------- */
 231
 232 /* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
 233 static void soft_spi_send (unsigned char n)
 234 {
 235         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 236         unsigned char bitpos;   /* bit position to receive */
 237         unsigned char i;        /* Loop Control */
 238
 239         /* bit position to send, start with most significant bit */
 240         bitpos = 0x80;
 241
 242         /* Send 8 bits to software SPI */
 243         for (i = 0; i < 8; i++) {       /* Loop for 8 bits */
 244                 immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 245
 246                 if (n & bitpos)
 247                         immap->im_cpm.cp_pbdat |= PB_SPIMOSI;   /* Set MOSI to 1 */
 248                 else
 249                         immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI;  /* Set MOSI to 0 */
 250                 udelay (10);
 251
 252                 immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 253                 udelay (10);
 254
 255                 bitpos >>= 1;   /* Shift for next bit position */
 256         }
 257 }
 258
 259 /* ------------------------------------------------------------------------- */
 260
 261 /* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
 262 static unsigned char soft_spi_read (void)
 263 {
 264         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 265
 266         unsigned char spi_byte = 0;     /* Return value, assume success */
 267         unsigned char bitpos;   /* bit position to receive */
 268         unsigned char i;        /* Loop Control */
 269
 270         /* bit position to receive, start with most significant bit */
 271         bitpos = 0x80;
 272
 273         /* Read 8 bits here */
 274         for (i = 0; i < 8; i++) {       /* Do 8 bits in loop */
 275                 immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 276                 udelay (10);
 277                 if (immap->im_cpm.cp_pbdat & PB_SPIMISO)        /* Get a bit of data */
 278                         spi_byte |= bitpos;     /* Set data accordingly */
 279                 immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 280                 udelay (10);
 281                 bitpos >>= 1;   /* Shift for next bit position */
 282         }
 283
 284         return spi_byte;        /* Return the byte read */
 285 }
 286
 287 /* ------------------------------------------------------------------------- */
 288
 289 void rtc_reset (void)
 290 {
 291         return;                 /* nothing to do */
 292 }
 293
 294 #else  /* not CONFIG_SXNI855T */
 295 /* ************************************************************************* */
 296
 297 static unsigned char rtc_read (unsigned char reg);
 298 static void rtc_write (unsigned char reg, unsigned char val);
 299
 300 static struct spi_slave *slave;
 301
 302 /* read clock time from DS1306 and return it in *tmp */
 303 int rtc_get (struct rtc_time *tmp)
 304 {
 305         unsigned char sec, min, hour, mday, wday, mon, year;
 306
 307         /*
 308          * Assuming Vcc = 2.0V (lowest speed)
 309          *
 310          * REVISIT: If we add an rtc_init() function we can do this
 311          * step just once.
 312          */
 313         if (!slave) {
 314                 slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 315                                 SPI_MODE_3 | SPI_CS_HIGH);
 316                 if (!slave)
 317                         return;
 318         }
 319
 320         if (spi_claim_bus(slave))
 321                 return;
 322
 323         sec = rtc_read (RTC_SECONDS);
 324         min = rtc_read (RTC_MINUTES);
 325         hour = rtc_read (RTC_HOURS);
 326         mday = rtc_read (RTC_DATE_OF_MONTH);
 327         wday = rtc_read (RTC_DAY_OF_WEEK);
 328         mon = rtc_read (RTC_MONTH);
 329         year = rtc_read (RTC_YEAR);
 330
 331         spi_release_bus(slave);
 332
 333         debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
 334                "hr: %02x min: %02x sec: %02x\n",
 335                year, mon, mday, wday, hour, min, sec);
 336         debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 337                rtc_read (RTC_DAY_OF_WEEK_ALARM0),
 338                rtc_read (RTC_HOURS_ALARM0),
 339                rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
 340         debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 341                rtc_read (RTC_DAY_OF_WEEK_ALARM1),
 342                rtc_read (RTC_HOURS_ALARM1),
 343                rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));
 344
 345         tmp->tm_sec = bcd2bin (sec & 0x7F);     /* convert Seconds */
 346         tmp->tm_min = bcd2bin (min & 0x7F);     /* convert Minutes */
 347
 348         /* convert Hours */
 349         tmp->tm_hour = (hour & 0x40)
 350                 ? ((hour & 0x20)        /* 12 hour mode */
 351                    ? bcd2bin (hour & 0x1F) + 11 /* PM */
 352                    : bcd2bin (hour & 0x1F) - 1  /* AM */
 353                 )
 354                 : bcd2bin (hour & 0x3F);        /* 24 hour mode */
 355
 356         tmp->tm_mday = bcd2bin (mday & 0x3F);   /* convert Day of the Month */
 357         tmp->tm_mon = bcd2bin (mon & 0x1F);     /* convert Month */
 358         tmp->tm_year = bcd2bin (year) + 2000;   /* convert Year */
 359         tmp->tm_wday = bcd2bin (wday & 0x07) - 1;       /* convert Day of the Week */
 360         tmp->tm_yday = 0;
 361         tmp->tm_isdst = 0;
 362
 363         debug ("Get 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         return 0;
 368 }
 369
 370 /* ------------------------------------------------------------------------- */
 371
 372 /* set clock time from *tmp in DS1306 RTC */
 373 int rtc_set (struct rtc_time *tmp)
 374 {
 375         /* Assuming Vcc = 2.0V (lowest speed) */
 376         if (!slave) {
 377                 slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 378                                 SPI_MODE_3 | SPI_CS_HIGH);
 379                 if (!slave)
 380                         return;
 381         }
 382
 383         if (spi_claim_bus(slave))
 384                 return;
 385
 386         debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 387                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 388                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 389
 390         rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));
 391         rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
 392         rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
 393         rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
 394         rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
 395         rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
 396         rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));
 397
 398         spi_release_bus(slave);
 399 }
 400
 401 /* ------------------------------------------------------------------------- */
 402
 403 /* reset the DS1306 */
 404 void rtc_reset (void)
 405 {
 406         /* Assuming Vcc = 2.0V (lowest speed) */
 407         if (!slave) {
 408                 slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 409                                 SPI_MODE_3 | SPI_CS_HIGH);
 410                 if (!slave)
 411                         return;
 412         }
 413
 414         if (spi_claim_bus(slave))
 415                 return;
 416
 417         /* clear the control register */
 418         rtc_write (RTC_CONTROL, 0x00);  /* 1st step: reset WP */
 419         rtc_write (RTC_CONTROL, 0x00);  /* 2nd step: reset 1Hz, AIE1, AIE0 */
 420
 421         /* reset all alarms */
 422         rtc_write (RTC_SECONDS_ALARM0, 0x00);
 423         rtc_write (RTC_SECONDS_ALARM1, 0x00);
 424         rtc_write (RTC_MINUTES_ALARM0, 0x00);
 425         rtc_write (RTC_MINUTES_ALARM1, 0x00);
 426         rtc_write (RTC_HOURS_ALARM0, 0x00);
 427         rtc_write (RTC_HOURS_ALARM1, 0x00);
 428         rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
 429         rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);
 430
 431         spi_release_bus(slave);
 432 }
 433
 434 /* ------------------------------------------------------------------------- */
 435
 436 static unsigned char rtc_read (unsigned char reg)
 437 {
 438         int ret;
 439
 440         ret = spi_w8r8(slave, reg);
 441         return ret < 0 ? 0 : ret;
 442 }
 443
 444 /* ------------------------------------------------------------------------- */
 445
 446 static void rtc_write (unsigned char reg, unsigned char val)
 447 {
 448         unsigned char dout[2];  /* SPI Output Data Bytes */
 449         unsigned char din[2];   /* SPI Input Data Bytes */
 450
 451         dout[0] = 0x80 | reg;
 452         dout[1] = val;
 453
 454         spi_xfer (slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
 455 }
 456
 457 #endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */
 458
 459 #endif