LXR uboot/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
  65static unsigned int bin2bcd (unsigned int n);
  66static unsigned char bcd2bin (unsigned char c);
  67
  68/* ************************************************************************* */
  69#ifdef CONFIG_SXNI855T          /* !!! SHOULD BE CHANGED TO NEW CODE !!! */
  70
  71static void soft_spi_send (unsigned char n);
  72static unsigned char soft_spi_read (void);
  73static void init_spi (void);
  74
  75/*-----------------------------------------------------------------------
  76 * Definitions
  77 */
  78
  79#define PB_SPISCK       0x00000002      /* PB 30 */
  80#define PB_SPIMOSI      0x00000004      /* PB 29 */
  81#define PB_SPIMISO      0x00000008      /* PB 28 */
  82#define PB_SPI_CE       0x00010000      /* PB 15 */
  83
  84/* ------------------------------------------------------------------------- */
  85
  86/* read clock time from DS1306 and return it in *tmp */
  87int rtc_get (struct rtc_time *tmp)
  88{
  89        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  90        unsigned char spi_byte; /* Data Byte */
  91
  92        init_spi ();            /* set port B for software SPI */
  93
  94        /* Now we can enable the DS1306 RTC */
  95        immap->im_cpm.cp_pbdat |= PB_SPI_CE;
  96        udelay (10);
  97
  98        /* Shift out the address (0) of the time in the Clock Chip */
  99        soft_spi_send (0);
 100
 101        /* Put the clock readings into the rtc_time structure */
 102        tmp->tm_sec = bcd2bin (soft_spi_read ());       /* Read seconds */
 103        tmp->tm_min = bcd2bin (soft_spi_read ());       /* Read minutes */
 104
 105        /* Hours are trickier */
 106        spi_byte = soft_spi_read ();    /* Read Hours into temporary value */
 107        if (spi_byte & 0x40) {
 108                /* 12 hour mode bit is set (time is in 1-12 format) */
 109                if (spi_byte & 0x20) {
 110                        /* since PM we add 11 to get 0-23 for hours */
 111                        tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
 112                } else {
 113                        /* since AM we subtract 1 to get 0-23 for hours */
 114                        tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
 115                }
 116        } else {
 117                /* Otherwise, 0-23 hour format */
 118                tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
 119        }
 120
 121        soft_spi_read ();       /* Read and discard Day of week */
 122        tmp->tm_mday = bcd2bin (soft_spi_read ());      /* Read Day of the Month */
 123        tmp->tm_mon = bcd2bin (soft_spi_read ());       /* Read Month */
 124
 125        /* Read Year and convert to this century */
 126        tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;
 127
 128        /* Now we can disable the DS1306 RTC */
 129        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 130        udelay (10);
 131
 132        GregorianDay (tmp);     /* Determine the day of week */
 133
 134        debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 135               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 136               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 137
 138        return 0;
 139}
 140
 141/* ------------------------------------------------------------------------- */
 142
 143/* set clock time in DS1306 RTC and in MPC8xx RTC */
 144int rtc_set (struct rtc_time *tmp)
 145{
 146        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 147
 148        init_spi ();            /* set port B for software SPI */
 149
 150        /* Now we can enable the DS1306 RTC */
 151        immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 152        udelay (10);
 153
 154        /* First disable write protect in the clock chip control register */
 155        soft_spi_send (0x8F);   /* send address of the control register */
 156        soft_spi_send (0x00);   /* send control register contents */
 157
 158        /* Now disable the DS1306 to terminate the write */
 159        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
 160        udelay (10);
 161
 162        /* Now enable the DS1306 to initiate a new write */
 163        immap->im_cpm.cp_pbdat |= PB_SPI_CE;
 164        udelay (10);
 165
 166        /* Next, send the address of the clock time write registers */
 167        soft_spi_send (0x80);   /* send address of the first time register */
 168
 169        /* Use Burst Mode to send all of the time data to the clock */
 170        bin2bcd (tmp->tm_sec);
 171        soft_spi_send (bin2bcd (tmp->tm_sec));  /* Send Seconds */
 172        soft_spi_send (bin2bcd (tmp->tm_min));  /* Send Minutes */
 173        soft_spi_send (bin2bcd (tmp->tm_hour)); /* Send Hour */
 174        soft_spi_send (bin2bcd (tmp->tm_wday)); /* Send Day of the Week */
 175        soft_spi_send (bin2bcd (tmp->tm_mday)); /* Send Day of Month */
 176        soft_spi_send (bin2bcd (tmp->tm_mon));  /* Send Month */
 177        soft_spi_send (bin2bcd (tmp->tm_year - 2000));  /* Send Year */
 178
 179        /* Now we can disable the Clock chip to terminate the burst write */
 180        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 181        udelay (10);
 182
 183        /* Now we can enable the Clock chip to initiate a new write */
 184        immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 185        udelay (10);
 186
 187        /* First we Enable write protect in the clock chip control register */
 188        soft_spi_send (0x8F);   /* send address of the control register */
 189        soft_spi_send (0x40);   /* send out Control Register contents */
 190
 191        /* Now disable the DS1306 */
 192        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /*  Disable DS1306 Chip */
 193        udelay (10);
 194
 195        /* Set standard MPC8xx clock to the same time so Linux will
 196         * see the time even if it doesn't have a DS1306 clock driver.
 197         * This helps with experimenting with standard kernels.
 198         */
 199        {
 200                ulong tim;
 201
 202                tim = mktime (tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
 203                              tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 204
 205                immap->im_sitk.sitk_rtck = KAPWR_KEY;
 206                immap->im_sit.sit_rtc = tim;
 207        }
 208
 209        debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 210               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 211               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 212
 213        return 0;
 214}
 215
 216/* ------------------------------------------------------------------------- */
 217
 218/* Initialize Port B for software SPI */
 219static void init_spi (void)
 220{
 221        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 222
 223        /* Force output pins to begin at logic 0 */
 224        immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);
 225
 226        /* Set these 3 signals as outputs */
 227        immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
 228
 229        immap->im_cpm.cp_pbdir &= ~PB_SPIMISO;  /* Make MISO pin an input */
 230        udelay (10);
 231}
 232
 233/* ------------------------------------------------------------------------- */
 234
 235/* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
 236static void soft_spi_send (unsigned char n)
 237{
 238        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 239        unsigned char bitpos;   /* bit position to receive */
 240        unsigned char i;        /* Loop Control */
 241
 242        /* bit position to send, start with most significant bit */
 243        bitpos = 0x80;
 244
 245        /* Send 8 bits to software SPI */
 246        for (i = 0; i < 8; i++) {       /* Loop for 8 bits */
 247                immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 248
 249                if (n & bitpos)
 250                        immap->im_cpm.cp_pbdat |= PB_SPIMOSI;   /* Set MOSI to 1 */
 251                else
 252                        immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI;  /* Set MOSI to 0 */
 253                udelay (10);
 254
 255                immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 256                udelay (10);
 257
 258                bitpos >>= 1;   /* Shift for next bit position */
 259        }
 260}
 261
 262/* ------------------------------------------------------------------------- */
 263
 264/* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
 265static unsigned char soft_spi_read (void)
 266{
 267        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 268
 269        unsigned char spi_byte = 0;     /* Return value, assume success */
 270        unsigned char bitpos;   /* bit position to receive */
 271        unsigned char i;        /* Loop Control */
 272
 273        /* bit position to receive, start with most significant bit */
 274        bitpos = 0x80;
 275
 276        /* Read 8 bits here */
 277        for (i = 0; i < 8; i++) {       /* Do 8 bits in loop */
 278                immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 279                udelay (10);
 280                if (immap->im_cpm.cp_pbdat & PB_SPIMISO)        /* Get a bit of data */
 281                        spi_byte |= bitpos;     /* Set data accordingly */
 282                immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 283                udelay (10);
 284                bitpos >>= 1;   /* Shift for next bit position */
 285        }
 286
 287        return spi_byte;        /* Return the byte read */
 288}
 289
 290/* ------------------------------------------------------------------------- */
 291
 292void rtc_reset (void)
 293{
 294        return;                 /* nothing to do */
 295}
 296
 297#else  /* not CONFIG_SXNI855T */
 298/* ************************************************************************* */
 299
 300static unsigned char rtc_read (unsigned char reg);
 301static void rtc_write (unsigned char reg, unsigned char val);
 302
 303static struct spi_slave *slave;
 304
 305/* read clock time from DS1306 and return it in *tmp */
 306int rtc_get (struct rtc_time *tmp)
 307{
 308        unsigned char sec, min, hour, mday, wday, mon, year;
 309
 310        /*
 311         * Assuming Vcc = 2.0V (lowest speed)
 312         *
 313         * REVISIT: If we add an rtc_init() function we can do this
 314         * step just once.
 315         */
 316        if (!slave) {
 317                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 318                                SPI_MODE_3 | SPI_CS_HIGH);
 319                if (!slave)
 320                        return;
 321        }
 322
 323        if (spi_claim_bus(slave))
 324                return;
 325
 326        sec = rtc_read (RTC_SECONDS);
 327        min = rtc_read (RTC_MINUTES);
 328        hour = rtc_read (RTC_HOURS);
 329        mday = rtc_read (RTC_DATE_OF_MONTH);
 330        wday = rtc_read (RTC_DAY_OF_WEEK);
 331        mon = rtc_read (RTC_MONTH);
 332        year = rtc_read (RTC_YEAR);
 333
 334        spi_release_bus(slave);
 335
 336        debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
 337               "hr: %02x min: %02x sec: %02x\n",
 338               year, mon, mday, wday, hour, min, sec);
 339        debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 340               rtc_read (RTC_DAY_OF_WEEK_ALARM0),
 341               rtc_read (RTC_HOURS_ALARM0),
 342               rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
 343        debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 344               rtc_read (RTC_DAY_OF_WEEK_ALARM1),
 345               rtc_read (RTC_HOURS_ALARM1),
 346               rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));
 347
 348        tmp->tm_sec = bcd2bin (sec & 0x7F);     /* convert Seconds */
 349        tmp->tm_min = bcd2bin (min & 0x7F);     /* convert Minutes */
 350
 351        /* convert Hours */
 352        tmp->tm_hour = (hour & 0x40)
 353                ? ((hour & 0x20)        /* 12 hour mode */
 354                   ? bcd2bin (hour & 0x1F) + 11 /* PM */
 355                   : bcd2bin (hour & 0x1F) - 1  /* AM */
 356                )
 357                : bcd2bin (hour & 0x3F);        /* 24 hour mode */
 358
 359        tmp->tm_mday = bcd2bin (mday & 0x3F);   /* convert Day of the Month */
 360        tmp->tm_mon = bcd2bin (mon & 0x1F);     /* convert Month */
 361        tmp->tm_year = bcd2bin (year) + 2000;   /* convert Year */
 362        tmp->tm_wday = bcd2bin (wday & 0x07) - 1;       /* convert Day of the Week */
 363        tmp->tm_yday = 0;
 364        tmp->tm_isdst = 0;
 365
 366        debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 367               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 368               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 369
 370        return 0;
 371}
 372
 373/* ------------------------------------------------------------------------- */
 374
 375/* set clock time from *tmp in DS1306 RTC */
 376int rtc_set (struct rtc_time *tmp)
 377{
 378        /* Assuming Vcc = 2.0V (lowest speed) */
 379        if (!slave) {
 380                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 381                                SPI_MODE_3 | SPI_CS_HIGH);
 382                if (!slave)
 383                        return;
 384        }
 385
 386        if (spi_claim_bus(slave))
 387                return;
 388
 389        debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 390               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 391               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 392
 393        rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));
 394        rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
 395        rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
 396        rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
 397        rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
 398        rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
 399        rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));
 400
 401        spi_release_bus(slave);
 402}
 403
 404/* ------------------------------------------------------------------------- */
 405
 406/* reset the DS1306 */
 407void rtc_reset (void)
 408{
 409        /* Assuming Vcc = 2.0V (lowest speed) */
 410        if (!slave) {
 411                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 412                                SPI_MODE_3 | SPI_CS_HIGH);
 413                if (!slave)
 414                        return;
 415        }
 416
 417        if (spi_claim_bus(slave))
 418                return;
 419
 420        /* clear the control register */
 421        rtc_write (RTC_CONTROL, 0x00);  /* 1st step: reset WP */
 422        rtc_write (RTC_CONTROL, 0x00);  /* 2nd step: reset 1Hz, AIE1, AIE0 */
 423
 424        /* reset all alarms */
 425        rtc_write (RTC_SECONDS_ALARM0, 0x00);
 426        rtc_write (RTC_SECONDS_ALARM1, 0x00);
 427        rtc_write (RTC_MINUTES_ALARM0, 0x00);
 428        rtc_write (RTC_MINUTES_ALARM1, 0x00);
 429        rtc_write (RTC_HOURS_ALARM0, 0x00);
 430        rtc_write (RTC_HOURS_ALARM1, 0x00);
 431        rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
 432        rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);
 433
 434        spi_release_bus(slave);
 435}
 436
 437/* ------------------------------------------------------------------------- */
 438
 439static unsigned char rtc_read (unsigned char reg)
 440{
 441        int ret;
 442
 443        ret = spi_w8r8(slave, reg);
 444        return ret < 0 ? 0 : ret;
 445}
 446
 447/* ------------------------------------------------------------------------- */
 448
 449static void rtc_write (unsigned char reg, unsigned char val)
 450{
 451        unsigned char dout[2];  /* SPI Output Data Bytes */
 452        unsigned char din[2];   /* SPI Input Data Bytes */
 453
 454        dout[0] = 0x80 | reg;
 455        dout[1] = val;
 456
 457        spi_xfer (slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
 458}
 459
 460#endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */
 461
 462/* ------------------------------------------------------------------------- */
 463
 464static unsigned char bcd2bin (unsigned char n)
 465{
 466        return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
 467}
 468
 469/* ------------------------------------------------------------------------- */
 470
 471static unsigned int bin2bcd (unsigned int n)
 472{
 473        return (((n / 10) << 4) | (n % 10));
 474}
 475/* ------------------------------------------------------------------------- */
 476
 477#endif
 478