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
  65/* ************************************************************************* */
  66#ifdef CONFIG_SXNI855T          /* !!! SHOULD BE CHANGED TO NEW CODE !!! */
  67
  68static void soft_spi_send (unsigned char n);
  69static unsigned char soft_spi_read (void);
  70static 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 */
  84int 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 */
 141int 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 */
 216static 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 */
 233static 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 */
 262static 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
 289void rtc_reset (void)
 290{
 291        return;                 /* nothing to do */
 292}
 293
 294#else  /* not CONFIG_SXNI855T */
 295/* ************************************************************************* */
 296
 297static unsigned char rtc_read (unsigned char reg);
 298static void rtc_write (unsigned char reg, unsigned char val);
 299
 300static struct spi_slave *slave;
 301
 302/* read clock time from DS1306 and return it in *tmp */
 303int 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 */
 373int 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 */
 404void 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
 436static 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
 446static 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
 460