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 * SPDX-License-Identifier:     GPL-2.0+
   8 */
   9
  10/*
  11 * Date & Time support for DS1306 RTC using SPI:
  12 *
  13 *    - SXNI855T:    it uses its own soft SPI here in this file
  14 *    - all other:   use the external spi_xfer() function
  15 *                   (see include/spi.h)
  16 */
  17
  18#include <common.h>
  19#include <command.h>
  20#include <rtc.h>
  21#include <spi.h>
  22
  23#if defined(CONFIG_CMD_DATE)
  24
  25#define RTC_SECONDS             0x00
  26#define RTC_MINUTES             0x01
  27#define RTC_HOURS               0x02
  28#define RTC_DAY_OF_WEEK         0x03
  29#define RTC_DATE_OF_MONTH       0x04
  30#define RTC_MONTH               0x05
  31#define RTC_YEAR                0x06
  32
  33#define RTC_SECONDS_ALARM0      0x07
  34#define RTC_MINUTES_ALARM0      0x08
  35#define RTC_HOURS_ALARM0        0x09
  36#define RTC_DAY_OF_WEEK_ALARM0  0x0a
  37
  38#define RTC_SECONDS_ALARM1      0x0b
  39#define RTC_MINUTES_ALARM1      0x0c
  40#define RTC_HOURS_ALARM1        0x0d
  41#define RTC_DAY_OF_WEEK_ALARM1  0x0e
  42
  43#define RTC_CONTROL             0x0f
  44#define RTC_STATUS              0x10
  45#define RTC_TRICKLE_CHARGER     0x11
  46
  47#define RTC_USER_RAM_BASE       0x20
  48
  49/* ************************************************************************* */
  50#ifdef CONFIG_SXNI855T          /* !!! SHOULD BE CHANGED TO NEW CODE !!! */
  51
  52static void soft_spi_send (unsigned char n);
  53static unsigned char soft_spi_read (void);
  54static void init_spi (void);
  55
  56/*-----------------------------------------------------------------------
  57 * Definitions
  58 */
  59
  60#define PB_SPISCK       0x00000002      /* PB 30 */
  61#define PB_SPIMOSI      0x00000004      /* PB 29 */
  62#define PB_SPIMISO      0x00000008      /* PB 28 */
  63#define PB_SPI_CE       0x00010000      /* PB 15 */
  64
  65/* ------------------------------------------------------------------------- */
  66
  67/* read clock time from DS1306 and return it in *tmp */
  68int rtc_get (struct rtc_time *tmp)
  69{
  70        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  71        unsigned char spi_byte; /* Data Byte */
  72
  73        init_spi ();            /* set port B for software SPI */
  74
  75        /* Now we can enable the DS1306 RTC */
  76        immap->im_cpm.cp_pbdat |= PB_SPI_CE;
  77        udelay (10);
  78
  79        /* Shift out the address (0) of the time in the Clock Chip */
  80        soft_spi_send (0);
  81
  82        /* Put the clock readings into the rtc_time structure */
  83        tmp->tm_sec = bcd2bin (soft_spi_read ());       /* Read seconds */
  84        tmp->tm_min = bcd2bin (soft_spi_read ());       /* Read minutes */
  85
  86        /* Hours are trickier */
  87        spi_byte = soft_spi_read ();    /* Read Hours into temporary value */
  88        if (spi_byte & 0x40) {
  89                /* 12 hour mode bit is set (time is in 1-12 format) */
  90                if (spi_byte & 0x20) {
  91                        /* since PM we add 11 to get 0-23 for hours */
  92                        tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
  93                } else {
  94                        /* since AM we subtract 1 to get 0-23 for hours */
  95                        tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
  96                }
  97        } else {
  98                /* Otherwise, 0-23 hour format */
  99                tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
 100        }
 101
 102        soft_spi_read ();       /* Read and discard Day of week */
 103        tmp->tm_mday = bcd2bin (soft_spi_read ());      /* Read Day of the Month */
 104        tmp->tm_mon = bcd2bin (soft_spi_read ());       /* Read Month */
 105
 106        /* Read Year and convert to this century */
 107        tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;
 108
 109        /* Now we can disable the DS1306 RTC */
 110        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 111        udelay (10);
 112
 113        rtc_calc_weekday(tmp);  /* Determine the day of week */
 114
 115        debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 116               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 117               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 118
 119        return 0;
 120}
 121
 122/* ------------------------------------------------------------------------- */
 123
 124/* set clock time in DS1306 RTC and in MPC8xx RTC */
 125int rtc_set (struct rtc_time *tmp)
 126{
 127        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 128
 129        init_spi ();            /* set port B for software SPI */
 130
 131        /* Now we can enable the DS1306 RTC */
 132        immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 133        udelay (10);
 134
 135        /* First disable write protect in the clock chip control register */
 136        soft_spi_send (0x8F);   /* send address of the control register */
 137        soft_spi_send (0x00);   /* send control register contents */
 138
 139        /* Now disable the DS1306 to terminate the write */
 140        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
 141        udelay (10);
 142
 143        /* Now enable the DS1306 to initiate a new write */
 144        immap->im_cpm.cp_pbdat |= PB_SPI_CE;
 145        udelay (10);
 146
 147        /* Next, send the address of the clock time write registers */
 148        soft_spi_send (0x80);   /* send address of the first time register */
 149
 150        /* Use Burst Mode to send all of the time data to the clock */
 151        bin2bcd (tmp->tm_sec);
 152        soft_spi_send (bin2bcd (tmp->tm_sec));  /* Send Seconds */
 153        soft_spi_send (bin2bcd (tmp->tm_min));  /* Send Minutes */
 154        soft_spi_send (bin2bcd (tmp->tm_hour)); /* Send Hour */
 155        soft_spi_send (bin2bcd (tmp->tm_wday)); /* Send Day of the Week */
 156        soft_spi_send (bin2bcd (tmp->tm_mday)); /* Send Day of Month */
 157        soft_spi_send (bin2bcd (tmp->tm_mon));  /* Send Month */
 158        soft_spi_send (bin2bcd (tmp->tm_year - 2000));  /* Send Year */
 159
 160        /* Now we can disable the Clock chip to terminate the burst write */
 161        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 162        udelay (10);
 163
 164        /* Now we can enable the Clock chip to initiate a new write */
 165        immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 166        udelay (10);
 167
 168        /* First we Enable write protect in the clock chip control register */
 169        soft_spi_send (0x8F);   /* send address of the control register */
 170        soft_spi_send (0x40);   /* send out Control Register contents */
 171
 172        /* Now disable the DS1306 */
 173        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /*  Disable DS1306 Chip */
 174        udelay (10);
 175
 176        /* Set standard MPC8xx clock to the same time so Linux will
 177         * see the time even if it doesn't have a DS1306 clock driver.
 178         * This helps with experimenting with standard kernels.
 179         */
 180        {
 181                ulong tim;
 182
 183                tim = rtc_mktime(tmp);
 184
 185                immap->im_sitk.sitk_rtck = KAPWR_KEY;
 186                immap->im_sit.sit_rtc = tim;
 187        }
 188
 189        debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 190               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 191               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 192
 193        return 0;
 194}
 195
 196/* ------------------------------------------------------------------------- */
 197
 198/* Initialize Port B for software SPI */
 199static void init_spi (void)
 200{
 201        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 202
 203        /* Force output pins to begin at logic 0 */
 204        immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);
 205
 206        /* Set these 3 signals as outputs */
 207        immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
 208
 209        immap->im_cpm.cp_pbdir &= ~PB_SPIMISO;  /* Make MISO pin an input */
 210        udelay (10);
 211}
 212
 213/* ------------------------------------------------------------------------- */
 214
 215/* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
 216static void soft_spi_send (unsigned char n)
 217{
 218        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 219        unsigned char bitpos;   /* bit position to receive */
 220        unsigned char i;        /* Loop Control */
 221
 222        /* bit position to send, start with most significant bit */
 223        bitpos = 0x80;
 224
 225        /* Send 8 bits to software SPI */
 226        for (i = 0; i < 8; i++) {       /* Loop for 8 bits */
 227                immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 228
 229                if (n & bitpos)
 230                        immap->im_cpm.cp_pbdat |= PB_SPIMOSI;   /* Set MOSI to 1 */
 231                else
 232                        immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI;  /* Set MOSI to 0 */
 233                udelay (10);
 234
 235                immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 236                udelay (10);
 237
 238                bitpos >>= 1;   /* Shift for next bit position */
 239        }
 240}
 241
 242/* ------------------------------------------------------------------------- */
 243
 244/* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
 245static unsigned char soft_spi_read (void)
 246{
 247        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 248
 249        unsigned char spi_byte = 0;     /* Return value, assume success */
 250        unsigned char bitpos;   /* bit position to receive */
 251        unsigned char i;        /* Loop Control */
 252
 253        /* bit position to receive, start with most significant bit */
 254        bitpos = 0x80;
 255
 256        /* Read 8 bits here */
 257        for (i = 0; i < 8; i++) {       /* Do 8 bits in loop */
 258                immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 259                udelay (10);
 260                if (immap->im_cpm.cp_pbdat & PB_SPIMISO)        /* Get a bit of data */
 261                        spi_byte |= bitpos;     /* Set data accordingly */
 262                immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 263                udelay (10);
 264                bitpos >>= 1;   /* Shift for next bit position */
 265        }
 266
 267        return spi_byte;        /* Return the byte read */
 268}
 269
 270/* ------------------------------------------------------------------------- */
 271
 272void rtc_reset (void)
 273{
 274        return;                 /* nothing to do */
 275}
 276
 277#else  /* not CONFIG_SXNI855T */
 278/* ************************************************************************* */
 279
 280static unsigned char rtc_read (unsigned char reg);
 281static void rtc_write (unsigned char reg, unsigned char val);
 282
 283static struct spi_slave *slave;
 284
 285/* read clock time from DS1306 and return it in *tmp */
 286int rtc_get (struct rtc_time *tmp)
 287{
 288        unsigned char sec, min, hour, mday, wday, mon, year;
 289
 290        /*
 291         * Assuming Vcc = 2.0V (lowest speed)
 292         *
 293         * REVISIT: If we add an rtc_init() function we can do this
 294         * step just once.
 295         */
 296        if (!slave) {
 297                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 298                                SPI_MODE_3 | SPI_CS_HIGH);
 299                if (!slave)
 300                        return;
 301        }
 302
 303        if (spi_claim_bus(slave))
 304                return;
 305
 306        sec = rtc_read (RTC_SECONDS);
 307        min = rtc_read (RTC_MINUTES);
 308        hour = rtc_read (RTC_HOURS);
 309        mday = rtc_read (RTC_DATE_OF_MONTH);
 310        wday = rtc_read (RTC_DAY_OF_WEEK);
 311        mon = rtc_read (RTC_MONTH);
 312        year = rtc_read (RTC_YEAR);
 313
 314        spi_release_bus(slave);
 315
 316        debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
 317               "hr: %02x min: %02x sec: %02x\n",
 318               year, mon, mday, wday, hour, min, sec);
 319        debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 320               rtc_read (RTC_DAY_OF_WEEK_ALARM0),
 321               rtc_read (RTC_HOURS_ALARM0),
 322               rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
 323        debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 324               rtc_read (RTC_DAY_OF_WEEK_ALARM1),
 325               rtc_read (RTC_HOURS_ALARM1),
 326               rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));
 327
 328        tmp->tm_sec = bcd2bin (sec & 0x7F);     /* convert Seconds */
 329        tmp->tm_min = bcd2bin (min & 0x7F);     /* convert Minutes */
 330
 331        /* convert Hours */
 332        tmp->tm_hour = (hour & 0x40)
 333                ? ((hour & 0x20)        /* 12 hour mode */
 334                   ? bcd2bin (hour & 0x1F) + 11 /* PM */
 335                   : bcd2bin (hour & 0x1F) - 1  /* AM */
 336                )
 337                : bcd2bin (hour & 0x3F);        /* 24 hour mode */
 338
 339        tmp->tm_mday = bcd2bin (mday & 0x3F);   /* convert Day of the Month */
 340        tmp->tm_mon = bcd2bin (mon & 0x1F);     /* convert Month */
 341        tmp->tm_year = bcd2bin (year) + 2000;   /* convert Year */
 342        tmp->tm_wday = bcd2bin (wday & 0x07) - 1;       /* convert Day of the Week */
 343        tmp->tm_yday = 0;
 344        tmp->tm_isdst = 0;
 345
 346        debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 347               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 348               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 349
 350        return 0;
 351}
 352
 353/* ------------------------------------------------------------------------- */
 354
 355/* set clock time from *tmp in DS1306 RTC */
 356int rtc_set (struct rtc_time *tmp)
 357{
 358        /* Assuming Vcc = 2.0V (lowest speed) */
 359        if (!slave) {
 360                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 361                                SPI_MODE_3 | SPI_CS_HIGH);
 362                if (!slave)
 363                        return;
 364        }
 365
 366        if (spi_claim_bus(slave))
 367                return;
 368
 369        debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 370               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 371               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 372
 373        rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));
 374        rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
 375        rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
 376        rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
 377        rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
 378        rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
 379        rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));
 380
 381        spi_release_bus(slave);
 382}
 383
 384/* ------------------------------------------------------------------------- */
 385
 386/* reset the DS1306 */
 387void rtc_reset (void)
 388{
 389        /* Assuming Vcc = 2.0V (lowest speed) */
 390        if (!slave) {
 391                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 392                                SPI_MODE_3 | SPI_CS_HIGH);
 393                if (!slave)
 394                        return;
 395        }
 396
 397        if (spi_claim_bus(slave))
 398                return;
 399
 400        /* clear the control register */
 401        rtc_write (RTC_CONTROL, 0x00);  /* 1st step: reset WP */
 402        rtc_write (RTC_CONTROL, 0x00);  /* 2nd step: reset 1Hz, AIE1, AIE0 */
 403
 404        /* reset all alarms */
 405        rtc_write (RTC_SECONDS_ALARM0, 0x00);
 406        rtc_write (RTC_SECONDS_ALARM1, 0x00);
 407        rtc_write (RTC_MINUTES_ALARM0, 0x00);
 408        rtc_write (RTC_MINUTES_ALARM1, 0x00);
 409        rtc_write (RTC_HOURS_ALARM0, 0x00);
 410        rtc_write (RTC_HOURS_ALARM1, 0x00);
 411        rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
 412        rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);
 413
 414        spi_release_bus(slave);
 415}
 416
 417/* ------------------------------------------------------------------------- */
 418
 419static unsigned char rtc_read (unsigned char reg)
 420{
 421        int ret;
 422
 423        ret = spi_w8r8(slave, reg);
 424        return ret < 0 ? 0 : ret;
 425}
 426
 427/* ------------------------------------------------------------------------- */
 428
 429static void rtc_write (unsigned char reg, unsigned char val)
 430{
 431        unsigned char dout[2];  /* SPI Output Data Bytes */
 432        unsigned char din[2];   /* SPI Input Data Bytes */
 433
 434        dout[0] = 0x80 | reg;
 435        dout[1] = val;
 436
 437        spi_xfer (slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
 438}
 439
 440#endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */
 441
 442#endif
 443