LXR uboot/drivers/rtc/ds1306.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2002 SIXNET, dge@sixnetio.com.
   4 *
   5 * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
   6 * Stephan Linz <linz@li-pro.net>
   7 */
   8
   9/*
  10 * Date & Time support for DS1306 RTC using SPI:
  11 *
  12 *    - SXNI855T:    it uses its own soft SPI here in this file
  13 *    - all other:   use the external spi_xfer() function
  14 *                   (see include/spi.h)
  15 */
  16
  17#include <common.h>
  18#include <command.h>
  19#include <rtc.h>
  20#include <spi.h>
  21
  22#define RTC_SECONDS             0x00
  23#define RTC_MINUTES             0x01
  24#define RTC_HOURS               0x02
  25#define RTC_DAY_OF_WEEK         0x03
  26#define RTC_DATE_OF_MONTH       0x04
  27#define RTC_MONTH               0x05
  28#define RTC_YEAR                0x06
  29
  30#define RTC_SECONDS_ALARM0      0x07
  31#define RTC_MINUTES_ALARM0      0x08
  32#define RTC_HOURS_ALARM0        0x09
  33#define RTC_DAY_OF_WEEK_ALARM0  0x0a
  34
  35#define RTC_SECONDS_ALARM1      0x0b
  36#define RTC_MINUTES_ALARM1      0x0c
  37#define RTC_HOURS_ALARM1        0x0d
  38#define RTC_DAY_OF_WEEK_ALARM1  0x0e
  39
  40#define RTC_CONTROL             0x0f
  41#define RTC_STATUS              0x10
  42#define RTC_TRICKLE_CHARGER     0x11
  43
  44#define RTC_USER_RAM_BASE       0x20
  45
  46/* ************************************************************************* */
  47#ifdef CONFIG_SXNI855T          /* !!! SHOULD BE CHANGED TO NEW CODE !!! */
  48
  49static void soft_spi_send (unsigned char n);
  50static unsigned char soft_spi_read (void);
  51static void init_spi (void);
  52
  53/*-----------------------------------------------------------------------
  54 * Definitions
  55 */
  56
  57#define PB_SPISCK       0x00000002      /* PB 30 */
  58#define PB_SPIMOSI      0x00000004      /* PB 29 */
  59#define PB_SPIMISO      0x00000008      /* PB 28 */
  60#define PB_SPI_CE       0x00010000      /* PB 15 */
  61
  62/* ------------------------------------------------------------------------- */
  63
  64/* read clock time from DS1306 and return it in *tmp */
  65int rtc_get (struct rtc_time *tmp)
  66{
  67        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  68        unsigned char spi_byte; /* Data Byte */
  69
  70        init_spi ();            /* set port B for software SPI */
  71
  72        /* Now we can enable the DS1306 RTC */
  73        immap->im_cpm.cp_pbdat |= PB_SPI_CE;
  74        udelay (10);
  75
  76        /* Shift out the address (0) of the time in the Clock Chip */
  77        soft_spi_send (0);
  78
  79        /* Put the clock readings into the rtc_time structure */
  80        tmp->tm_sec = bcd2bin (soft_spi_read ());       /* Read seconds */
  81        tmp->tm_min = bcd2bin (soft_spi_read ());       /* Read minutes */
  82
  83        /* Hours are trickier */
  84        spi_byte = soft_spi_read ();    /* Read Hours into temporary value */
  85        if (spi_byte & 0x40) {
  86                /* 12 hour mode bit is set (time is in 1-12 format) */
  87                if (spi_byte & 0x20) {
  88                        /* since PM we add 11 to get 0-23 for hours */
  89                        tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
  90                } else {
  91                        /* since AM we subtract 1 to get 0-23 for hours */
  92                        tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
  93                }
  94        } else {
  95                /* Otherwise, 0-23 hour format */
  96                tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
  97        }
  98
  99        soft_spi_read ();       /* Read and discard Day of week */
 100        tmp->tm_mday = bcd2bin (soft_spi_read ());      /* Read Day of the Month */
 101        tmp->tm_mon = bcd2bin (soft_spi_read ());       /* Read Month */
 102
 103        /* Read Year and convert to this century */
 104        tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;
 105
 106        /* Now we can disable the DS1306 RTC */
 107        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 108        udelay (10);
 109
 110        rtc_calc_weekday(tmp);  /* Determine the day of week */
 111
 112        debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 113               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 114               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 115
 116        return 0;
 117}
 118
 119/* ------------------------------------------------------------------------- */
 120
 121/* set clock time in DS1306 RTC and in MPC8xx RTC */
 122int rtc_set (struct rtc_time *tmp)
 123{
 124        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 125
 126        init_spi ();            /* set port B for software SPI */
 127
 128        /* Now we can enable the DS1306 RTC */
 129        immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 130        udelay (10);
 131
 132        /* First disable write protect in the clock chip control register */
 133        soft_spi_send (0x8F);   /* send address of the control register */
 134        soft_spi_send (0x00);   /* send control register contents */
 135
 136        /* Now disable the DS1306 to terminate the write */
 137        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
 138        udelay (10);
 139
 140        /* Now enable the DS1306 to initiate a new write */
 141        immap->im_cpm.cp_pbdat |= PB_SPI_CE;
 142        udelay (10);
 143
 144        /* Next, send the address of the clock time write registers */
 145        soft_spi_send (0x80);   /* send address of the first time register */
 146
 147        /* Use Burst Mode to send all of the time data to the clock */
 148        bin2bcd (tmp->tm_sec);
 149        soft_spi_send (bin2bcd (tmp->tm_sec));  /* Send Seconds */
 150        soft_spi_send (bin2bcd (tmp->tm_min));  /* Send Minutes */
 151        soft_spi_send (bin2bcd (tmp->tm_hour)); /* Send Hour */
 152        soft_spi_send (bin2bcd (tmp->tm_wday)); /* Send Day of the Week */
 153        soft_spi_send (bin2bcd (tmp->tm_mday)); /* Send Day of Month */
 154        soft_spi_send (bin2bcd (tmp->tm_mon));  /* Send Month */
 155        soft_spi_send (bin2bcd (tmp->tm_year - 2000));  /* Send Year */
 156
 157        /* Now we can disable the Clock chip to terminate the burst write */
 158        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /* Disable DS1306 Chip */
 159        udelay (10);
 160
 161        /* Now we can enable the Clock chip to initiate a new write */
 162        immap->im_cpm.cp_pbdat |= PB_SPI_CE;    /* Enable DS1306 Chip */
 163        udelay (10);
 164
 165        /* First we Enable write protect in the clock chip control register */
 166        soft_spi_send (0x8F);   /* send address of the control register */
 167        soft_spi_send (0x40);   /* send out Control Register contents */
 168
 169        /* Now disable the DS1306 */
 170        immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;   /*  Disable DS1306 Chip */
 171        udelay (10);
 172
 173        /* Set standard MPC8xx clock to the same time so Linux will
 174         * see the time even if it doesn't have a DS1306 clock driver.
 175         * This helps with experimenting with standard kernels.
 176         */
 177        {
 178                ulong tim;
 179
 180                tim = rtc_mktime(tmp);
 181
 182                immap->im_sitk.sitk_rtck = KAPWR_KEY;
 183                immap->im_sit.sit_rtc = tim;
 184        }
 185
 186        debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 187               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 188               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 189
 190        return 0;
 191}
 192
 193/* ------------------------------------------------------------------------- */
 194
 195/* Initialize Port B for software SPI */
 196static void init_spi (void)
 197{
 198        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 199
 200        /* Force output pins to begin at logic 0 */
 201        immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);
 202
 203        /* Set these 3 signals as outputs */
 204        immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
 205
 206        immap->im_cpm.cp_pbdir &= ~PB_SPIMISO;  /* Make MISO pin an input */
 207        udelay (10);
 208}
 209
 210/* ------------------------------------------------------------------------- */
 211
 212/* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
 213static void soft_spi_send (unsigned char n)
 214{
 215        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 216        unsigned char bitpos;   /* bit position to receive */
 217        unsigned char i;        /* Loop Control */
 218
 219        /* bit position to send, start with most significant bit */
 220        bitpos = 0x80;
 221
 222        /* Send 8 bits to software SPI */
 223        for (i = 0; i < 8; i++) {       /* Loop for 8 bits */
 224                immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 225
 226                if (n & bitpos)
 227                        immap->im_cpm.cp_pbdat |= PB_SPIMOSI;   /* Set MOSI to 1 */
 228                else
 229                        immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI;  /* Set MOSI to 0 */
 230                udelay (10);
 231
 232                immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 233                udelay (10);
 234
 235                bitpos >>= 1;   /* Shift for next bit position */
 236        }
 237}
 238
 239/* ------------------------------------------------------------------------- */
 240
 241/* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
 242static unsigned char soft_spi_read (void)
 243{
 244        volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 245
 246        unsigned char spi_byte = 0;     /* Return value, assume success */
 247        unsigned char bitpos;   /* bit position to receive */
 248        unsigned char i;        /* Loop Control */
 249
 250        /* bit position to receive, start with most significant bit */
 251        bitpos = 0x80;
 252
 253        /* Read 8 bits here */
 254        for (i = 0; i < 8; i++) {       /* Do 8 bits in loop */
 255                immap->im_cpm.cp_pbdat |= PB_SPISCK;    /* Raise SCK */
 256                udelay (10);
 257                if (immap->im_cpm.cp_pbdat & PB_SPIMISO)        /* Get a bit of data */
 258                        spi_byte |= bitpos;     /* Set data accordingly */
 259                immap->im_cpm.cp_pbdat &= ~PB_SPISCK;   /* Lower SCK */
 260                udelay (10);
 261                bitpos >>= 1;   /* Shift for next bit position */
 262        }
 263
 264        return spi_byte;        /* Return the byte read */
 265}
 266
 267/* ------------------------------------------------------------------------- */
 268
 269void rtc_reset (void)
 270{
 271        return;                 /* nothing to do */
 272}
 273
 274#else  /* not CONFIG_SXNI855T */
 275/* ************************************************************************* */
 276
 277static unsigned char rtc_read (unsigned char reg);
 278static void rtc_write (unsigned char reg, unsigned char val);
 279
 280static struct spi_slave *slave;
 281
 282/* read clock time from DS1306 and return it in *tmp */
 283int rtc_get (struct rtc_time *tmp)
 284{
 285        unsigned char sec, min, hour, mday, wday, mon, year;
 286
 287        /*
 288         * Assuming Vcc = 2.0V (lowest speed)
 289         *
 290         * REVISIT: If we add an rtc_init() function we can do this
 291         * step just once.
 292         */
 293        if (!slave) {
 294                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 295                                SPI_MODE_3 | SPI_CS_HIGH);
 296                if (!slave)
 297                        return;
 298        }
 299
 300        if (spi_claim_bus(slave))
 301                return;
 302
 303        sec = rtc_read (RTC_SECONDS);
 304        min = rtc_read (RTC_MINUTES);
 305        hour = rtc_read (RTC_HOURS);
 306        mday = rtc_read (RTC_DATE_OF_MONTH);
 307        wday = rtc_read (RTC_DAY_OF_WEEK);
 308        mon = rtc_read (RTC_MONTH);
 309        year = rtc_read (RTC_YEAR);
 310
 311        spi_release_bus(slave);
 312
 313        debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
 314               "hr: %02x min: %02x sec: %02x\n",
 315               year, mon, mday, wday, hour, min, sec);
 316        debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 317               rtc_read (RTC_DAY_OF_WEEK_ALARM0),
 318               rtc_read (RTC_HOURS_ALARM0),
 319               rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
 320        debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n",
 321               rtc_read (RTC_DAY_OF_WEEK_ALARM1),
 322               rtc_read (RTC_HOURS_ALARM1),
 323               rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));
 324
 325        tmp->tm_sec = bcd2bin (sec & 0x7F);     /* convert Seconds */
 326        tmp->tm_min = bcd2bin (min & 0x7F);     /* convert Minutes */
 327
 328        /* convert Hours */
 329        tmp->tm_hour = (hour & 0x40)
 330                ? ((hour & 0x20)        /* 12 hour mode */
 331                   ? bcd2bin (hour & 0x1F) + 11 /* PM */
 332                   : bcd2bin (hour & 0x1F) - 1  /* AM */
 333                )
 334                : bcd2bin (hour & 0x3F);        /* 24 hour mode */
 335
 336        tmp->tm_mday = bcd2bin (mday & 0x3F);   /* convert Day of the Month */
 337        tmp->tm_mon = bcd2bin (mon & 0x1F);     /* convert Month */
 338        tmp->tm_year = bcd2bin (year) + 2000;   /* convert Year */
 339        tmp->tm_wday = bcd2bin (wday & 0x07) - 1;       /* convert Day of the Week */
 340        tmp->tm_yday = 0;
 341        tmp->tm_isdst = 0;
 342
 343        debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 344               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 345               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 346
 347        return 0;
 348}
 349
 350/* ------------------------------------------------------------------------- */
 351
 352/* set clock time from *tmp in DS1306 RTC */
 353int rtc_set (struct rtc_time *tmp)
 354{
 355        /* Assuming Vcc = 2.0V (lowest speed) */
 356        if (!slave) {
 357                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 358                                SPI_MODE_3 | SPI_CS_HIGH);
 359                if (!slave)
 360                        return;
 361        }
 362
 363        if (spi_claim_bus(slave))
 364                return;
 365
 366        debug ("Set 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        rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));
 371        rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
 372        rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
 373        rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
 374        rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
 375        rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
 376        rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));
 377
 378        spi_release_bus(slave);
 379}
 380
 381/* ------------------------------------------------------------------------- */
 382
 383/* reset the DS1306 */
 384void rtc_reset (void)
 385{
 386        /* Assuming Vcc = 2.0V (lowest speed) */
 387        if (!slave) {
 388                slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
 389                                SPI_MODE_3 | SPI_CS_HIGH);
 390                if (!slave)
 391                        return;
 392        }
 393
 394        if (spi_claim_bus(slave))
 395                return;
 396
 397        /* clear the control register */
 398        rtc_write (RTC_CONTROL, 0x00);  /* 1st step: reset WP */
 399        rtc_write (RTC_CONTROL, 0x00);  /* 2nd step: reset 1Hz, AIE1, AIE0 */
 400
 401        /* reset all alarms */
 402        rtc_write (RTC_SECONDS_ALARM0, 0x00);
 403        rtc_write (RTC_SECONDS_ALARM1, 0x00);
 404        rtc_write (RTC_MINUTES_ALARM0, 0x00);
 405        rtc_write (RTC_MINUTES_ALARM1, 0x00);
 406        rtc_write (RTC_HOURS_ALARM0, 0x00);
 407        rtc_write (RTC_HOURS_ALARM1, 0x00);
 408        rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
 409        rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);
 410
 411        spi_release_bus(slave);
 412}
 413
 414/* ------------------------------------------------------------------------- */
 415
 416static unsigned char rtc_read (unsigned char reg)
 417{
 418        int ret;
 419
 420        ret = spi_w8r8(slave, reg);
 421        return ret < 0 ? 0 : ret;
 422}
 423
 424/* ------------------------------------------------------------------------- */
 425
 426static void rtc_write (unsigned char reg, unsigned char val)
 427{
 428        unsigned char dout[2];  /* SPI Output Data Bytes */
 429        unsigned char din[2];   /* SPI Input Data Bytes */
 430
 431        dout[0] = 0x80 | reg;
 432        dout[1] = val;
 433
 434        spi_xfer (slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
 435}
 436
 437#endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */
 438