uboot/drivers/rtc/ds1307.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2001, 2002, 2003
   4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   5 * Keith Outwater, keith_outwater@mvis.com`
   6 * Steven Scholz, steven.scholz@imc-berlin.de
   7 */
   8
   9/*
  10 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
  11 * DS1307 and DS1338/9 Real Time Clock (RTC).
  12 *
  13 * based on ds1337.c
  14 */
  15
  16#include <common.h>
  17#include <command.h>
  18#include <dm.h>
  19#include <rtc.h>
  20#include <i2c.h>
  21
  22enum ds_type {
  23        ds_1307,
  24        ds_1337,
  25        ds_1340,
  26        m41t11,
  27        mcp794xx,
  28};
  29
  30/*
  31 * RTC register addresses
  32 */
  33#define RTC_SEC_REG_ADDR        0x00
  34#define RTC_MIN_REG_ADDR        0x01
  35#define RTC_HR_REG_ADDR         0x02
  36#define RTC_DAY_REG_ADDR        0x03
  37#define RTC_DATE_REG_ADDR       0x04
  38#define RTC_MON_REG_ADDR        0x05
  39#define RTC_YR_REG_ADDR         0x06
  40#define RTC_CTL_REG_ADDR        0x07
  41
  42#define RTC_SEC_BIT_CH          0x80    /* Clock Halt (in Register 0)   */
  43
  44#define RTC_CTL_BIT_RS0         0x01    /* Rate select 0                */
  45#define RTC_CTL_BIT_RS1         0x02    /* Rate select 1                */
  46#define RTC_CTL_BIT_SQWE        0x10    /* Square Wave Enable           */
  47#define RTC_CTL_BIT_OUT         0x80    /* Output Control               */
  48
  49/* MCP7941X-specific bits */
  50#define MCP7941X_BIT_ST         0x80
  51#define MCP7941X_BIT_VBATEN     0x08
  52
  53#ifndef CONFIG_DM_RTC
  54
  55/*---------------------------------------------------------------------*/
  56#undef DEBUG_RTC
  57
  58#ifdef DEBUG_RTC
  59#define DEBUGR(fmt, args...) printf(fmt, ##args)
  60#else
  61#define DEBUGR(fmt, args...)
  62#endif
  63/*---------------------------------------------------------------------*/
  64
  65#ifndef CONFIG_SYS_I2C_RTC_ADDR
  66# define CONFIG_SYS_I2C_RTC_ADDR        0x68
  67#endif
  68
  69#if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
  70# error The DS1307 is specified only up to 100kHz!
  71#endif
  72
  73static uchar rtc_read (uchar reg);
  74static void rtc_write (uchar reg, uchar val);
  75
  76/*
  77 * Get the current time from the RTC
  78 */
  79int rtc_get (struct rtc_time *tmp)
  80{
  81        int rel = 0;
  82        uchar sec, min, hour, mday, wday, mon, year;
  83
  84#ifdef CONFIG_RTC_MCP79411
  85read_rtc:
  86#endif
  87        sec = rtc_read (RTC_SEC_REG_ADDR);
  88        min = rtc_read (RTC_MIN_REG_ADDR);
  89        hour = rtc_read (RTC_HR_REG_ADDR);
  90        wday = rtc_read (RTC_DAY_REG_ADDR);
  91        mday = rtc_read (RTC_DATE_REG_ADDR);
  92        mon = rtc_read (RTC_MON_REG_ADDR);
  93        year = rtc_read (RTC_YR_REG_ADDR);
  94
  95        DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  96                "hr: %02x min: %02x sec: %02x\n",
  97                year, mon, mday, wday, hour, min, sec);
  98
  99#ifdef CONFIG_RTC_DS1307
 100        if (sec & RTC_SEC_BIT_CH) {
 101                printf ("### Warning: RTC oscillator has stopped\n");
 102                /* clear the CH flag */
 103                rtc_write (RTC_SEC_REG_ADDR,
 104                           rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
 105                rel = -1;
 106        }
 107#endif
 108
 109#ifdef CONFIG_RTC_MCP79411
 110        /* make sure that the backup battery is enabled */
 111        if (!(wday & MCP7941X_BIT_VBATEN)) {
 112                rtc_write(RTC_DAY_REG_ADDR,
 113                          wday | MCP7941X_BIT_VBATEN);
 114        }
 115
 116        /* clock halted?  turn it on, so clock can tick. */
 117        if (!(sec & MCP7941X_BIT_ST)) {
 118                rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST);
 119                printf("Started RTC\n");
 120                goto read_rtc;
 121        }
 122#endif
 123
 124
 125        tmp->tm_sec  = bcd2bin (sec & 0x7F);
 126        tmp->tm_min  = bcd2bin (min & 0x7F);
 127        tmp->tm_hour = bcd2bin (hour & 0x3F);
 128        tmp->tm_mday = bcd2bin (mday & 0x3F);
 129        tmp->tm_mon  = bcd2bin (mon & 0x1F);
 130        tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
 131        tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
 132        tmp->tm_yday = 0;
 133        tmp->tm_isdst= 0;
 134
 135        DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 136                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 137                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 138
 139        return rel;
 140}
 141
 142
 143/*
 144 * Set the RTC
 145 */
 146int rtc_set (struct rtc_time *tmp)
 147{
 148        DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 149                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 150                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 151
 152        if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
 153                printf("WARNING: year should be between 1970 and 2069!\n");
 154
 155        rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
 156        rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
 157#ifdef CONFIG_RTC_MCP79411
 158        rtc_write (RTC_DAY_REG_ADDR,
 159                   bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN);
 160#else
 161        rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
 162#endif
 163        rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
 164        rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
 165        rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
 166#ifdef CONFIG_RTC_MCP79411
 167        rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST);
 168#else
 169        rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
 170#endif
 171
 172        return 0;
 173}
 174
 175
 176/*
 177 * Reset the RTC. We setting the date back to 1970-01-01.
 178 * We also enable the oscillator output on the SQW/OUT pin and program
 179 * it for 32,768 Hz output. Note that according to the datasheet, turning
 180 * on the square wave output increases the current drain on the backup
 181 * battery to something between 480nA and 800nA.
 182 */
 183void rtc_reset (void)
 184{
 185        rtc_write (RTC_SEC_REG_ADDR, 0x00);     /* clearing Clock Halt  */
 186        rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
 187}
 188
 189
 190/*
 191 * Helper functions
 192 */
 193
 194static
 195uchar rtc_read (uchar reg)
 196{
 197        return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
 198}
 199
 200
 201static void rtc_write (uchar reg, uchar val)
 202{
 203        i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 204}
 205
 206#endif /* !CONFIG_DM_RTC */
 207
 208#ifdef CONFIG_DM_RTC
 209static int ds1307_rtc_set(struct udevice *dev, const struct rtc_time *tm)
 210{
 211        int ret;
 212        uchar buf[7];
 213        enum ds_type type = dev_get_driver_data(dev);
 214
 215        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 216              tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
 217              tm->tm_hour, tm->tm_min, tm->tm_sec);
 218
 219        if (tm->tm_year < 1970 || tm->tm_year > 2069)
 220                printf("WARNING: year should be between 1970 and 2069!\n");
 221
 222        buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
 223        buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
 224        buf[RTC_DAY_REG_ADDR] = bin2bcd(tm->tm_wday + 1);
 225        buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
 226        buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
 227        buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
 228        buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
 229
 230        if (type == mcp794xx) {
 231                buf[RTC_DAY_REG_ADDR] |= MCP7941X_BIT_VBATEN;
 232                buf[RTC_SEC_REG_ADDR] |= MCP7941X_BIT_ST;
 233        }
 234
 235        ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
 236        if (ret < 0)
 237                return ret;
 238
 239        return 0;
 240}
 241
 242static int ds1307_rtc_get(struct udevice *dev, struct rtc_time *tm)
 243{
 244        int ret;
 245        uchar buf[7];
 246        enum ds_type type = dev_get_driver_data(dev);
 247
 248read_rtc:
 249        ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
 250        if (ret < 0)
 251                return ret;
 252
 253        if (type == ds_1307) {
 254                if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
 255                        printf("### Warning: RTC oscillator has stopped\n");
 256                        /* clear the CH flag */
 257                        buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
 258                        dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
 259                                         buf[RTC_SEC_REG_ADDR]);
 260                        return -1;
 261                }
 262        }
 263
 264        if (type == m41t11) {
 265                /* clock halted?  turn it on, so clock can tick. */
 266                if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
 267                        buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
 268                        dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
 269                                         MCP7941X_BIT_ST);
 270                        dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
 271                                         buf[RTC_SEC_REG_ADDR]);
 272                        goto read_rtc;
 273                }
 274        }
 275
 276        if (type == mcp794xx) {
 277                /* make sure that the backup battery is enabled */
 278                if (!(buf[RTC_DAY_REG_ADDR] & MCP7941X_BIT_VBATEN)) {
 279                        dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR,
 280                                         buf[RTC_DAY_REG_ADDR] |
 281                                         MCP7941X_BIT_VBATEN);
 282                }
 283
 284                /* clock halted?  turn it on, so clock can tick. */
 285                if (!(buf[RTC_SEC_REG_ADDR] & MCP7941X_BIT_ST)) {
 286                        dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
 287                                         MCP7941X_BIT_ST);
 288                        printf("Started RTC\n");
 289                        goto read_rtc;
 290                }
 291        }
 292
 293        tm->tm_sec  = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
 294        tm->tm_min  = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
 295        tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
 296        tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
 297        tm->tm_mon  = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
 298        tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) +
 299                              (bcd2bin(buf[RTC_YR_REG_ADDR]) >= 70 ?
 300                               1900 : 2000);
 301        tm->tm_wday = bcd2bin((buf[RTC_DAY_REG_ADDR] - 1) & 0x07);
 302        tm->tm_yday = 0;
 303        tm->tm_isdst = 0;
 304
 305        debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 306              tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
 307              tm->tm_hour, tm->tm_min, tm->tm_sec);
 308
 309        return 0;
 310}
 311
 312static int ds1307_rtc_reset(struct udevice *dev)
 313{
 314        int ret;
 315
 316        /* clear Clock Halt */
 317        ret = dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 0x00);
 318        if (ret < 0)
 319                return ret;
 320        ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
 321                               RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 |
 322                               RTC_CTL_BIT_RS0);
 323        if (ret < 0)
 324                return ret;
 325
 326        return 0;
 327}
 328
 329static int ds1307_probe(struct udevice *dev)
 330{
 331        i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
 332                           DM_I2C_CHIP_WR_ADDRESS);
 333
 334        return 0;
 335}
 336
 337static const struct rtc_ops ds1307_rtc_ops = {
 338        .get = ds1307_rtc_get,
 339        .set = ds1307_rtc_set,
 340        .reset = ds1307_rtc_reset,
 341};
 342
 343static const struct udevice_id ds1307_rtc_ids[] = {
 344        { .compatible = "dallas,ds1307", .data = ds_1307 },
 345        { .compatible = "dallas,ds1337", .data = ds_1337 },
 346        { .compatible = "dallas,ds1340", .data = ds_1340 },
 347        { .compatible = "microchip,mcp7941x", .data = mcp794xx },
 348        { .compatible = "st,m41t11", .data = m41t11 },
 349        { }
 350};
 351
 352U_BOOT_DRIVER(rtc_ds1307) = {
 353        .name   = "rtc-ds1307",
 354        .id     = UCLASS_RTC,
 355        .probe  = ds1307_probe,
 356        .of_match = ds1307_rtc_ids,
 357        .ops    = &ds1307_rtc_ops,
 358};
 359#endif /* CONFIG_DM_RTC */
 360