LXR uboot/drivers/rtc/ds3231.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2006
   4 * Markus Klotzbuecher, mk@denx.de
   5 *
   6 * (C) Copyright 2019 NXP
   7 * Chuanhua Han <chuanhua.han@nxp.com>
   8 */
   9
  10/*
  11 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
  12 * Extremly Accurate DS3231 Real Time Clock (RTC).
  13 *
  14 * copied from ds1337.c
  15 */
  16
  17#include <common.h>
  18#include <command.h>
  19#include <dm.h>
  20#include <log.h>
  21#include <rtc.h>
  22#include <i2c.h>
  23
  24/*
  25 * RTC register addresses
  26 */
  27#define RTC_SEC_REG_ADDR        0x0
  28#define RTC_MIN_REG_ADDR        0x1
  29#define RTC_HR_REG_ADDR         0x2
  30#define RTC_DAY_REG_ADDR        0x3
  31#define RTC_DATE_REG_ADDR       0x4
  32#define RTC_MON_REG_ADDR        0x5
  33#define RTC_YR_REG_ADDR         0x6
  34#define RTC_CTL_REG_ADDR        0x0e
  35#define RTC_STAT_REG_ADDR       0x0f
  36
  37
  38/*
  39 * RTC control register bits
  40 */
  41#define RTC_CTL_BIT_A1IE        0x1     /* Alarm 1 interrupt enable     */
  42#define RTC_CTL_BIT_A2IE        0x2     /* Alarm 2 interrupt enable     */
  43#define RTC_CTL_BIT_INTCN       0x4     /* Interrupt control            */
  44#define RTC_CTL_BIT_RS1         0x8     /* Rate select 1                */
  45#define RTC_CTL_BIT_RS2         0x10    /* Rate select 2                */
  46#define RTC_CTL_BIT_DOSC        0x80    /* Disable Oscillator           */
  47
  48/*
  49 * RTC status register bits
  50 */
  51#define RTC_STAT_BIT_A1F        0x1     /* Alarm 1 flag                 */
  52#define RTC_STAT_BIT_A2F        0x2     /* Alarm 2 flag                 */
  53#define RTC_STAT_BIT_OSF        0x80    /* Oscillator stop flag         */
  54#define RTC_STAT_BIT_BB32KHZ    0x40    /* Battery backed 32KHz Output  */
  55#define RTC_STAT_BIT_EN32KHZ    0x8     /* Enable 32KHz Output  */
  56
  57
  58#if !CONFIG_IS_ENABLED(DM_RTC)
  59static uchar rtc_read (uchar reg);
  60static void rtc_write (uchar reg, uchar val);
  61
  62
  63/*
  64 * Get the current time from the RTC
  65 */
  66int rtc_get (struct rtc_time *tmp)
  67{
  68        int rel = 0;
  69        uchar sec, min, hour, mday, wday, mon_cent, year, control, status;
  70
  71        control = rtc_read (RTC_CTL_REG_ADDR);
  72        status = rtc_read (RTC_STAT_REG_ADDR);
  73        sec = rtc_read (RTC_SEC_REG_ADDR);
  74        min = rtc_read (RTC_MIN_REG_ADDR);
  75        hour = rtc_read (RTC_HR_REG_ADDR);
  76        wday = rtc_read (RTC_DAY_REG_ADDR);
  77        mday = rtc_read (RTC_DATE_REG_ADDR);
  78        mon_cent = rtc_read (RTC_MON_REG_ADDR);
  79        year = rtc_read (RTC_YR_REG_ADDR);
  80
  81        debug("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  82                "hr: %02x min: %02x sec: %02x control: %02x status: %02x\n",
  83                year, mon_cent, mday, wday, hour, min, sec, control, status);
  84
  85        if (status & RTC_STAT_BIT_OSF) {
  86                printf ("### Warning: RTC oscillator has stopped\n");
  87                /* clear the OSF flag */
  88                rtc_write (RTC_STAT_REG_ADDR,
  89                           rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF);
  90                rel = -1;
  91        }
  92
  93        tmp->tm_sec  = bcd2bin (sec & 0x7F);
  94        tmp->tm_min  = bcd2bin (min & 0x7F);
  95        tmp->tm_hour = bcd2bin (hour & 0x3F);
  96        tmp->tm_mday = bcd2bin (mday & 0x3F);
  97        tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
  98        tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
  99        tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
 100        tmp->tm_yday = 0;
 101        tmp->tm_isdst= 0;
 102
 103        debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 104                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 105                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 106
 107        return rel;
 108}
 109
 110
 111/*
 112 * Set the RTC
 113 */
 114int rtc_set (struct rtc_time *tmp)
 115{
 116        uchar century;
 117
 118        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 119                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 120                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 121
 122        rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
 123
 124        century = (tmp->tm_year >= 2000) ? 0x80 : 0;
 125        rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century);
 126
 127        rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
 128        rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
 129        rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
 130        rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
 131        rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
 132
 133        return 0;
 134}
 135
 136
 137/*
 138 * Reset the RTC.  We also enable the oscillator output on the
 139 * SQW/INTB* pin and program it for 32,768 Hz output. Note that
 140 * according to the datasheet, turning on the square wave output
 141 * increases the current drain on the backup battery from about
 142 * 600 nA to 2uA.
 143 */
 144void rtc_reset (void)
 145{
 146        rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);
 147}
 148
 149/*
 150 * Enable 32KHz output
 151 */
 152#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
 153void rtc_enable_32khz_output(void)
 154{
 155        rtc_write(RTC_STAT_REG_ADDR,
 156                  RTC_STAT_BIT_BB32KHZ | RTC_STAT_BIT_EN32KHZ);
 157}
 158#endif
 159
 160/*
 161 * Helper functions
 162 */
 163
 164static
 165uchar rtc_read (uchar reg)
 166{
 167        return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
 168}
 169
 170
 171static void rtc_write (uchar reg, uchar val)
 172{
 173        i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 174}
 175#else
 176static int ds3231_rtc_get(struct udevice *dev, struct rtc_time *tmp)
 177{
 178        uchar sec, min, hour, mday, wday, mon_cent, year, status;
 179
 180        status = dm_i2c_reg_read(dev, RTC_STAT_REG_ADDR);
 181        sec = dm_i2c_reg_read(dev, RTC_SEC_REG_ADDR);
 182        min = dm_i2c_reg_read(dev, RTC_MIN_REG_ADDR);
 183        hour = dm_i2c_reg_read(dev, RTC_HR_REG_ADDR);
 184        wday = dm_i2c_reg_read(dev, RTC_DAY_REG_ADDR);
 185        mday = dm_i2c_reg_read(dev, RTC_DATE_REG_ADDR);
 186        mon_cent = dm_i2c_reg_read(dev, RTC_MON_REG_ADDR);
 187        year = dm_i2c_reg_read(dev, RTC_YR_REG_ADDR);
 188
 189        if (status & RTC_STAT_BIT_OSF) {
 190                printf("### Warning: RTC oscillator has stopped\n");
 191                /* clear the OSF flag */
 192                dm_i2c_reg_write(dev, RTC_STAT_REG_ADDR,
 193                                 dm_i2c_reg_read(dev, RTC_STAT_REG_ADDR)
 194                                                & ~RTC_STAT_BIT_OSF);
 195                return -EINVAL;
 196        }
 197
 198        tmp->tm_sec  = bcd2bin(sec & 0x7F);
 199        tmp->tm_min  = bcd2bin(min & 0x7F);
 200        tmp->tm_hour = bcd2bin(hour & 0x3F);
 201        tmp->tm_mday = bcd2bin(mday & 0x3F);
 202        tmp->tm_mon  = bcd2bin(mon_cent & 0x1F);
 203        tmp->tm_year = bcd2bin(year) + ((mon_cent & 0x80) ? 2000 : 1900);
 204        tmp->tm_wday = bcd2bin((wday - 1) & 0x07);
 205        tmp->tm_yday = 0;
 206        tmp->tm_isdst = 0;
 207
 208        debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 209              tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 210              tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 211
 212        return 0;
 213}
 214
 215static int ds3231_rtc_set(struct udevice *dev, const struct rtc_time *tmp)
 216{
 217        uchar century;
 218
 219        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 220              tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 221              tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 222
 223        dm_i2c_reg_write(dev, RTC_YR_REG_ADDR, bin2bcd(tmp->tm_year % 100));
 224
 225        century = (tmp->tm_year >= 2000) ? 0x80 : 0;
 226        dm_i2c_reg_write(dev, RTC_MON_REG_ADDR, bin2bcd(tmp->tm_mon) | century);
 227
 228        dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR, bin2bcd(tmp->tm_wday + 1));
 229        dm_i2c_reg_write(dev, RTC_DATE_REG_ADDR, bin2bcd(tmp->tm_mday));
 230        dm_i2c_reg_write(dev, RTC_HR_REG_ADDR, bin2bcd(tmp->tm_hour));
 231        dm_i2c_reg_write(dev, RTC_MIN_REG_ADDR, bin2bcd(tmp->tm_min));
 232        dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, bin2bcd(tmp->tm_sec));
 233
 234        return 0;
 235}
 236
 237static int ds3231_rtc_reset(struct udevice *dev)
 238{
 239        int ret;
 240
 241        ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
 242                               RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);
 243        if (ret < 0)
 244                return ret;
 245
 246        return 0;
 247}
 248
 249static int ds3231_probe(struct udevice *dev)
 250{
 251        i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
 252                        DM_I2C_CHIP_WR_ADDRESS);
 253
 254        return 0;
 255}
 256
 257#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
 258int rtc_enable_32khz_output(int busnum, int chip_addr)
 259{
 260        int ret;
 261        struct udevice *dev;
 262
 263        ret = i2c_get_chip_for_busnum(busnum, chip_addr, 1, &dev);
 264        if (!ret) {
 265                ret = dm_i2c_reg_write(dev, RTC_STAT_REG_ADDR,
 266                                       RTC_STAT_BIT_BB32KHZ |
 267                                       RTC_STAT_BIT_EN32KHZ);
 268        }
 269        return ret;
 270}
 271#endif
 272
 273static const struct rtc_ops ds3231_rtc_ops = {
 274        .get = ds3231_rtc_get,
 275        .set = ds3231_rtc_set,
 276        .reset = ds3231_rtc_reset,
 277};
 278
 279static const struct udevice_id ds3231_rtc_ids[] = {
 280        { .compatible = "dallas,ds3231" },
 281        { .compatible = "dallas,ds3232" },
 282        { }
 283};
 284
 285U_BOOT_DRIVER(rtc_ds3231) = {
 286        .name   = "rtc-ds3231",
 287        .id     = UCLASS_RTC,
 288        .probe  = ds3231_probe,
 289        .of_match = ds3231_rtc_ids,
 290        .ops    = &ds3231_rtc_ops,
 291};
 292#endif
 293