drivers/rtc/rv3028.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * RTC driver for the Micro Crystal RV3028
   4  *
   5  * based on linux driver from
   6  * Copyright (C) 2019 Micro Crystal SA
   7  *
   8  * Alexandre Belloni <alexandre.belloni@bootlin.com>
   9  *
  10  */
  11
  12 #include <dm.h>
  13 #include <i2c.h>
  14 #include <rtc.h>
  15
  16 #define RV3028_SEC                      0x00
  17 #define RV3028_MIN                      0x01
  18 #define RV3028_HOUR                     0x02
  19 #define RV3028_WDAY                     0x03
  20 #define RV3028_DAY                      0x04
  21 #define RV3028_MONTH                    0x05
  22 #define RV3028_YEAR                     0x06
  23 #define RV3028_ALARM_MIN                0x07
  24 #define RV3028_ALARM_HOUR               0x08
  25 #define RV3028_ALARM_DAY                0x09
  26 #define RV3028_STATUS                   0x0E
  27 #define RV3028_CTRL1                    0x0F
  28 #define RV3028_CTRL2                    0x10
  29 #define RV3028_EVT_CTRL                 0x13
  30 #define RV3028_TS_COUNT                 0x14
  31 #define RV3028_TS_SEC                   0x15
  32 #define RV3028_RAM1                     0x1F
  33 #define RV3028_EEPROM_ADDR              0x25
  34 #define RV3028_EEPROM_DATA              0x26
  35 #define RV3028_EEPROM_CMD               0x27
  36 #define RV3028_CLKOUT                   0x35
  37 #define RV3028_OFFSET                   0x36
  38 #define RV3028_BACKUP                   0x37
  39
  40 #define RV3028_STATUS_PORF              BIT(0)
  41 #define RV3028_STATUS_EVF               BIT(1)
  42 #define RV3028_STATUS_AF                BIT(2)
  43 #define RV3028_STATUS_TF                BIT(3)
  44 #define RV3028_STATUS_UF                BIT(4)
  45 #define RV3028_STATUS_BSF               BIT(5)
  46 #define RV3028_STATUS_CLKF              BIT(6)
  47 #define RV3028_STATUS_EEBUSY            BIT(7)
  48
  49 #define RV3028_CLKOUT_FD_MASK           GENMASK(2, 0)
  50 #define RV3028_CLKOUT_PORIE             BIT(3)
  51 #define RV3028_CLKOUT_CLKSY             BIT(6)
  52 #define RV3028_CLKOUT_CLKOE             BIT(7)
  53
  54 #define RV3028_CTRL1_EERD               BIT(3)
  55 #define RV3028_CTRL1_WADA               BIT(5)
  56
  57 #define RV3028_CTRL2_RESET              BIT(0)
  58 #define RV3028_CTRL2_12_24              BIT(1)
  59 #define RV3028_CTRL2_EIE                BIT(2)
  60 #define RV3028_CTRL2_AIE                BIT(3)
  61 #define RV3028_CTRL2_TIE                BIT(4)
  62 #define RV3028_CTRL2_UIE                BIT(5)
  63 #define RV3028_CTRL2_TSE                BIT(7)
  64
  65 #define RV3028_EVT_CTRL_TSR             BIT(2)
  66
  67 #define RV3028_EEPROM_CMD_UPDATE        0x11
  68 #define RV3028_EEPROM_CMD_WRITE         0x21
  69 #define RV3028_EEPROM_CMD_READ          0x22
  70
  71 #define RV3028_EEBUSY_POLL              10000
  72 #define RV3028_EEBUSY_TIMEOUT           100000
  73
  74 #define RV3028_BACKUP_TCE               BIT(5)
  75 #define RV3028_BACKUP_TCR_MASK          GENMASK(1, 0)
  76
  77 #define OFFSET_STEP_PPT                 953674
  78
  79 #define RTC_RV3028_LEN                  7
  80
  81 static int rv3028_rtc_get(struct udevice *dev, struct rtc_time *tm)
  82 {
  83         u8 regs[RTC_RV3028_LEN];
  84         u8 status;
  85         int ret;
  86
  87         ret = dm_i2c_read(dev, RV3028_STATUS, &status, 1);
  88         if (ret < 0) {
  89                 printf("%s: error reading RTC status: %x\n", __func__, ret);
  90                 return -EIO;
  91         }
  92
  93         if (status & RV3028_STATUS_PORF) {
  94                 printf("Voltage low, data is invalid.\n");
  95                 return -EINVAL;
  96         }
  97
  98         ret = dm_i2c_read(dev, RV3028_SEC, regs, sizeof(regs));
  99         if (ret < 0) {
 100                 printf("%s: error reading RTC: %x\n", __func__, ret);
 101                 return -EIO;
 102         }
 103
 104         tm->tm_sec = bcd2bin(regs[RV3028_SEC] & 0x7f);
 105         tm->tm_min = bcd2bin(regs[RV3028_MIN] & 0x7f);
 106         tm->tm_hour = bcd2bin(regs[RV3028_HOUR] & 0x3f);
 107         tm->tm_wday = regs[RV3028_WDAY] & 0x7;
 108         tm->tm_mday = bcd2bin(regs[RV3028_DAY] & 0x3f);
 109         tm->tm_mon  = bcd2bin(regs[RV3028_MONTH] & 0x1f);
 110         tm->tm_year = bcd2bin(regs[RV3028_YEAR]) + 2000;
 111         tm->tm_yday = 0;
 112         tm->tm_isdst = 0;
 113
 114         debug("%s: %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n",
 115               __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
 116               tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
 117
 118         return 0;
 119 }
 120
 121 static int rv3028_rtc_set(struct udevice *dev, const struct rtc_time *tm)
 122 {
 123         u8 regs[RTC_RV3028_LEN];
 124         u8 status;
 125         int ret;
 126
 127         debug("%s: %4d-%02d-%02d (wday=%d( %2d:%02d:%02d\n",
 128               __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
 129               tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
 130
 131         if (tm->tm_year < 2000) {
 132                 printf("%s: year %d (before 2000) not supported\n",
 133                        __func__, tm->tm_year);
 134                 return -EINVAL;
 135         }
 136
 137         regs[RV3028_SEC] = bin2bcd(tm->tm_sec);
 138         regs[RV3028_MIN] = bin2bcd(tm->tm_min);
 139         regs[RV3028_HOUR] = bin2bcd(tm->tm_hour);
 140         regs[RV3028_WDAY]  = tm->tm_wday;
 141         regs[RV3028_DAY]   = bin2bcd(tm->tm_mday);
 142         regs[RV3028_MONTH] = bin2bcd(tm->tm_mon);
 143         regs[RV3028_YEAR]  = bin2bcd(tm->tm_year - 2000);
 144
 145         ret = dm_i2c_write(dev, RV3028_SEC, regs, sizeof(regs));
 146         if (ret) {
 147                 printf("%s: set rtc error: %d\n", __func__, ret);
 148                 return ret;
 149         }
 150
 151         ret = dm_i2c_read(dev, RV3028_STATUS, &status, 1);
 152         if (ret < 0) {
 153                 printf("%s: error reading RTC status: %x\n", __func__, ret);
 154                 return -EIO;
 155         }
 156         status |= RV3028_STATUS_PORF;
 157         return dm_i2c_write(dev, RV3028_STATUS, &status, 1);
 158 }
 159
 160 static int rv3028_rtc_reset(struct udevice *dev)
 161 {
 162         return 0;
 163 }
 164
 165 static int rv3028_rtc_read8(struct udevice *dev, unsigned int reg)
 166 {
 167         u8 data;
 168         int ret;
 169
 170         ret = dm_i2c_read(dev, reg, &data, sizeof(data));
 171         return ret < 0 ? ret : data;
 172 }
 173
 174 static int rv3028_rtc_write8(struct udevice *dev, unsigned int reg, int val)
 175 {
 176         u8 data = val;
 177
 178         return dm_i2c_write(dev, reg, &data, 1);
 179 }
 180
 181 static int rv3028_probe(struct udevice *dev)
 182 {
 183         i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
 184                                 DM_I2C_CHIP_WR_ADDRESS);
 185
 186         return 0;
 187 }
 188
 189 static const struct rtc_ops rv3028_rtc_ops = {
 190         .get = rv3028_rtc_get,
 191         .set = rv3028_rtc_set,
 192         .read8 = rv3028_rtc_read8,
 193         .write8 = rv3028_rtc_write8,
 194         .reset = rv3028_rtc_reset,
 195 };
 196
 197 static const struct udevice_id rv3028_rtc_ids[] = {
 198         { .compatible = "microcrystal,rv3028" },
 199         { }
 200 };
 201
 202 U_BOOT_DRIVER(rtc_rv3028) = {
 203         .name   = "rtc-rv3028",
 204         .id     = UCLASS_RTC,
 205         .probe  = rv3028_probe,
 206         .of_match = rv3028_rtc_ids,
 207         .ops    = &rv3028_rtc_ops,
 208 };