uboot/drivers/rtc/rv8803.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Date & Time support for Micro Crystal RV-8803-C7.
   4 *
   5 * based on ds1307.c which is
   6 *   (C) Copyright 2001, 2002, 2003
   7 *   Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   8 *   Keith Outwater, keith_outwater@mvis.com`
   9 *   Steven Scholz, steven.scholz@imc-berlin.de
  10 *
  11 */
  12
  13#include <common.h>
  14#include <command.h>
  15#include <dm.h>
  16#include <log.h>
  17#include <rtc.h>
  18#include <i2c.h>
  19#include <linux/bitops.h>
  20
  21/*
  22 * RTC register addresses
  23 */
  24#define RTC_SEC_REG_ADDR        0x00
  25#define RTC_MIN_REG_ADDR        0x01
  26#define RTC_HR_REG_ADDR         0x02
  27#define RTC_DAY_REG_ADDR        0x03
  28#define RTC_DATE_REG_ADDR       0x04
  29#define RTC_MON_REG_ADDR        0x05
  30#define RTC_YR_REG_ADDR         0x06
  31
  32#define RTC_FLAG_REG_ADDR       0x0E
  33#define RTC_FLAG_BIT_V1F        BIT(0)
  34#define RTC_FLAG_BIT_V2F        BIT(1)
  35
  36#define RTC_CTL_REG_ADDR        0x0F
  37#define RTC_CTL_BIT_RST         BIT(0)
  38
  39static int rv8803_rtc_set(struct udevice *dev, const struct rtc_time *tm)
  40{
  41        int ret;
  42        u8 buf[7];
  43
  44        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  45              tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  46              tm->tm_hour, tm->tm_min, tm->tm_sec);
  47
  48        if (tm->tm_year < 2000 || tm->tm_year > 2099)
  49                printf("WARNING: year should be between 2000 and 2099!\n");
  50
  51        buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
  52        buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
  53        buf[RTC_DAY_REG_ADDR] = 1 << (tm->tm_wday & 0x7);
  54        buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
  55        buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
  56        buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
  57        buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
  58
  59        ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
  60        if (ret < 0)
  61                return ret;
  62
  63        return 0;
  64}
  65
  66static int rv8803_rtc_get(struct udevice *dev, struct rtc_time *tm)
  67{
  68        int ret;
  69        u8 buf[7];
  70        int flags;
  71
  72        flags = dm_i2c_reg_read(dev, RTC_FLAG_REG_ADDR);
  73        if (flags < 0)
  74                return flags;
  75        debug("%s: flags=%Xh\n", __func__, flags);
  76
  77        if (flags & RTC_FLAG_BIT_V1F)
  78                printf("### Warning: temperature compensation has stopped\n");
  79
  80        if (flags & RTC_FLAG_BIT_V2F) {
  81                printf("### Warning: Voltage low, data is invalid\n");
  82                return -1;
  83        }
  84
  85        ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
  86        if (ret < 0)
  87                return ret;
  88
  89        tm->tm_sec  = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
  90        tm->tm_min  = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
  91        tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
  92        tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
  93        tm->tm_mon  = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
  94        tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000;
  95        tm->tm_wday = fls(buf[RTC_DAY_REG_ADDR] & 0x7F) - 1;
  96        tm->tm_yday = 0;
  97        tm->tm_isdst = 0;
  98
  99        debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 100              tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
 101              tm->tm_hour, tm->tm_min, tm->tm_sec);
 102
 103        return 0;
 104}
 105
 106static int rv8803_rtc_reset(struct udevice *dev)
 107{
 108        int ret;
 109        struct rtc_time tmp = {
 110                .tm_year = 2000,
 111                .tm_mon = 1,
 112                .tm_mday = 1,
 113                .tm_hour = 0,
 114                .tm_min = 0,
 115                .tm_sec = 0,
 116        };
 117
 118        /* assert reset */
 119        ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, RTC_CTL_BIT_RST);
 120        if (ret < 0)
 121                return ret;
 122
 123        /* clear all flags */
 124        ret = dm_i2c_reg_write(dev, RTC_FLAG_REG_ADDR, 0);
 125        if (ret < 0)
 126                return ret;
 127
 128        ret = rv8803_rtc_set(dev, &tmp);
 129        if (ret < 0)
 130                return ret;
 131
 132        /* clear reset */
 133        ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, 0);
 134        if (ret < 0)
 135                return ret;
 136
 137        debug("RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
 138              tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
 139              tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
 140
 141        return 0;
 142}
 143
 144static int rv8803_probe(struct udevice *dev)
 145{
 146        i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
 147                           DM_I2C_CHIP_WR_ADDRESS);
 148
 149        return 0;
 150}
 151
 152static const struct rtc_ops rv8803_rtc_ops = {
 153        .get = rv8803_rtc_get,
 154        .set = rv8803_rtc_set,
 155        .reset = rv8803_rtc_reset,
 156};
 157
 158static const struct udevice_id rv8803_rtc_ids[] = {
 159        { .compatible = "microcrystal,rv8803", },
 160        { .compatible = "epson,rx8803" },
 161        { .compatible = "epson,rx8900" },
 162        { }
 163};
 164
 165U_BOOT_DRIVER(rtc_rv8803) = {
 166        .name   = "rtc-rv8803",
 167        .id     = UCLASS_RTC,
 168        .probe  = rv8803_probe,
 169        .of_match = rv8803_rtc_ids,
 170        .ops    = &rv8803_rtc_ops,
 171};
 172