drivers/rtc/rv3029.c

   1 /*
   2  * (C) Copyright 2010
   3  * Heiko Schocher, DENX Software Engineering, hs@denx.de
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7 #include <common.h>
   8 #include <command.h>
   9 #include <i2c.h>
  10 #include <rtc.h>
  11
  12 #define RTC_RV3029_CTRL1        0x00
  13 #define RTC_RV3029_CTRL1_EERE   (1 << 3)
  14
  15 #define RTC_RV3029_CTRL_STATUS  0x03
  16 #define RTC_RV3029_CTRLS_EEBUSY (1 << 7)
  17
  18 #define RTC_RV3029_CTRL_RESET   0x04
  19 #define RTC_RV3029_CTRL_SYS_R   (1 << 4)
  20
  21 #define RTC_RV3029_CLOCK_PAGE   0x08
  22 #define RTC_RV3029_PAGE_LEN     7
  23
  24 #define RV3029C2_W_SECONDS      0x00
  25 #define RV3029C2_W_MINUTES      0x01
  26 #define RV3029C2_W_HOURS        0x02
  27 #define RV3029C2_W_DATE         0x03
  28 #define RV3029C2_W_DAYS         0x04
  29 #define RV3029C2_W_MONTHS       0x05
  30 #define RV3029C2_W_YEARS        0x06
  31
  32 #define RV3029C2_REG_HR_12_24          (1 << 6)  /* 24h/12h mode */
  33 #define RV3029C2_REG_HR_PM             (1 << 5)  /* PM/AM bit in 12h mode */
  34
  35 #define RTC_RV3029_EEPROM_CTRL  0x30
  36 #define RTC_RV3029_TRICKLE_1K   (1 << 4)
  37 #define RTC_RV3029_TRICKLE_5K   (1 << 5)
  38 #define RTC_RV3029_TRICKLE_20K  (1 << 6)
  39 #define RTC_RV3029_TRICKLE_80K  (1 << 7)
  40
  41 int rtc_get( struct rtc_time *tmp )
  42 {
  43         int     ret;
  44         unsigned char buf[RTC_RV3029_PAGE_LEN];
  45
  46         ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CLOCK_PAGE, 1, buf, \
  47                         RTC_RV3029_PAGE_LEN);
  48         if (ret) {
  49                 printf("%s: error reading RTC: %x\n", __func__, ret);
  50                 return -1;
  51         }
  52         tmp->tm_sec  = bcd2bin( buf[RV3029C2_W_SECONDS] & 0x7f);
  53         tmp->tm_min  = bcd2bin( buf[RV3029C2_W_MINUTES] & 0x7f);
  54         if (buf[RV3029C2_W_HOURS] & RV3029C2_REG_HR_12_24) {
  55                 /* 12h format */
  56                 tmp->tm_hour = bcd2bin(buf[RV3029C2_W_HOURS] & 0x1f);
  57                 if (buf[RV3029C2_W_HOURS] & RV3029C2_REG_HR_PM)
  58                         /* PM flag set */
  59                         tmp->tm_hour += 12;
  60         } else
  61                 tmp->tm_hour = bcd2bin(buf[RV3029C2_W_HOURS] & 0x3f);
  62
  63         tmp->tm_mday = bcd2bin( buf[RV3029C2_W_DATE] & 0x3F );
  64         tmp->tm_mon  = bcd2bin( buf[RV3029C2_W_MONTHS] & 0x1F );
  65         tmp->tm_wday = bcd2bin( buf[RV3029C2_W_DAYS] & 0x07 );
  66         /* RTC supports only years > 1999 */
  67         tmp->tm_year = bcd2bin( buf[RV3029C2_W_YEARS]) + 2000;
  68         tmp->tm_yday = 0;
  69         tmp->tm_isdst = 0;
  70
  71         debug( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  72                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  73                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
  74
  75         return 0;
  76 }
  77
  78 int rtc_set( struct rtc_time *tmp )
  79 {
  80         int     ret;
  81         unsigned char buf[RTC_RV3029_PAGE_LEN];
  82
  83         debug( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  84                 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  85                 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  86
  87         if (tmp->tm_year < 2000) {
  88                 printf("RTC: year %d < 2000 not possible\n", tmp->tm_year);
  89                 return -1;
  90         }
  91         buf[RV3029C2_W_SECONDS] = bin2bcd(tmp->tm_sec);
  92         buf[RV3029C2_W_MINUTES] = bin2bcd(tmp->tm_min);
  93         buf[RV3029C2_W_HOURS] = bin2bcd(tmp->tm_hour);
  94         /* set 24h format */
  95         buf[RV3029C2_W_HOURS] &= ~RV3029C2_REG_HR_12_24;
  96         buf[RV3029C2_W_DATE] = bin2bcd(tmp->tm_mday);
  97         buf[RV3029C2_W_DAYS] = bin2bcd(tmp->tm_wday);
  98         buf[RV3029C2_W_MONTHS] = bin2bcd(tmp->tm_mon);
  99         tmp->tm_year -= 2000;
 100         buf[RV3029C2_W_YEARS] = bin2bcd(tmp->tm_year);
 101         ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CLOCK_PAGE, 1,
 102                         buf, RTC_RV3029_PAGE_LEN);
 103
 104         /* give the RTC some time to update */
 105         udelay(1000);
 106         return ret;
 107 }
 108
 109 /* sets EERE-Bit  (automatic EEPROM refresh) */
 110 static void set_eere_bit(int state)
 111 {
 112         unsigned char reg_ctrl1;
 113
 114         (void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
 115                         &reg_ctrl1, 1);
 116
 117         if (state)
 118                 reg_ctrl1 |= RTC_RV3029_CTRL1_EERE;
 119         else
 120                 reg_ctrl1 &= (~RTC_RV3029_CTRL1_EERE);
 121
 122         (void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
 123                 &reg_ctrl1, 1);
 124 }
 125
 126 /* waits until EEPROM page is no longer busy (times out after 10ms*loops) */
 127 static int wait_eebusy(int loops)
 128 {
 129         int i;
 130         unsigned char ctrl_status;
 131
 132         for (i = 0; i < loops; i++) {
 133                 (void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_STATUS,
 134                         1, &ctrl_status, 1);
 135
 136                 if ((ctrl_status & RTC_RV3029_CTRLS_EEBUSY) == 0)
 137                         break;
 138                 udelay(10000);
 139         }
 140         return i;
 141 }
 142
 143 void rtc_reset (void)
 144 {
 145         unsigned char buf[RTC_RV3029_PAGE_LEN];
 146
 147         buf[0] = RTC_RV3029_CTRL_SYS_R;
 148         (void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_RESET, 1,
 149                         buf, 1);
 150
 151 #if defined(CONFIG_SYS_RV3029_TCR)
 152         /*
 153          * because EEPROM_CTRL register is in EEPROM page it is necessary to
 154          * disable automatic EEPROM refresh and check if EEPROM is busy
 155          * before EEPORM_CTRL register may be accessed
 156          */
 157         set_eere_bit(0);
 158         wait_eebusy(100);
 159         /* read current trickle charger setting */
 160         (void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_EEPROM_CTRL,
 161                         1, buf, 1);
 162         /* enable automatic EEPROM refresh again */
 163         set_eere_bit(1);
 164
 165         /*
 166          * to minimize EEPROM access write trickle charger setting only if it
 167          * differs from current value
 168          */
 169         if ((buf[0] & 0xF0) != CONFIG_SYS_RV3029_TCR) {
 170                 buf[0] = (buf[0] & 0x0F) | CONFIG_SYS_RV3029_TCR;
 171                 /*
 172                  * write trickle charger setting (disable autom. EEPROM
 173                  * refresh and wait until EEPROM is idle)
 174                  */
 175                 set_eere_bit(0);
 176                 wait_eebusy(100);
 177                 (void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR,
 178                                 RTC_RV3029_EEPROM_CTRL, 1, buf, 1);
 179                 /*
 180                  * it is necessary to wait 10ms before EEBUSY-Bit may be read
 181                  * (this is not documented in the data sheet yet, but the
 182                  * manufacturer recommends it)
 183                  */
 184                 udelay(10000);
 185                 /* wait until EEPROM write access is finished */
 186                 wait_eebusy(100);
 187                 set_eere_bit(1);
 188         }
 189 #endif
 190 }