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