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      1 /*
      2  * rs5c372.c
      3  *
      4  * Device driver for Ricoh's Real Time Controller RS5C372A.
      5  *
      6  * Copyright (C) 2004 Gary Jennejohn garyj (at) denx.de
      7  *
      8  * Based in part in ds1307.c -
      9  * (C) Copyright 2001, 2002, 2003
     10  * Wolfgang Denk, DENX Software Engineering, wd (at) denx.de.
     11  * Keith Outwater, keith_outwater (at) mvis.com`
     12  * Steven Scholz, steven.scholz (at) imc-berlin.de
     13  *
     14  * See file CREDITS for list of people who contributed to this
     15  * project.
     16  *
     17  * This program is free software; you can redistribute it and/or modify
     18  * it under the terms of the GNU General Public License version 2 as
     19  * published by the Free Software Foundation.
     20  */
     21 
     22 #include <common.h>
     23 #include <command.h>
     24 #include <rtc.h>
     25 #include <i2c.h>
     26 
     27 #if defined(CONFIG_CMD_DATE)
     28 /*
     29  * Reads are always done starting with register 15, which requires some
     30  * jumping-through-hoops to access the data correctly.
     31  *
     32  * Writes are always done starting with register 0.
     33  */
     34 
     35 #define DEBUG 0
     36 
     37 #if DEBUG
     38 static unsigned int rtc_debug = DEBUG;
     39 #else
     40 #define rtc_debug 0	/* gcc will remove all the debug code for us */
     41 #endif
     42 
     43 #ifndef CONFIG_SYS_I2C_RTC_ADDR
     44 #define CONFIG_SYS_I2C_RTC_ADDR 0x32
     45 #endif
     46 
     47 #define RS5C372_RAM_SIZE 0x10
     48 #define RATE_32000HZ	0x80	/* Rate Select 32.000KHz */
     49 #define RATE_32768HZ	0x00	/* Rate Select 32.768KHz */
     50 
     51 #define STATUS_XPT  0x10    /* data invalid because voltage was 0 */
     52 
     53 #define USE_24HOUR_MODE 0x20
     54 #define TWELVE_HOUR_MODE(n) ((((n) >> 5) & 1) == 0)
     55 #define HOURS_AP(n)	(((n) >> 5) & 1)
     56 #define HOURS_12(n)	bcd2bin((n) & 0x1F)
     57 #define HOURS_24(n)	bcd2bin((n) & 0x3F)
     58 
     59 
     60 static int setup_done = 0;
     61 
     62 static int
     63 rs5c372_readram(unsigned char *buf, int len)
     64 {
     65 	int ret;
     66 
     67 	ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, len);
     68 	if (ret != 0) {
     69 		printf("%s: failed to read\n", __FUNCTION__);
     70 		return ret;
     71 	}
     72 
     73 	if (buf[0] & STATUS_XPT)
     74 		printf("### Warning: RTC lost power\n");
     75 
     76 	return ret;
     77 }
     78 
     79 static void
     80 rs5c372_enable(void)
     81 {
     82 	unsigned char buf[RS5C372_RAM_SIZE + 1];
     83 	int ret;
     84 
     85 	/* note that this returns reg. 15 in buf[1] */
     86 	ret = rs5c372_readram(&buf[1], RS5C372_RAM_SIZE);
     87 	if (ret != 0) {
     88 		printf("%s: failed\n", __FUNCTION__);
     89 		return;
     90 	}
     91 
     92 	buf[0] = 0;
     93 	/* we want to start writing at register 0 so we have to copy the */
     94 	/* register contents up one slot */
     95 	for (ret = 2; ret < 9; ret++)
     96 		buf[ret - 1] = buf[ret];
     97 	/* registers 0 to 6 (time values) are not touched */
     98 	buf[8] = RATE_32768HZ; /* reg. 7 */
     99 	buf[9] = 0; /* reg. 8 */
    100 	buf[10] = 0; /* reg. 9 */
    101 	buf[11] = 0; /* reg. 10 */
    102 	buf[12] = 0; /* reg. 11 */
    103 	buf[13] = 0; /* reg. 12 */
    104 	buf[14] = 0; /* reg. 13 */
    105 	buf[15] = 0; /* reg. 14 */
    106 	buf[16] = USE_24HOUR_MODE; /* reg. 15 */
    107 	ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, RS5C372_RAM_SIZE+1);
    108 	if (ret != 0) {
    109 		printf("%s: failed\n", __FUNCTION__);
    110 		return;
    111 	}
    112 	setup_done = 1;
    113 
    114 	return;
    115 }
    116 
    117 static void
    118 rs5c372_convert_to_time(struct rtc_time *dt, unsigned char *buf)
    119 {
    120 	/* buf[0] is register 15 */
    121 	dt->tm_sec = bcd2bin(buf[1]);
    122 	dt->tm_min = bcd2bin(buf[2]);
    123 
    124 	if (TWELVE_HOUR_MODE(buf[0])) {
    125 		dt->tm_hour = HOURS_12(buf[3]);
    126 		if (HOURS_AP(buf[3])) /* PM */
    127 			dt->tm_hour += 12;
    128 	} else /* 24-hour-mode */
    129 		dt->tm_hour = HOURS_24(buf[3]);
    130 
    131 	dt->tm_mday = bcd2bin(buf[5]);
    132 	dt->tm_mon = bcd2bin(buf[6]);
    133 	dt->tm_year = bcd2bin(buf[7]);
    134 	if (dt->tm_year >= 70)
    135 		dt->tm_year += 1900;
    136 	else
    137 		dt->tm_year += 2000;
    138 	/* 0 is Sunday */
    139 	dt->tm_wday = bcd2bin(buf[4] & 0x07);
    140 	dt->tm_yday = 0;
    141 	dt->tm_isdst= 0;
    142 
    143 	if(rtc_debug > 2) {
    144 		printf("rs5c372_convert_to_time: year = %d\n", dt->tm_year);
    145 		printf("rs5c372_convert_to_time: mon  = %d\n", dt->tm_mon);
    146 		printf("rs5c372_convert_to_time: mday = %d\n", dt->tm_mday);
    147 		printf("rs5c372_convert_to_time: hour = %d\n", dt->tm_hour);
    148 		printf("rs5c372_convert_to_time: min  = %d\n", dt->tm_min);
    149 		printf("rs5c372_convert_to_time: sec  = %d\n", dt->tm_sec);
    150 	}
    151 }
    152 
    153 /*
    154  * Get the current time from the RTC
    155  */
    156 int
    157 rtc_get (struct rtc_time *tmp)
    158 {
    159 	unsigned char buf[RS5C372_RAM_SIZE];
    160 	int ret;
    161 
    162 	if (!setup_done)
    163 		rs5c372_enable();
    164 
    165 	if (!setup_done)
    166 		return -1;
    167 
    168 	memset(buf, 0, sizeof(buf));
    169 
    170 	/* note that this returns reg. 15 in buf[0] */
    171 	ret = rs5c372_readram(buf, RS5C372_RAM_SIZE);
    172 	if (ret != 0) {
    173 		printf("%s: failed\n", __FUNCTION__);
    174 		return -1;
    175 	}
    176 
    177 	rs5c372_convert_to_time(tmp, buf);
    178 
    179 	return 0;
    180 }
    181 
    182 /*
    183  * Set the RTC
    184  */
    185 int rtc_set (struct rtc_time *tmp)
    186 {
    187 	unsigned char buf[8], reg15;
    188 	int ret;
    189 
    190 	if (!setup_done)
    191 		rs5c372_enable();
    192 
    193 	if (!setup_done)
    194 		return -1;
    195 
    196 	if(rtc_debug > 2) {
    197 		printf("rtc_set: tm_year = %d\n", tmp->tm_year);
    198 		printf("rtc_set: tm_mon	 = %d\n", tmp->tm_mon);
    199 		printf("rtc_set: tm_mday = %d\n", tmp->tm_mday);
    200 		printf("rtc_set: tm_hour = %d\n", tmp->tm_hour);
    201 		printf("rtc_set: tm_min	 = %d\n", tmp->tm_min);
    202 		printf("rtc_set: tm_sec	 = %d\n", tmp->tm_sec);
    203 	}
    204 
    205 	memset(buf, 0, sizeof(buf));
    206 
    207 	/* only read register 15 */
    208 	ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 1);
    209 
    210 	if (ret == 0) {
    211 		/* need to save register 15 */
    212 		reg15 = buf[0];
    213 		buf[0] = 0;	/* register address on RS5C372 */
    214 		buf[1] = bin2bcd(tmp->tm_sec);
    215 		buf[2] = bin2bcd(tmp->tm_min);
    216 		/* need to handle 12 hour mode */
    217 		if (TWELVE_HOUR_MODE(reg15)) {
    218 			if (tmp->tm_hour >= 12) { /* PM */
    219 				/* 12 PM is a special case */
    220 				if (tmp->tm_hour == 12)
    221 					buf[3] = bin2bcd(tmp->tm_hour);
    222 				else
    223 					buf[3] = bin2bcd(tmp->tm_hour - 12);
    224 				buf[3] |= 0x20;
    225 			}
    226 		} else {
    227 			buf[3] = bin2bcd(tmp->tm_hour);
    228 		}
    229 
    230 		buf[4] = bin2bcd(tmp->tm_wday);
    231 		buf[5] = bin2bcd(tmp->tm_mday);
    232 		buf[6] = bin2bcd(tmp->tm_mon);
    233 		if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
    234 			printf("WARNING: year should be between 1970 and 2069!\n");
    235 		buf[7] = bin2bcd(tmp->tm_year % 100);
    236 
    237 		ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 8);
    238 		if (ret != 0) {
    239 			printf("rs5c372_set_datetime(), i2c_master_send() returned %d\n",ret);
    240 			return -1;
    241 		}
    242 	} else {
    243 		return -1;
    244 	}
    245 
    246 	return 0;
    247 }
    248 
    249 /*
    250  * Reset the RTC.
    251  */
    252 void
    253 rtc_reset (void)
    254 {
    255 	if (!setup_done)
    256 		rs5c372_enable();
    257 }
    258 
    259 #endif
    260