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