1 /* 2 * (C) Copyright 2001, 2002, 2003 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * Keith Outwater, keith_outwater@mvis.com` 5 * Steven Scholz, steven.scholz@imc-berlin.de 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 /* 11 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim) 12 * DS1307 and DS1338/9 Real Time Clock (RTC). 13 * 14 * based on ds1337.c 15 */ 16 17 #include <common.h> 18 #include <command.h> 19 #include <dm.h> 20 #include <rtc.h> 21 #include <i2c.h> 22 23 enum ds_type { 24 ds_1307, 25 ds_1337, 26 ds_1340, 27 mcp794xx, 28 }; 29 30 /* 31 * RTC register addresses 32 */ 33 #define RTC_SEC_REG_ADDR 0x00 34 #define RTC_MIN_REG_ADDR 0x01 35 #define RTC_HR_REG_ADDR 0x02 36 #define RTC_DAY_REG_ADDR 0x03 37 #define RTC_DATE_REG_ADDR 0x04 38 #define RTC_MON_REG_ADDR 0x05 39 #define RTC_YR_REG_ADDR 0x06 40 #define RTC_CTL_REG_ADDR 0x07 41 42 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */ 43 44 #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */ 45 #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */ 46 #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */ 47 #define RTC_CTL_BIT_OUT 0x80 /* Output Control */ 48 49 /* MCP7941X-specific bits */ 50 #define MCP7941X_BIT_ST 0x80 51 #define MCP7941X_BIT_VBATEN 0x08 52 53 #ifndef CONFIG_DM_RTC 54 55 #if defined(CONFIG_CMD_DATE) 56 57 /*---------------------------------------------------------------------*/ 58 #undef DEBUG_RTC 59 60 #ifdef DEBUG_RTC 61 #define DEBUGR(fmt, args...) printf(fmt, ##args) 62 #else 63 #define DEBUGR(fmt, args...) 64 #endif 65 /*---------------------------------------------------------------------*/ 66 67 #ifndef CONFIG_SYS_I2C_RTC_ADDR 68 # define CONFIG_SYS_I2C_RTC_ADDR 0x68 69 #endif 70 71 #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000) 72 # error The DS1307 is specified only up to 100kHz! 73 #endif 74 75 static uchar rtc_read (uchar reg); 76 static void rtc_write (uchar reg, uchar val); 77 78 /* 79 * Get the current time from the RTC 80 */ 81 int rtc_get (struct rtc_time *tmp) 82 { 83 int rel = 0; 84 uchar sec, min, hour, mday, wday, mon, year; 85 86 #ifdef CONFIG_RTC_MCP79411 87 read_rtc: 88 #endif 89 sec = rtc_read (RTC_SEC_REG_ADDR); 90 min = rtc_read (RTC_MIN_REG_ADDR); 91 hour = rtc_read (RTC_HR_REG_ADDR); 92 wday = rtc_read (RTC_DAY_REG_ADDR); 93 mday = rtc_read (RTC_DATE_REG_ADDR); 94 mon = rtc_read (RTC_MON_REG_ADDR); 95 year = rtc_read (RTC_YR_REG_ADDR); 96 97 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 98 "hr: %02x min: %02x sec: %02x\n", 99 year, mon, mday, wday, hour, min, sec); 100 101 #ifdef CONFIG_RTC_DS1307 102 if (sec & RTC_SEC_BIT_CH) { 103 printf ("### Warning: RTC oscillator has stopped\n"); 104 /* clear the CH flag */ 105 rtc_write (RTC_SEC_REG_ADDR, 106 rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH); 107 rel = -1; 108 } 109 #endif 110 111 #ifdef CONFIG_RTC_MCP79411 112 /* make sure that the backup battery is enabled */ 113 if (!(wday & MCP7941X_BIT_VBATEN)) { 114 rtc_write(RTC_DAY_REG_ADDR, 115 wday | MCP7941X_BIT_VBATEN); 116 } 117 118 /* clock halted? turn it on, so clock can tick. */ 119 if (!(sec & MCP7941X_BIT_ST)) { 120 rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST); 121 printf("Started RTC\n"); 122 goto read_rtc; 123 } 124 #endif 125 126 127 tmp->tm_sec = bcd2bin (sec & 0x7F); 128 tmp->tm_min = bcd2bin (min & 0x7F); 129 tmp->tm_hour = bcd2bin (hour & 0x3F); 130 tmp->tm_mday = bcd2bin (mday & 0x3F); 131 tmp->tm_mon = bcd2bin (mon & 0x1F); 132 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); 133 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07); 134 tmp->tm_yday = 0; 135 tmp->tm_isdst= 0; 136 137 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 138 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 139 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 140 141 return rel; 142 } 143 144 145 /* 146 * Set the RTC 147 */ 148 int rtc_set (struct rtc_time *tmp) 149 { 150 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 151 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 152 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 153 154 if (tmp->tm_year < 1970 || tmp->tm_year > 2069) 155 printf("WARNING: year should be between 1970 and 2069!\n"); 156 157 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); 158 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); 159 #ifdef CONFIG_RTC_MCP79411 160 rtc_write (RTC_DAY_REG_ADDR, 161 bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN); 162 #else 163 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1)); 164 #endif 165 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); 166 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); 167 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); 168 #ifdef CONFIG_RTC_MCP79411 169 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST); 170 #else 171 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); 172 #endif 173 174 return 0; 175 } 176 177 178 /* 179 * Reset the RTC. We setting the date back to 1970-01-01. 180 * We also enable the oscillator output on the SQW/OUT pin and program 181 * it for 32,768 Hz output. Note that according to the datasheet, turning 182 * on the square wave output increases the current drain on the backup 183 * battery to something between 480nA and 800nA. 184 */ 185 void rtc_reset (void) 186 { 187 struct rtc_time tmp; 188 189 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */ 190 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0); 191 192 tmp.tm_year = 1970; 193 tmp.tm_mon = 1; 194 tmp.tm_mday= 1; 195 tmp.tm_hour = 0; 196 tmp.tm_min = 0; 197 tmp.tm_sec = 0; 198 199 rtc_set(&tmp); 200 201 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n", 202 tmp.tm_year, tmp.tm_mon, tmp.tm_mday, 203 tmp.tm_hour, tmp.tm_min, tmp.tm_sec); 204 205 return; 206 } 207 208 209 /* 210 * Helper functions 211 */ 212 213 static 214 uchar rtc_read (uchar reg) 215 { 216 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 217 } 218 219 220 static void rtc_write (uchar reg, uchar val) 221 { 222 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val); 223 } 224 225 #endif /* CONFIG_CMD_DATE*/ 226 227 #endif /* !CONFIG_DM_RTC */ 228 229 #ifdef CONFIG_DM_RTC 230 static int ds1307_rtc_set(struct udevice *dev, const struct rtc_time *tm) 231 { 232 int ret; 233 uchar buf[7]; 234 enum ds_type type = dev_get_driver_data(dev); 235 236 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 237 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, 238 tm->tm_hour, tm->tm_min, tm->tm_sec); 239 240 if (tm->tm_year < 1970 || tm->tm_year > 2069) 241 printf("WARNING: year should be between 1970 and 2069!\n"); 242 243 buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100); 244 buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon); 245 buf[RTC_DAY_REG_ADDR] = bin2bcd(tm->tm_wday + 1); 246 buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday); 247 buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour); 248 buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min); 249 buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec); 250 251 if (type == mcp794xx) { 252 buf[RTC_DAY_REG_ADDR] |= MCP7941X_BIT_VBATEN; 253 buf[RTC_SEC_REG_ADDR] |= MCP7941X_BIT_ST; 254 } 255 256 ret = dm_i2c_write(dev, 0, buf, sizeof(buf)); 257 if (ret < 0) 258 return ret; 259 260 return 0; 261 } 262 263 static int ds1307_rtc_get(struct udevice *dev, struct rtc_time *tm) 264 { 265 int ret; 266 uchar buf[7]; 267 enum ds_type type = dev_get_driver_data(dev); 268 269 read_rtc: 270 ret = dm_i2c_read(dev, 0, buf, sizeof(buf)); 271 if (ret < 0) 272 return ret; 273 274 if (type == ds_1307) { 275 if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) { 276 printf("### Warning: RTC oscillator has stopped\n"); 277 /* clear the CH flag */ 278 buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH; 279 dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 280 buf[RTC_SEC_REG_ADDR]); 281 return -1; 282 } 283 } 284 285 if (type == mcp794xx) { 286 /* make sure that the backup battery is enabled */ 287 if (!(buf[RTC_DAY_REG_ADDR] & MCP7941X_BIT_VBATEN)) { 288 dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR, 289 buf[RTC_DAY_REG_ADDR] | 290 MCP7941X_BIT_VBATEN); 291 } 292 293 /* clock halted? turn it on, so clock can tick. */ 294 if (!(buf[RTC_SEC_REG_ADDR] & MCP7941X_BIT_ST)) { 295 dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 296 MCP7941X_BIT_ST); 297 printf("Started RTC\n"); 298 goto read_rtc; 299 } 300 } 301 302 tm->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F); 303 tm->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F); 304 tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F); 305 tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F); 306 tm->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F); 307 tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 308 (bcd2bin(buf[RTC_YR_REG_ADDR]) >= 70 ? 309 1900 : 2000); 310 tm->tm_wday = bcd2bin((buf[RTC_DAY_REG_ADDR] - 1) & 0x07); 311 tm->tm_yday = 0; 312 tm->tm_isdst = 0; 313 314 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 315 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, 316 tm->tm_hour, tm->tm_min, tm->tm_sec); 317 318 return 0; 319 } 320 321 static int ds1307_rtc_reset(struct udevice *dev) 322 { 323 int ret; 324 struct rtc_time tmp = { 325 .tm_year = 1970, 326 .tm_mon = 1, 327 .tm_mday = 1, 328 .tm_hour = 0, 329 .tm_min = 0, 330 .tm_sec = 0, 331 }; 332 333 /* clear Clock Halt */ 334 ret = dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 0x00); 335 if (ret < 0) 336 return ret; 337 ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, 338 RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | 339 RTC_CTL_BIT_RS0); 340 if (ret < 0) 341 return ret; 342 343 ret = ds1307_rtc_set(dev, &tmp); 344 if (ret < 0) 345 return ret; 346 347 debug("RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n", 348 tmp.tm_year, tmp.tm_mon, tmp.tm_mday, 349 tmp.tm_hour, tmp.tm_min, tmp.tm_sec); 350 351 return 0; 352 } 353 354 static int ds1307_probe(struct udevice *dev) 355 { 356 i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS | 357 DM_I2C_CHIP_WR_ADDRESS); 358 359 return 0; 360 } 361 362 static const struct rtc_ops ds1307_rtc_ops = { 363 .get = ds1307_rtc_get, 364 .set = ds1307_rtc_set, 365 .reset = ds1307_rtc_reset, 366 }; 367 368 static const struct udevice_id ds1307_rtc_ids[] = { 369 { .compatible = "dallas,ds1307", .data = ds_1307 }, 370 { .compatible = "dallas,ds1337", .data = ds_1337 }, 371 { .compatible = "dallas,ds1340", .data = ds_1340 }, 372 { .compatible = "microchip,mcp7941x", .data = mcp794xx }, 373 { } 374 }; 375 376 U_BOOT_DRIVER(rtc_ds1307) = { 377 .name = "rtc-ds1307", 378 .id = UCLASS_RTC, 379 .probe = ds1307_probe, 380 .of_match = ds1307_rtc_ids, 381 .ops = &ds1307_rtc_ops, 382 }; 383 #endif /* CONFIG_DM_RTC */ 384