1 /* 2 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips. 3 * 4 * Copyright (C) 2005 James Chapman (ds1337 core) 5 * Copyright (C) 2006 David Brownell 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/slab.h> 15 #include <linux/i2c.h> 16 #include <linux/string.h> 17 #include <linux/rtc.h> 18 #include <linux/bcd.h> 19 20 21 22 /* We can't determine type by probing, but if we expect pre-Linux code 23 * to have set the chip up as a clock (turning on the oscillator and 24 * setting the date and time), Linux can ignore the non-clock features. 25 * That's a natural job for a factory or repair bench. 26 */ 27 enum ds_type { 28 ds_1307, 29 ds_1337, 30 ds_1338, 31 ds_1339, 32 ds_1340, 33 m41t00, 34 // rs5c372 too? different address... 35 }; 36 37 38 /* RTC registers don't differ much, except for the century flag */ 39 #define DS1307_REG_SECS 0x00 /* 00-59 */ 40 # define DS1307_BIT_CH 0x80 41 # define DS1340_BIT_nEOSC 0x80 42 #define DS1307_REG_MIN 0x01 /* 00-59 */ 43 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */ 44 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */ 45 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */ 46 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */ 47 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */ 48 #define DS1307_REG_WDAY 0x03 /* 01-07 */ 49 #define DS1307_REG_MDAY 0x04 /* 01-31 */ 50 #define DS1307_REG_MONTH 0x05 /* 01-12 */ 51 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */ 52 #define DS1307_REG_YEAR 0x06 /* 00-99 */ 53 54 /* Other registers (control, status, alarms, trickle charge, NVRAM, etc) 55 * start at 7, and they differ a LOT. Only control and status matter for 56 * basic RTC date and time functionality; be careful using them. 57 */ 58 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */ 59 # define DS1307_BIT_OUT 0x80 60 # define DS1338_BIT_OSF 0x20 61 # define DS1307_BIT_SQWE 0x10 62 # define DS1307_BIT_RS1 0x02 63 # define DS1307_BIT_RS0 0x01 64 #define DS1337_REG_CONTROL 0x0e 65 # define DS1337_BIT_nEOSC 0x80 66 # define DS1339_BIT_BBSQI 0x20 67 # define DS1337_BIT_RS2 0x10 68 # define DS1337_BIT_RS1 0x08 69 # define DS1337_BIT_INTCN 0x04 70 # define DS1337_BIT_A2IE 0x02 71 # define DS1337_BIT_A1IE 0x01 72 #define DS1340_REG_CONTROL 0x07 73 # define DS1340_BIT_OUT 0x80 74 # define DS1340_BIT_FT 0x40 75 # define DS1340_BIT_CALIB_SIGN 0x20 76 # define DS1340_M_CALIBRATION 0x1f 77 #define DS1340_REG_FLAG 0x09 78 # define DS1340_BIT_OSF 0x80 79 #define DS1337_REG_STATUS 0x0f 80 # define DS1337_BIT_OSF 0x80 81 # define DS1337_BIT_A2I 0x02 82 # define DS1337_BIT_A1I 0x01 83 #define DS1339_REG_ALARM1_SECS 0x07 84 #define DS1339_REG_TRICKLE 0x10 85 86 87 88 struct ds1307 { 89 u8 regs[11]; 90 enum ds_type type; 91 unsigned long flags; 92 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */ 93 #define HAS_ALARM 1 /* bit 1 == irq claimed */ 94 struct i2c_client *client; 95 struct rtc_device *rtc; 96 struct work_struct work; 97 }; 98 99 struct chip_desc { 100 unsigned nvram56:1; 101 unsigned alarm:1; 102 }; 103 104 static const struct chip_desc chips[] = { 105 [ds_1307] = { 106 .nvram56 = 1, 107 }, 108 [ds_1337] = { 109 .alarm = 1, 110 }, 111 [ds_1338] = { 112 .nvram56 = 1, 113 }, 114 [ds_1339] = { 115 .alarm = 1, 116 }, 117 [ds_1340] = { 118 }, 119 [m41t00] = { 120 }, }; 121 122 static const struct i2c_device_id ds1307_id[] = { 123 { "ds1307", ds_1307 }, 124 { "ds1337", ds_1337 }, 125 { "ds1338", ds_1338 }, 126 { "ds1339", ds_1339 }, 127 { "ds1340", ds_1340 }, 128 { "m41t00", m41t00 }, 129 { } 130 }; 131 MODULE_DEVICE_TABLE(i2c, ds1307_id); 132 133 /*----------------------------------------------------------------------*/ 134 135 /* 136 * The IRQ logic includes a "real" handler running in IRQ context just 137 * long enough to schedule this workqueue entry. We need a task context 138 * to talk to the RTC, since I2C I/O calls require that; and disable the 139 * IRQ until we clear its status on the chip, so that this handler can 140 * work with any type of triggering (not just falling edge). 141 * 142 * The ds1337 and ds1339 both have two alarms, but we only use the first 143 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm 144 * signal; ds1339 chips have only one alarm signal. 145 */ 146 static void ds1307_work(struct work_struct *work) 147 { 148 struct ds1307 *ds1307; 149 struct i2c_client *client; 150 struct mutex *lock; 151 int stat, control; 152 153 ds1307 = container_of(work, struct ds1307, work); 154 client = ds1307->client; 155 lock = &ds1307->rtc->ops_lock; 156 157 mutex_lock(lock); 158 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS); 159 if (stat < 0) 160 goto out; 161 162 if (stat & DS1337_BIT_A1I) { 163 stat &= ~DS1337_BIT_A1I; 164 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat); 165 166 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL); 167 if (control < 0) 168 goto out; 169 170 control &= ~DS1337_BIT_A1IE; 171 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control); 172 173 /* rtc_update_irq() assumes that it is called 174 * from IRQ-disabled context. 175 */ 176 local_irq_disable(); 177 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF); 178 local_irq_enable(); 179 } 180 181 out: 182 if (test_bit(HAS_ALARM, &ds1307->flags)) 183 enable_irq(client->irq); 184 mutex_unlock(lock); 185 } 186 187 static irqreturn_t ds1307_irq(int irq, void *dev_id) 188 { 189 struct i2c_client *client = dev_id; 190 struct ds1307 *ds1307 = i2c_get_clientdata(client); 191 192 disable_irq_nosync(irq); 193 schedule_work(&ds1307->work); 194 return IRQ_HANDLED; 195 } 196 197 /*----------------------------------------------------------------------*/ 198 199 static int ds1307_get_time(struct device *dev, struct rtc_time *t) 200 { 201 struct ds1307 *ds1307 = dev_get_drvdata(dev); 202 int tmp; 203 204 /* read the RTC date and time registers all at once */ 205 tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 206 DS1307_REG_SECS, 7, ds1307->regs); 207 if (tmp != 7) { 208 dev_err(dev, "%s error %d\n", "read", tmp); 209 return -EIO; 210 } 211 212 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n", 213 "read", 214 ds1307->regs[0], ds1307->regs[1], 215 ds1307->regs[2], ds1307->regs[3], 216 ds1307->regs[4], ds1307->regs[5], 217 ds1307->regs[6]); 218 219 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f); 220 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f); 221 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f; 222 t->tm_hour = bcd2bin(tmp); 223 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1; 224 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f); 225 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f; 226 t->tm_mon = bcd2bin(tmp) - 1; 227 228 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */ 229 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100; 230 231 dev_dbg(dev, "%s secs=%d, mins=%d, " 232 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", 233 "read", t->tm_sec, t->tm_min, 234 t->tm_hour, t->tm_mday, 235 t->tm_mon, t->tm_year, t->tm_wday); 236 237 /* initial clock setting can be undefined */ 238 return rtc_valid_tm(t); 239 } 240 241 static int ds1307_set_time(struct device *dev, struct rtc_time *t) 242 { 243 struct ds1307 *ds1307 = dev_get_drvdata(dev); 244 int result; 245 int tmp; 246 u8 *buf = ds1307->regs; 247 248 dev_dbg(dev, "%s secs=%d, mins=%d, " 249 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", 250 "write", t->tm_sec, t->tm_min, 251 t->tm_hour, t->tm_mday, 252 t->tm_mon, t->tm_year, t->tm_wday); 253 254 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec); 255 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min); 256 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour); 257 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1); 258 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday); 259 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1); 260 261 /* assume 20YY not 19YY */ 262 tmp = t->tm_year - 100; 263 buf[DS1307_REG_YEAR] = bin2bcd(tmp); 264 265 switch (ds1307->type) { 266 case ds_1337: 267 case ds_1339: 268 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY; 269 break; 270 case ds_1340: 271 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN 272 | DS1340_BIT_CENTURY; 273 break; 274 default: 275 break; 276 } 277 278 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n", 279 "write", buf[0], buf[1], buf[2], buf[3], 280 buf[4], buf[5], buf[6]); 281 282 result = i2c_smbus_write_i2c_block_data(ds1307->client, 0, 7, buf); 283 if (result < 0) { 284 dev_err(dev, "%s error %d\n", "write", result); 285 return result; 286 } 287 return 0; 288 } 289 290 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t) 291 { 292 struct i2c_client *client = to_i2c_client(dev); 293 struct ds1307 *ds1307 = i2c_get_clientdata(client); 294 int ret; 295 296 if (!test_bit(HAS_ALARM, &ds1307->flags)) 297 return -EINVAL; 298 299 /* read all ALARM1, ALARM2, and status registers at once */ 300 ret = i2c_smbus_read_i2c_block_data(client, 301 DS1339_REG_ALARM1_SECS, 9, ds1307->regs); 302 if (ret != 9) { 303 dev_err(dev, "%s error %d\n", "alarm read", ret); 304 return -EIO; 305 } 306 307 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n", 308 "alarm read", 309 ds1307->regs[0], ds1307->regs[1], 310 ds1307->regs[2], ds1307->regs[3], 311 ds1307->regs[4], ds1307->regs[5], 312 ds1307->regs[6], ds1307->regs[7], 313 ds1307->regs[8]); 314 315 /* report alarm time (ALARM1); assume 24 hour and day-of-month modes, 316 * and that all four fields are checked matches 317 */ 318 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f); 319 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f); 320 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f); 321 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f); 322 t->time.tm_mon = -1; 323 t->time.tm_year = -1; 324 t->time.tm_wday = -1; 325 t->time.tm_yday = -1; 326 t->time.tm_isdst = -1; 327 328 /* ... and status */ 329 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE); 330 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I); 331 332 dev_dbg(dev, "%s secs=%d, mins=%d, " 333 "hours=%d, mday=%d, enabled=%d, pending=%d\n", 334 "alarm read", t->time.tm_sec, t->time.tm_min, 335 t->time.tm_hour, t->time.tm_mday, 336 t->enabled, t->pending); 337 338 return 0; 339 } 340 341 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t) 342 { 343 struct i2c_client *client = to_i2c_client(dev); 344 struct ds1307 *ds1307 = i2c_get_clientdata(client); 345 unsigned char *buf = ds1307->regs; 346 u8 control, status; 347 int ret; 348 349 if (!test_bit(HAS_ALARM, &ds1307->flags)) 350 return -EINVAL; 351 352 dev_dbg(dev, "%s secs=%d, mins=%d, " 353 "hours=%d, mday=%d, enabled=%d, pending=%d\n", 354 "alarm set", t->time.tm_sec, t->time.tm_min, 355 t->time.tm_hour, t->time.tm_mday, 356 t->enabled, t->pending); 357 358 /* read current status of both alarms and the chip */ 359 ret = i2c_smbus_read_i2c_block_data(client, 360 DS1339_REG_ALARM1_SECS, 9, buf); 361 if (ret != 9) { 362 dev_err(dev, "%s error %d\n", "alarm write", ret); 363 return -EIO; 364 } 365 control = ds1307->regs[7]; 366 status = ds1307->regs[8]; 367 368 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n", 369 "alarm set (old status)", 370 ds1307->regs[0], ds1307->regs[1], 371 ds1307->regs[2], ds1307->regs[3], 372 ds1307->regs[4], ds1307->regs[5], 373 ds1307->regs[6], control, status); 374 375 /* set ALARM1, using 24 hour and day-of-month modes */ 376 buf[0] = bin2bcd(t->time.tm_sec); 377 buf[1] = bin2bcd(t->time.tm_min); 378 buf[2] = bin2bcd(t->time.tm_hour); 379 buf[3] = bin2bcd(t->time.tm_mday); 380 381 /* set ALARM2 to non-garbage */ 382 buf[4] = 0; 383 buf[5] = 0; 384 buf[6] = 0; 385 386 /* optionally enable ALARM1 */ 387 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE); 388 if (t->enabled) { 389 dev_dbg(dev, "alarm IRQ armed\n"); 390 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */ 391 } 392 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I); 393 394 ret = i2c_smbus_write_i2c_block_data(client, 395 DS1339_REG_ALARM1_SECS, 9, buf); 396 if (ret < 0) { 397 dev_err(dev, "can't set alarm time\n"); 398 return ret; 399 } 400 401 return 0; 402 } 403 404 static int ds1307_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 405 { 406 struct i2c_client *client = to_i2c_client(dev); 407 struct ds1307 *ds1307 = i2c_get_clientdata(client); 408 int ret; 409 410 switch (cmd) { 411 case RTC_AIE_OFF: 412 if (!test_bit(HAS_ALARM, &ds1307->flags)) 413 return -ENOTTY; 414 415 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL); 416 if (ret < 0) 417 return ret; 418 419 ret &= ~DS1337_BIT_A1IE; 420 421 ret = i2c_smbus_write_byte_data(client, 422 DS1337_REG_CONTROL, ret); 423 if (ret < 0) 424 return ret; 425 426 break; 427 428 case RTC_AIE_ON: 429 if (!test_bit(HAS_ALARM, &ds1307->flags)) 430 return -ENOTTY; 431 432 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL); 433 if (ret < 0) 434 return ret; 435 436 ret |= DS1337_BIT_A1IE; 437 438 ret = i2c_smbus_write_byte_data(client, 439 DS1337_REG_CONTROL, ret); 440 if (ret < 0) 441 return ret; 442 443 break; 444 445 default: 446 return -ENOIOCTLCMD; 447 } 448 449 return 0; 450 } 451 452 static const struct rtc_class_ops ds13xx_rtc_ops = { 453 .read_time = ds1307_get_time, 454 .set_time = ds1307_set_time, 455 .read_alarm = ds1337_read_alarm, 456 .set_alarm = ds1337_set_alarm, 457 .ioctl = ds1307_ioctl, 458 }; 459 460 /*----------------------------------------------------------------------*/ 461 462 #define NVRAM_SIZE 56 463 464 static ssize_t 465 ds1307_nvram_read(struct kobject *kobj, struct bin_attribute *attr, 466 char *buf, loff_t off, size_t count) 467 { 468 struct i2c_client *client; 469 struct ds1307 *ds1307; 470 int result; 471 472 client = kobj_to_i2c_client(kobj); 473 ds1307 = i2c_get_clientdata(client); 474 475 if (unlikely(off >= NVRAM_SIZE)) 476 return 0; 477 if ((off + count) > NVRAM_SIZE) 478 count = NVRAM_SIZE - off; 479 if (unlikely(!count)) 480 return count; 481 482 result = i2c_smbus_read_i2c_block_data(client, 8 + off, count, buf); 483 if (result < 0) 484 dev_err(&client->dev, "%s error %d\n", "nvram read", result); 485 return result; 486 } 487 488 static ssize_t 489 ds1307_nvram_write(struct kobject *kobj, struct bin_attribute *attr, 490 char *buf, loff_t off, size_t count) 491 { 492 struct i2c_client *client; 493 int result; 494 495 client = kobj_to_i2c_client(kobj); 496 497 if (unlikely(off >= NVRAM_SIZE)) 498 return -EFBIG; 499 if ((off + count) > NVRAM_SIZE) 500 count = NVRAM_SIZE - off; 501 if (unlikely(!count)) 502 return count; 503 504 result = i2c_smbus_write_i2c_block_data(client, 8 + off, count, buf); 505 if (result < 0) { 506 dev_err(&client->dev, "%s error %d\n", "nvram write", result); 507 return result; 508 } 509 return count; 510 } 511 512 static struct bin_attribute nvram = { 513 .attr = { 514 .name = "nvram", 515 .mode = S_IRUGO | S_IWUSR, 516 }, 517 518 .read = ds1307_nvram_read, 519 .write = ds1307_nvram_write, 520 .size = NVRAM_SIZE, 521 }; 522 523 /*----------------------------------------------------------------------*/ 524 525 static struct i2c_driver ds1307_driver; 526 527 static int __devinit ds1307_probe(struct i2c_client *client, 528 const struct i2c_device_id *id) 529 { 530 struct ds1307 *ds1307; 531 int err = -ENODEV; 532 int tmp; 533 const struct chip_desc *chip = &chips[id->driver_data]; 534 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 535 int want_irq = false; 536 unsigned char *buf; 537 538 if (!i2c_check_functionality(adapter, 539 I2C_FUNC_SMBUS_WRITE_BYTE_DATA | 540 I2C_FUNC_SMBUS_I2C_BLOCK)) 541 return -EIO; 542 543 if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) 544 return -ENOMEM; 545 546 ds1307->client = client; 547 i2c_set_clientdata(client, ds1307); 548 ds1307->type = id->driver_data; 549 buf = ds1307->regs; 550 551 switch (ds1307->type) { 552 case ds_1337: 553 case ds_1339: 554 /* has IRQ? */ 555 if (ds1307->client->irq > 0 && chip->alarm) { 556 INIT_WORK(&ds1307->work, ds1307_work); 557 want_irq = true; 558 } 559 /* get registers that the "rtc" read below won't read... */ 560 tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 561 DS1337_REG_CONTROL, 2, buf); 562 if (tmp != 2) { 563 pr_debug("read error %d\n", tmp); 564 err = -EIO; 565 goto exit_free; 566 } 567 568 /* oscillator off? turn it on, so clock can tick. */ 569 if (ds1307->regs[0] & DS1337_BIT_nEOSC) 570 ds1307->regs[0] &= ~DS1337_BIT_nEOSC; 571 572 /* Using IRQ? Disable the square wave and both alarms. 573 * For ds1339, be sure alarms can trigger when we're 574 * running on Vbackup (BBSQI); we assume ds1337 will 575 * ignore that bit 576 */ 577 if (want_irq) { 578 ds1307->regs[0] |= DS1337_BIT_INTCN | DS1339_BIT_BBSQI; 579 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE); 580 } 581 582 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, 583 ds1307->regs[0]); 584 585 /* oscillator fault? clear flag, and warn */ 586 if (ds1307->regs[1] & DS1337_BIT_OSF) { 587 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, 588 ds1307->regs[1] & ~DS1337_BIT_OSF); 589 dev_warn(&client->dev, "SET TIME!\n"); 590 } 591 break; 592 default: 593 break; 594 } 595 596 read_rtc: 597 /* read RTC registers */ 598 tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 0, 8, buf); 599 if (tmp != 8) { 600 pr_debug("read error %d\n", tmp); 601 err = -EIO; 602 goto exit_free; 603 } 604 605 /* minimal sanity checking; some chips (like DS1340) don't 606 * specify the extra bits as must-be-zero, but there are 607 * still a few values that are clearly out-of-range. 608 */ 609 tmp = ds1307->regs[DS1307_REG_SECS]; 610 switch (ds1307->type) { 611 case ds_1307: 612 case m41t00: 613 /* clock halted? turn it on, so clock can tick. */ 614 if (tmp & DS1307_BIT_CH) { 615 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0); 616 dev_warn(&client->dev, "SET TIME!\n"); 617 goto read_rtc; 618 } 619 break; 620 case ds_1338: 621 /* clock halted? turn it on, so clock can tick. */ 622 if (tmp & DS1307_BIT_CH) 623 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0); 624 625 /* oscillator fault? clear flag, and warn */ 626 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) { 627 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL, 628 ds1307->regs[DS1307_REG_CONTROL] 629 & ~DS1338_BIT_OSF); 630 dev_warn(&client->dev, "SET TIME!\n"); 631 goto read_rtc; 632 } 633 break; 634 case ds_1340: 635 /* clock halted? turn it on, so clock can tick. */ 636 if (tmp & DS1340_BIT_nEOSC) 637 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0); 638 639 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG); 640 if (tmp < 0) { 641 pr_debug("read error %d\n", tmp); 642 err = -EIO; 643 goto exit_free; 644 } 645 646 /* oscillator fault? clear flag, and warn */ 647 if (tmp & DS1340_BIT_OSF) { 648 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0); 649 dev_warn(&client->dev, "SET TIME!\n"); 650 } 651 break; 652 case ds_1337: 653 case ds_1339: 654 break; 655 } 656 657 tmp = ds1307->regs[DS1307_REG_HOUR]; 658 switch (ds1307->type) { 659 case ds_1340: 660 case m41t00: 661 /* NOTE: ignores century bits; fix before deploying 662 * systems that will run through year 2100. 663 */ 664 break; 665 default: 666 if (!(tmp & DS1307_BIT_12HR)) 667 break; 668 669 /* Be sure we're in 24 hour mode. Multi-master systems 670 * take note... 671 */ 672 tmp = bcd2bin(tmp & 0x1f); 673 if (tmp == 12) 674 tmp = 0; 675 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM) 676 tmp += 12; 677 i2c_smbus_write_byte_data(client, 678 DS1307_REG_HOUR, 679 bin2bcd(tmp)); 680 } 681 682 ds1307->rtc = rtc_device_register(client->name, &client->dev, 683 &ds13xx_rtc_ops, THIS_MODULE); 684 if (IS_ERR(ds1307->rtc)) { 685 err = PTR_ERR(ds1307->rtc); 686 dev_err(&client->dev, 687 "unable to register the class device\n"); 688 goto exit_free; 689 } 690 691 if (want_irq) { 692 err = request_irq(client->irq, ds1307_irq, 0, 693 ds1307->rtc->name, client); 694 if (err) { 695 dev_err(&client->dev, 696 "unable to request IRQ!\n"); 697 goto exit_irq; 698 } 699 set_bit(HAS_ALARM, &ds1307->flags); 700 dev_dbg(&client->dev, "got IRQ %d\n", client->irq); 701 } 702 703 if (chip->nvram56) { 704 err = sysfs_create_bin_file(&client->dev.kobj, &nvram); 705 if (err == 0) { 706 set_bit(HAS_NVRAM, &ds1307->flags); 707 dev_info(&client->dev, "56 bytes nvram\n"); 708 } 709 } 710 711 return 0; 712 713 exit_irq: 714 if (ds1307->rtc) 715 rtc_device_unregister(ds1307->rtc); 716 exit_free: 717 kfree(ds1307); 718 return err; 719 } 720 721 static int __devexit ds1307_remove(struct i2c_client *client) 722 { 723 struct ds1307 *ds1307 = i2c_get_clientdata(client); 724 725 if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) { 726 free_irq(client->irq, client); 727 cancel_work_sync(&ds1307->work); 728 } 729 730 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags)) 731 sysfs_remove_bin_file(&client->dev.kobj, &nvram); 732 733 rtc_device_unregister(ds1307->rtc); 734 kfree(ds1307); 735 return 0; 736 } 737 738 static struct i2c_driver ds1307_driver = { 739 .driver = { 740 .name = "rtc-ds1307", 741 .owner = THIS_MODULE, 742 }, 743 .probe = ds1307_probe, 744 .remove = __devexit_p(ds1307_remove), 745 .id_table = ds1307_id, 746 }; 747 748 static int __init ds1307_init(void) 749 { 750 return i2c_add_driver(&ds1307_driver); 751 } 752 module_init(ds1307_init); 753 754 static void __exit ds1307_exit(void) 755 { 756 i2c_del_driver(&ds1307_driver); 757 } 758 module_exit(ds1307_exit); 759 760 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips"); 761 MODULE_LICENSE("GPL"); 762