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 * Copyright (C) 2009 Matthias Fuchs (rx8025 support) 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13#include <linux/module.h> 14#include <linux/init.h> 15#include <linux/slab.h> 16#include <linux/i2c.h> 17#include <linux/string.h> 18#include <linux/rtc.h> 19#include <linux/bcd.h> 20 21 22 23/* We can't determine type by probing, but if we expect pre-Linux code 24 * to have set the chip up as a clock (turning on the oscillator and 25 * setting the date and time), Linux can ignore the non-clock features. 26 * That's a natural job for a factory or repair bench. 27 */ 28enum ds_type { 29 ds_1307, 30 ds_1337, 31 ds_1338, 32 ds_1339, 33 ds_1340, 34 ds_1388, 35 ds_3231, 36 m41t00, 37 rx_8025, 38 // rs5c372 too? different address... 39}; 40 41 42/* RTC registers don't differ much, except for the century flag */ 43#define DS1307_REG_SECS 0x00 /* 00-59 */ 44# define DS1307_BIT_CH 0x80 45# define DS1340_BIT_nEOSC 0x80 46#define DS1307_REG_MIN 0x01 /* 00-59 */ 47#define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */ 48# define DS1307_BIT_12HR 0x40 /* in REG_HOUR */ 49# define DS1307_BIT_PM 0x20 /* in REG_HOUR */ 50# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */ 51# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */ 52#define DS1307_REG_WDAY 0x03 /* 01-07 */ 53#define DS1307_REG_MDAY 0x04 /* 01-31 */ 54#define DS1307_REG_MONTH 0x05 /* 01-12 */ 55# define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */ 56#define DS1307_REG_YEAR 0x06 /* 00-99 */ 57 58/* Other registers (control, status, alarms, trickle charge, NVRAM, etc) 59 * start at 7, and they differ a LOT. Only control and status matter for 60 * basic RTC date and time functionality; be careful using them. 61 */ 62#define DS1307_REG_CONTROL 0x07 /* or ds1338 */ 63# define DS1307_BIT_OUT 0x80 64# define DS1338_BIT_OSF 0x20 65# define DS1307_BIT_SQWE 0x10 66# define DS1307_BIT_RS1 0x02 67# define DS1307_BIT_RS0 0x01 68#define DS1337_REG_CONTROL 0x0e 69# define DS1337_BIT_nEOSC 0x80 70# define DS1339_BIT_BBSQI 0x20 71# define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */ 72# define DS1337_BIT_RS2 0x10 73# define DS1337_BIT_RS1 0x08 74# define DS1337_BIT_INTCN 0x04 75# define DS1337_BIT_A2IE 0x02 76# define DS1337_BIT_A1IE 0x01 77#define DS1340_REG_CONTROL 0x07 78# define DS1340_BIT_OUT 0x80 79# define DS1340_BIT_FT 0x40 80# define DS1340_BIT_CALIB_SIGN 0x20 81# define DS1340_M_CALIBRATION 0x1f 82#define DS1340_REG_FLAG 0x09 83# define DS1340_BIT_OSF 0x80 84#define DS1337_REG_STATUS 0x0f 85# define DS1337_BIT_OSF 0x80 86# define DS1337_BIT_A2I 0x02 87# define DS1337_BIT_A1I 0x01 88#define DS1339_REG_ALARM1_SECS 0x07 89#define DS1339_REG_TRICKLE 0x10 90 91#define RX8025_REG_CTRL1 0x0e 92# define RX8025_BIT_2412 0x20 93#define RX8025_REG_CTRL2 0x0f 94# define RX8025_BIT_PON 0x10 95# define RX8025_BIT_VDET 0x40 96# define RX8025_BIT_XST 0x20 97 98 99struct ds1307 { 100 u8 offset; /* register's offset */ 101 u8 regs[11]; 102 enum ds_type type; 103 unsigned long flags; 104#define HAS_NVRAM 0 /* bit 0 == sysfs file active */ 105#define HAS_ALARM 1 /* bit 1 == irq claimed */ 106 struct i2c_client *client; 107 struct rtc_device *rtc; 108 struct work_struct work; 109 s32 (*read_block_data)(struct i2c_client *client, u8 command, 110 u8 length, u8 *values); 111 s32 (*write_block_data)(struct i2c_client *client, u8 command, 112 u8 length, const u8 *values); 113}; 114 115struct chip_desc { 116 unsigned nvram56:1; 117 unsigned alarm:1; 118}; 119 120static const struct chip_desc chips[] = { 121[ds_1307] = { 122 .nvram56 = 1, 123}, 124[ds_1337] = { 125 .alarm = 1, 126}, 127[ds_1338] = { 128 .nvram56 = 1, 129}, 130[ds_1339] = { 131 .alarm = 1, 132}, 133[ds_1340] = { 134}, 135[ds_3231] = { 136 .alarm = 1, 137}, 138[m41t00] = { 139}, 140[rx_8025] = { 141}, }; 142 143static const struct i2c_device_id ds1307_id[] = { 144 { "ds1307", ds_1307 }, 145 { "ds1337", ds_1337 }, 146 { "ds1338", ds_1338 }, 147 { "ds1339", ds_1339 }, 148 { "ds1388", ds_1388 }, 149 { "ds1340", ds_1340 }, 150 { "ds3231", ds_3231 }, 151 { "m41t00", m41t00 }, 152 { "rx8025", rx_8025 }, 153 { } 154}; 155MODULE_DEVICE_TABLE(i2c, ds1307_id); 156 157/*----------------------------------------------------------------------*/ 158 159#define BLOCK_DATA_MAX_TRIES 10 160 161static s32 ds1307_read_block_data_once(struct i2c_client *client, u8 command, 162 u8 length, u8 *values) 163{ 164 s32 i, data; 165 166 for (i = 0; i < length; i++) { 167 data = i2c_smbus_read_byte_data(client, command + i); 168 if (data < 0) 169 return data; 170 values[i] = data; 171 } 172 return i; 173} 174 175static s32 ds1307_read_block_data(struct i2c_client *client, u8 command, 176 u8 length, u8 *values) 177{ 178 u8 oldvalues[I2C_SMBUS_BLOCK_MAX]; 179 s32 ret; 180 int tries = 0; 181 182 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length); 183 ret = ds1307_read_block_data_once(client, command, length, values); 184 if (ret < 0) 185 return ret; 186 do { 187 if (++tries > BLOCK_DATA_MAX_TRIES) { 188 dev_err(&client->dev, 189 "ds1307_read_block_data failed\n"); 190 return -EIO; 191 } 192 memcpy(oldvalues, values, length); 193 ret = ds1307_read_block_data_once(client, command, length, 194 values); 195 if (ret < 0) 196 return ret; 197 } while (memcmp(oldvalues, values, length)); 198 return length; 199} 200 201static s32 ds1307_write_block_data(struct i2c_client *client, u8 command, 202 u8 length, const u8 *values) 203{ 204 u8 currvalues[I2C_SMBUS_BLOCK_MAX]; 205 int tries = 0; 206 207 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length); 208 do { 209 s32 i, ret; 210 211 if (++tries > BLOCK_DATA_MAX_TRIES) { 212 dev_err(&client->dev, 213 "ds1307_write_block_data failed\n"); 214 return -EIO; 215 } 216 for (i = 0; i < length; i++) { 217 ret = i2c_smbus_write_byte_data(client, command + i, 218 values[i]); 219 if (ret < 0) 220 return ret; 221 } 222 ret = ds1307_read_block_data_once(client, command, length, 223 currvalues); 224 if (ret < 0) 225 return ret; 226 } while (memcmp(currvalues, values, length)); 227 return length; 228} 229 230/*----------------------------------------------------------------------*/ 231 232/* 233 * The IRQ logic includes a "real" handler running in IRQ context just 234 * long enough to schedule this workqueue entry. We need a task context 235 * to talk to the RTC, since I2C I/O calls require that; and disable the 236 * IRQ until we clear its status on the chip, so that this handler can 237 * work with any type of triggering (not just falling edge). 238 * 239 * The ds1337 and ds1339 both have two alarms, but we only use the first 240 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm 241 * signal; ds1339 chips have only one alarm signal. 242 */ 243static void ds1307_work(struct work_struct *work) 244{ 245 struct ds1307 *ds1307; 246 struct i2c_client *client; 247 struct mutex *lock; 248 int stat, control; 249 250 ds1307 = container_of(work, struct ds1307, work); 251 client = ds1307->client; 252 lock = &ds1307->rtc->ops_lock; 253 254 mutex_lock(lock); 255 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS); 256 if (stat < 0) 257 goto out; 258 259 if (stat & DS1337_BIT_A1I) { 260 stat &= ~DS1337_BIT_A1I; 261 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat); 262 263 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL); 264 if (control < 0) 265 goto out; 266 267 control &= ~DS1337_BIT_A1IE; 268 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control); 269 270 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF); 271 } 272 273out: 274 if (test_bit(HAS_ALARM, &ds1307->flags)) 275 enable_irq(client->irq); 276 mutex_unlock(lock); 277} 278 279static irqreturn_t ds1307_irq(int irq, void *dev_id) 280{ 281 struct i2c_client *client = dev_id; 282 struct ds1307 *ds1307 = i2c_get_clientdata(client); 283 284 disable_irq_nosync(irq); 285 schedule_work(&ds1307->work); 286 return IRQ_HANDLED; 287} 288 289/*----------------------------------------------------------------------*/ 290 291static int ds1307_get_time(struct device *dev, struct rtc_time *t) 292{ 293 struct ds1307 *ds1307 = dev_get_drvdata(dev); 294 int tmp; 295 296 /* read the RTC date and time registers all at once */ 297 tmp = ds1307->read_block_data(ds1307->client, 298 ds1307->offset, 7, ds1307->regs); 299 if (tmp != 7) { 300 dev_err(dev, "%s error %d\n", "read", tmp); 301 return -EIO; 302 } 303 304 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n", 305 "read", 306 ds1307->regs[0], ds1307->regs[1], 307 ds1307->regs[2], ds1307->regs[3], 308 ds1307->regs[4], ds1307->regs[5], 309 ds1307->regs[6]); 310 311 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f); 312 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f); 313 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f; 314 t->tm_hour = bcd2bin(tmp); 315 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1; 316 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f); 317 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f; 318 t->tm_mon = bcd2bin(tmp) - 1; 319 320 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */ 321 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100; 322 323 dev_dbg(dev, "%s secs=%d, mins=%d, " 324 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", 325 "read", t->tm_sec, t->tm_min, 326 t->tm_hour, t->tm_mday, 327 t->tm_mon, t->tm_year, t->tm_wday); 328 329 /* initial clock setting can be undefined */ 330 return rtc_valid_tm(t); 331} 332 333static int ds1307_set_time(struct device *dev, struct rtc_time *t) 334{ 335 struct ds1307 *ds1307 = dev_get_drvdata(dev); 336 int result; 337 int tmp; 338 u8 *buf = ds1307->regs; 339 340 dev_dbg(dev, "%s secs=%d, mins=%d, " 341 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", 342 "write", t->tm_sec, t->tm_min, 343 t->tm_hour, t->tm_mday, 344 t->tm_mon, t->tm_year, t->tm_wday); 345 346 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec); 347 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min); 348 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour); 349 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1); 350 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday); 351 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1); 352 353 /* assume 20YY not 19YY */ 354 tmp = t->tm_year - 100; 355 buf[DS1307_REG_YEAR] = bin2bcd(tmp); 356 357 switch (ds1307->type) { 358 case ds_1337: 359 case ds_1339: 360 case ds_3231: 361 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY; 362 break; 363 case ds_1340: 364 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN 365 | DS1340_BIT_CENTURY; 366 break; 367 default: 368 break; 369 } 370 371 dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n", 372 "write", buf[0], buf[1], buf[2], buf[3], 373 buf[4], buf[5], buf[6]); 374 375 result = ds1307->write_block_data(ds1307->client, 376 ds1307->offset, 7, buf); 377 if (result < 0) { 378 dev_err(dev, "%s error %d\n", "write", result); 379 return result; 380 } 381 return 0; 382} 383 384static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t) 385{ 386 struct i2c_client *client = to_i2c_client(dev); 387 struct ds1307 *ds1307 = i2c_get_clientdata(client); 388 int ret; 389 390 if (!test_bit(HAS_ALARM, &ds1307->flags)) 391 return -EINVAL; 392 393 /* read all ALARM1, ALARM2, and status registers at once */ 394 ret = ds1307->read_block_data(client, 395 DS1339_REG_ALARM1_SECS, 9, ds1307->regs); 396 if (ret != 9) { 397 dev_err(dev, "%s error %d\n", "alarm read", ret); 398 return -EIO; 399 } 400 401 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n", 402 "alarm read", 403 ds1307->regs[0], ds1307->regs[1], 404 ds1307->regs[2], ds1307->regs[3], 405 ds1307->regs[4], ds1307->regs[5], 406 ds1307->regs[6], ds1307->regs[7], 407 ds1307->regs[8]); 408 409 /* report alarm time (ALARM1); assume 24 hour and day-of-month modes, 410 * and that all four fields are checked matches 411 */ 412 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f); 413 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f); 414 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f); 415 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f); 416 t->time.tm_mon = -1; 417 t->time.tm_year = -1; 418 t->time.tm_wday = -1; 419 t->time.tm_yday = -1; 420 t->time.tm_isdst = -1; 421 422 /* ... and status */ 423 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE); 424 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I); 425 426 dev_dbg(dev, "%s secs=%d, mins=%d, " 427 "hours=%d, mday=%d, enabled=%d, pending=%d\n", 428 "alarm read", t->time.tm_sec, t->time.tm_min, 429 t->time.tm_hour, t->time.tm_mday, 430 t->enabled, t->pending); 431 432 return 0; 433} 434 435static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t) 436{ 437 struct i2c_client *client = to_i2c_client(dev); 438 struct ds1307 *ds1307 = i2c_get_clientdata(client); 439 unsigned char *buf = ds1307->regs; 440 u8 control, status; 441 int ret; 442 443 if (!test_bit(HAS_ALARM, &ds1307->flags)) 444 return -EINVAL; 445 446 dev_dbg(dev, "%s secs=%d, mins=%d, " 447 "hours=%d, mday=%d, enabled=%d, pending=%d\n", 448 "alarm set", t->time.tm_sec, t->time.tm_min, 449 t->time.tm_hour, t->time.tm_mday, 450 t->enabled, t->pending); 451 452 /* read current status of both alarms and the chip */ 453 ret = ds1307->read_block_data(client, 454 DS1339_REG_ALARM1_SECS, 9, buf); 455 if (ret != 9) { 456 dev_err(dev, "%s error %d\n", "alarm write", ret); 457 return -EIO; 458 } 459 control = ds1307->regs[7]; 460 status = ds1307->regs[8]; 461 462 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n", 463 "alarm set (old status)", 464 ds1307->regs[0], ds1307->regs[1], 465 ds1307->regs[2], ds1307->regs[3], 466 ds1307->regs[4], ds1307->regs[5], 467 ds1307->regs[6], control, status); 468 469 /* set ALARM1, using 24 hour and day-of-month modes */ 470 buf[0] = bin2bcd(t->time.tm_sec); 471 buf[1] = bin2bcd(t->time.tm_min); 472 buf[2] = bin2bcd(t->time.tm_hour); 473 buf[3] = bin2bcd(t->time.tm_mday); 474 475 /* set ALARM2 to non-garbage */ 476 buf[4] = 0; 477 buf[5] = 0; 478 buf[6] = 0; 479 480 /* optionally enable ALARM1 */ 481 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE); 482 if (t->enabled) { 483 dev_dbg(dev, "alarm IRQ armed\n"); 484 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */ 485 } 486 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I); 487 488 ret = ds1307->write_block_data(client, 489 DS1339_REG_ALARM1_SECS, 9, buf); 490 if (ret < 0) { 491 dev_err(dev, "can't set alarm time\n"); 492 return ret; 493 } 494 495 return 0; 496} 497 498static int ds1307_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 499{ 500 struct i2c_client *client = to_i2c_client(dev); 501 struct ds1307 *ds1307 = i2c_get_clientdata(client); 502 int ret; 503 504 switch (cmd) { 505 case RTC_AIE_OFF: 506 if (!test_bit(HAS_ALARM, &ds1307->flags)) 507 return -ENOTTY; 508 509 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL); 510 if (ret < 0) 511 return ret; 512 513 ret &= ~DS1337_BIT_A1IE; 514 515 ret = i2c_smbus_write_byte_data(client, 516 DS1337_REG_CONTROL, ret); 517 if (ret < 0) 518 return ret; 519 520 break; 521 522 case RTC_AIE_ON: 523 if (!test_bit(HAS_ALARM, &ds1307->flags)) 524 return -ENOTTY; 525 526 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL); 527 if (ret < 0) 528 return ret; 529 530 ret |= DS1337_BIT_A1IE; 531 532 ret = i2c_smbus_write_byte_data(client, 533 DS1337_REG_CONTROL, ret); 534 if (ret < 0) 535 return ret; 536 537 break; 538 539 default: 540 return -ENOIOCTLCMD; 541 } 542 543 return 0; 544} 545 546static const struct rtc_class_ops ds13xx_rtc_ops = { 547 .read_time = ds1307_get_time, 548 .set_time = ds1307_set_time, 549 .read_alarm = ds1337_read_alarm, 550 .set_alarm = ds1337_set_alarm, 551 .ioctl = ds1307_ioctl, 552}; 553 554/*----------------------------------------------------------------------*/ 555 556#define NVRAM_SIZE 56 557 558static ssize_t 559ds1307_nvram_read(struct file *filp, struct kobject *kobj, 560 struct bin_attribute *attr, 561 char *buf, loff_t off, size_t count) 562{ 563 struct i2c_client *client; 564 struct ds1307 *ds1307; 565 int result; 566 567 client = kobj_to_i2c_client(kobj); 568 ds1307 = i2c_get_clientdata(client); 569 570 if (unlikely(off >= NVRAM_SIZE)) 571 return 0; 572 if ((off + count) > NVRAM_SIZE) 573 count = NVRAM_SIZE - off; 574 if (unlikely(!count)) 575 return count; 576 577 result = ds1307->read_block_data(client, 8 + off, count, buf); 578 if (result < 0) 579 dev_err(&client->dev, "%s error %d\n", "nvram read", result); 580 return result; 581} 582 583static ssize_t 584ds1307_nvram_write(struct file *filp, struct kobject *kobj, 585 struct bin_attribute *attr, 586 char *buf, loff_t off, size_t count) 587{ 588 struct i2c_client *client; 589 struct ds1307 *ds1307; 590 int result; 591 592 client = kobj_to_i2c_client(kobj); 593 ds1307 = i2c_get_clientdata(client); 594 595 if (unlikely(off >= NVRAM_SIZE)) 596 return -EFBIG; 597 if ((off + count) > NVRAM_SIZE) 598 count = NVRAM_SIZE - off; 599 if (unlikely(!count)) 600 return count; 601 602 result = ds1307->write_block_data(client, 8 + off, count, buf); 603 if (result < 0) { 604 dev_err(&client->dev, "%s error %d\n", "nvram write", result); 605 return result; 606 } 607 return count; 608} 609 610static struct bin_attribute nvram = { 611 .attr = { 612 .name = "nvram", 613 .mode = S_IRUGO | S_IWUSR, 614 }, 615 616 .read = ds1307_nvram_read, 617 .write = ds1307_nvram_write, 618 .size = NVRAM_SIZE, 619}; 620 621/*----------------------------------------------------------------------*/ 622 623static struct i2c_driver ds1307_driver; 624 625static int __devinit ds1307_probe(struct i2c_client *client, 626 const struct i2c_device_id *id) 627{ 628 struct ds1307 *ds1307; 629 int err = -ENODEV; 630 int tmp; 631 const struct chip_desc *chip = &chips[id->driver_data]; 632 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 633 int want_irq = false; 634 unsigned char *buf; 635 static const int bbsqi_bitpos[] = { 636 [ds_1337] = 0, 637 [ds_1339] = DS1339_BIT_BBSQI, 638 [ds_3231] = DS3231_BIT_BBSQW, 639 }; 640 641 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA) 642 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) 643 return -EIO; 644 645 if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) 646 return -ENOMEM; 647 648 i2c_set_clientdata(client, ds1307); 649 650 ds1307->client = client; 651 ds1307->type = id->driver_data; 652 ds1307->offset = 0; 653 654 buf = ds1307->regs; 655 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) { 656 ds1307->read_block_data = i2c_smbus_read_i2c_block_data; 657 ds1307->write_block_data = i2c_smbus_write_i2c_block_data; 658 } else { 659 ds1307->read_block_data = ds1307_read_block_data; 660 ds1307->write_block_data = ds1307_write_block_data; 661 } 662 663 switch (ds1307->type) { 664 case ds_1337: 665 case ds_1339: 666 case ds_3231: 667 /* has IRQ? */ 668 if (ds1307->client->irq > 0 && chip->alarm) { 669 INIT_WORK(&ds1307->work, ds1307_work); 670 want_irq = true; 671 } 672 /* get registers that the "rtc" read below won't read... */ 673 tmp = ds1307->read_block_data(ds1307->client, 674 DS1337_REG_CONTROL, 2, buf); 675 if (tmp != 2) { 676 pr_debug("read error %d\n", tmp); 677 err = -EIO; 678 goto exit_free; 679 } 680 681 /* oscillator off? turn it on, so clock can tick. */ 682 if (ds1307->regs[0] & DS1337_BIT_nEOSC) 683 ds1307->regs[0] &= ~DS1337_BIT_nEOSC; 684 685 /* Using IRQ? Disable the square wave and both alarms. 686 * For some variants, be sure alarms can trigger when we're 687 * running on Vbackup (BBSQI/BBSQW) 688 */ 689 if (want_irq) { 690 ds1307->regs[0] |= DS1337_BIT_INTCN 691 | bbsqi_bitpos[ds1307->type]; 692 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE); 693 } 694 695 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, 696 ds1307->regs[0]); 697 698 /* oscillator fault? clear flag, and warn */ 699 if (ds1307->regs[1] & DS1337_BIT_OSF) { 700 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, 701 ds1307->regs[1] & ~DS1337_BIT_OSF); 702 dev_warn(&client->dev, "SET TIME!\n"); 703 } 704 break; 705 706 case rx_8025: 707 tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 708 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf); 709 if (tmp != 2) { 710 pr_debug("read error %d\n", tmp); 711 err = -EIO; 712 goto exit_free; 713 } 714 715 /* oscillator off? turn it on, so clock can tick. */ 716 if (!(ds1307->regs[1] & RX8025_BIT_XST)) { 717 ds1307->regs[1] |= RX8025_BIT_XST; 718 i2c_smbus_write_byte_data(client, 719 RX8025_REG_CTRL2 << 4 | 0x08, 720 ds1307->regs[1]); 721 dev_warn(&client->dev, 722 "oscillator stop detected - SET TIME!\n"); 723 } 724 725 if (ds1307->regs[1] & RX8025_BIT_PON) { 726 ds1307->regs[1] &= ~RX8025_BIT_PON; 727 i2c_smbus_write_byte_data(client, 728 RX8025_REG_CTRL2 << 4 | 0x08, 729 ds1307->regs[1]); 730 dev_warn(&client->dev, "power-on detected\n"); 731 } 732 733 if (ds1307->regs[1] & RX8025_BIT_VDET) { 734 ds1307->regs[1] &= ~RX8025_BIT_VDET; 735 i2c_smbus_write_byte_data(client, 736 RX8025_REG_CTRL2 << 4 | 0x08, 737 ds1307->regs[1]); 738 dev_warn(&client->dev, "voltage drop detected\n"); 739 } 740 741 /* make sure we are running in 24hour mode */ 742 if (!(ds1307->regs[0] & RX8025_BIT_2412)) { 743 u8 hour; 744 745 /* switch to 24 hour mode */ 746 i2c_smbus_write_byte_data(client, 747 RX8025_REG_CTRL1 << 4 | 0x08, 748 ds1307->regs[0] | 749 RX8025_BIT_2412); 750 751 tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 752 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf); 753 if (tmp != 2) { 754 pr_debug("read error %d\n", tmp); 755 err = -EIO; 756 goto exit_free; 757 } 758 759 /* correct hour */ 760 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]); 761 if (hour == 12) 762 hour = 0; 763 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM) 764 hour += 12; 765 766 i2c_smbus_write_byte_data(client, 767 DS1307_REG_HOUR << 4 | 0x08, 768 hour); 769 } 770 break; 771 case ds_1388: 772 ds1307->offset = 1; /* Seconds starts at 1 */ 773 break; 774 default: 775 break; 776 } 777 778read_rtc: 779 /* read RTC registers */ 780 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf); 781 if (tmp != 8) { 782 pr_debug("read error %d\n", tmp); 783 err = -EIO; 784 goto exit_free; 785 } 786 787 /* minimal sanity checking; some chips (like DS1340) don't 788 * specify the extra bits as must-be-zero, but there are 789 * still a few values that are clearly out-of-range. 790 */ 791 tmp = ds1307->regs[DS1307_REG_SECS]; 792 switch (ds1307->type) { 793 case ds_1307: 794 case m41t00: 795 /* clock halted? turn it on, so clock can tick. */ 796 if (tmp & DS1307_BIT_CH) { 797 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0); 798 dev_warn(&client->dev, "SET TIME!\n"); 799 goto read_rtc; 800 } 801 break; 802 case ds_1338: 803 /* clock halted? turn it on, so clock can tick. */ 804 if (tmp & DS1307_BIT_CH) 805 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0); 806 807 /* oscillator fault? clear flag, and warn */ 808 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) { 809 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL, 810 ds1307->regs[DS1307_REG_CONTROL] 811 & ~DS1338_BIT_OSF); 812 dev_warn(&client->dev, "SET TIME!\n"); 813 goto read_rtc; 814 } 815 break; 816 case ds_1340: 817 /* clock halted? turn it on, so clock can tick. */ 818 if (tmp & DS1340_BIT_nEOSC) 819 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0); 820 821 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG); 822 if (tmp < 0) { 823 pr_debug("read error %d\n", tmp); 824 err = -EIO; 825 goto exit_free; 826 } 827 828 /* oscillator fault? clear flag, and warn */ 829 if (tmp & DS1340_BIT_OSF) { 830 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0); 831 dev_warn(&client->dev, "SET TIME!\n"); 832 } 833 break; 834 case rx_8025: 835 case ds_1337: 836 case ds_1339: 837 case ds_1388: 838 case ds_3231: 839 break; 840 } 841 842 tmp = ds1307->regs[DS1307_REG_HOUR]; 843 switch (ds1307->type) { 844 case ds_1340: 845 case m41t00: 846 /* NOTE: ignores century bits; fix before deploying 847 * systems that will run through year 2100. 848 */ 849 break; 850 case rx_8025: 851 break; 852 default: 853 if (!(tmp & DS1307_BIT_12HR)) 854 break; 855 856 /* Be sure we're in 24 hour mode. Multi-master systems 857 * take note... 858 */ 859 tmp = bcd2bin(tmp & 0x1f); 860 if (tmp == 12) 861 tmp = 0; 862 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM) 863 tmp += 12; 864 i2c_smbus_write_byte_data(client, 865 ds1307->offset + DS1307_REG_HOUR, 866 bin2bcd(tmp)); 867 } 868 869 ds1307->rtc = rtc_device_register(client->name, &client->dev, 870 &ds13xx_rtc_ops, THIS_MODULE); 871 if (IS_ERR(ds1307->rtc)) { 872 err = PTR_ERR(ds1307->rtc); 873 dev_err(&client->dev, 874 "unable to register the class device\n"); 875 goto exit_free; 876 } 877 878 if (want_irq) { 879 err = request_irq(client->irq, ds1307_irq, IRQF_SHARED, 880 ds1307->rtc->name, client); 881 if (err) { 882 dev_err(&client->dev, 883 "unable to request IRQ!\n"); 884 goto exit_irq; 885 } 886 887 device_set_wakeup_capable(&client->dev, 1); 888 set_bit(HAS_ALARM, &ds1307->flags); 889 dev_dbg(&client->dev, "got IRQ %d\n", client->irq); 890 } 891 892 if (chip->nvram56) { 893 err = sysfs_create_bin_file(&client->dev.kobj, &nvram); 894 if (err == 0) { 895 set_bit(HAS_NVRAM, &ds1307->flags); 896 dev_info(&client->dev, "56 bytes nvram\n"); 897 } 898 } 899 900 return 0; 901 902exit_irq: 903 rtc_device_unregister(ds1307->rtc); 904exit_free: 905 kfree(ds1307); 906 return err; 907} 908 909static int __devexit ds1307_remove(struct i2c_client *client) 910{ 911 struct ds1307 *ds1307 = i2c_get_clientdata(client); 912 913 if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) { 914 free_irq(client->irq, client); 915 cancel_work_sync(&ds1307->work); 916 } 917 918 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags)) 919 sysfs_remove_bin_file(&client->dev.kobj, &nvram); 920 921 rtc_device_unregister(ds1307->rtc); 922 kfree(ds1307); 923 return 0; 924} 925 926static struct i2c_driver ds1307_driver = { 927 .driver = { 928 .name = "rtc-ds1307", 929 .owner = THIS_MODULE, 930 }, 931 .probe = ds1307_probe, 932 .remove = __devexit_p(ds1307_remove), 933 .id_table = ds1307_id, 934}; 935 936static int __init ds1307_init(void) 937{ 938 return i2c_add_driver(&ds1307_driver); 939} 940module_init(ds1307_init); 941 942static void __exit ds1307_exit(void) 943{ 944 i2c_del_driver(&ds1307_driver); 945} 946module_exit(ds1307_exit); 947 948MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips"); 949MODULE_LICENSE("GPL"); 950