1 /* 2 * RTC client/driver for the Maxim/Dallas DS1374 Real-Time Clock over I2C 3 * 4 * Based on code by Randy Vinson <rvinson@mvista.com>, 5 * which was based on the m41t00.c by Mark Greer <mgreer@mvista.com>. 6 * 7 * Copyright (C) 2014 Rose Technology 8 * Copyright (C) 2006-2007 Freescale Semiconductor 9 * 10 * 2005 (c) MontaVista Software, Inc. This file is licensed under 11 * the terms of the GNU General Public License version 2. This program 12 * is licensed "as is" without any warranty of any kind, whether express 13 * or implied. 14 */ 15 /* 16 * It would be more efficient to use i2c msgs/i2c_transfer directly but, as 17 * recommended in .../Documentation/i2c/writing-clients.rst section 18 * "Sending and receiving", using SMBus level communication is preferred. 19 */ 20 21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 23 #include <linux/kernel.h> 24 #include <linux/module.h> 25 #include <linux/interrupt.h> 26 #include <linux/i2c.h> 27 #include <linux/rtc.h> 28 #include <linux/bcd.h> 29 #include <linux/workqueue.h> 30 #include <linux/slab.h> 31 #include <linux/pm.h> 32 #ifdef CONFIG_RTC_DRV_DS1374_WDT 33 #include <linux/fs.h> 34 #include <linux/ioctl.h> 35 #include <linux/miscdevice.h> 36 #include <linux/reboot.h> 37 #include <linux/watchdog.h> 38 #endif 39 40 #define DS1374_REG_TOD0 0x00 /* Time of Day */ 41 #define DS1374_REG_TOD1 0x01 42 #define DS1374_REG_TOD2 0x02 43 #define DS1374_REG_TOD3 0x03 44 #define DS1374_REG_WDALM0 0x04 /* Watchdog/Alarm */ 45 #define DS1374_REG_WDALM1 0x05 46 #define DS1374_REG_WDALM2 0x06 47 #define DS1374_REG_CR 0x07 /* Control */ 48 #define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */ 49 #define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */ 50 #define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */ 51 #define DS1374_REG_SR 0x08 /* Status */ 52 #define DS1374_REG_SR_OSF 0x80 /* Oscillator Stop Flag */ 53 #define DS1374_REG_SR_AF 0x01 /* Alarm Flag */ 54 #define DS1374_REG_TCR 0x09 /* Trickle Charge */ 55 56 static const struct i2c_device_id ds1374_id[] = { 57 { "ds1374", 0 }, 58 { } 59 }; 60 MODULE_DEVICE_TABLE(i2c, ds1374_id); 61 62 #ifdef CONFIG_OF 63 static const struct of_device_id ds1374_of_match[] = { 64 { .compatible = "dallas,ds1374" }, 65 { } 66 }; 67 MODULE_DEVICE_TABLE(of, ds1374_of_match); 68 #endif 69 70 struct ds1374 { 71 struct i2c_client *client; 72 struct rtc_device *rtc; 73 struct work_struct work; 74 75 /* The mutex protects alarm operations, and prevents a race 76 * between the enable_irq() in the workqueue and the free_irq() 77 * in the remove function. 78 */ 79 struct mutex mutex; 80 int exiting; 81 }; 82 83 static struct i2c_driver ds1374_driver; 84 85 static int ds1374_read_rtc(struct i2c_client *client, u32 *time, 86 int reg, int nbytes) 87 { 88 u8 buf[4]; 89 int ret; 90 int i; 91 92 if (WARN_ON(nbytes > 4)) 93 return -EINVAL; 94 95 ret = i2c_smbus_read_i2c_block_data(client, reg, nbytes, buf); 96 97 if (ret < 0) 98 return ret; 99 if (ret < nbytes) 100 return -EIO; 101 102 for (i = nbytes - 1, *time = 0; i >= 0; i--) 103 *time = (*time << 8) | buf[i]; 104 105 return 0; 106 } 107 108 static int ds1374_write_rtc(struct i2c_client *client, u32 time, 109 int reg, int nbytes) 110 { 111 u8 buf[4]; 112 int i; 113 114 if (nbytes > 4) { 115 WARN_ON(1); 116 return -EINVAL; 117 } 118 119 for (i = 0; i < nbytes; i++) { 120 buf[i] = time & 0xff; 121 time >>= 8; 122 } 123 124 return i2c_smbus_write_i2c_block_data(client, reg, nbytes, buf); 125 } 126 127 static int ds1374_check_rtc_status(struct i2c_client *client) 128 { 129 int ret = 0; 130 int control, stat; 131 132 stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR); 133 if (stat < 0) 134 return stat; 135 136 if (stat & DS1374_REG_SR_OSF) 137 dev_warn(&client->dev, 138 "oscillator discontinuity flagged, time unreliable\n"); 139 140 stat &= ~(DS1374_REG_SR_OSF | DS1374_REG_SR_AF); 141 142 ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat); 143 if (ret < 0) 144 return ret; 145 146 /* If the alarm is pending, clear it before requesting 147 * the interrupt, so an interrupt event isn't reported 148 * before everything is initialized. 149 */ 150 151 control = i2c_smbus_read_byte_data(client, DS1374_REG_CR); 152 if (control < 0) 153 return control; 154 155 control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE); 156 return i2c_smbus_write_byte_data(client, DS1374_REG_CR, control); 157 } 158 159 static int ds1374_read_time(struct device *dev, struct rtc_time *time) 160 { 161 struct i2c_client *client = to_i2c_client(dev); 162 u32 itime; 163 int ret; 164 165 ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4); 166 if (!ret) 167 rtc_time64_to_tm(itime, time); 168 169 return ret; 170 } 171 172 static int ds1374_set_time(struct device *dev, struct rtc_time *time) 173 { 174 struct i2c_client *client = to_i2c_client(dev); 175 unsigned long itime = rtc_tm_to_time64(time); 176 177 return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4); 178 } 179 180 #ifndef CONFIG_RTC_DRV_DS1374_WDT 181 /* The ds1374 has a decrementer for an alarm, rather than a comparator. 182 * If the time of day is changed, then the alarm will need to be 183 * reset. 184 */ 185 static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 186 { 187 struct i2c_client *client = to_i2c_client(dev); 188 struct ds1374 *ds1374 = i2c_get_clientdata(client); 189 u32 now, cur_alarm; 190 int cr, sr; 191 int ret = 0; 192 193 if (client->irq <= 0) 194 return -EINVAL; 195 196 mutex_lock(&ds1374->mutex); 197 198 cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR); 199 if (ret < 0) 200 goto out; 201 202 sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR); 203 if (ret < 0) 204 goto out; 205 206 ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4); 207 if (ret) 208 goto out; 209 210 ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3); 211 if (ret) 212 goto out; 213 214 rtc_time64_to_tm(now + cur_alarm, &alarm->time); 215 alarm->enabled = !!(cr & DS1374_REG_CR_WACE); 216 alarm->pending = !!(sr & DS1374_REG_SR_AF); 217 218 out: 219 mutex_unlock(&ds1374->mutex); 220 return ret; 221 } 222 223 static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 224 { 225 struct i2c_client *client = to_i2c_client(dev); 226 struct ds1374 *ds1374 = i2c_get_clientdata(client); 227 struct rtc_time now; 228 unsigned long new_alarm, itime; 229 int cr; 230 int ret = 0; 231 232 if (client->irq <= 0) 233 return -EINVAL; 234 235 ret = ds1374_read_time(dev, &now); 236 if (ret < 0) 237 return ret; 238 239 new_alarm = rtc_tm_to_time64(&alarm->time); 240 itime = rtc_tm_to_time64(&now); 241 242 /* This can happen due to races, in addition to dates that are 243 * truly in the past. To avoid requiring the caller to check for 244 * races, dates in the past are assumed to be in the recent past 245 * (i.e. not something that we'd rather the caller know about via 246 * an error), and the alarm is set to go off as soon as possible. 247 */ 248 if (time_before_eq(new_alarm, itime)) 249 new_alarm = 1; 250 else 251 new_alarm -= itime; 252 253 mutex_lock(&ds1374->mutex); 254 255 ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR); 256 if (ret < 0) 257 goto out; 258 259 /* Disable any existing alarm before setting the new one 260 * (or lack thereof). */ 261 cr &= ~DS1374_REG_CR_WACE; 262 263 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); 264 if (ret < 0) 265 goto out; 266 267 ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3); 268 if (ret) 269 goto out; 270 271 if (alarm->enabled) { 272 cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE; 273 cr &= ~DS1374_REG_CR_WDALM; 274 275 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); 276 } 277 278 out: 279 mutex_unlock(&ds1374->mutex); 280 return ret; 281 } 282 #endif 283 284 static irqreturn_t ds1374_irq(int irq, void *dev_id) 285 { 286 struct i2c_client *client = dev_id; 287 struct ds1374 *ds1374 = i2c_get_clientdata(client); 288 289 disable_irq_nosync(irq); 290 schedule_work(&ds1374->work); 291 return IRQ_HANDLED; 292 } 293 294 static void ds1374_work(struct work_struct *work) 295 { 296 struct ds1374 *ds1374 = container_of(work, struct ds1374, work); 297 struct i2c_client *client = ds1374->client; 298 int stat, control; 299 300 mutex_lock(&ds1374->mutex); 301 302 stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR); 303 if (stat < 0) 304 goto unlock; 305 306 if (stat & DS1374_REG_SR_AF) { 307 stat &= ~DS1374_REG_SR_AF; 308 i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat); 309 310 control = i2c_smbus_read_byte_data(client, DS1374_REG_CR); 311 if (control < 0) 312 goto out; 313 314 control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE); 315 i2c_smbus_write_byte_data(client, DS1374_REG_CR, control); 316 317 rtc_update_irq(ds1374->rtc, 1, RTC_AF | RTC_IRQF); 318 } 319 320 out: 321 if (!ds1374->exiting) 322 enable_irq(client->irq); 323 unlock: 324 mutex_unlock(&ds1374->mutex); 325 } 326 327 #ifndef CONFIG_RTC_DRV_DS1374_WDT 328 static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled) 329 { 330 struct i2c_client *client = to_i2c_client(dev); 331 struct ds1374 *ds1374 = i2c_get_clientdata(client); 332 int ret; 333 334 mutex_lock(&ds1374->mutex); 335 336 ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR); 337 if (ret < 0) 338 goto out; 339 340 if (enabled) { 341 ret |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE; 342 ret &= ~DS1374_REG_CR_WDALM; 343 } else { 344 ret &= ~DS1374_REG_CR_WACE; 345 } 346 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret); 347 348 out: 349 mutex_unlock(&ds1374->mutex); 350 return ret; 351 } 352 #endif 353 354 static const struct rtc_class_ops ds1374_rtc_ops = { 355 .read_time = ds1374_read_time, 356 .set_time = ds1374_set_time, 357 #ifndef CONFIG_RTC_DRV_DS1374_WDT 358 .read_alarm = ds1374_read_alarm, 359 .set_alarm = ds1374_set_alarm, 360 .alarm_irq_enable = ds1374_alarm_irq_enable, 361 #endif 362 }; 363 364 #ifdef CONFIG_RTC_DRV_DS1374_WDT 365 /* 366 ***************************************************************************** 367 * 368 * Watchdog Driver 369 * 370 ***************************************************************************** 371 */ 372 static struct i2c_client *save_client; 373 /* Default margin */ 374 #define WD_TIMO 131762 375 376 #define DRV_NAME "DS1374 Watchdog" 377 378 static int wdt_margin = WD_TIMO; 379 static unsigned long wdt_is_open; 380 module_param(wdt_margin, int, 0); 381 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)"); 382 383 static const struct watchdog_info ds1374_wdt_info = { 384 .identity = "DS1374 WTD", 385 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | 386 WDIOF_MAGICCLOSE, 387 }; 388 389 static int ds1374_wdt_settimeout(unsigned int timeout) 390 { 391 int ret = -ENOIOCTLCMD; 392 int cr; 393 394 ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR); 395 if (ret < 0) 396 goto out; 397 398 /* Disable any existing watchdog/alarm before setting the new one */ 399 cr &= ~DS1374_REG_CR_WACE; 400 401 ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr); 402 if (ret < 0) 403 goto out; 404 405 /* Set new watchdog time */ 406 ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3); 407 if (ret) { 408 pr_info("couldn't set new watchdog time\n"); 409 goto out; 410 } 411 412 /* Enable watchdog timer */ 413 cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM; 414 cr &= ~DS1374_REG_CR_AIE; 415 416 ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr); 417 if (ret < 0) 418 goto out; 419 420 return 0; 421 out: 422 return ret; 423 } 424 425 426 /* 427 * Reload the watchdog timer. (ie, pat the watchdog) 428 */ 429 static void ds1374_wdt_ping(void) 430 { 431 u32 val; 432 int ret = 0; 433 434 ret = ds1374_read_rtc(save_client, &val, DS1374_REG_WDALM0, 3); 435 if (ret) 436 pr_info("WD TICK FAIL!!!!!!!!!! %i\n", ret); 437 } 438 439 static void ds1374_wdt_disable(void) 440 { 441 int cr; 442 443 cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR); 444 /* Disable watchdog timer */ 445 cr &= ~DS1374_REG_CR_WACE; 446 447 i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr); 448 } 449 450 /* 451 * Watchdog device is opened, and watchdog starts running. 452 */ 453 static int ds1374_wdt_open(struct inode *inode, struct file *file) 454 { 455 struct ds1374 *ds1374 = i2c_get_clientdata(save_client); 456 457 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { 458 mutex_lock(&ds1374->mutex); 459 if (test_and_set_bit(0, &wdt_is_open)) { 460 mutex_unlock(&ds1374->mutex); 461 return -EBUSY; 462 } 463 /* 464 * Activate 465 */ 466 wdt_is_open = 1; 467 mutex_unlock(&ds1374->mutex); 468 return stream_open(inode, file); 469 } 470 return -ENODEV; 471 } 472 473 /* 474 * Close the watchdog device. 475 */ 476 static int ds1374_wdt_release(struct inode *inode, struct file *file) 477 { 478 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) 479 clear_bit(0, &wdt_is_open); 480 481 return 0; 482 } 483 484 /* 485 * Pat the watchdog whenever device is written to. 486 */ 487 static ssize_t ds1374_wdt_write(struct file *file, const char __user *data, 488 size_t len, loff_t *ppos) 489 { 490 if (len) { 491 ds1374_wdt_ping(); 492 return 1; 493 } 494 return 0; 495 } 496 497 static ssize_t ds1374_wdt_read(struct file *file, char __user *data, 498 size_t len, loff_t *ppos) 499 { 500 return 0; 501 } 502 503 /* 504 * Handle commands from user-space. 505 */ 506 static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd, 507 unsigned long arg) 508 { 509 int new_margin, options; 510 511 switch (cmd) { 512 case WDIOC_GETSUPPORT: 513 return copy_to_user((struct watchdog_info __user *)arg, 514 &ds1374_wdt_info, sizeof(ds1374_wdt_info)) ? -EFAULT : 0; 515 516 case WDIOC_GETSTATUS: 517 case WDIOC_GETBOOTSTATUS: 518 return put_user(0, (int __user *)arg); 519 case WDIOC_KEEPALIVE: 520 ds1374_wdt_ping(); 521 return 0; 522 case WDIOC_SETTIMEOUT: 523 if (get_user(new_margin, (int __user *)arg)) 524 return -EFAULT; 525 526 /* the hardware's tick rate is 4096 Hz, so 527 * the counter value needs to be scaled accordingly 528 */ 529 new_margin <<= 12; 530 if (new_margin < 1 || new_margin > 16777216) 531 return -EINVAL; 532 533 wdt_margin = new_margin; 534 ds1374_wdt_settimeout(new_margin); 535 ds1374_wdt_ping(); 536 /* fallthrough */ 537 case WDIOC_GETTIMEOUT: 538 /* when returning ... inverse is true */ 539 return put_user((wdt_margin >> 12), (int __user *)arg); 540 case WDIOC_SETOPTIONS: 541 if (copy_from_user(&options, (int __user *)arg, sizeof(int))) 542 return -EFAULT; 543 544 if (options & WDIOS_DISABLECARD) { 545 pr_info("disable watchdog\n"); 546 ds1374_wdt_disable(); 547 return 0; 548 } 549 550 if (options & WDIOS_ENABLECARD) { 551 pr_info("enable watchdog\n"); 552 ds1374_wdt_settimeout(wdt_margin); 553 ds1374_wdt_ping(); 554 return 0; 555 } 556 return -EINVAL; 557 } 558 return -ENOTTY; 559 } 560 561 static long ds1374_wdt_unlocked_ioctl(struct file *file, unsigned int cmd, 562 unsigned long arg) 563 { 564 int ret; 565 struct ds1374 *ds1374 = i2c_get_clientdata(save_client); 566 567 mutex_lock(&ds1374->mutex); 568 ret = ds1374_wdt_ioctl(file, cmd, arg); 569 mutex_unlock(&ds1374->mutex); 570 571 return ret; 572 } 573 574 static int ds1374_wdt_notify_sys(struct notifier_block *this, 575 unsigned long code, void *unused) 576 { 577 if (code == SYS_DOWN || code == SYS_HALT) 578 /* Disable Watchdog */ 579 ds1374_wdt_disable(); 580 return NOTIFY_DONE; 581 } 582 583 static const struct file_operations ds1374_wdt_fops = { 584 .owner = THIS_MODULE, 585 .read = ds1374_wdt_read, 586 .unlocked_ioctl = ds1374_wdt_unlocked_ioctl, 587 .compat_ioctl = compat_ptr_ioctl, 588 .write = ds1374_wdt_write, 589 .open = ds1374_wdt_open, 590 .release = ds1374_wdt_release, 591 .llseek = no_llseek, 592 }; 593 594 static struct miscdevice ds1374_miscdev = { 595 .minor = WATCHDOG_MINOR, 596 .name = "watchdog", 597 .fops = &ds1374_wdt_fops, 598 }; 599 600 static struct notifier_block ds1374_wdt_notifier = { 601 .notifier_call = ds1374_wdt_notify_sys, 602 }; 603 604 #endif /*CONFIG_RTC_DRV_DS1374_WDT*/ 605 /* 606 ***************************************************************************** 607 * 608 * Driver Interface 609 * 610 ***************************************************************************** 611 */ 612 static int ds1374_probe(struct i2c_client *client, 613 const struct i2c_device_id *id) 614 { 615 struct ds1374 *ds1374; 616 int ret; 617 618 ds1374 = devm_kzalloc(&client->dev, sizeof(struct ds1374), GFP_KERNEL); 619 if (!ds1374) 620 return -ENOMEM; 621 622 ds1374->rtc = devm_rtc_allocate_device(&client->dev); 623 if (IS_ERR(ds1374->rtc)) 624 return PTR_ERR(ds1374->rtc); 625 626 ds1374->client = client; 627 i2c_set_clientdata(client, ds1374); 628 629 INIT_WORK(&ds1374->work, ds1374_work); 630 mutex_init(&ds1374->mutex); 631 632 ret = ds1374_check_rtc_status(client); 633 if (ret) 634 return ret; 635 636 if (client->irq > 0) { 637 ret = devm_request_irq(&client->dev, client->irq, ds1374_irq, 0, 638 "ds1374", client); 639 if (ret) { 640 dev_err(&client->dev, "unable to request IRQ\n"); 641 return ret; 642 } 643 644 device_set_wakeup_capable(&client->dev, 1); 645 } 646 647 ds1374->rtc->ops = &ds1374_rtc_ops; 648 ds1374->rtc->range_max = U32_MAX; 649 650 ret = rtc_register_device(ds1374->rtc); 651 if (ret) 652 return ret; 653 654 #ifdef CONFIG_RTC_DRV_DS1374_WDT 655 save_client = client; 656 ret = misc_register(&ds1374_miscdev); 657 if (ret) 658 return ret; 659 ret = register_reboot_notifier(&ds1374_wdt_notifier); 660 if (ret) { 661 misc_deregister(&ds1374_miscdev); 662 return ret; 663 } 664 ds1374_wdt_settimeout(131072); 665 #endif 666 667 return 0; 668 } 669 670 static int ds1374_remove(struct i2c_client *client) 671 { 672 struct ds1374 *ds1374 = i2c_get_clientdata(client); 673 #ifdef CONFIG_RTC_DRV_DS1374_WDT 674 misc_deregister(&ds1374_miscdev); 675 ds1374_miscdev.parent = NULL; 676 unregister_reboot_notifier(&ds1374_wdt_notifier); 677 #endif 678 679 if (client->irq > 0) { 680 mutex_lock(&ds1374->mutex); 681 ds1374->exiting = 1; 682 mutex_unlock(&ds1374->mutex); 683 684 devm_free_irq(&client->dev, client->irq, client); 685 cancel_work_sync(&ds1374->work); 686 } 687 688 return 0; 689 } 690 691 #ifdef CONFIG_PM_SLEEP 692 static int ds1374_suspend(struct device *dev) 693 { 694 struct i2c_client *client = to_i2c_client(dev); 695 696 if (client->irq > 0 && device_may_wakeup(&client->dev)) 697 enable_irq_wake(client->irq); 698 return 0; 699 } 700 701 static int ds1374_resume(struct device *dev) 702 { 703 struct i2c_client *client = to_i2c_client(dev); 704 705 if (client->irq > 0 && device_may_wakeup(&client->dev)) 706 disable_irq_wake(client->irq); 707 return 0; 708 } 709 #endif 710 711 static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume); 712 713 static struct i2c_driver ds1374_driver = { 714 .driver = { 715 .name = "rtc-ds1374", 716 .of_match_table = of_match_ptr(ds1374_of_match), 717 .pm = &ds1374_pm, 718 }, 719 .probe = ds1374_probe, 720 .remove = ds1374_remove, 721 .id_table = ds1374_id, 722 }; 723 724 module_i2c_driver(ds1374_driver); 725 726 MODULE_AUTHOR("Scott Wood <scottwood@freescale.com>"); 727 MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver"); 728 MODULE_LICENSE("GPL"); 729