1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock 4 * 5 * Copyright (C) 2009-2011 Freescale Semiconductor. 6 * Author: Jack Lan <jack.lan@freescale.com> 7 * Copyright (C) 2008 MIMOMax Wireless Ltd. 8 */ 9 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/interrupt.h> 15 #include <linux/i2c.h> 16 #include <linux/spi/spi.h> 17 #include <linux/rtc.h> 18 #include <linux/bcd.h> 19 #include <linux/slab.h> 20 #include <linux/regmap.h> 21 #include <linux/hwmon.h> 22 23 #define DS3232_REG_SECONDS 0x00 24 #define DS3232_REG_MINUTES 0x01 25 #define DS3232_REG_HOURS 0x02 26 #define DS3232_REG_AMPM 0x02 27 #define DS3232_REG_DAY 0x03 28 #define DS3232_REG_DATE 0x04 29 #define DS3232_REG_MONTH 0x05 30 #define DS3232_REG_CENTURY 0x05 31 #define DS3232_REG_YEAR 0x06 32 #define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */ 33 #define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */ 34 #define DS3232_REG_CR 0x0E /* Control register */ 35 # define DS3232_REG_CR_nEOSC 0x80 36 # define DS3232_REG_CR_INTCN 0x04 37 # define DS3232_REG_CR_A2IE 0x02 38 # define DS3232_REG_CR_A1IE 0x01 39 40 #define DS3232_REG_SR 0x0F /* control/status register */ 41 # define DS3232_REG_SR_OSF 0x80 42 # define DS3232_REG_SR_BSY 0x04 43 # define DS3232_REG_SR_A2F 0x02 44 # define DS3232_REG_SR_A1F 0x01 45 46 #define DS3232_REG_TEMPERATURE 0x11 47 #define DS3232_REG_SRAM_START 0x14 48 #define DS3232_REG_SRAM_END 0xFF 49 50 #define DS3232_REG_SRAM_SIZE 236 51 52 struct ds3232 { 53 struct device *dev; 54 struct regmap *regmap; 55 int irq; 56 struct rtc_device *rtc; 57 58 bool suspended; 59 }; 60 61 static int ds3232_check_rtc_status(struct device *dev) 62 { 63 struct ds3232 *ds3232 = dev_get_drvdata(dev); 64 int ret = 0; 65 int control, stat; 66 67 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); 68 if (ret) 69 return ret; 70 71 if (stat & DS3232_REG_SR_OSF) 72 dev_warn(dev, 73 "oscillator discontinuity flagged, " 74 "time unreliable\n"); 75 76 stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); 77 78 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat); 79 if (ret) 80 return ret; 81 82 /* If the alarm is pending, clear it before requesting 83 * the interrupt, so an interrupt event isn't reported 84 * before everything is initialized. 85 */ 86 87 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); 88 if (ret) 89 return ret; 90 91 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); 92 control |= DS3232_REG_CR_INTCN; 93 94 return regmap_write(ds3232->regmap, DS3232_REG_CR, control); 95 } 96 97 static int ds3232_read_time(struct device *dev, struct rtc_time *time) 98 { 99 struct ds3232 *ds3232 = dev_get_drvdata(dev); 100 int ret; 101 u8 buf[7]; 102 unsigned int year, month, day, hour, minute, second; 103 unsigned int week, twelve_hr, am_pm; 104 unsigned int century, add_century = 0; 105 106 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7); 107 if (ret) 108 return ret; 109 110 second = buf[0]; 111 minute = buf[1]; 112 hour = buf[2]; 113 week = buf[3]; 114 day = buf[4]; 115 month = buf[5]; 116 year = buf[6]; 117 118 /* Extract additional information for AM/PM and century */ 119 120 twelve_hr = hour & 0x40; 121 am_pm = hour & 0x20; 122 century = month & 0x80; 123 124 /* Write to rtc_time structure */ 125 126 time->tm_sec = bcd2bin(second); 127 time->tm_min = bcd2bin(minute); 128 if (twelve_hr) { 129 /* Convert to 24 hr */ 130 if (am_pm) 131 time->tm_hour = bcd2bin(hour & 0x1F) + 12; 132 else 133 time->tm_hour = bcd2bin(hour & 0x1F); 134 } else { 135 time->tm_hour = bcd2bin(hour); 136 } 137 138 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */ 139 time->tm_wday = bcd2bin(week) - 1; 140 time->tm_mday = bcd2bin(day); 141 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */ 142 time->tm_mon = bcd2bin(month & 0x7F) - 1; 143 if (century) 144 add_century = 100; 145 146 time->tm_year = bcd2bin(year) + add_century; 147 148 return 0; 149 } 150 151 static int ds3232_set_time(struct device *dev, struct rtc_time *time) 152 { 153 struct ds3232 *ds3232 = dev_get_drvdata(dev); 154 u8 buf[7]; 155 156 /* Extract time from rtc_time and load into ds3232*/ 157 158 buf[0] = bin2bcd(time->tm_sec); 159 buf[1] = bin2bcd(time->tm_min); 160 buf[2] = bin2bcd(time->tm_hour); 161 /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */ 162 buf[3] = bin2bcd(time->tm_wday + 1); 163 buf[4] = bin2bcd(time->tm_mday); /* Date */ 164 /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */ 165 buf[5] = bin2bcd(time->tm_mon + 1); 166 if (time->tm_year >= 100) { 167 buf[5] |= 0x80; 168 buf[6] = bin2bcd(time->tm_year - 100); 169 } else { 170 buf[6] = bin2bcd(time->tm_year); 171 } 172 173 return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7); 174 } 175 176 /* 177 * DS3232 has two alarm, we only use alarm1 178 * According to linux specification, only support one-shot alarm 179 * no periodic alarm mode 180 */ 181 static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 182 { 183 struct ds3232 *ds3232 = dev_get_drvdata(dev); 184 int control, stat; 185 int ret; 186 u8 buf[4]; 187 188 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); 189 if (ret) 190 goto out; 191 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); 192 if (ret) 193 goto out; 194 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4); 195 if (ret) 196 goto out; 197 198 alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F); 199 alarm->time.tm_min = bcd2bin(buf[1] & 0x7F); 200 alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F); 201 alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F); 202 203 alarm->enabled = !!(control & DS3232_REG_CR_A1IE); 204 alarm->pending = !!(stat & DS3232_REG_SR_A1F); 205 206 ret = 0; 207 out: 208 return ret; 209 } 210 211 /* 212 * linux rtc-module does not support wday alarm 213 * and only 24h time mode supported indeed 214 */ 215 static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 216 { 217 struct ds3232 *ds3232 = dev_get_drvdata(dev); 218 int control, stat; 219 int ret; 220 u8 buf[4]; 221 222 if (ds3232->irq <= 0) 223 return -EINVAL; 224 225 buf[0] = bin2bcd(alarm->time.tm_sec); 226 buf[1] = bin2bcd(alarm->time.tm_min); 227 buf[2] = bin2bcd(alarm->time.tm_hour); 228 buf[3] = bin2bcd(alarm->time.tm_mday); 229 230 /* clear alarm interrupt enable bit */ 231 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); 232 if (ret) 233 goto out; 234 control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); 235 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); 236 if (ret) 237 goto out; 238 239 /* clear any pending alarm flag */ 240 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); 241 if (ret) 242 goto out; 243 stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); 244 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat); 245 if (ret) 246 goto out; 247 248 ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4); 249 if (ret) 250 goto out; 251 252 if (alarm->enabled) { 253 control |= DS3232_REG_CR_A1IE; 254 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); 255 } 256 out: 257 return ret; 258 } 259 260 static int ds3232_update_alarm(struct device *dev, unsigned int enabled) 261 { 262 struct ds3232 *ds3232 = dev_get_drvdata(dev); 263 int control; 264 int ret; 265 266 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); 267 if (ret) 268 return ret; 269 270 if (enabled) 271 /* enable alarm1 interrupt */ 272 control |= DS3232_REG_CR_A1IE; 273 else 274 /* disable alarm1 interrupt */ 275 control &= ~(DS3232_REG_CR_A1IE); 276 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); 277 278 return ret; 279 } 280 281 /* 282 * Temperature sensor support for ds3232/ds3234 devices. 283 * A user-initiated temperature conversion is not started by this function, 284 * so the temperature is updated once every 64 seconds. 285 */ 286 static int ds3232_hwmon_read_temp(struct device *dev, long int *mC) 287 { 288 struct ds3232 *ds3232 = dev_get_drvdata(dev); 289 u8 temp_buf[2]; 290 s16 temp; 291 int ret; 292 293 ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_TEMPERATURE, temp_buf, 294 sizeof(temp_buf)); 295 if (ret < 0) 296 return ret; 297 298 /* 299 * Temperature is represented as a 10-bit code with a resolution of 300 * 0.25 degree celsius and encoded in two's complement format. 301 */ 302 temp = (temp_buf[0] << 8) | temp_buf[1]; 303 temp >>= 6; 304 *mC = temp * 250; 305 306 return 0; 307 } 308 309 static umode_t ds3232_hwmon_is_visible(const void *data, 310 enum hwmon_sensor_types type, 311 u32 attr, int channel) 312 { 313 if (type != hwmon_temp) 314 return 0; 315 316 switch (attr) { 317 case hwmon_temp_input: 318 return 0444; 319 default: 320 return 0; 321 } 322 } 323 324 static int ds3232_hwmon_read(struct device *dev, 325 enum hwmon_sensor_types type, 326 u32 attr, int channel, long *temp) 327 { 328 int err; 329 330 switch (attr) { 331 case hwmon_temp_input: 332 err = ds3232_hwmon_read_temp(dev, temp); 333 break; 334 default: 335 err = -EOPNOTSUPP; 336 break; 337 } 338 339 return err; 340 } 341 342 static const struct hwmon_channel_info * const ds3232_hwmon_info[] = { 343 HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), 344 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), 345 NULL 346 }; 347 348 static const struct hwmon_ops ds3232_hwmon_hwmon_ops = { 349 .is_visible = ds3232_hwmon_is_visible, 350 .read = ds3232_hwmon_read, 351 }; 352 353 static const struct hwmon_chip_info ds3232_hwmon_chip_info = { 354 .ops = &ds3232_hwmon_hwmon_ops, 355 .info = ds3232_hwmon_info, 356 }; 357 358 static void ds3232_hwmon_register(struct device *dev, const char *name) 359 { 360 struct ds3232 *ds3232 = dev_get_drvdata(dev); 361 struct device *hwmon_dev; 362 363 if (!IS_ENABLED(CONFIG_RTC_DRV_DS3232_HWMON)) 364 return; 365 366 hwmon_dev = devm_hwmon_device_register_with_info(dev, name, ds3232, 367 &ds3232_hwmon_chip_info, 368 NULL); 369 if (IS_ERR(hwmon_dev)) { 370 dev_err(dev, "unable to register hwmon device %ld\n", 371 PTR_ERR(hwmon_dev)); 372 } 373 } 374 375 static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled) 376 { 377 struct ds3232 *ds3232 = dev_get_drvdata(dev); 378 379 if (ds3232->irq <= 0) 380 return -EINVAL; 381 382 return ds3232_update_alarm(dev, enabled); 383 } 384 385 static irqreturn_t ds3232_irq(int irq, void *dev_id) 386 { 387 struct device *dev = dev_id; 388 struct ds3232 *ds3232 = dev_get_drvdata(dev); 389 int ret; 390 int stat, control; 391 392 guard(rtc_ops)(ds3232->rtc); 393 394 ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); 395 if (ret) 396 return IRQ_HANDLED; 397 398 if (stat & DS3232_REG_SR_A1F) { 399 ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); 400 if (ret) { 401 dev_warn(ds3232->dev, 402 "Read Control Register error %d\n", ret); 403 return IRQ_HANDLED; 404 } 405 /* disable alarm1 interrupt */ 406 control &= ~(DS3232_REG_CR_A1IE); 407 ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); 408 if (ret) { 409 dev_warn(ds3232->dev, 410 "Write Control Register error %d\n", ret); 411 return IRQ_HANDLED; 412 } 413 414 /* clear the alarm pend flag */ 415 stat &= ~DS3232_REG_SR_A1F; 416 ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat); 417 if (ret) { 418 dev_warn(ds3232->dev, 419 "Write Status Register error %d\n", ret); 420 return IRQ_HANDLED; 421 } 422 423 rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF); 424 } 425 426 return IRQ_HANDLED; 427 } 428 429 static const struct rtc_class_ops ds3232_rtc_ops = { 430 .read_time = ds3232_read_time, 431 .set_time = ds3232_set_time, 432 .read_alarm = ds3232_read_alarm, 433 .set_alarm = ds3232_set_alarm, 434 .alarm_irq_enable = ds3232_alarm_irq_enable, 435 }; 436 437 static int ds3232_nvmem_read(void *priv, unsigned int offset, void *val, 438 size_t bytes) 439 { 440 struct regmap *ds3232_regmap = (struct regmap *)priv; 441 442 return regmap_bulk_read(ds3232_regmap, DS3232_REG_SRAM_START + offset, 443 val, bytes); 444 } 445 446 static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val, 447 size_t bytes) 448 { 449 struct regmap *ds3232_regmap = (struct regmap *)priv; 450 451 return regmap_bulk_write(ds3232_regmap, DS3232_REG_SRAM_START + offset, 452 val, bytes); 453 } 454 455 static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq, 456 const char *name) 457 { 458 struct ds3232 *ds3232; 459 int ret; 460 struct nvmem_config nvmem_cfg = { 461 .name = "ds3232_sram", 462 .stride = 1, 463 .size = DS3232_REG_SRAM_SIZE, 464 .word_size = 1, 465 .reg_read = ds3232_nvmem_read, 466 .reg_write = ds3232_nvmem_write, 467 .priv = regmap, 468 .type = NVMEM_TYPE_BATTERY_BACKED 469 }; 470 471 ds3232 = devm_kzalloc_obj(dev, *ds3232); 472 if (!ds3232) 473 return -ENOMEM; 474 475 ds3232->regmap = regmap; 476 ds3232->irq = irq; 477 ds3232->dev = dev; 478 dev_set_drvdata(dev, ds3232); 479 480 ret = ds3232_check_rtc_status(dev); 481 if (ret) 482 return ret; 483 484 if (ds3232->irq > 0) 485 device_init_wakeup(dev, true); 486 487 ds3232_hwmon_register(dev, name); 488 489 ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops, 490 THIS_MODULE); 491 if (IS_ERR(ds3232->rtc)) 492 return PTR_ERR(ds3232->rtc); 493 494 ret = devm_rtc_nvmem_register(ds3232->rtc, &nvmem_cfg); 495 if(ret) 496 return ret; 497 498 if (ds3232->irq > 0) { 499 ret = devm_request_threaded_irq(dev, ds3232->irq, NULL, 500 ds3232_irq, 501 IRQF_SHARED | IRQF_ONESHOT, 502 name, dev); 503 if (ret) { 504 device_set_wakeup_capable(dev, 0); 505 ds3232->irq = 0; 506 dev_err(dev, "unable to request IRQ\n"); 507 } 508 } 509 510 return 0; 511 } 512 513 #if IS_ENABLED(CONFIG_I2C) 514 515 #ifdef CONFIG_PM_SLEEP 516 static int ds3232_suspend(struct device *dev) 517 { 518 struct ds3232 *ds3232 = dev_get_drvdata(dev); 519 520 if (device_may_wakeup(dev)) { 521 if (enable_irq_wake(ds3232->irq)) 522 dev_warn_once(dev, "Cannot set wakeup source\n"); 523 } 524 525 return 0; 526 } 527 528 static int ds3232_resume(struct device *dev) 529 { 530 struct ds3232 *ds3232 = dev_get_drvdata(dev); 531 532 if (device_may_wakeup(dev)) 533 disable_irq_wake(ds3232->irq); 534 535 return 0; 536 } 537 #endif 538 539 static const struct dev_pm_ops ds3232_pm_ops = { 540 SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume) 541 }; 542 543 static int ds3232_i2c_probe(struct i2c_client *client) 544 { 545 struct regmap *regmap; 546 static const struct regmap_config config = { 547 .reg_bits = 8, 548 .val_bits = 8, 549 .max_register = DS3232_REG_SRAM_END, 550 }; 551 552 regmap = devm_regmap_init_i2c(client, &config); 553 if (IS_ERR(regmap)) { 554 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n", 555 __func__, PTR_ERR(regmap)); 556 return PTR_ERR(regmap); 557 } 558 559 return ds3232_probe(&client->dev, regmap, client->irq, client->name); 560 } 561 562 static const struct i2c_device_id ds3232_id[] = { 563 { .name = "ds3232" }, 564 { } 565 }; 566 MODULE_DEVICE_TABLE(i2c, ds3232_id); 567 568 static const __maybe_unused struct of_device_id ds3232_of_match[] = { 569 { .compatible = "dallas,ds3232" }, 570 { } 571 }; 572 MODULE_DEVICE_TABLE(of, ds3232_of_match); 573 574 static struct i2c_driver ds3232_driver = { 575 .driver = { 576 .name = "rtc-ds3232", 577 .of_match_table = of_match_ptr(ds3232_of_match), 578 .pm = &ds3232_pm_ops, 579 }, 580 .probe = ds3232_i2c_probe, 581 .id_table = ds3232_id, 582 }; 583 584 static int ds3232_register_driver(void) 585 { 586 return i2c_add_driver(&ds3232_driver); 587 } 588 589 static void ds3232_unregister_driver(void) 590 { 591 i2c_del_driver(&ds3232_driver); 592 } 593 594 #else 595 596 static int ds3232_register_driver(void) 597 { 598 return 0; 599 } 600 601 static void ds3232_unregister_driver(void) 602 { 603 } 604 605 #endif 606 607 #if IS_ENABLED(CONFIG_SPI_MASTER) 608 609 static int ds3234_probe(struct spi_device *spi) 610 { 611 int res; 612 unsigned int tmp; 613 static const struct regmap_config config = { 614 .reg_bits = 8, 615 .val_bits = 8, 616 .max_register = DS3232_REG_SRAM_END, 617 .write_flag_mask = 0x80, 618 }; 619 struct regmap *regmap; 620 621 regmap = devm_regmap_init_spi(spi, &config); 622 if (IS_ERR(regmap)) { 623 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n", 624 __func__, PTR_ERR(regmap)); 625 return PTR_ERR(regmap); 626 } 627 628 spi->mode = SPI_MODE_3; 629 spi->bits_per_word = 8; 630 spi_setup(spi); 631 632 res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp); 633 if (res) 634 return res; 635 636 /* Control settings 637 * 638 * CONTROL_REG 639 * BIT 7 6 5 4 3 2 1 0 640 * EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE 641 * 642 * 0 0 0 1 1 1 0 0 643 * 644 * CONTROL_STAT_REG 645 * BIT 7 6 5 4 3 2 1 0 646 * OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F 647 * 648 * 1 0 0 0 1 0 0 0 649 */ 650 res = regmap_read(regmap, DS3232_REG_CR, &tmp); 651 if (res) 652 return res; 653 res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c); 654 if (res) 655 return res; 656 657 res = regmap_read(regmap, DS3232_REG_SR, &tmp); 658 if (res) 659 return res; 660 res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88); 661 if (res) 662 return res; 663 664 /* Print our settings */ 665 res = regmap_read(regmap, DS3232_REG_CR, &tmp); 666 if (res) 667 return res; 668 dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp); 669 670 res = regmap_read(regmap, DS3232_REG_SR, &tmp); 671 if (res) 672 return res; 673 dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp); 674 675 return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234"); 676 } 677 678 static struct spi_driver ds3234_driver = { 679 .driver = { 680 .name = "ds3234", 681 }, 682 .probe = ds3234_probe, 683 }; 684 685 static int ds3234_register_driver(void) 686 { 687 return spi_register_driver(&ds3234_driver); 688 } 689 690 static void ds3234_unregister_driver(void) 691 { 692 spi_unregister_driver(&ds3234_driver); 693 } 694 695 #else 696 697 static int ds3234_register_driver(void) 698 { 699 return 0; 700 } 701 702 static void ds3234_unregister_driver(void) 703 { 704 } 705 706 #endif 707 708 static int __init ds323x_init(void) 709 { 710 int ret; 711 712 ret = ds3232_register_driver(); 713 if (ret) { 714 pr_err("Failed to register ds3232 driver: %d\n", ret); 715 return ret; 716 } 717 718 ret = ds3234_register_driver(); 719 if (ret) { 720 pr_err("Failed to register ds3234 driver: %d\n", ret); 721 ds3232_unregister_driver(); 722 } 723 724 return ret; 725 } 726 module_init(ds323x_init) 727 728 static void __exit ds323x_exit(void) 729 { 730 ds3234_unregister_driver(); 731 ds3232_unregister_driver(); 732 } 733 module_exit(ds323x_exit) 734 735 MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>"); 736 MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>"); 737 MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver"); 738 MODULE_LICENSE("GPL"); 739 MODULE_ALIAS("spi:ds3234"); 740