1 /* 2 * An rtc driver for the Dallas DS1511 3 * 4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp> 5 * Copyright (C) 2007 Andrew Sharp <andy.sharp@onstor.com> 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 * Real time clock driver for the Dallas 1511 chip, which also 12 * contains a watchdog timer. There is a tiny amount of code that 13 * platform code could use to mess with the watchdog device a little 14 * bit, but not a full watchdog driver. 15 */ 16 17 #include <linux/bcd.h> 18 #include <linux/init.h> 19 #include <linux/kernel.h> 20 #include <linux/delay.h> 21 #include <linux/interrupt.h> 22 #include <linux/rtc.h> 23 #include <linux/platform_device.h> 24 #include <linux/io.h> 25 26 #define DRV_VERSION "0.6" 27 28 enum ds1511reg { 29 DS1511_SEC = 0x0, 30 DS1511_MIN = 0x1, 31 DS1511_HOUR = 0x2, 32 DS1511_DOW = 0x3, 33 DS1511_DOM = 0x4, 34 DS1511_MONTH = 0x5, 35 DS1511_YEAR = 0x6, 36 DS1511_CENTURY = 0x7, 37 DS1511_AM1_SEC = 0x8, 38 DS1511_AM2_MIN = 0x9, 39 DS1511_AM3_HOUR = 0xa, 40 DS1511_AM4_DATE = 0xb, 41 DS1511_WD_MSEC = 0xc, 42 DS1511_WD_SEC = 0xd, 43 DS1511_CONTROL_A = 0xe, 44 DS1511_CONTROL_B = 0xf, 45 DS1511_RAMADDR_LSB = 0x10, 46 DS1511_RAMDATA = 0x13 47 }; 48 49 #define DS1511_BLF1 0x80 50 #define DS1511_BLF2 0x40 51 #define DS1511_PRS 0x20 52 #define DS1511_PAB 0x10 53 #define DS1511_TDF 0x08 54 #define DS1511_KSF 0x04 55 #define DS1511_WDF 0x02 56 #define DS1511_IRQF 0x01 57 #define DS1511_TE 0x80 58 #define DS1511_CS 0x40 59 #define DS1511_BME 0x20 60 #define DS1511_TPE 0x10 61 #define DS1511_TIE 0x08 62 #define DS1511_KIE 0x04 63 #define DS1511_WDE 0x02 64 #define DS1511_WDS 0x01 65 #define DS1511_RAM_MAX 0xff 66 67 #define RTC_CMD DS1511_CONTROL_B 68 #define RTC_CMD1 DS1511_CONTROL_A 69 70 #define RTC_ALARM_SEC DS1511_AM1_SEC 71 #define RTC_ALARM_MIN DS1511_AM2_MIN 72 #define RTC_ALARM_HOUR DS1511_AM3_HOUR 73 #define RTC_ALARM_DATE DS1511_AM4_DATE 74 75 #define RTC_SEC DS1511_SEC 76 #define RTC_MIN DS1511_MIN 77 #define RTC_HOUR DS1511_HOUR 78 #define RTC_DOW DS1511_DOW 79 #define RTC_DOM DS1511_DOM 80 #define RTC_MON DS1511_MONTH 81 #define RTC_YEAR DS1511_YEAR 82 #define RTC_CENTURY DS1511_CENTURY 83 84 #define RTC_TIE DS1511_TIE 85 #define RTC_TE DS1511_TE 86 87 struct rtc_plat_data { 88 struct rtc_device *rtc; 89 void __iomem *ioaddr; /* virtual base address */ 90 unsigned long baseaddr; /* physical base address */ 91 int size; /* amount of memory mapped */ 92 int irq; 93 unsigned int irqen; 94 int alrm_sec; 95 int alrm_min; 96 int alrm_hour; 97 int alrm_mday; 98 }; 99 100 static DEFINE_SPINLOCK(ds1511_lock); 101 102 static __iomem char *ds1511_base; 103 static u32 reg_spacing = 1; 104 105 static noinline void 106 rtc_write(uint8_t val, uint32_t reg) 107 { 108 writeb(val, ds1511_base + (reg * reg_spacing)); 109 } 110 111 static inline void 112 rtc_write_alarm(uint8_t val, enum ds1511reg reg) 113 { 114 rtc_write((val | 0x80), reg); 115 } 116 117 static noinline uint8_t 118 rtc_read(enum ds1511reg reg) 119 { 120 return readb(ds1511_base + (reg * reg_spacing)); 121 } 122 123 static inline void 124 rtc_disable_update(void) 125 { 126 rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD); 127 } 128 129 static void 130 rtc_enable_update(void) 131 { 132 rtc_write((rtc_read(RTC_CMD) | RTC_TE), RTC_CMD); 133 } 134 135 /* 136 * #define DS1511_WDOG_RESET_SUPPORT 137 * 138 * Uncomment this if you want to use these routines in 139 * some platform code. 140 */ 141 #ifdef DS1511_WDOG_RESET_SUPPORT 142 /* 143 * just enough code to set the watchdog timer so that it 144 * will reboot the system 145 */ 146 void 147 ds1511_wdog_set(unsigned long deciseconds) 148 { 149 /* 150 * the wdog timer can take 99.99 seconds 151 */ 152 deciseconds %= 10000; 153 /* 154 * set the wdog values in the wdog registers 155 */ 156 rtc_write(BIN2BCD(deciseconds % 100), DS1511_WD_MSEC); 157 rtc_write(BIN2BCD(deciseconds / 100), DS1511_WD_SEC); 158 /* 159 * set wdog enable and wdog 'steering' bit to issue a reset 160 */ 161 rtc_write(DS1511_WDE | DS1511_WDS, RTC_CMD); 162 } 163 164 void 165 ds1511_wdog_disable(void) 166 { 167 /* 168 * clear wdog enable and wdog 'steering' bits 169 */ 170 rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE | DS1511_WDS), RTC_CMD); 171 /* 172 * clear the wdog counter 173 */ 174 rtc_write(0, DS1511_WD_MSEC); 175 rtc_write(0, DS1511_WD_SEC); 176 } 177 #endif 178 179 /* 180 * set the rtc chip's idea of the time. 181 * stupidly, some callers call with year unmolested; 182 * and some call with year = year - 1900. thanks. 183 */ 184 int 185 ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm) 186 { 187 u8 mon, day, dow, hrs, min, sec, yrs, cen; 188 unsigned int flags; 189 190 /* 191 * won't have to change this for a while 192 */ 193 if (rtc_tm->tm_year < 1900) { 194 rtc_tm->tm_year += 1900; 195 } 196 197 if (rtc_tm->tm_year < 1970) { 198 return -EINVAL; 199 } 200 yrs = rtc_tm->tm_year % 100; 201 cen = rtc_tm->tm_year / 100; 202 mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */ 203 day = rtc_tm->tm_mday; 204 dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */ 205 hrs = rtc_tm->tm_hour; 206 min = rtc_tm->tm_min; 207 sec = rtc_tm->tm_sec; 208 209 if ((mon > 12) || (day == 0)) { 210 return -EINVAL; 211 } 212 213 if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year)) { 214 return -EINVAL; 215 } 216 217 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) { 218 return -EINVAL; 219 } 220 221 /* 222 * each register is a different number of valid bits 223 */ 224 sec = BIN2BCD(sec) & 0x7f; 225 min = BIN2BCD(min) & 0x7f; 226 hrs = BIN2BCD(hrs) & 0x3f; 227 day = BIN2BCD(day) & 0x3f; 228 mon = BIN2BCD(mon) & 0x1f; 229 yrs = BIN2BCD(yrs) & 0xff; 230 cen = BIN2BCD(cen) & 0xff; 231 232 spin_lock_irqsave(&ds1511_lock, flags); 233 rtc_disable_update(); 234 rtc_write(cen, RTC_CENTURY); 235 rtc_write(yrs, RTC_YEAR); 236 rtc_write((rtc_read(RTC_MON) & 0xe0) | mon, RTC_MON); 237 rtc_write(day, RTC_DOM); 238 rtc_write(hrs, RTC_HOUR); 239 rtc_write(min, RTC_MIN); 240 rtc_write(sec, RTC_SEC); 241 rtc_write(dow, RTC_DOW); 242 rtc_enable_update(); 243 spin_unlock_irqrestore(&ds1511_lock, flags); 244 245 return 0; 246 } 247 248 int 249 ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm) 250 { 251 unsigned int century; 252 unsigned int flags; 253 254 spin_lock_irqsave(&ds1511_lock, flags); 255 rtc_disable_update(); 256 257 rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f; 258 rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f; 259 rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f; 260 rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f; 261 rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7; 262 rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f; 263 rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f; 264 century = rtc_read(RTC_CENTURY); 265 266 rtc_enable_update(); 267 spin_unlock_irqrestore(&ds1511_lock, flags); 268 269 rtc_tm->tm_sec = BCD2BIN(rtc_tm->tm_sec); 270 rtc_tm->tm_min = BCD2BIN(rtc_tm->tm_min); 271 rtc_tm->tm_hour = BCD2BIN(rtc_tm->tm_hour); 272 rtc_tm->tm_mday = BCD2BIN(rtc_tm->tm_mday); 273 rtc_tm->tm_wday = BCD2BIN(rtc_tm->tm_wday); 274 rtc_tm->tm_mon = BCD2BIN(rtc_tm->tm_mon); 275 rtc_tm->tm_year = BCD2BIN(rtc_tm->tm_year); 276 century = BCD2BIN(century) * 100; 277 278 /* 279 * Account for differences between how the RTC uses the values 280 * and how they are defined in a struct rtc_time; 281 */ 282 century += rtc_tm->tm_year; 283 rtc_tm->tm_year = century - 1900; 284 285 rtc_tm->tm_mon--; 286 287 if (rtc_valid_tm(rtc_tm) < 0) { 288 dev_err(dev, "retrieved date/time is not valid.\n"); 289 rtc_time_to_tm(0, rtc_tm); 290 } 291 return 0; 292 } 293 294 /* 295 * write the alarm register settings 296 * 297 * we only have the use to interrupt every second, otherwise 298 * known as the update interrupt, or the interrupt if the whole 299 * date/hours/mins/secs matches. the ds1511 has many more 300 * permutations, but the kernel doesn't. 301 */ 302 static void 303 ds1511_rtc_update_alarm(struct rtc_plat_data *pdata) 304 { 305 unsigned long flags; 306 307 spin_lock_irqsave(&pdata->rtc->irq_lock, flags); 308 rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ? 309 0x80 : BIN2BCD(pdata->alrm_mday) & 0x3f, 310 RTC_ALARM_DATE); 311 rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ? 312 0x80 : BIN2BCD(pdata->alrm_hour) & 0x3f, 313 RTC_ALARM_HOUR); 314 rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ? 315 0x80 : BIN2BCD(pdata->alrm_min) & 0x7f, 316 RTC_ALARM_MIN); 317 rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ? 318 0x80 : BIN2BCD(pdata->alrm_sec) & 0x7f, 319 RTC_ALARM_SEC); 320 rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD); 321 rtc_read(RTC_CMD1); /* clear interrupts */ 322 spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags); 323 } 324 325 static int 326 ds1511_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 327 { 328 struct platform_device *pdev = to_platform_device(dev); 329 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 330 331 if (pdata->irq < 0) { 332 return -EINVAL; 333 } 334 pdata->alrm_mday = alrm->time.tm_mday; 335 pdata->alrm_hour = alrm->time.tm_hour; 336 pdata->alrm_min = alrm->time.tm_min; 337 pdata->alrm_sec = alrm->time.tm_sec; 338 if (alrm->enabled) { 339 pdata->irqen |= RTC_AF; 340 } 341 ds1511_rtc_update_alarm(pdata); 342 return 0; 343 } 344 345 static int 346 ds1511_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 347 { 348 struct platform_device *pdev = to_platform_device(dev); 349 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 350 351 if (pdata->irq < 0) { 352 return -EINVAL; 353 } 354 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday; 355 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour; 356 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min; 357 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec; 358 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0; 359 return 0; 360 } 361 362 static irqreturn_t 363 ds1511_interrupt(int irq, void *dev_id) 364 { 365 struct platform_device *pdev = dev_id; 366 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 367 unsigned long events = RTC_IRQF; 368 369 /* 370 * read and clear interrupt 371 */ 372 if (!(rtc_read(RTC_CMD1) & DS1511_IRQF)) { 373 return IRQ_NONE; 374 } 375 if (rtc_read(RTC_ALARM_SEC) & 0x80) { 376 events |= RTC_UF; 377 } else { 378 events |= RTC_AF; 379 } 380 rtc_update_irq(pdata->rtc, 1, events); 381 return IRQ_HANDLED; 382 } 383 384 static void 385 ds1511_rtc_release(struct device *dev) 386 { 387 struct platform_device *pdev = to_platform_device(dev); 388 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 389 390 if (pdata->irq >= 0) { 391 pdata->irqen = 0; 392 ds1511_rtc_update_alarm(pdata); 393 } 394 } 395 396 static int 397 ds1511_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 398 { 399 struct platform_device *pdev = to_platform_device(dev); 400 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 401 402 if (pdata->irq < 0) { 403 return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */ 404 } 405 switch (cmd) { 406 case RTC_AIE_OFF: 407 pdata->irqen &= ~RTC_AF; 408 ds1511_rtc_update_alarm(pdata); 409 break; 410 case RTC_AIE_ON: 411 pdata->irqen |= RTC_AF; 412 ds1511_rtc_update_alarm(pdata); 413 break; 414 case RTC_UIE_OFF: 415 pdata->irqen &= ~RTC_UF; 416 ds1511_rtc_update_alarm(pdata); 417 break; 418 case RTC_UIE_ON: 419 pdata->irqen |= RTC_UF; 420 ds1511_rtc_update_alarm(pdata); 421 break; 422 default: 423 return -ENOIOCTLCMD; 424 } 425 return 0; 426 } 427 428 static const struct rtc_class_ops ds1511_rtc_ops = { 429 .read_time = ds1511_rtc_read_time, 430 .set_time = ds1511_rtc_set_time, 431 .read_alarm = ds1511_rtc_read_alarm, 432 .set_alarm = ds1511_rtc_set_alarm, 433 .release = ds1511_rtc_release, 434 .ioctl = ds1511_rtc_ioctl, 435 }; 436 437 static ssize_t 438 ds1511_nvram_read(struct kobject *kobj, struct bin_attribute *ba, 439 char *buf, loff_t pos, size_t size) 440 { 441 ssize_t count; 442 443 /* 444 * if count is more than one, turn on "burst" mode 445 * turn it off when you're done 446 */ 447 if (size > 1) { 448 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD); 449 } 450 if (pos > DS1511_RAM_MAX) { 451 pos = DS1511_RAM_MAX; 452 } 453 if (size + pos > DS1511_RAM_MAX + 1) { 454 size = DS1511_RAM_MAX - pos + 1; 455 } 456 rtc_write(pos, DS1511_RAMADDR_LSB); 457 for (count = 0; size > 0; count++, size--) { 458 *buf++ = rtc_read(DS1511_RAMDATA); 459 } 460 if (count > 1) { 461 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD); 462 } 463 return count; 464 } 465 466 static ssize_t 467 ds1511_nvram_write(struct kobject *kobj, struct bin_attribute *bin_attr, 468 char *buf, loff_t pos, size_t size) 469 { 470 ssize_t count; 471 472 /* 473 * if count is more than one, turn on "burst" mode 474 * turn it off when you're done 475 */ 476 if (size > 1) { 477 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD); 478 } 479 if (pos > DS1511_RAM_MAX) { 480 pos = DS1511_RAM_MAX; 481 } 482 if (size + pos > DS1511_RAM_MAX + 1) { 483 size = DS1511_RAM_MAX - pos + 1; 484 } 485 rtc_write(pos, DS1511_RAMADDR_LSB); 486 for (count = 0; size > 0; count++, size--) { 487 rtc_write(*buf++, DS1511_RAMDATA); 488 } 489 if (count > 1) { 490 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD); 491 } 492 return count; 493 } 494 495 static struct bin_attribute ds1511_nvram_attr = { 496 .attr = { 497 .name = "nvram", 498 .mode = S_IRUGO | S_IWUGO, 499 .owner = THIS_MODULE, 500 }, 501 .size = DS1511_RAM_MAX, 502 .read = ds1511_nvram_read, 503 .write = ds1511_nvram_write, 504 }; 505 506 static int __devinit 507 ds1511_rtc_probe(struct platform_device *pdev) 508 { 509 struct rtc_device *rtc; 510 struct resource *res; 511 struct rtc_plat_data *pdata = NULL; 512 int ret = 0; 513 514 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 515 if (!res) { 516 return -ENODEV; 517 } 518 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 519 if (!pdata) { 520 return -ENOMEM; 521 } 522 pdata->irq = -1; 523 pdata->size = res->end - res->start + 1; 524 if (!request_mem_region(res->start, pdata->size, pdev->name)) { 525 ret = -EBUSY; 526 goto out; 527 } 528 pdata->baseaddr = res->start; 529 pdata->size = pdata->size; 530 ds1511_base = ioremap(pdata->baseaddr, pdata->size); 531 if (!ds1511_base) { 532 ret = -ENOMEM; 533 goto out; 534 } 535 pdata->ioaddr = ds1511_base; 536 pdata->irq = platform_get_irq(pdev, 0); 537 538 /* 539 * turn on the clock and the crystal, etc. 540 */ 541 rtc_write(0, RTC_CMD); 542 rtc_write(0, RTC_CMD1); 543 /* 544 * clear the wdog counter 545 */ 546 rtc_write(0, DS1511_WD_MSEC); 547 rtc_write(0, DS1511_WD_SEC); 548 /* 549 * start the clock 550 */ 551 rtc_enable_update(); 552 553 /* 554 * check for a dying bat-tree 555 */ 556 if (rtc_read(RTC_CMD1) & DS1511_BLF1) { 557 dev_warn(&pdev->dev, "voltage-low detected.\n"); 558 } 559 560 /* 561 * if the platform has an interrupt in mind for this device, 562 * then by all means, set it 563 */ 564 if (pdata->irq >= 0) { 565 rtc_read(RTC_CMD1); 566 if (request_irq(pdata->irq, ds1511_interrupt, 567 IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) { 568 569 dev_warn(&pdev->dev, "interrupt not available.\n"); 570 pdata->irq = -1; 571 } 572 } 573 574 rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_rtc_ops, 575 THIS_MODULE); 576 if (IS_ERR(rtc)) { 577 ret = PTR_ERR(rtc); 578 goto out; 579 } 580 pdata->rtc = rtc; 581 platform_set_drvdata(pdev, pdata); 582 ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr); 583 if (ret) { 584 goto out; 585 } 586 return 0; 587 out: 588 if (pdata->rtc) { 589 rtc_device_unregister(pdata->rtc); 590 } 591 if (pdata->irq >= 0) { 592 free_irq(pdata->irq, pdev); 593 } 594 if (ds1511_base) { 595 iounmap(ds1511_base); 596 ds1511_base = NULL; 597 } 598 if (pdata->baseaddr) { 599 release_mem_region(pdata->baseaddr, pdata->size); 600 } 601 602 kfree(pdata); 603 return ret; 604 } 605 606 static int __devexit 607 ds1511_rtc_remove(struct platform_device *pdev) 608 { 609 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 610 611 sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr); 612 rtc_device_unregister(pdata->rtc); 613 pdata->rtc = NULL; 614 if (pdata->irq >= 0) { 615 /* 616 * disable the alarm interrupt 617 */ 618 rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD); 619 rtc_read(RTC_CMD1); 620 free_irq(pdata->irq, pdev); 621 } 622 iounmap(pdata->ioaddr); 623 ds1511_base = NULL; 624 release_mem_region(pdata->baseaddr, pdata->size); 625 kfree(pdata); 626 return 0; 627 } 628 629 /* work with hotplug and coldplug */ 630 MODULE_ALIAS("platform:ds1511"); 631 632 static struct platform_driver ds1511_rtc_driver = { 633 .probe = ds1511_rtc_probe, 634 .remove = __devexit_p(ds1511_rtc_remove), 635 .driver = { 636 .name = "ds1511", 637 .owner = THIS_MODULE, 638 }, 639 }; 640 641 static int __init 642 ds1511_rtc_init(void) 643 { 644 return platform_driver_register(&ds1511_rtc_driver); 645 } 646 647 static void __exit 648 ds1511_rtc_exit(void) 649 { 650 return platform_driver_unregister(&ds1511_rtc_driver); 651 } 652 653 module_init(ds1511_rtc_init); 654 module_exit(ds1511_rtc_exit); 655 656 MODULE_AUTHOR("Andrew Sharp <andy.sharp@onstor.com>"); 657 MODULE_DESCRIPTION("Dallas DS1511 RTC driver"); 658 MODULE_LICENSE("GPL"); 659 MODULE_VERSION(DRV_VERSION); 660