1 /* drivers/rtc/rtc-s3c.c 2 * 3 * Copyright (c) 2004,2006 Simtec Electronics 4 * Ben Dooks, <ben@simtec.co.uk> 5 * http://armlinux.simtec.co.uk/ 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 * S3C2410/S3C2440/S3C24XX Internal RTC Driver 12 */ 13 14 #include <linux/module.h> 15 #include <linux/fs.h> 16 #include <linux/string.h> 17 #include <linux/init.h> 18 #include <linux/platform_device.h> 19 #include <linux/interrupt.h> 20 #include <linux/rtc.h> 21 #include <linux/bcd.h> 22 #include <linux/clk.h> 23 24 #include <asm/hardware.h> 25 #include <asm/uaccess.h> 26 #include <asm/io.h> 27 #include <asm/irq.h> 28 #include <asm/rtc.h> 29 30 #include <asm/mach/time.h> 31 32 #include <asm/arch/regs-rtc.h> 33 34 /* I have yet to find an S3C implementation with more than one 35 * of these rtc blocks in */ 36 37 static struct resource *s3c_rtc_mem; 38 39 static void __iomem *s3c_rtc_base; 40 static int s3c_rtc_alarmno = NO_IRQ; 41 static int s3c_rtc_tickno = NO_IRQ; 42 static int s3c_rtc_freq = 1; 43 44 static DEFINE_SPINLOCK(s3c_rtc_pie_lock); 45 static unsigned int tick_count; 46 47 /* IRQ Handlers */ 48 49 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) 50 { 51 struct rtc_device *rdev = id; 52 53 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF); 54 return IRQ_HANDLED; 55 } 56 57 static irqreturn_t s3c_rtc_tickirq(int irq, void *id) 58 { 59 struct rtc_device *rdev = id; 60 61 rtc_update_irq(rdev, tick_count++, RTC_PF | RTC_IRQF); 62 return IRQ_HANDLED; 63 } 64 65 /* Update control registers */ 66 static void s3c_rtc_setaie(int to) 67 { 68 unsigned int tmp; 69 70 pr_debug("%s: aie=%d\n", __FUNCTION__, to); 71 72 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN; 73 74 if (to) 75 tmp |= S3C2410_RTCALM_ALMEN; 76 77 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM); 78 } 79 80 static void s3c_rtc_setpie(int to) 81 { 82 unsigned int tmp; 83 84 pr_debug("%s: pie=%d\n", __FUNCTION__, to); 85 86 spin_lock_irq(&s3c_rtc_pie_lock); 87 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE; 88 89 if (to) 90 tmp |= S3C2410_TICNT_ENABLE; 91 92 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 93 spin_unlock_irq(&s3c_rtc_pie_lock); 94 } 95 96 static void s3c_rtc_setfreq(int freq) 97 { 98 unsigned int tmp; 99 100 spin_lock_irq(&s3c_rtc_pie_lock); 101 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE; 102 103 s3c_rtc_freq = freq; 104 105 tmp |= (128 / freq)-1; 106 107 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 108 spin_unlock_irq(&s3c_rtc_pie_lock); 109 } 110 111 /* Time read/write */ 112 113 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) 114 { 115 unsigned int have_retried = 0; 116 void __iomem *base = s3c_rtc_base; 117 118 retry_get_time: 119 rtc_tm->tm_min = readb(base + S3C2410_RTCMIN); 120 rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR); 121 rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE); 122 rtc_tm->tm_mon = readb(base + S3C2410_RTCMON); 123 rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR); 124 rtc_tm->tm_sec = readb(base + S3C2410_RTCSEC); 125 126 /* the only way to work out wether the system was mid-update 127 * when we read it is to check the second counter, and if it 128 * is zero, then we re-try the entire read 129 */ 130 131 if (rtc_tm->tm_sec == 0 && !have_retried) { 132 have_retried = 1; 133 goto retry_get_time; 134 } 135 136 pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n", 137 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday, 138 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec); 139 140 BCD_TO_BIN(rtc_tm->tm_sec); 141 BCD_TO_BIN(rtc_tm->tm_min); 142 BCD_TO_BIN(rtc_tm->tm_hour); 143 BCD_TO_BIN(rtc_tm->tm_mday); 144 BCD_TO_BIN(rtc_tm->tm_mon); 145 BCD_TO_BIN(rtc_tm->tm_year); 146 147 rtc_tm->tm_year += 100; 148 rtc_tm->tm_mon -= 1; 149 150 return 0; 151 } 152 153 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm) 154 { 155 void __iomem *base = s3c_rtc_base; 156 int year = tm->tm_year - 100; 157 158 pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n", 159 tm->tm_year, tm->tm_mon, tm->tm_mday, 160 tm->tm_hour, tm->tm_min, tm->tm_sec); 161 162 /* we get around y2k by simply not supporting it */ 163 164 if (year < 0 || year >= 100) { 165 dev_err(dev, "rtc only supports 100 years\n"); 166 return -EINVAL; 167 } 168 169 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_RTCSEC); 170 writeb(BIN2BCD(tm->tm_min), base + S3C2410_RTCMIN); 171 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_RTCHOUR); 172 writeb(BIN2BCD(tm->tm_mday), base + S3C2410_RTCDATE); 173 writeb(BIN2BCD(tm->tm_mon + 1), base + S3C2410_RTCMON); 174 writeb(BIN2BCD(year), base + S3C2410_RTCYEAR); 175 176 return 0; 177 } 178 179 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm) 180 { 181 struct rtc_time *alm_tm = &alrm->time; 182 void __iomem *base = s3c_rtc_base; 183 unsigned int alm_en; 184 185 alm_tm->tm_sec = readb(base + S3C2410_ALMSEC); 186 alm_tm->tm_min = readb(base + S3C2410_ALMMIN); 187 alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR); 188 alm_tm->tm_mon = readb(base + S3C2410_ALMMON); 189 alm_tm->tm_mday = readb(base + S3C2410_ALMDATE); 190 alm_tm->tm_year = readb(base + S3C2410_ALMYEAR); 191 192 alm_en = readb(base + S3C2410_RTCALM); 193 194 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0; 195 196 pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n", 197 alm_en, 198 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday, 199 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec); 200 201 202 /* decode the alarm enable field */ 203 204 if (alm_en & S3C2410_RTCALM_SECEN) 205 BCD_TO_BIN(alm_tm->tm_sec); 206 else 207 alm_tm->tm_sec = 0xff; 208 209 if (alm_en & S3C2410_RTCALM_MINEN) 210 BCD_TO_BIN(alm_tm->tm_min); 211 else 212 alm_tm->tm_min = 0xff; 213 214 if (alm_en & S3C2410_RTCALM_HOUREN) 215 BCD_TO_BIN(alm_tm->tm_hour); 216 else 217 alm_tm->tm_hour = 0xff; 218 219 if (alm_en & S3C2410_RTCALM_DAYEN) 220 BCD_TO_BIN(alm_tm->tm_mday); 221 else 222 alm_tm->tm_mday = 0xff; 223 224 if (alm_en & S3C2410_RTCALM_MONEN) { 225 BCD_TO_BIN(alm_tm->tm_mon); 226 alm_tm->tm_mon -= 1; 227 } else { 228 alm_tm->tm_mon = 0xff; 229 } 230 231 if (alm_en & S3C2410_RTCALM_YEAREN) 232 BCD_TO_BIN(alm_tm->tm_year); 233 else 234 alm_tm->tm_year = 0xffff; 235 236 return 0; 237 } 238 239 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 240 { 241 struct rtc_time *tm = &alrm->time; 242 void __iomem *base = s3c_rtc_base; 243 unsigned int alrm_en; 244 245 pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n", 246 alrm->enabled, 247 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff, 248 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec); 249 250 251 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN; 252 writeb(0x00, base + S3C2410_RTCALM); 253 254 if (tm->tm_sec < 60 && tm->tm_sec >= 0) { 255 alrm_en |= S3C2410_RTCALM_SECEN; 256 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC); 257 } 258 259 if (tm->tm_min < 60 && tm->tm_min >= 0) { 260 alrm_en |= S3C2410_RTCALM_MINEN; 261 writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN); 262 } 263 264 if (tm->tm_hour < 24 && tm->tm_hour >= 0) { 265 alrm_en |= S3C2410_RTCALM_HOUREN; 266 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR); 267 } 268 269 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en); 270 271 writeb(alrm_en, base + S3C2410_RTCALM); 272 273 if (0) { 274 alrm_en = readb(base + S3C2410_RTCALM); 275 alrm_en &= ~S3C2410_RTCALM_ALMEN; 276 writeb(alrm_en, base + S3C2410_RTCALM); 277 disable_irq_wake(s3c_rtc_alarmno); 278 } 279 280 if (alrm->enabled) 281 enable_irq_wake(s3c_rtc_alarmno); 282 else 283 disable_irq_wake(s3c_rtc_alarmno); 284 285 return 0; 286 } 287 288 static int s3c_rtc_ioctl(struct device *dev, 289 unsigned int cmd, unsigned long arg) 290 { 291 unsigned int ret = -ENOIOCTLCMD; 292 293 switch (cmd) { 294 case RTC_AIE_OFF: 295 case RTC_AIE_ON: 296 s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0); 297 ret = 0; 298 break; 299 300 case RTC_PIE_OFF: 301 case RTC_PIE_ON: 302 tick_count = 0; 303 s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0); 304 ret = 0; 305 break; 306 307 case RTC_IRQP_READ: 308 ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg); 309 break; 310 311 case RTC_IRQP_SET: 312 /* check for power of 2 */ 313 314 if ((arg & (arg-1)) != 0 || arg < 1) { 315 ret = -EINVAL; 316 goto exit; 317 } 318 319 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg); 320 321 s3c_rtc_setfreq(arg); 322 ret = 0; 323 break; 324 325 case RTC_UIE_ON: 326 case RTC_UIE_OFF: 327 ret = -EINVAL; 328 } 329 330 exit: 331 return ret; 332 } 333 334 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) 335 { 336 unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT); 337 338 seq_printf(seq, "periodic_IRQ\t: %s\n", 339 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" ); 340 341 seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq); 342 343 return 0; 344 } 345 346 static int s3c_rtc_open(struct device *dev) 347 { 348 struct platform_device *pdev = to_platform_device(dev); 349 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 350 int ret; 351 352 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq, 353 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev); 354 355 if (ret) { 356 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret); 357 return ret; 358 } 359 360 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq, 361 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev); 362 363 if (ret) { 364 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret); 365 goto tick_err; 366 } 367 368 return ret; 369 370 tick_err: 371 free_irq(s3c_rtc_alarmno, rtc_dev); 372 return ret; 373 } 374 375 static void s3c_rtc_release(struct device *dev) 376 { 377 struct platform_device *pdev = to_platform_device(dev); 378 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 379 380 /* do not clear AIE here, it may be needed for wake */ 381 382 s3c_rtc_setpie(0); 383 free_irq(s3c_rtc_alarmno, rtc_dev); 384 free_irq(s3c_rtc_tickno, rtc_dev); 385 } 386 387 static const struct rtc_class_ops s3c_rtcops = { 388 .open = s3c_rtc_open, 389 .release = s3c_rtc_release, 390 .ioctl = s3c_rtc_ioctl, 391 .read_time = s3c_rtc_gettime, 392 .set_time = s3c_rtc_settime, 393 .read_alarm = s3c_rtc_getalarm, 394 .set_alarm = s3c_rtc_setalarm, 395 .proc = s3c_rtc_proc, 396 }; 397 398 static void s3c_rtc_enable(struct platform_device *pdev, int en) 399 { 400 void __iomem *base = s3c_rtc_base; 401 unsigned int tmp; 402 403 if (s3c_rtc_base == NULL) 404 return; 405 406 if (!en) { 407 tmp = readb(base + S3C2410_RTCCON); 408 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON); 409 410 tmp = readb(base + S3C2410_TICNT); 411 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT); 412 } else { 413 /* re-enable the device, and check it is ok */ 414 415 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){ 416 dev_info(&pdev->dev, "rtc disabled, re-enabling\n"); 417 418 tmp = readb(base + S3C2410_RTCCON); 419 writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON); 420 } 421 422 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){ 423 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n"); 424 425 tmp = readb(base + S3C2410_RTCCON); 426 writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON); 427 } 428 429 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){ 430 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n"); 431 432 tmp = readb(base + S3C2410_RTCCON); 433 writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON); 434 } 435 } 436 } 437 438 static int s3c_rtc_remove(struct platform_device *dev) 439 { 440 struct rtc_device *rtc = platform_get_drvdata(dev); 441 442 platform_set_drvdata(dev, NULL); 443 rtc_device_unregister(rtc); 444 445 s3c_rtc_setpie(0); 446 s3c_rtc_setaie(0); 447 448 iounmap(s3c_rtc_base); 449 release_resource(s3c_rtc_mem); 450 kfree(s3c_rtc_mem); 451 452 return 0; 453 } 454 455 static int s3c_rtc_probe(struct platform_device *pdev) 456 { 457 struct rtc_device *rtc; 458 struct resource *res; 459 int ret; 460 461 pr_debug("%s: probe=%p\n", __FUNCTION__, pdev); 462 463 /* find the IRQs */ 464 465 s3c_rtc_tickno = platform_get_irq(pdev, 1); 466 if (s3c_rtc_tickno < 0) { 467 dev_err(&pdev->dev, "no irq for rtc tick\n"); 468 return -ENOENT; 469 } 470 471 s3c_rtc_alarmno = platform_get_irq(pdev, 0); 472 if (s3c_rtc_alarmno < 0) { 473 dev_err(&pdev->dev, "no irq for alarm\n"); 474 return -ENOENT; 475 } 476 477 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n", 478 s3c_rtc_tickno, s3c_rtc_alarmno); 479 480 /* get the memory region */ 481 482 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 483 if (res == NULL) { 484 dev_err(&pdev->dev, "failed to get memory region resource\n"); 485 return -ENOENT; 486 } 487 488 s3c_rtc_mem = request_mem_region(res->start, 489 res->end-res->start+1, 490 pdev->name); 491 492 if (s3c_rtc_mem == NULL) { 493 dev_err(&pdev->dev, "failed to reserve memory region\n"); 494 ret = -ENOENT; 495 goto err_nores; 496 } 497 498 s3c_rtc_base = ioremap(res->start, res->end - res->start + 1); 499 if (s3c_rtc_base == NULL) { 500 dev_err(&pdev->dev, "failed ioremap()\n"); 501 ret = -EINVAL; 502 goto err_nomap; 503 } 504 505 /* check to see if everything is setup correctly */ 506 507 s3c_rtc_enable(pdev, 1); 508 509 pr_debug("s3c2410_rtc: RTCCON=%02x\n", 510 readb(s3c_rtc_base + S3C2410_RTCCON)); 511 512 s3c_rtc_setfreq(s3c_rtc_freq); 513 514 /* register RTC and exit */ 515 516 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops, 517 THIS_MODULE); 518 519 if (IS_ERR(rtc)) { 520 dev_err(&pdev->dev, "cannot attach rtc\n"); 521 ret = PTR_ERR(rtc); 522 goto err_nortc; 523 } 524 525 rtc->max_user_freq = 128; 526 527 platform_set_drvdata(pdev, rtc); 528 return 0; 529 530 err_nortc: 531 s3c_rtc_enable(pdev, 0); 532 iounmap(s3c_rtc_base); 533 534 err_nomap: 535 release_resource(s3c_rtc_mem); 536 537 err_nores: 538 return ret; 539 } 540 541 #ifdef CONFIG_PM 542 543 /* RTC Power management control */ 544 545 static struct timespec s3c_rtc_delta; 546 547 static int ticnt_save; 548 549 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) 550 { 551 /* save TICNT for anyone using periodic interrupts */ 552 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT); 553 s3c_rtc_enable(pdev, 0); 554 return 0; 555 } 556 557 static int s3c_rtc_resume(struct platform_device *pdev) 558 { 559 s3c_rtc_enable(pdev, 1); 560 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT); 561 return 0; 562 } 563 #else 564 #define s3c_rtc_suspend NULL 565 #define s3c_rtc_resume NULL 566 #endif 567 568 static struct platform_driver s3c2410_rtcdrv = { 569 .probe = s3c_rtc_probe, 570 .remove = s3c_rtc_remove, 571 .suspend = s3c_rtc_suspend, 572 .resume = s3c_rtc_resume, 573 .driver = { 574 .name = "s3c2410-rtc", 575 .owner = THIS_MODULE, 576 }, 577 }; 578 579 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n"; 580 581 static int __init s3c_rtc_init(void) 582 { 583 printk(banner); 584 return platform_driver_register(&s3c2410_rtcdrv); 585 } 586 587 static void __exit s3c_rtc_exit(void) 588 { 589 platform_driver_unregister(&s3c2410_rtcdrv); 590 } 591 592 module_init(s3c_rtc_init); 593 module_exit(s3c_rtc_exit); 594 595 MODULE_DESCRIPTION("Samsung S3C RTC Driver"); 596 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 597 MODULE_LICENSE("GPL"); 598