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 #include <linux/log2.h> 24 25 #include <asm/hardware.h> 26 #include <asm/uaccess.h> 27 #include <asm/io.h> 28 #include <asm/irq.h> 29 #include <asm/rtc.h> 30 31 #include <asm/mach/time.h> 32 33 #include <asm/plat-s3c/regs-rtc.h> 34 35 /* I have yet to find an S3C implementation with more than one 36 * of these rtc blocks in */ 37 38 static struct resource *s3c_rtc_mem; 39 40 static void __iomem *s3c_rtc_base; 41 static int s3c_rtc_alarmno = NO_IRQ; 42 static int s3c_rtc_tickno = NO_IRQ; 43 static int s3c_rtc_freq = 1; 44 45 static DEFINE_SPINLOCK(s3c_rtc_pie_lock); 46 static unsigned int tick_count; 47 48 /* IRQ Handlers */ 49 50 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) 51 { 52 struct rtc_device *rdev = id; 53 54 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF); 55 return IRQ_HANDLED; 56 } 57 58 static irqreturn_t s3c_rtc_tickirq(int irq, void *id) 59 { 60 struct rtc_device *rdev = id; 61 62 rtc_update_irq(rdev, tick_count++, RTC_PF | RTC_IRQF); 63 return IRQ_HANDLED; 64 } 65 66 /* Update control registers */ 67 static void s3c_rtc_setaie(int to) 68 { 69 unsigned int tmp; 70 71 pr_debug("%s: aie=%d\n", __func__, to); 72 73 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN; 74 75 if (to) 76 tmp |= S3C2410_RTCALM_ALMEN; 77 78 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM); 79 } 80 81 static void s3c_rtc_setpie(int to) 82 { 83 unsigned int tmp; 84 85 pr_debug("%s: pie=%d\n", __func__, to); 86 87 spin_lock_irq(&s3c_rtc_pie_lock); 88 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE; 89 90 if (to) 91 tmp |= S3C2410_TICNT_ENABLE; 92 93 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 94 spin_unlock_irq(&s3c_rtc_pie_lock); 95 } 96 97 static void s3c_rtc_setfreq(int freq) 98 { 99 unsigned int tmp; 100 101 spin_lock_irq(&s3c_rtc_pie_lock); 102 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE; 103 104 s3c_rtc_freq = freq; 105 106 tmp |= (128 / freq)-1; 107 108 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 109 spin_unlock_irq(&s3c_rtc_pie_lock); 110 } 111 112 /* Time read/write */ 113 114 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) 115 { 116 unsigned int have_retried = 0; 117 void __iomem *base = s3c_rtc_base; 118 119 retry_get_time: 120 rtc_tm->tm_min = readb(base + S3C2410_RTCMIN); 121 rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR); 122 rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE); 123 rtc_tm->tm_mon = readb(base + S3C2410_RTCMON); 124 rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR); 125 rtc_tm->tm_sec = readb(base + S3C2410_RTCSEC); 126 127 /* the only way to work out wether the system was mid-update 128 * when we read it is to check the second counter, and if it 129 * is zero, then we re-try the entire read 130 */ 131 132 if (rtc_tm->tm_sec == 0 && !have_retried) { 133 have_retried = 1; 134 goto retry_get_time; 135 } 136 137 pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n", 138 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday, 139 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec); 140 141 BCD_TO_BIN(rtc_tm->tm_sec); 142 BCD_TO_BIN(rtc_tm->tm_min); 143 BCD_TO_BIN(rtc_tm->tm_hour); 144 BCD_TO_BIN(rtc_tm->tm_mday); 145 BCD_TO_BIN(rtc_tm->tm_mon); 146 BCD_TO_BIN(rtc_tm->tm_year); 147 148 rtc_tm->tm_year += 100; 149 rtc_tm->tm_mon -= 1; 150 151 return 0; 152 } 153 154 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm) 155 { 156 void __iomem *base = s3c_rtc_base; 157 int year = tm->tm_year - 100; 158 159 pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n", 160 tm->tm_year, tm->tm_mon, tm->tm_mday, 161 tm->tm_hour, tm->tm_min, tm->tm_sec); 162 163 /* we get around y2k by simply not supporting it */ 164 165 if (year < 0 || year >= 100) { 166 dev_err(dev, "rtc only supports 100 years\n"); 167 return -EINVAL; 168 } 169 170 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_RTCSEC); 171 writeb(BIN2BCD(tm->tm_min), base + S3C2410_RTCMIN); 172 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_RTCHOUR); 173 writeb(BIN2BCD(tm->tm_mday), base + S3C2410_RTCDATE); 174 writeb(BIN2BCD(tm->tm_mon + 1), base + S3C2410_RTCMON); 175 writeb(BIN2BCD(year), base + S3C2410_RTCYEAR); 176 177 return 0; 178 } 179 180 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm) 181 { 182 struct rtc_time *alm_tm = &alrm->time; 183 void __iomem *base = s3c_rtc_base; 184 unsigned int alm_en; 185 186 alm_tm->tm_sec = readb(base + S3C2410_ALMSEC); 187 alm_tm->tm_min = readb(base + S3C2410_ALMMIN); 188 alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR); 189 alm_tm->tm_mon = readb(base + S3C2410_ALMMON); 190 alm_tm->tm_mday = readb(base + S3C2410_ALMDATE); 191 alm_tm->tm_year = readb(base + S3C2410_ALMYEAR); 192 193 alm_en = readb(base + S3C2410_RTCALM); 194 195 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0; 196 197 pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n", 198 alm_en, 199 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday, 200 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec); 201 202 203 /* decode the alarm enable field */ 204 205 if (alm_en & S3C2410_RTCALM_SECEN) 206 BCD_TO_BIN(alm_tm->tm_sec); 207 else 208 alm_tm->tm_sec = 0xff; 209 210 if (alm_en & S3C2410_RTCALM_MINEN) 211 BCD_TO_BIN(alm_tm->tm_min); 212 else 213 alm_tm->tm_min = 0xff; 214 215 if (alm_en & S3C2410_RTCALM_HOUREN) 216 BCD_TO_BIN(alm_tm->tm_hour); 217 else 218 alm_tm->tm_hour = 0xff; 219 220 if (alm_en & S3C2410_RTCALM_DAYEN) 221 BCD_TO_BIN(alm_tm->tm_mday); 222 else 223 alm_tm->tm_mday = 0xff; 224 225 if (alm_en & S3C2410_RTCALM_MONEN) { 226 BCD_TO_BIN(alm_tm->tm_mon); 227 alm_tm->tm_mon -= 1; 228 } else { 229 alm_tm->tm_mon = 0xff; 230 } 231 232 if (alm_en & S3C2410_RTCALM_YEAREN) 233 BCD_TO_BIN(alm_tm->tm_year); 234 else 235 alm_tm->tm_year = 0xffff; 236 237 return 0; 238 } 239 240 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 241 { 242 struct rtc_time *tm = &alrm->time; 243 void __iomem *base = s3c_rtc_base; 244 unsigned int alrm_en; 245 246 pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n", 247 alrm->enabled, 248 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff, 249 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec); 250 251 252 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN; 253 writeb(0x00, base + S3C2410_RTCALM); 254 255 if (tm->tm_sec < 60 && tm->tm_sec >= 0) { 256 alrm_en |= S3C2410_RTCALM_SECEN; 257 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC); 258 } 259 260 if (tm->tm_min < 60 && tm->tm_min >= 0) { 261 alrm_en |= S3C2410_RTCALM_MINEN; 262 writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN); 263 } 264 265 if (tm->tm_hour < 24 && tm->tm_hour >= 0) { 266 alrm_en |= S3C2410_RTCALM_HOUREN; 267 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR); 268 } 269 270 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en); 271 272 writeb(alrm_en, base + S3C2410_RTCALM); 273 274 if (0) { 275 alrm_en = readb(base + S3C2410_RTCALM); 276 alrm_en &= ~S3C2410_RTCALM_ALMEN; 277 writeb(alrm_en, base + S3C2410_RTCALM); 278 disable_irq_wake(s3c_rtc_alarmno); 279 } 280 281 if (alrm->enabled) 282 enable_irq_wake(s3c_rtc_alarmno); 283 else 284 disable_irq_wake(s3c_rtc_alarmno); 285 286 return 0; 287 } 288 289 static int s3c_rtc_ioctl(struct device *dev, 290 unsigned int cmd, unsigned long arg) 291 { 292 unsigned int ret = -ENOIOCTLCMD; 293 294 switch (cmd) { 295 case RTC_AIE_OFF: 296 case RTC_AIE_ON: 297 s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0); 298 ret = 0; 299 break; 300 301 case RTC_PIE_OFF: 302 case RTC_PIE_ON: 303 tick_count = 0; 304 s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0); 305 ret = 0; 306 break; 307 308 case RTC_IRQP_READ: 309 ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg); 310 break; 311 312 case RTC_IRQP_SET: 313 if (!is_power_of_2(arg)) { 314 ret = -EINVAL; 315 goto exit; 316 } 317 318 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg); 319 320 s3c_rtc_setfreq(arg); 321 ret = 0; 322 break; 323 324 case RTC_UIE_ON: 325 case RTC_UIE_OFF: 326 ret = -EINVAL; 327 } 328 329 exit: 330 return ret; 331 } 332 333 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) 334 { 335 unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT); 336 337 seq_printf(seq, "periodic_IRQ\t: %s\n", 338 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" ); 339 340 seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq); 341 342 return 0; 343 } 344 345 static int s3c_rtc_open(struct device *dev) 346 { 347 struct platform_device *pdev = to_platform_device(dev); 348 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 349 int ret; 350 351 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq, 352 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev); 353 354 if (ret) { 355 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret); 356 return ret; 357 } 358 359 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq, 360 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev); 361 362 if (ret) { 363 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret); 364 goto tick_err; 365 } 366 367 return ret; 368 369 tick_err: 370 free_irq(s3c_rtc_alarmno, rtc_dev); 371 return ret; 372 } 373 374 static void s3c_rtc_release(struct device *dev) 375 { 376 struct platform_device *pdev = to_platform_device(dev); 377 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 378 379 /* do not clear AIE here, it may be needed for wake */ 380 381 s3c_rtc_setpie(0); 382 free_irq(s3c_rtc_alarmno, rtc_dev); 383 free_irq(s3c_rtc_tickno, rtc_dev); 384 } 385 386 static const struct rtc_class_ops s3c_rtcops = { 387 .open = s3c_rtc_open, 388 .release = s3c_rtc_release, 389 .ioctl = s3c_rtc_ioctl, 390 .read_time = s3c_rtc_gettime, 391 .set_time = s3c_rtc_settime, 392 .read_alarm = s3c_rtc_getalarm, 393 .set_alarm = s3c_rtc_setalarm, 394 .proc = s3c_rtc_proc, 395 }; 396 397 static void s3c_rtc_enable(struct platform_device *pdev, int en) 398 { 399 void __iomem *base = s3c_rtc_base; 400 unsigned int tmp; 401 402 if (s3c_rtc_base == NULL) 403 return; 404 405 if (!en) { 406 tmp = readb(base + S3C2410_RTCCON); 407 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON); 408 409 tmp = readb(base + S3C2410_TICNT); 410 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT); 411 } else { 412 /* re-enable the device, and check it is ok */ 413 414 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){ 415 dev_info(&pdev->dev, "rtc disabled, re-enabling\n"); 416 417 tmp = readb(base + S3C2410_RTCCON); 418 writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON); 419 } 420 421 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){ 422 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n"); 423 424 tmp = readb(base + S3C2410_RTCCON); 425 writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON); 426 } 427 428 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){ 429 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n"); 430 431 tmp = readb(base + S3C2410_RTCCON); 432 writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON); 433 } 434 } 435 } 436 437 static int s3c_rtc_remove(struct platform_device *dev) 438 { 439 struct rtc_device *rtc = platform_get_drvdata(dev); 440 441 platform_set_drvdata(dev, NULL); 442 rtc_device_unregister(rtc); 443 444 s3c_rtc_setpie(0); 445 s3c_rtc_setaie(0); 446 447 iounmap(s3c_rtc_base); 448 release_resource(s3c_rtc_mem); 449 kfree(s3c_rtc_mem); 450 451 return 0; 452 } 453 454 static int s3c_rtc_probe(struct platform_device *pdev) 455 { 456 struct rtc_device *rtc; 457 struct resource *res; 458 int ret; 459 460 pr_debug("%s: probe=%p\n", __func__, pdev); 461 462 /* find the IRQs */ 463 464 s3c_rtc_tickno = platform_get_irq(pdev, 1); 465 if (s3c_rtc_tickno < 0) { 466 dev_err(&pdev->dev, "no irq for rtc tick\n"); 467 return -ENOENT; 468 } 469 470 s3c_rtc_alarmno = platform_get_irq(pdev, 0); 471 if (s3c_rtc_alarmno < 0) { 472 dev_err(&pdev->dev, "no irq for alarm\n"); 473 return -ENOENT; 474 } 475 476 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n", 477 s3c_rtc_tickno, s3c_rtc_alarmno); 478 479 /* get the memory region */ 480 481 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 482 if (res == NULL) { 483 dev_err(&pdev->dev, "failed to get memory region resource\n"); 484 return -ENOENT; 485 } 486 487 s3c_rtc_mem = request_mem_region(res->start, 488 res->end-res->start+1, 489 pdev->name); 490 491 if (s3c_rtc_mem == NULL) { 492 dev_err(&pdev->dev, "failed to reserve memory region\n"); 493 ret = -ENOENT; 494 goto err_nores; 495 } 496 497 s3c_rtc_base = ioremap(res->start, res->end - res->start + 1); 498 if (s3c_rtc_base == NULL) { 499 dev_err(&pdev->dev, "failed ioremap()\n"); 500 ret = -EINVAL; 501 goto err_nomap; 502 } 503 504 /* check to see if everything is setup correctly */ 505 506 s3c_rtc_enable(pdev, 1); 507 508 pr_debug("s3c2410_rtc: RTCCON=%02x\n", 509 readb(s3c_rtc_base + S3C2410_RTCCON)); 510 511 s3c_rtc_setfreq(s3c_rtc_freq); 512 513 /* register RTC and exit */ 514 515 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops, 516 THIS_MODULE); 517 518 if (IS_ERR(rtc)) { 519 dev_err(&pdev->dev, "cannot attach rtc\n"); 520 ret = PTR_ERR(rtc); 521 goto err_nortc; 522 } 523 524 rtc->max_user_freq = 128; 525 526 platform_set_drvdata(pdev, rtc); 527 return 0; 528 529 err_nortc: 530 s3c_rtc_enable(pdev, 0); 531 iounmap(s3c_rtc_base); 532 533 err_nomap: 534 release_resource(s3c_rtc_mem); 535 536 err_nores: 537 return ret; 538 } 539 540 #ifdef CONFIG_PM 541 542 /* RTC Power management control */ 543 544 static int ticnt_save; 545 546 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) 547 { 548 /* save TICNT for anyone using periodic interrupts */ 549 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT); 550 s3c_rtc_enable(pdev, 0); 551 return 0; 552 } 553 554 static int s3c_rtc_resume(struct platform_device *pdev) 555 { 556 s3c_rtc_enable(pdev, 1); 557 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT); 558 return 0; 559 } 560 #else 561 #define s3c_rtc_suspend NULL 562 #define s3c_rtc_resume NULL 563 #endif 564 565 static struct platform_driver s3c2410_rtcdrv = { 566 .probe = s3c_rtc_probe, 567 .remove = s3c_rtc_remove, 568 .suspend = s3c_rtc_suspend, 569 .resume = s3c_rtc_resume, 570 .driver = { 571 .name = "s3c2410-rtc", 572 .owner = THIS_MODULE, 573 }, 574 }; 575 576 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n"; 577 578 static int __init s3c_rtc_init(void) 579 { 580 printk(banner); 581 return platform_driver_register(&s3c2410_rtcdrv); 582 } 583 584 static void __exit s3c_rtc_exit(void) 585 { 586 platform_driver_unregister(&s3c2410_rtcdrv); 587 } 588 589 module_init(s3c_rtc_init); 590 module_exit(s3c_rtc_exit); 591 592 MODULE_DESCRIPTION("Samsung S3C RTC Driver"); 593 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 594 MODULE_LICENSE("GPL"); 595 MODULE_ALIAS("platform:s3c2410-rtc"); 596