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