1 /* drivers/rtc/rtc-s3c.c 2 * 3 * Copyright (c) 2010 Samsung Electronics Co., Ltd. 4 * http://www.samsung.com/ 5 * 6 * Copyright (c) 2004,2006 Simtec Electronics 7 * Ben Dooks, <ben@simtec.co.uk> 8 * http://armlinux.simtec.co.uk/ 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 * 14 * S3C2410/S3C2440/S3C24XX Internal RTC Driver 15 */ 16 17 #include <linux/module.h> 18 #include <linux/fs.h> 19 #include <linux/string.h> 20 #include <linux/init.h> 21 #include <linux/platform_device.h> 22 #include <linux/interrupt.h> 23 #include <linux/rtc.h> 24 #include <linux/bcd.h> 25 #include <linux/clk.h> 26 #include <linux/log2.h> 27 #include <linux/slab.h> 28 29 #include <mach/hardware.h> 30 #include <asm/uaccess.h> 31 #include <asm/io.h> 32 #include <asm/irq.h> 33 #include <plat/regs-rtc.h> 34 35 enum s3c_cpu_type { 36 TYPE_S3C2410, 37 TYPE_S3C64XX, 38 }; 39 40 /* I have yet to find an S3C implementation with more than one 41 * of these rtc blocks in */ 42 43 static struct resource *s3c_rtc_mem; 44 45 static struct clk *rtc_clk; 46 static void __iomem *s3c_rtc_base; 47 static int s3c_rtc_alarmno = NO_IRQ; 48 static int s3c_rtc_tickno = NO_IRQ; 49 static bool wake_en; 50 static enum s3c_cpu_type s3c_rtc_cpu_type; 51 52 static DEFINE_SPINLOCK(s3c_rtc_pie_lock); 53 54 /* IRQ Handlers */ 55 56 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) 57 { 58 struct rtc_device *rdev = id; 59 60 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF); 61 62 if (s3c_rtc_cpu_type == TYPE_S3C64XX) 63 writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP); 64 65 return IRQ_HANDLED; 66 } 67 68 static irqreturn_t s3c_rtc_tickirq(int irq, void *id) 69 { 70 struct rtc_device *rdev = id; 71 72 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF); 73 74 if (s3c_rtc_cpu_type == TYPE_S3C64XX) 75 writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP); 76 77 return IRQ_HANDLED; 78 } 79 80 /* Update control registers */ 81 static int s3c_rtc_setaie(struct device *dev, unsigned int enabled) 82 { 83 unsigned int tmp; 84 85 pr_debug("%s: aie=%d\n", __func__, enabled); 86 87 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN; 88 89 if (enabled) 90 tmp |= S3C2410_RTCALM_ALMEN; 91 92 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM); 93 94 return 0; 95 } 96 97 static int s3c_rtc_setfreq(struct device *dev, int freq) 98 { 99 struct platform_device *pdev = to_platform_device(dev); 100 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 101 unsigned int tmp = 0; 102 103 if (!is_power_of_2(freq)) 104 return -EINVAL; 105 106 spin_lock_irq(&s3c_rtc_pie_lock); 107 108 if (s3c_rtc_cpu_type == TYPE_S3C2410) { 109 tmp = readb(s3c_rtc_base + S3C2410_TICNT); 110 tmp &= S3C2410_TICNT_ENABLE; 111 } 112 113 tmp |= (rtc_dev->max_user_freq / freq)-1; 114 115 writel(tmp, s3c_rtc_base + S3C2410_TICNT); 116 spin_unlock_irq(&s3c_rtc_pie_lock); 117 118 return 0; 119 } 120 121 /* Time read/write */ 122 123 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) 124 { 125 unsigned int have_retried = 0; 126 void __iomem *base = s3c_rtc_base; 127 128 retry_get_time: 129 rtc_tm->tm_min = readb(base + S3C2410_RTCMIN); 130 rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR); 131 rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE); 132 rtc_tm->tm_mon = readb(base + S3C2410_RTCMON); 133 rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR); 134 rtc_tm->tm_sec = readb(base + S3C2410_RTCSEC); 135 136 /* the only way to work out wether the system was mid-update 137 * when we read it is to check the second counter, and if it 138 * is zero, then we re-try the entire read 139 */ 140 141 if (rtc_tm->tm_sec == 0 && !have_retried) { 142 have_retried = 1; 143 goto retry_get_time; 144 } 145 146 pr_debug("read time %04d.%02d.%02d %02d:%02d:%02d\n", 147 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday, 148 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec); 149 150 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec); 151 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min); 152 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour); 153 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday); 154 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon); 155 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year); 156 157 rtc_tm->tm_year += 100; 158 rtc_tm->tm_mon -= 1; 159 160 return rtc_valid_tm(rtc_tm); 161 } 162 163 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm) 164 { 165 void __iomem *base = s3c_rtc_base; 166 int year = tm->tm_year - 100; 167 168 pr_debug("set time %04d.%02d.%02d %02d:%02d:%02d\n", 169 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 170 tm->tm_hour, tm->tm_min, tm->tm_sec); 171 172 /* we get around y2k by simply not supporting it */ 173 174 if (year < 0 || year >= 100) { 175 dev_err(dev, "rtc only supports 100 years\n"); 176 return -EINVAL; 177 } 178 179 writeb(bin2bcd(tm->tm_sec), base + S3C2410_RTCSEC); 180 writeb(bin2bcd(tm->tm_min), base + S3C2410_RTCMIN); 181 writeb(bin2bcd(tm->tm_hour), base + S3C2410_RTCHOUR); 182 writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE); 183 writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON); 184 writeb(bin2bcd(year), base + S3C2410_RTCYEAR); 185 186 return 0; 187 } 188 189 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm) 190 { 191 struct rtc_time *alm_tm = &alrm->time; 192 void __iomem *base = s3c_rtc_base; 193 unsigned int alm_en; 194 195 alm_tm->tm_sec = readb(base + S3C2410_ALMSEC); 196 alm_tm->tm_min = readb(base + S3C2410_ALMMIN); 197 alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR); 198 alm_tm->tm_mon = readb(base + S3C2410_ALMMON); 199 alm_tm->tm_mday = readb(base + S3C2410_ALMDATE); 200 alm_tm->tm_year = readb(base + S3C2410_ALMYEAR); 201 202 alm_en = readb(base + S3C2410_RTCALM); 203 204 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0; 205 206 pr_debug("read alarm %d, %04d.%02d.%02d %02d:%02d:%02d\n", 207 alm_en, 208 1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday, 209 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec); 210 211 212 /* decode the alarm enable field */ 213 214 if (alm_en & S3C2410_RTCALM_SECEN) 215 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec); 216 else 217 alm_tm->tm_sec = -1; 218 219 if (alm_en & S3C2410_RTCALM_MINEN) 220 alm_tm->tm_min = bcd2bin(alm_tm->tm_min); 221 else 222 alm_tm->tm_min = -1; 223 224 if (alm_en & S3C2410_RTCALM_HOUREN) 225 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour); 226 else 227 alm_tm->tm_hour = -1; 228 229 if (alm_en & S3C2410_RTCALM_DAYEN) 230 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday); 231 else 232 alm_tm->tm_mday = -1; 233 234 if (alm_en & S3C2410_RTCALM_MONEN) { 235 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon); 236 alm_tm->tm_mon -= 1; 237 } else { 238 alm_tm->tm_mon = -1; 239 } 240 241 if (alm_en & S3C2410_RTCALM_YEAREN) 242 alm_tm->tm_year = bcd2bin(alm_tm->tm_year); 243 else 244 alm_tm->tm_year = -1; 245 246 return 0; 247 } 248 249 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 250 { 251 struct rtc_time *tm = &alrm->time; 252 void __iomem *base = s3c_rtc_base; 253 unsigned int alrm_en; 254 255 pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n", 256 alrm->enabled, 257 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 258 tm->tm_hour, tm->tm_min, tm->tm_sec); 259 260 261 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN; 262 writeb(0x00, base + S3C2410_RTCALM); 263 264 if (tm->tm_sec < 60 && tm->tm_sec >= 0) { 265 alrm_en |= S3C2410_RTCALM_SECEN; 266 writeb(bin2bcd(tm->tm_sec), base + S3C2410_ALMSEC); 267 } 268 269 if (tm->tm_min < 60 && tm->tm_min >= 0) { 270 alrm_en |= S3C2410_RTCALM_MINEN; 271 writeb(bin2bcd(tm->tm_min), base + S3C2410_ALMMIN); 272 } 273 274 if (tm->tm_hour < 24 && tm->tm_hour >= 0) { 275 alrm_en |= S3C2410_RTCALM_HOUREN; 276 writeb(bin2bcd(tm->tm_hour), base + S3C2410_ALMHOUR); 277 } 278 279 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en); 280 281 writeb(alrm_en, base + S3C2410_RTCALM); 282 283 s3c_rtc_setaie(dev, alrm->enabled); 284 285 return 0; 286 } 287 288 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) 289 { 290 unsigned int ticnt; 291 292 if (s3c_rtc_cpu_type == TYPE_S3C64XX) { 293 ticnt = readw(s3c_rtc_base + S3C2410_RTCCON); 294 ticnt &= S3C64XX_RTCCON_TICEN; 295 } else { 296 ticnt = readb(s3c_rtc_base + S3C2410_TICNT); 297 ticnt &= S3C2410_TICNT_ENABLE; 298 } 299 300 seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt ? "yes" : "no"); 301 return 0; 302 } 303 304 static int s3c_rtc_open(struct device *dev) 305 { 306 struct platform_device *pdev = to_platform_device(dev); 307 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 308 int ret; 309 310 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq, 311 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev); 312 313 if (ret) { 314 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret); 315 return ret; 316 } 317 318 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq, 319 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev); 320 321 if (ret) { 322 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret); 323 goto tick_err; 324 } 325 326 return ret; 327 328 tick_err: 329 free_irq(s3c_rtc_alarmno, rtc_dev); 330 return ret; 331 } 332 333 static void s3c_rtc_release(struct device *dev) 334 { 335 struct platform_device *pdev = to_platform_device(dev); 336 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 337 338 /* do not clear AIE here, it may be needed for wake */ 339 340 free_irq(s3c_rtc_alarmno, rtc_dev); 341 free_irq(s3c_rtc_tickno, rtc_dev); 342 } 343 344 static const struct rtc_class_ops s3c_rtcops = { 345 .open = s3c_rtc_open, 346 .release = s3c_rtc_release, 347 .read_time = s3c_rtc_gettime, 348 .set_time = s3c_rtc_settime, 349 .read_alarm = s3c_rtc_getalarm, 350 .set_alarm = s3c_rtc_setalarm, 351 .proc = s3c_rtc_proc, 352 .alarm_irq_enable = s3c_rtc_setaie, 353 }; 354 355 static void s3c_rtc_enable(struct platform_device *pdev, int en) 356 { 357 void __iomem *base = s3c_rtc_base; 358 unsigned int tmp; 359 360 if (s3c_rtc_base == NULL) 361 return; 362 363 if (!en) { 364 tmp = readw(base + S3C2410_RTCCON); 365 if (s3c_rtc_cpu_type == TYPE_S3C64XX) 366 tmp &= ~S3C64XX_RTCCON_TICEN; 367 tmp &= ~S3C2410_RTCCON_RTCEN; 368 writew(tmp, base + S3C2410_RTCCON); 369 370 if (s3c_rtc_cpu_type == TYPE_S3C2410) { 371 tmp = readb(base + S3C2410_TICNT); 372 tmp &= ~S3C2410_TICNT_ENABLE; 373 writeb(tmp, base + S3C2410_TICNT); 374 } 375 } else { 376 /* re-enable the device, and check it is ok */ 377 378 if ((readw(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) { 379 dev_info(&pdev->dev, "rtc disabled, re-enabling\n"); 380 381 tmp = readw(base + S3C2410_RTCCON); 382 writew(tmp | S3C2410_RTCCON_RTCEN, 383 base + S3C2410_RTCCON); 384 } 385 386 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) { 387 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n"); 388 389 tmp = readw(base + S3C2410_RTCCON); 390 writew(tmp & ~S3C2410_RTCCON_CNTSEL, 391 base + S3C2410_RTCCON); 392 } 393 394 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) { 395 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n"); 396 397 tmp = readw(base + S3C2410_RTCCON); 398 writew(tmp & ~S3C2410_RTCCON_CLKRST, 399 base + S3C2410_RTCCON); 400 } 401 } 402 } 403 404 static int __devexit s3c_rtc_remove(struct platform_device *dev) 405 { 406 struct rtc_device *rtc = platform_get_drvdata(dev); 407 408 platform_set_drvdata(dev, NULL); 409 rtc_device_unregister(rtc); 410 411 s3c_rtc_setaie(&dev->dev, 0); 412 413 clk_disable(rtc_clk); 414 clk_put(rtc_clk); 415 rtc_clk = NULL; 416 417 iounmap(s3c_rtc_base); 418 release_resource(s3c_rtc_mem); 419 kfree(s3c_rtc_mem); 420 421 return 0; 422 } 423 424 static int __devinit s3c_rtc_probe(struct platform_device *pdev) 425 { 426 struct rtc_device *rtc; 427 struct rtc_time rtc_tm; 428 struct resource *res; 429 int ret; 430 431 pr_debug("%s: probe=%p\n", __func__, pdev); 432 433 /* find the IRQs */ 434 435 s3c_rtc_tickno = platform_get_irq(pdev, 1); 436 if (s3c_rtc_tickno < 0) { 437 dev_err(&pdev->dev, "no irq for rtc tick\n"); 438 return -ENOENT; 439 } 440 441 s3c_rtc_alarmno = platform_get_irq(pdev, 0); 442 if (s3c_rtc_alarmno < 0) { 443 dev_err(&pdev->dev, "no irq for alarm\n"); 444 return -ENOENT; 445 } 446 447 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n", 448 s3c_rtc_tickno, s3c_rtc_alarmno); 449 450 /* get the memory region */ 451 452 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 453 if (res == NULL) { 454 dev_err(&pdev->dev, "failed to get memory region resource\n"); 455 return -ENOENT; 456 } 457 458 s3c_rtc_mem = request_mem_region(res->start, 459 res->end-res->start+1, 460 pdev->name); 461 462 if (s3c_rtc_mem == NULL) { 463 dev_err(&pdev->dev, "failed to reserve memory region\n"); 464 ret = -ENOENT; 465 goto err_nores; 466 } 467 468 s3c_rtc_base = ioremap(res->start, res->end - res->start + 1); 469 if (s3c_rtc_base == NULL) { 470 dev_err(&pdev->dev, "failed ioremap()\n"); 471 ret = -EINVAL; 472 goto err_nomap; 473 } 474 475 rtc_clk = clk_get(&pdev->dev, "rtc"); 476 if (IS_ERR(rtc_clk)) { 477 dev_err(&pdev->dev, "failed to find rtc clock source\n"); 478 ret = PTR_ERR(rtc_clk); 479 rtc_clk = NULL; 480 goto err_clk; 481 } 482 483 clk_enable(rtc_clk); 484 485 /* check to see if everything is setup correctly */ 486 487 s3c_rtc_enable(pdev, 1); 488 489 pr_debug("s3c2410_rtc: RTCCON=%02x\n", 490 readw(s3c_rtc_base + S3C2410_RTCCON)); 491 492 device_init_wakeup(&pdev->dev, 1); 493 494 /* register RTC and exit */ 495 496 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops, 497 THIS_MODULE); 498 499 if (IS_ERR(rtc)) { 500 dev_err(&pdev->dev, "cannot attach rtc\n"); 501 ret = PTR_ERR(rtc); 502 goto err_nortc; 503 } 504 505 s3c_rtc_cpu_type = platform_get_device_id(pdev)->driver_data; 506 507 /* Check RTC Time */ 508 509 s3c_rtc_gettime(NULL, &rtc_tm); 510 511 if (rtc_valid_tm(&rtc_tm)) { 512 rtc_tm.tm_year = 100; 513 rtc_tm.tm_mon = 0; 514 rtc_tm.tm_mday = 1; 515 rtc_tm.tm_hour = 0; 516 rtc_tm.tm_min = 0; 517 rtc_tm.tm_sec = 0; 518 519 s3c_rtc_settime(NULL, &rtc_tm); 520 521 dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n"); 522 } 523 524 if (s3c_rtc_cpu_type == TYPE_S3C64XX) 525 rtc->max_user_freq = 32768; 526 else 527 rtc->max_user_freq = 128; 528 529 platform_set_drvdata(pdev, rtc); 530 531 s3c_rtc_setfreq(&pdev->dev, 1); 532 533 return 0; 534 535 err_nortc: 536 s3c_rtc_enable(pdev, 0); 537 clk_disable(rtc_clk); 538 clk_put(rtc_clk); 539 540 err_clk: 541 iounmap(s3c_rtc_base); 542 543 err_nomap: 544 release_resource(s3c_rtc_mem); 545 546 err_nores: 547 return ret; 548 } 549 550 #ifdef CONFIG_PM 551 552 /* RTC Power management control */ 553 554 static int ticnt_save, ticnt_en_save; 555 556 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) 557 { 558 /* save TICNT for anyone using periodic interrupts */ 559 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT); 560 if (s3c_rtc_cpu_type == TYPE_S3C64XX) { 561 ticnt_en_save = readw(s3c_rtc_base + S3C2410_RTCCON); 562 ticnt_en_save &= S3C64XX_RTCCON_TICEN; 563 } 564 s3c_rtc_enable(pdev, 0); 565 566 if (device_may_wakeup(&pdev->dev) && !wake_en) { 567 if (enable_irq_wake(s3c_rtc_alarmno) == 0) 568 wake_en = true; 569 else 570 dev_err(&pdev->dev, "enable_irq_wake failed\n"); 571 } 572 573 return 0; 574 } 575 576 static int s3c_rtc_resume(struct platform_device *pdev) 577 { 578 unsigned int tmp; 579 580 s3c_rtc_enable(pdev, 1); 581 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT); 582 if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) { 583 tmp = readw(s3c_rtc_base + S3C2410_RTCCON); 584 writew(tmp | ticnt_en_save, s3c_rtc_base + S3C2410_RTCCON); 585 } 586 587 if (device_may_wakeup(&pdev->dev) && wake_en) { 588 disable_irq_wake(s3c_rtc_alarmno); 589 wake_en = false; 590 } 591 592 return 0; 593 } 594 #else 595 #define s3c_rtc_suspend NULL 596 #define s3c_rtc_resume NULL 597 #endif 598 599 static struct platform_device_id s3c_rtc_driver_ids[] = { 600 { 601 .name = "s3c2410-rtc", 602 .driver_data = TYPE_S3C2410, 603 }, { 604 .name = "s3c64xx-rtc", 605 .driver_data = TYPE_S3C64XX, 606 }, 607 { } 608 }; 609 610 MODULE_DEVICE_TABLE(platform, s3c_rtc_driver_ids); 611 612 static struct platform_driver s3c_rtc_driver = { 613 .probe = s3c_rtc_probe, 614 .remove = __devexit_p(s3c_rtc_remove), 615 .suspend = s3c_rtc_suspend, 616 .resume = s3c_rtc_resume, 617 .id_table = s3c_rtc_driver_ids, 618 .driver = { 619 .name = "s3c-rtc", 620 .owner = THIS_MODULE, 621 }, 622 }; 623 624 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n"; 625 626 static int __init s3c_rtc_init(void) 627 { 628 printk(banner); 629 return platform_driver_register(&s3c_rtc_driver); 630 } 631 632 static void __exit s3c_rtc_exit(void) 633 { 634 platform_driver_unregister(&s3c_rtc_driver); 635 } 636 637 module_init(s3c_rtc_init); 638 module_exit(s3c_rtc_exit); 639 640 MODULE_DESCRIPTION("Samsung S3C RTC Driver"); 641 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 642 MODULE_LICENSE("GPL"); 643 MODULE_ALIAS("platform:s3c2410-rtc"); 644