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 #include <linux/slab.h> 25 26 #include <mach/hardware.h> 27 #include <asm/uaccess.h> 28 #include <asm/io.h> 29 #include <asm/irq.h> 30 #include <plat/regs-rtc.h> 31 32 /* I have yet to find an S3C implementation with more than one 33 * of these rtc blocks in */ 34 35 static struct resource *s3c_rtc_mem; 36 37 static void __iomem *s3c_rtc_base; 38 static int s3c_rtc_alarmno = NO_IRQ; 39 static int s3c_rtc_tickno = NO_IRQ; 40 41 static DEFINE_SPINLOCK(s3c_rtc_pie_lock); 42 43 /* IRQ Handlers */ 44 45 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) 46 { 47 struct rtc_device *rdev = id; 48 49 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF); 50 return IRQ_HANDLED; 51 } 52 53 static irqreturn_t s3c_rtc_tickirq(int irq, void *id) 54 { 55 struct rtc_device *rdev = id; 56 57 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF); 58 return IRQ_HANDLED; 59 } 60 61 /* Update control registers */ 62 static void s3c_rtc_setaie(int to) 63 { 64 unsigned int tmp; 65 66 pr_debug("%s: aie=%d\n", __func__, to); 67 68 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN; 69 70 if (to) 71 tmp |= S3C2410_RTCALM_ALMEN; 72 73 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM); 74 } 75 76 static int s3c_rtc_setpie(struct device *dev, int enabled) 77 { 78 unsigned int tmp; 79 80 pr_debug("%s: pie=%d\n", __func__, enabled); 81 82 spin_lock_irq(&s3c_rtc_pie_lock); 83 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE; 84 85 if (enabled) 86 tmp |= S3C2410_TICNT_ENABLE; 87 88 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 89 spin_unlock_irq(&s3c_rtc_pie_lock); 90 91 return 0; 92 } 93 94 static int s3c_rtc_setfreq(struct device *dev, int freq) 95 { 96 unsigned int tmp; 97 98 if (!is_power_of_2(freq)) 99 return -EINVAL; 100 101 spin_lock_irq(&s3c_rtc_pie_lock); 102 103 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE; 104 tmp |= (128 / freq)-1; 105 106 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 107 spin_unlock_irq(&s3c_rtc_pie_lock); 108 109 return 0; 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 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec); 142 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min); 143 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour); 144 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday); 145 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon); 146 rtc_tm->tm_year = bcd2bin(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 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec); 207 else 208 alm_tm->tm_sec = 0xff; 209 210 if (alm_en & S3C2410_RTCALM_MINEN) 211 alm_tm->tm_min = bcd2bin(alm_tm->tm_min); 212 else 213 alm_tm->tm_min = 0xff; 214 215 if (alm_en & S3C2410_RTCALM_HOUREN) 216 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour); 217 else 218 alm_tm->tm_hour = 0xff; 219 220 if (alm_en & S3C2410_RTCALM_DAYEN) 221 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday); 222 else 223 alm_tm->tm_mday = 0xff; 224 225 if (alm_en & S3C2410_RTCALM_MONEN) { 226 alm_tm->tm_mon = bcd2bin(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 alm_tm->tm_year = bcd2bin(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 s3c_rtc_setaie(alrm->enabled); 275 276 if (alrm->enabled) 277 enable_irq_wake(s3c_rtc_alarmno); 278 else 279 disable_irq_wake(s3c_rtc_alarmno); 280 281 return 0; 282 } 283 284 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) 285 { 286 unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT); 287 288 seq_printf(seq, "periodic_IRQ\t: %s\n", 289 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" ); 290 return 0; 291 } 292 293 static int s3c_rtc_open(struct device *dev) 294 { 295 struct platform_device *pdev = to_platform_device(dev); 296 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 297 int ret; 298 299 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq, 300 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev); 301 302 if (ret) { 303 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret); 304 return ret; 305 } 306 307 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq, 308 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev); 309 310 if (ret) { 311 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret); 312 goto tick_err; 313 } 314 315 return ret; 316 317 tick_err: 318 free_irq(s3c_rtc_alarmno, rtc_dev); 319 return ret; 320 } 321 322 static void s3c_rtc_release(struct device *dev) 323 { 324 struct platform_device *pdev = to_platform_device(dev); 325 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 326 327 /* do not clear AIE here, it may be needed for wake */ 328 329 s3c_rtc_setpie(dev, 0); 330 free_irq(s3c_rtc_alarmno, rtc_dev); 331 free_irq(s3c_rtc_tickno, rtc_dev); 332 } 333 334 static const struct rtc_class_ops s3c_rtcops = { 335 .open = s3c_rtc_open, 336 .release = s3c_rtc_release, 337 .read_time = s3c_rtc_gettime, 338 .set_time = s3c_rtc_settime, 339 .read_alarm = s3c_rtc_getalarm, 340 .set_alarm = s3c_rtc_setalarm, 341 .irq_set_freq = s3c_rtc_setfreq, 342 .irq_set_state = s3c_rtc_setpie, 343 .proc = s3c_rtc_proc, 344 }; 345 346 static void s3c_rtc_enable(struct platform_device *pdev, int en) 347 { 348 void __iomem *base = s3c_rtc_base; 349 unsigned int tmp; 350 351 if (s3c_rtc_base == NULL) 352 return; 353 354 if (!en) { 355 tmp = readb(base + S3C2410_RTCCON); 356 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON); 357 358 tmp = readb(base + S3C2410_TICNT); 359 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT); 360 } else { 361 /* re-enable the device, and check it is ok */ 362 363 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){ 364 dev_info(&pdev->dev, "rtc disabled, re-enabling\n"); 365 366 tmp = readb(base + S3C2410_RTCCON); 367 writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON); 368 } 369 370 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){ 371 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n"); 372 373 tmp = readb(base + S3C2410_RTCCON); 374 writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON); 375 } 376 377 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){ 378 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n"); 379 380 tmp = readb(base + S3C2410_RTCCON); 381 writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON); 382 } 383 } 384 } 385 386 static int __devexit s3c_rtc_remove(struct platform_device *dev) 387 { 388 struct rtc_device *rtc = platform_get_drvdata(dev); 389 390 platform_set_drvdata(dev, NULL); 391 rtc_device_unregister(rtc); 392 393 s3c_rtc_setpie(&dev->dev, 0); 394 s3c_rtc_setaie(0); 395 396 iounmap(s3c_rtc_base); 397 release_resource(s3c_rtc_mem); 398 kfree(s3c_rtc_mem); 399 400 return 0; 401 } 402 403 static int __devinit s3c_rtc_probe(struct platform_device *pdev) 404 { 405 struct rtc_device *rtc; 406 struct resource *res; 407 int ret; 408 409 pr_debug("%s: probe=%p\n", __func__, pdev); 410 411 /* find the IRQs */ 412 413 s3c_rtc_tickno = platform_get_irq(pdev, 1); 414 if (s3c_rtc_tickno < 0) { 415 dev_err(&pdev->dev, "no irq for rtc tick\n"); 416 return -ENOENT; 417 } 418 419 s3c_rtc_alarmno = platform_get_irq(pdev, 0); 420 if (s3c_rtc_alarmno < 0) { 421 dev_err(&pdev->dev, "no irq for alarm\n"); 422 return -ENOENT; 423 } 424 425 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n", 426 s3c_rtc_tickno, s3c_rtc_alarmno); 427 428 /* get the memory region */ 429 430 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 431 if (res == NULL) { 432 dev_err(&pdev->dev, "failed to get memory region resource\n"); 433 return -ENOENT; 434 } 435 436 s3c_rtc_mem = request_mem_region(res->start, 437 res->end-res->start+1, 438 pdev->name); 439 440 if (s3c_rtc_mem == NULL) { 441 dev_err(&pdev->dev, "failed to reserve memory region\n"); 442 ret = -ENOENT; 443 goto err_nores; 444 } 445 446 s3c_rtc_base = ioremap(res->start, res->end - res->start + 1); 447 if (s3c_rtc_base == NULL) { 448 dev_err(&pdev->dev, "failed ioremap()\n"); 449 ret = -EINVAL; 450 goto err_nomap; 451 } 452 453 /* check to see if everything is setup correctly */ 454 455 s3c_rtc_enable(pdev, 1); 456 457 pr_debug("s3c2410_rtc: RTCCON=%02x\n", 458 readb(s3c_rtc_base + S3C2410_RTCCON)); 459 460 s3c_rtc_setfreq(&pdev->dev, 1); 461 462 device_init_wakeup(&pdev->dev, 1); 463 464 /* register RTC and exit */ 465 466 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops, 467 THIS_MODULE); 468 469 if (IS_ERR(rtc)) { 470 dev_err(&pdev->dev, "cannot attach rtc\n"); 471 ret = PTR_ERR(rtc); 472 goto err_nortc; 473 } 474 475 rtc->max_user_freq = 128; 476 477 platform_set_drvdata(pdev, rtc); 478 return 0; 479 480 err_nortc: 481 s3c_rtc_enable(pdev, 0); 482 iounmap(s3c_rtc_base); 483 484 err_nomap: 485 release_resource(s3c_rtc_mem); 486 487 err_nores: 488 return ret; 489 } 490 491 #ifdef CONFIG_PM 492 493 /* RTC Power management control */ 494 495 static int ticnt_save; 496 497 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) 498 { 499 /* save TICNT for anyone using periodic interrupts */ 500 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT); 501 s3c_rtc_enable(pdev, 0); 502 return 0; 503 } 504 505 static int s3c_rtc_resume(struct platform_device *pdev) 506 { 507 s3c_rtc_enable(pdev, 1); 508 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT); 509 return 0; 510 } 511 #else 512 #define s3c_rtc_suspend NULL 513 #define s3c_rtc_resume NULL 514 #endif 515 516 static struct platform_driver s3c2410_rtc_driver = { 517 .probe = s3c_rtc_probe, 518 .remove = __devexit_p(s3c_rtc_remove), 519 .suspend = s3c_rtc_suspend, 520 .resume = s3c_rtc_resume, 521 .driver = { 522 .name = "s3c2410-rtc", 523 .owner = THIS_MODULE, 524 }, 525 }; 526 527 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n"; 528 529 static int __init s3c_rtc_init(void) 530 { 531 printk(banner); 532 return platform_driver_register(&s3c2410_rtc_driver); 533 } 534 535 static void __exit s3c_rtc_exit(void) 536 { 537 platform_driver_unregister(&s3c2410_rtc_driver); 538 } 539 540 module_init(s3c_rtc_init); 541 module_exit(s3c_rtc_exit); 542 543 MODULE_DESCRIPTION("Samsung S3C RTC Driver"); 544 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 545 MODULE_LICENSE("GPL"); 546 MODULE_ALIAS("platform:s3c2410-rtc"); 547