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 <mach/hardware.h> 26 #include <asm/uaccess.h> 27 #include <asm/io.h> 28 #include <asm/irq.h> 29 #include <plat/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 40 static DEFINE_SPINLOCK(s3c_rtc_pie_lock); 41 42 /* IRQ Handlers */ 43 44 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) 45 { 46 struct rtc_device *rdev = id; 47 48 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF); 49 return IRQ_HANDLED; 50 } 51 52 static irqreturn_t s3c_rtc_tickirq(int irq, void *id) 53 { 54 struct rtc_device *rdev = id; 55 56 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF); 57 return IRQ_HANDLED; 58 } 59 60 /* Update control registers */ 61 static void s3c_rtc_setaie(int to) 62 { 63 unsigned int tmp; 64 65 pr_debug("%s: aie=%d\n", __func__, to); 66 67 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN; 68 69 if (to) 70 tmp |= S3C2410_RTCALM_ALMEN; 71 72 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM); 73 } 74 75 static int s3c_rtc_setpie(struct device *dev, int enabled) 76 { 77 unsigned int tmp; 78 79 pr_debug("%s: pie=%d\n", __func__, enabled); 80 81 spin_lock_irq(&s3c_rtc_pie_lock); 82 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE; 83 84 if (enabled) 85 tmp |= S3C2410_TICNT_ENABLE; 86 87 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 88 spin_unlock_irq(&s3c_rtc_pie_lock); 89 90 return 0; 91 } 92 93 static int s3c_rtc_setfreq(struct device *dev, int freq) 94 { 95 unsigned int tmp; 96 97 if (!is_power_of_2(freq)) 98 return -EINVAL; 99 100 spin_lock_irq(&s3c_rtc_pie_lock); 101 102 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE; 103 tmp |= (128 / freq)-1; 104 105 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 106 spin_unlock_irq(&s3c_rtc_pie_lock); 107 108 return 0; 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 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec); 141 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min); 142 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour); 143 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday); 144 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon); 145 rtc_tm->tm_year = bcd2bin(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 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec); 206 else 207 alm_tm->tm_sec = 0xff; 208 209 if (alm_en & S3C2410_RTCALM_MINEN) 210 alm_tm->tm_min = bcd2bin(alm_tm->tm_min); 211 else 212 alm_tm->tm_min = 0xff; 213 214 if (alm_en & S3C2410_RTCALM_HOUREN) 215 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour); 216 else 217 alm_tm->tm_hour = 0xff; 218 219 if (alm_en & S3C2410_RTCALM_DAYEN) 220 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday); 221 else 222 alm_tm->tm_mday = 0xff; 223 224 if (alm_en & S3C2410_RTCALM_MONEN) { 225 alm_tm->tm_mon = bcd2bin(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 alm_tm->tm_year = bcd2bin(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 s3c_rtc_setaie(alrm->enabled); 274 275 if (alrm->enabled) 276 enable_irq_wake(s3c_rtc_alarmno); 277 else 278 disable_irq_wake(s3c_rtc_alarmno); 279 280 return 0; 281 } 282 283 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) 284 { 285 unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT); 286 287 seq_printf(seq, "periodic_IRQ\t: %s\n", 288 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" ); 289 return 0; 290 } 291 292 static int s3c_rtc_open(struct device *dev) 293 { 294 struct platform_device *pdev = to_platform_device(dev); 295 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 296 int ret; 297 298 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq, 299 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev); 300 301 if (ret) { 302 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret); 303 return ret; 304 } 305 306 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq, 307 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev); 308 309 if (ret) { 310 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret); 311 goto tick_err; 312 } 313 314 return ret; 315 316 tick_err: 317 free_irq(s3c_rtc_alarmno, rtc_dev); 318 return ret; 319 } 320 321 static void s3c_rtc_release(struct device *dev) 322 { 323 struct platform_device *pdev = to_platform_device(dev); 324 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 325 326 /* do not clear AIE here, it may be needed for wake */ 327 328 s3c_rtc_setpie(dev, 0); 329 free_irq(s3c_rtc_alarmno, rtc_dev); 330 free_irq(s3c_rtc_tickno, rtc_dev); 331 } 332 333 static const struct rtc_class_ops s3c_rtcops = { 334 .open = s3c_rtc_open, 335 .release = s3c_rtc_release, 336 .read_time = s3c_rtc_gettime, 337 .set_time = s3c_rtc_settime, 338 .read_alarm = s3c_rtc_getalarm, 339 .set_alarm = s3c_rtc_setalarm, 340 .irq_set_freq = s3c_rtc_setfreq, 341 .irq_set_state = s3c_rtc_setpie, 342 .proc = s3c_rtc_proc, 343 }; 344 345 static void s3c_rtc_enable(struct platform_device *pdev, int en) 346 { 347 void __iomem *base = s3c_rtc_base; 348 unsigned int tmp; 349 350 if (s3c_rtc_base == NULL) 351 return; 352 353 if (!en) { 354 tmp = readb(base + S3C2410_RTCCON); 355 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON); 356 357 tmp = readb(base + S3C2410_TICNT); 358 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT); 359 } else { 360 /* re-enable the device, and check it is ok */ 361 362 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){ 363 dev_info(&pdev->dev, "rtc disabled, re-enabling\n"); 364 365 tmp = readb(base + S3C2410_RTCCON); 366 writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON); 367 } 368 369 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){ 370 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n"); 371 372 tmp = readb(base + S3C2410_RTCCON); 373 writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON); 374 } 375 376 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){ 377 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n"); 378 379 tmp = readb(base + S3C2410_RTCCON); 380 writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON); 381 } 382 } 383 } 384 385 static int __devexit s3c_rtc_remove(struct platform_device *dev) 386 { 387 struct rtc_device *rtc = platform_get_drvdata(dev); 388 389 platform_set_drvdata(dev, NULL); 390 rtc_device_unregister(rtc); 391 392 s3c_rtc_setpie(&dev->dev, 0); 393 s3c_rtc_setaie(0); 394 395 iounmap(s3c_rtc_base); 396 release_resource(s3c_rtc_mem); 397 kfree(s3c_rtc_mem); 398 399 return 0; 400 } 401 402 static int __devinit s3c_rtc_probe(struct platform_device *pdev) 403 { 404 struct rtc_device *rtc; 405 struct resource *res; 406 int ret; 407 408 pr_debug("%s: probe=%p\n", __func__, pdev); 409 410 /* find the IRQs */ 411 412 s3c_rtc_tickno = platform_get_irq(pdev, 1); 413 if (s3c_rtc_tickno < 0) { 414 dev_err(&pdev->dev, "no irq for rtc tick\n"); 415 return -ENOENT; 416 } 417 418 s3c_rtc_alarmno = platform_get_irq(pdev, 0); 419 if (s3c_rtc_alarmno < 0) { 420 dev_err(&pdev->dev, "no irq for alarm\n"); 421 return -ENOENT; 422 } 423 424 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n", 425 s3c_rtc_tickno, s3c_rtc_alarmno); 426 427 /* get the memory region */ 428 429 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 430 if (res == NULL) { 431 dev_err(&pdev->dev, "failed to get memory region resource\n"); 432 return -ENOENT; 433 } 434 435 s3c_rtc_mem = request_mem_region(res->start, 436 res->end-res->start+1, 437 pdev->name); 438 439 if (s3c_rtc_mem == NULL) { 440 dev_err(&pdev->dev, "failed to reserve memory region\n"); 441 ret = -ENOENT; 442 goto err_nores; 443 } 444 445 s3c_rtc_base = ioremap(res->start, res->end - res->start + 1); 446 if (s3c_rtc_base == NULL) { 447 dev_err(&pdev->dev, "failed ioremap()\n"); 448 ret = -EINVAL; 449 goto err_nomap; 450 } 451 452 /* check to see if everything is setup correctly */ 453 454 s3c_rtc_enable(pdev, 1); 455 456 pr_debug("s3c2410_rtc: RTCCON=%02x\n", 457 readb(s3c_rtc_base + S3C2410_RTCCON)); 458 459 s3c_rtc_setfreq(&pdev->dev, 1); 460 461 device_init_wakeup(&pdev->dev, 1); 462 463 /* register RTC and exit */ 464 465 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops, 466 THIS_MODULE); 467 468 if (IS_ERR(rtc)) { 469 dev_err(&pdev->dev, "cannot attach rtc\n"); 470 ret = PTR_ERR(rtc); 471 goto err_nortc; 472 } 473 474 rtc->max_user_freq = 128; 475 476 platform_set_drvdata(pdev, rtc); 477 return 0; 478 479 err_nortc: 480 s3c_rtc_enable(pdev, 0); 481 iounmap(s3c_rtc_base); 482 483 err_nomap: 484 release_resource(s3c_rtc_mem); 485 486 err_nores: 487 return ret; 488 } 489 490 #ifdef CONFIG_PM 491 492 /* RTC Power management control */ 493 494 static int ticnt_save; 495 496 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) 497 { 498 /* save TICNT for anyone using periodic interrupts */ 499 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT); 500 s3c_rtc_enable(pdev, 0); 501 return 0; 502 } 503 504 static int s3c_rtc_resume(struct platform_device *pdev) 505 { 506 s3c_rtc_enable(pdev, 1); 507 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT); 508 return 0; 509 } 510 #else 511 #define s3c_rtc_suspend NULL 512 #define s3c_rtc_resume NULL 513 #endif 514 515 static struct platform_driver s3c2410_rtc_driver = { 516 .probe = s3c_rtc_probe, 517 .remove = __devexit_p(s3c_rtc_remove), 518 .suspend = s3c_rtc_suspend, 519 .resume = s3c_rtc_resume, 520 .driver = { 521 .name = "s3c2410-rtc", 522 .owner = THIS_MODULE, 523 }, 524 }; 525 526 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n"; 527 528 static int __init s3c_rtc_init(void) 529 { 530 printk(banner); 531 return platform_driver_register(&s3c2410_rtc_driver); 532 } 533 534 static void __exit s3c_rtc_exit(void) 535 { 536 platform_driver_unregister(&s3c2410_rtc_driver); 537 } 538 539 module_init(s3c_rtc_init); 540 module_exit(s3c_rtc_exit); 541 542 MODULE_DESCRIPTION("Samsung S3C RTC Driver"); 543 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 544 MODULE_LICENSE("GPL"); 545 MODULE_ALIAS("platform:s3c2410-rtc"); 546