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 <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 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 spin_lock_irq(&s3c_rtc_pie_lock); 98 99 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE; 100 tmp |= (128 / freq)-1; 101 102 writeb(tmp, s3c_rtc_base + S3C2410_TICNT); 103 spin_unlock_irq(&s3c_rtc_pie_lock); 104 105 return 0; 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 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec); 138 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min); 139 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour); 140 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday); 141 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon); 142 rtc_tm->tm_year = bcd2bin(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 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec); 203 else 204 alm_tm->tm_sec = 0xff; 205 206 if (alm_en & S3C2410_RTCALM_MINEN) 207 alm_tm->tm_min = bcd2bin(alm_tm->tm_min); 208 else 209 alm_tm->tm_min = 0xff; 210 211 if (alm_en & S3C2410_RTCALM_HOUREN) 212 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour); 213 else 214 alm_tm->tm_hour = 0xff; 215 216 if (alm_en & S3C2410_RTCALM_DAYEN) 217 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday); 218 else 219 alm_tm->tm_mday = 0xff; 220 221 if (alm_en & S3C2410_RTCALM_MONEN) { 222 alm_tm->tm_mon = bcd2bin(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 alm_tm->tm_year = bcd2bin(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 s3c_rtc_setaie(alrm->enabled); 271 272 if (alrm->enabled) 273 enable_irq_wake(s3c_rtc_alarmno); 274 else 275 disable_irq_wake(s3c_rtc_alarmno); 276 277 return 0; 278 } 279 280 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) 281 { 282 unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT); 283 284 seq_printf(seq, "periodic_IRQ\t: %s\n", 285 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" ); 286 return 0; 287 } 288 289 static int s3c_rtc_open(struct device *dev) 290 { 291 struct platform_device *pdev = to_platform_device(dev); 292 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 293 int ret; 294 295 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq, 296 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev); 297 298 if (ret) { 299 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret); 300 return ret; 301 } 302 303 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq, 304 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev); 305 306 if (ret) { 307 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret); 308 goto tick_err; 309 } 310 311 return ret; 312 313 tick_err: 314 free_irq(s3c_rtc_alarmno, rtc_dev); 315 return ret; 316 } 317 318 static void s3c_rtc_release(struct device *dev) 319 { 320 struct platform_device *pdev = to_platform_device(dev); 321 struct rtc_device *rtc_dev = platform_get_drvdata(pdev); 322 323 /* do not clear AIE here, it may be needed for wake */ 324 325 s3c_rtc_setpie(dev, 0); 326 free_irq(s3c_rtc_alarmno, rtc_dev); 327 free_irq(s3c_rtc_tickno, rtc_dev); 328 } 329 330 static const struct rtc_class_ops s3c_rtcops = { 331 .open = s3c_rtc_open, 332 .release = s3c_rtc_release, 333 .read_time = s3c_rtc_gettime, 334 .set_time = s3c_rtc_settime, 335 .read_alarm = s3c_rtc_getalarm, 336 .set_alarm = s3c_rtc_setalarm, 337 .irq_set_freq = s3c_rtc_setfreq, 338 .irq_set_state = s3c_rtc_setpie, 339 .proc = s3c_rtc_proc, 340 }; 341 342 static void s3c_rtc_enable(struct platform_device *pdev, int en) 343 { 344 void __iomem *base = s3c_rtc_base; 345 unsigned int tmp; 346 347 if (s3c_rtc_base == NULL) 348 return; 349 350 if (!en) { 351 tmp = readb(base + S3C2410_RTCCON); 352 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON); 353 354 tmp = readb(base + S3C2410_TICNT); 355 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT); 356 } else { 357 /* re-enable the device, and check it is ok */ 358 359 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){ 360 dev_info(&pdev->dev, "rtc disabled, re-enabling\n"); 361 362 tmp = readb(base + S3C2410_RTCCON); 363 writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON); 364 } 365 366 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){ 367 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n"); 368 369 tmp = readb(base + S3C2410_RTCCON); 370 writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON); 371 } 372 373 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){ 374 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n"); 375 376 tmp = readb(base + S3C2410_RTCCON); 377 writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON); 378 } 379 } 380 } 381 382 static int __devexit s3c_rtc_remove(struct platform_device *dev) 383 { 384 struct rtc_device *rtc = platform_get_drvdata(dev); 385 386 platform_set_drvdata(dev, NULL); 387 rtc_device_unregister(rtc); 388 389 s3c_rtc_setpie(&dev->dev, 0); 390 s3c_rtc_setaie(0); 391 392 iounmap(s3c_rtc_base); 393 release_resource(s3c_rtc_mem); 394 kfree(s3c_rtc_mem); 395 396 return 0; 397 } 398 399 static int __devinit s3c_rtc_probe(struct platform_device *pdev) 400 { 401 struct rtc_device *rtc; 402 struct resource *res; 403 int ret; 404 405 pr_debug("%s: probe=%p\n", __func__, pdev); 406 407 /* find the IRQs */ 408 409 s3c_rtc_tickno = platform_get_irq(pdev, 1); 410 if (s3c_rtc_tickno < 0) { 411 dev_err(&pdev->dev, "no irq for rtc tick\n"); 412 return -ENOENT; 413 } 414 415 s3c_rtc_alarmno = platform_get_irq(pdev, 0); 416 if (s3c_rtc_alarmno < 0) { 417 dev_err(&pdev->dev, "no irq for alarm\n"); 418 return -ENOENT; 419 } 420 421 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n", 422 s3c_rtc_tickno, s3c_rtc_alarmno); 423 424 /* get the memory region */ 425 426 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 427 if (res == NULL) { 428 dev_err(&pdev->dev, "failed to get memory region resource\n"); 429 return -ENOENT; 430 } 431 432 s3c_rtc_mem = request_mem_region(res->start, 433 res->end-res->start+1, 434 pdev->name); 435 436 if (s3c_rtc_mem == NULL) { 437 dev_err(&pdev->dev, "failed to reserve memory region\n"); 438 ret = -ENOENT; 439 goto err_nores; 440 } 441 442 s3c_rtc_base = ioremap(res->start, res->end - res->start + 1); 443 if (s3c_rtc_base == NULL) { 444 dev_err(&pdev->dev, "failed ioremap()\n"); 445 ret = -EINVAL; 446 goto err_nomap; 447 } 448 449 /* check to see if everything is setup correctly */ 450 451 s3c_rtc_enable(pdev, 1); 452 453 pr_debug("s3c2410_rtc: RTCCON=%02x\n", 454 readb(s3c_rtc_base + S3C2410_RTCCON)); 455 456 s3c_rtc_setfreq(&pdev->dev, 1); 457 458 device_init_wakeup(&pdev->dev, 1); 459 460 /* register RTC and exit */ 461 462 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops, 463 THIS_MODULE); 464 465 if (IS_ERR(rtc)) { 466 dev_err(&pdev->dev, "cannot attach rtc\n"); 467 ret = PTR_ERR(rtc); 468 goto err_nortc; 469 } 470 471 rtc->max_user_freq = 128; 472 473 platform_set_drvdata(pdev, rtc); 474 return 0; 475 476 err_nortc: 477 s3c_rtc_enable(pdev, 0); 478 iounmap(s3c_rtc_base); 479 480 err_nomap: 481 release_resource(s3c_rtc_mem); 482 483 err_nores: 484 return ret; 485 } 486 487 #ifdef CONFIG_PM 488 489 /* RTC Power management control */ 490 491 static int ticnt_save; 492 493 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state) 494 { 495 /* save TICNT for anyone using periodic interrupts */ 496 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT); 497 s3c_rtc_enable(pdev, 0); 498 return 0; 499 } 500 501 static int s3c_rtc_resume(struct platform_device *pdev) 502 { 503 s3c_rtc_enable(pdev, 1); 504 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT); 505 return 0; 506 } 507 #else 508 #define s3c_rtc_suspend NULL 509 #define s3c_rtc_resume NULL 510 #endif 511 512 static struct platform_driver s3c2410_rtc_driver = { 513 .probe = s3c_rtc_probe, 514 .remove = __devexit_p(s3c_rtc_remove), 515 .suspend = s3c_rtc_suspend, 516 .resume = s3c_rtc_resume, 517 .driver = { 518 .name = "s3c2410-rtc", 519 .owner = THIS_MODULE, 520 }, 521 }; 522 523 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n"; 524 525 static int __init s3c_rtc_init(void) 526 { 527 printk(banner); 528 return platform_driver_register(&s3c2410_rtc_driver); 529 } 530 531 static void __exit s3c_rtc_exit(void) 532 { 533 platform_driver_unregister(&s3c2410_rtc_driver); 534 } 535 536 module_init(s3c_rtc_init); 537 module_exit(s3c_rtc_exit); 538 539 MODULE_DESCRIPTION("Samsung S3C RTC Driver"); 540 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 541 MODULE_LICENSE("GPL"); 542 MODULE_ALIAS("platform:s3c2410-rtc"); 543