drivers/rtc/rtc-sh.c

   1 /*
   2  * SuperH On-Chip RTC Support
   3  *
   4  * Copyright (C) 2006  Paul Mundt
   5  *
   6  * Based on the old arch/sh/kernel/cpu/rtc.c by:
   7  *
   8  *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
   9  *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
  10  *
  11  * This file is subject to the terms and conditions of the GNU General Public
  12  * License.  See the file "COPYING" in the main directory of this archive
  13  * for more details.
  14  */
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/bcd.h>
  18 #include <linux/rtc.h>
  19 #include <linux/init.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/io.h>
  25
  26 #ifdef CONFIG_CPU_SH3
  27 #define rtc_reg_size            sizeof(u16)
  28 #define RTC_BIT_INVERTED        0       /* No bug on SH7708, SH7709A */
  29 #elif defined(CONFIG_CPU_SH4)
  30 #define rtc_reg_size            sizeof(u32)
  31 #define RTC_BIT_INVERTED        0x40    /* bug on SH7750, SH7750S */
  32 #endif
  33
  34 #define RTC_REG(r)      ((r) * rtc_reg_size)
  35
  36 #define R64CNT          RTC_REG(0)
  37 #define RSECCNT         RTC_REG(1)
  38 #define RMINCNT         RTC_REG(2)
  39 #define RHRCNT          RTC_REG(3)
  40 #define RWKCNT          RTC_REG(4)
  41 #define RDAYCNT         RTC_REG(5)
  42 #define RMONCNT         RTC_REG(6)
  43 #define RYRCNT          RTC_REG(7)
  44 #define RSECAR          RTC_REG(8)
  45 #define RMINAR          RTC_REG(9)
  46 #define RHRAR           RTC_REG(10)
  47 #define RWKAR           RTC_REG(11)
  48 #define RDAYAR          RTC_REG(12)
  49 #define RMONAR          RTC_REG(13)
  50 #define RCR1            RTC_REG(14)
  51 #define RCR2            RTC_REG(15)
  52
  53 /* RCR1 Bits */
  54 #define RCR1_CF         0x80    /* Carry Flag             */
  55 #define RCR1_CIE        0x10    /* Carry Interrupt Enable */
  56 #define RCR1_AIE        0x08    /* Alarm Interrupt Enable */
  57 #define RCR1_AF         0x01    /* Alarm Flag             */
  58
  59 /* RCR2 Bits */
  60 #define RCR2_PEF        0x80    /* PEriodic interrupt Flag */
  61 #define RCR2_PESMASK    0x70    /* Periodic interrupt Set  */
  62 #define RCR2_RTCEN      0x08    /* ENable RTC              */
  63 #define RCR2_ADJ        0x04    /* ADJustment (30-second)  */
  64 #define RCR2_RESET      0x02    /* Reset bit               */
  65 #define RCR2_START      0x01    /* Start bit               */
  66
  67 struct sh_rtc {
  68         void __iomem *regbase;
  69         unsigned long regsize;
  70         struct resource *res;
  71         unsigned int alarm_irq, periodic_irq, carry_irq;
  72         struct rtc_device *rtc_dev;
  73         spinlock_t lock;
  74 };
  75
  76 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
  77 {
  78         struct platform_device *pdev = to_platform_device(dev_id);
  79         struct sh_rtc *rtc = platform_get_drvdata(pdev);
  80         unsigned int tmp, events = 0;
  81
  82         spin_lock(&rtc->lock);
  83
  84         tmp = readb(rtc->regbase + RCR1);
  85
  86         if (tmp & RCR1_AF)
  87                 events |= RTC_AF | RTC_IRQF;
  88
  89         tmp &= ~(RCR1_CF | RCR1_AF);
  90
  91         writeb(tmp, rtc->regbase + RCR1);
  92
  93         rtc_update_irq(&rtc->rtc_dev->class_dev, 1, events);
  94
  95         spin_unlock(&rtc->lock);
  96
  97         return IRQ_HANDLED;
  98 }
  99
 100 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
 101 {
 102         struct platform_device *pdev = to_platform_device(dev_id);
 103         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 104
 105         spin_lock(&rtc->lock);
 106
 107         rtc_update_irq(&rtc->rtc_dev->class_dev, 1, RTC_PF | RTC_IRQF);
 108
 109         spin_unlock(&rtc->lock);
 110
 111         return IRQ_HANDLED;
 112 }
 113
 114 static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
 115 {
 116         struct sh_rtc *rtc = dev_get_drvdata(dev);
 117         unsigned int tmp;
 118
 119         spin_lock_irq(&rtc->lock);
 120
 121         tmp = readb(rtc->regbase + RCR2);
 122
 123         if (enable) {
 124                 tmp &= ~RCR2_PESMASK;
 125                 tmp |= RCR2_PEF | (2 << 4);
 126         } else
 127                 tmp &= ~(RCR2_PESMASK | RCR2_PEF);
 128
 129         writeb(tmp, rtc->regbase + RCR2);
 130
 131         spin_unlock_irq(&rtc->lock);
 132 }
 133
 134 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
 135 {
 136         struct sh_rtc *rtc = dev_get_drvdata(dev);
 137         unsigned int tmp;
 138
 139         spin_lock_irq(&rtc->lock);
 140
 141         tmp = readb(rtc->regbase + RCR1);
 142
 143         if (enable)
 144                 tmp |= RCR1_AIE;
 145         else
 146                 tmp &= ~RCR1_AIE;
 147
 148         writeb(tmp, rtc->regbase + RCR1);
 149
 150         spin_unlock_irq(&rtc->lock);
 151 }
 152
 153 static int sh_rtc_open(struct device *dev)
 154 {
 155         struct sh_rtc *rtc = dev_get_drvdata(dev);
 156         unsigned int tmp;
 157         int ret;
 158
 159         tmp = readb(rtc->regbase + RCR1);
 160         tmp &= ~RCR1_CF;
 161         tmp |= RCR1_CIE;
 162         writeb(tmp, rtc->regbase + RCR1);
 163
 164         ret = request_irq(rtc->periodic_irq, sh_rtc_periodic, IRQF_DISABLED,
 165                           "sh-rtc period", dev);
 166         if (unlikely(ret)) {
 167                 dev_err(dev, "request period IRQ failed with %d, IRQ %d\n",
 168                         ret, rtc->periodic_irq);
 169                 return ret;
 170         }
 171
 172         ret = request_irq(rtc->carry_irq, sh_rtc_interrupt, IRQF_DISABLED,
 173                           "sh-rtc carry", dev);
 174         if (unlikely(ret)) {
 175                 dev_err(dev, "request carry IRQ failed with %d, IRQ %d\n",
 176                         ret, rtc->carry_irq);
 177                 free_irq(rtc->periodic_irq, dev);
 178                 goto err_bad_carry;
 179         }
 180
 181         ret = request_irq(rtc->alarm_irq, sh_rtc_interrupt, IRQF_DISABLED,
 182                           "sh-rtc alarm", dev);
 183         if (unlikely(ret)) {
 184                 dev_err(dev, "request alarm IRQ failed with %d, IRQ %d\n",
 185                         ret, rtc->alarm_irq);
 186                 goto err_bad_alarm;
 187         }
 188
 189         return 0;
 190
 191 err_bad_alarm:
 192         free_irq(rtc->carry_irq, dev);
 193 err_bad_carry:
 194         free_irq(rtc->periodic_irq, dev);
 195
 196         return ret;
 197 }
 198
 199 static void sh_rtc_release(struct device *dev)
 200 {
 201         struct sh_rtc *rtc = dev_get_drvdata(dev);
 202
 203         sh_rtc_setpie(dev, 0);
 204
 205         free_irq(rtc->periodic_irq, dev);
 206         free_irq(rtc->carry_irq, dev);
 207         free_irq(rtc->alarm_irq, dev);
 208 }
 209
 210 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
 211 {
 212         struct sh_rtc *rtc = dev_get_drvdata(dev);
 213         unsigned int tmp;
 214
 215         tmp = readb(rtc->regbase + RCR1);
 216         seq_printf(seq, "alarm_IRQ\t: %s\n",
 217                    (tmp & RCR1_AIE) ? "yes" : "no");
 218         seq_printf(seq, "carry_IRQ\t: %s\n",
 219                    (tmp & RCR1_CIE) ? "yes" : "no");
 220
 221         tmp = readb(rtc->regbase + RCR2);
 222         seq_printf(seq, "periodic_IRQ\t: %s\n",
 223                    (tmp & RCR2_PEF) ? "yes" : "no");
 224
 225         return 0;
 226 }
 227
 228 static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 229 {
 230         unsigned int ret = -ENOIOCTLCMD;
 231
 232         switch (cmd) {
 233         case RTC_PIE_OFF:
 234         case RTC_PIE_ON:
 235                 sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
 236                 ret = 0;
 237                 break;
 238         case RTC_AIE_OFF:
 239         case RTC_AIE_ON:
 240                 sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
 241                 ret = 0;
 242                 break;
 243         }
 244
 245         return ret;
 246 }
 247
 248 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
 249 {
 250         struct platform_device *pdev = to_platform_device(dev);
 251         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 252         unsigned int sec128, sec2, yr, yr100, cf_bit;
 253
 254         do {
 255                 unsigned int tmp;
 256
 257                 spin_lock_irq(&rtc->lock);
 258
 259                 tmp = readb(rtc->regbase + RCR1);
 260                 tmp &= ~RCR1_CF; /* Clear CF-bit */
 261                 tmp |= RCR1_CIE;
 262                 writeb(tmp, rtc->regbase + RCR1);
 263
 264                 sec128 = readb(rtc->regbase + R64CNT);
 265
 266                 tm->tm_sec      = BCD2BIN(readb(rtc->regbase + RSECCNT));
 267                 tm->tm_min      = BCD2BIN(readb(rtc->regbase + RMINCNT));
 268                 tm->tm_hour     = BCD2BIN(readb(rtc->regbase + RHRCNT));
 269                 tm->tm_wday     = BCD2BIN(readb(rtc->regbase + RWKCNT));
 270                 tm->tm_mday     = BCD2BIN(readb(rtc->regbase + RDAYCNT));
 271                 tm->tm_mon      = BCD2BIN(readb(rtc->regbase + RMONCNT)) - 1;
 272
 273 #if defined(CONFIG_CPU_SH4)
 274                 yr  = readw(rtc->regbase + RYRCNT);
 275                 yr100 = BCD2BIN(yr >> 8);
 276                 yr &= 0xff;
 277 #else
 278                 yr  = readb(rtc->regbase + RYRCNT);
 279                 yr100 = BCD2BIN((yr == 0x99) ? 0x19 : 0x20);
 280 #endif
 281
 282                 tm->tm_year = (yr100 * 100 + BCD2BIN(yr)) - 1900;
 283
 284                 sec2 = readb(rtc->regbase + R64CNT);
 285                 cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
 286
 287                 spin_unlock_irq(&rtc->lock);
 288         } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
 289
 290 #if RTC_BIT_INVERTED != 0
 291         if ((sec128 & RTC_BIT_INVERTED))
 292                 tm->tm_sec--;
 293 #endif
 294
 295         dev_dbg(&dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 296                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 297                 __FUNCTION__,
 298                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 299                 tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
 300
 301         if (rtc_valid_tm(tm) < 0)
 302                 dev_err(dev, "invalid date\n");
 303
 304         return 0;
 305 }
 306
 307 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
 308 {
 309         struct platform_device *pdev = to_platform_device(dev);
 310         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 311         unsigned int tmp;
 312         int year;
 313
 314         spin_lock_irq(&rtc->lock);
 315
 316         /* Reset pre-scaler & stop RTC */
 317         tmp = readb(rtc->regbase + RCR2);
 318         tmp |= RCR2_RESET;
 319         writeb(tmp, rtc->regbase + RCR2);
 320
 321         writeb(BIN2BCD(tm->tm_sec),  rtc->regbase + RSECCNT);
 322         writeb(BIN2BCD(tm->tm_min),  rtc->regbase + RMINCNT);
 323         writeb(BIN2BCD(tm->tm_hour), rtc->regbase + RHRCNT);
 324         writeb(BIN2BCD(tm->tm_wday), rtc->regbase + RWKCNT);
 325         writeb(BIN2BCD(tm->tm_mday), rtc->regbase + RDAYCNT);
 326         writeb(BIN2BCD(tm->tm_mon + 1), rtc->regbase + RMONCNT);
 327
 328 #ifdef CONFIG_CPU_SH3
 329         year = tm->tm_year % 100;
 330         writeb(BIN2BCD(year), rtc->regbase + RYRCNT);
 331 #else
 332         year = (BIN2BCD((tm->tm_year + 1900) / 100) << 8) |
 333                 BIN2BCD(tm->tm_year % 100);
 334         writew(year, rtc->regbase + RYRCNT);
 335 #endif
 336
 337         /* Start RTC */
 338         tmp = readb(rtc->regbase + RCR2);
 339         tmp &= ~RCR2_RESET;
 340         tmp |= RCR2_RTCEN | RCR2_START;
 341         writeb(tmp, rtc->regbase + RCR2);
 342
 343         spin_unlock_irq(&rtc->lock);
 344
 345         return 0;
 346 }
 347
 348 static struct rtc_class_ops sh_rtc_ops = {
 349         .open           = sh_rtc_open,
 350         .release        = sh_rtc_release,
 351         .ioctl          = sh_rtc_ioctl,
 352         .read_time      = sh_rtc_read_time,
 353         .set_time       = sh_rtc_set_time,
 354         .proc           = sh_rtc_proc,
 355 };
 356
 357 static int __devinit sh_rtc_probe(struct platform_device *pdev)
 358 {
 359         struct sh_rtc *rtc;
 360         struct resource *res;
 361         int ret = -ENOENT;
 362
 363         rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
 364         if (unlikely(!rtc))
 365                 return -ENOMEM;
 366
 367         spin_lock_init(&rtc->lock);
 368
 369         rtc->periodic_irq = platform_get_irq(pdev, 0);
 370         if (unlikely(rtc->periodic_irq < 0)) {
 371                 dev_err(&pdev->dev, "No IRQ for period\n");
 372                 goto err_badres;
 373         }
 374
 375         rtc->carry_irq = platform_get_irq(pdev, 1);
 376         if (unlikely(rtc->carry_irq < 0)) {
 377                 dev_err(&pdev->dev, "No IRQ for carry\n");
 378                 goto err_badres;
 379         }
 380
 381         rtc->alarm_irq = platform_get_irq(pdev, 2);
 382         if (unlikely(rtc->alarm_irq < 0)) {
 383                 dev_err(&pdev->dev, "No IRQ for alarm\n");
 384                 goto err_badres;
 385         }
 386
 387         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 388         if (unlikely(res == NULL)) {
 389                 dev_err(&pdev->dev, "No IO resource\n");
 390                 goto err_badres;
 391         }
 392
 393         rtc->regsize = res->end - res->start + 1;
 394
 395         rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
 396         if (unlikely(!rtc->res)) {
 397                 ret = -EBUSY;
 398                 goto err_badres;
 399         }
 400
 401         rtc->regbase = (void __iomem *)rtc->res->start;
 402         if (unlikely(!rtc->regbase)) {
 403                 ret = -EINVAL;
 404                 goto err_badmap;
 405         }
 406
 407         rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
 408                                            &sh_rtc_ops, THIS_MODULE);
 409         if (IS_ERR(rtc)) {
 410                 ret = PTR_ERR(rtc->rtc_dev);
 411                 goto err_badmap;
 412         }
 413
 414         platform_set_drvdata(pdev, rtc);
 415
 416         return 0;
 417
 418 err_badmap:
 419         release_resource(rtc->res);
 420 err_badres:
 421         kfree(rtc);
 422
 423         return ret;
 424 }
 425
 426 static int __devexit sh_rtc_remove(struct platform_device *pdev)
 427 {
 428         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 429
 430         if (likely(rtc->rtc_dev))
 431                 rtc_device_unregister(rtc->rtc_dev);
 432
 433         sh_rtc_setpie(&pdev->dev, 0);
 434         sh_rtc_setaie(&pdev->dev, 0);
 435
 436         release_resource(rtc->res);
 437
 438         platform_set_drvdata(pdev, NULL);
 439
 440         kfree(rtc);
 441
 442         return 0;
 443 }
 444 static struct platform_driver sh_rtc_platform_driver = {
 445         .driver         = {
 446                 .name   = "sh-rtc",
 447                 .owner  = THIS_MODULE,
 448         },
 449         .probe          = sh_rtc_probe,
 450         .remove         = __devexit_p(sh_rtc_remove),
 451 };
 452
 453 static int __init sh_rtc_init(void)
 454 {
 455         return platform_driver_register(&sh_rtc_platform_driver);
 456 }
 457
 458 static void __exit sh_rtc_exit(void)
 459 {
 460         platform_driver_unregister(&sh_rtc_platform_driver);
 461 }
 462
 463 module_init(sh_rtc_init);
 464 module_exit(sh_rtc_exit);
 465
 466 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
 467 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
 468 MODULE_LICENSE("GPL");