drivers/rtc/rtc-sh.c

   1 /*
   2  * SuperH On-Chip RTC Support
   3  *
   4  * Copyright (C) 2006 - 2009  Paul Mundt
   5  * Copyright (C) 2006  Jamie Lenehan
   6  * Copyright (C) 2008  Angelo Castello
   7  *
   8  * Based on the old arch/sh/kernel/cpu/rtc.c by:
   9  *
  10  *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
  11  *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
  12  *
  13  * This file is subject to the terms and conditions of the GNU General Public
  14  * License.  See the file "COPYING" in the main directory of this archive
  15  * for more details.
  16  */
  17 #include <linux/module.h>
  18 #include <linux/kernel.h>
  19 #include <linux/bcd.h>
  20 #include <linux/rtc.h>
  21 #include <linux/init.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/io.h>
  27 #include <linux/log2.h>
  28 #include <linux/clk.h>
  29 #include <linux/slab.h>
  30 #ifdef CONFIG_SUPERH
  31 #include <asm/rtc.h>
  32 #else
  33 /* Default values for RZ/A RTC */
  34 #define rtc_reg_size            sizeof(u16)
  35 #define RTC_BIT_INVERTED        0       /* no chip bugs */
  36 #define RTC_CAP_4_DIGIT_YEAR    (1 << 0)
  37 #define RTC_DEF_CAPABILITIES    RTC_CAP_4_DIGIT_YEAR
  38 #endif
  39
  40 #define DRV_NAME        "sh-rtc"
  41
  42 #define RTC_REG(r)      ((r) * rtc_reg_size)
  43
  44 #define R64CNT          RTC_REG(0)
  45
  46 #define RSECCNT         RTC_REG(1)      /* RTC sec */
  47 #define RMINCNT         RTC_REG(2)      /* RTC min */
  48 #define RHRCNT          RTC_REG(3)      /* RTC hour */
  49 #define RWKCNT          RTC_REG(4)      /* RTC week */
  50 #define RDAYCNT         RTC_REG(5)      /* RTC day */
  51 #define RMONCNT         RTC_REG(6)      /* RTC month */
  52 #define RYRCNT          RTC_REG(7)      /* RTC year */
  53 #define RSECAR          RTC_REG(8)      /* ALARM sec */
  54 #define RMINAR          RTC_REG(9)      /* ALARM min */
  55 #define RHRAR           RTC_REG(10)     /* ALARM hour */
  56 #define RWKAR           RTC_REG(11)     /* ALARM week */
  57 #define RDAYAR          RTC_REG(12)     /* ALARM day */
  58 #define RMONAR          RTC_REG(13)     /* ALARM month */
  59 #define RCR1            RTC_REG(14)     /* Control */
  60 #define RCR2            RTC_REG(15)     /* Control */
  61
  62 /*
  63  * Note on RYRAR and RCR3: Up until this point most of the register
  64  * definitions are consistent across all of the available parts. However,
  65  * the placement of the optional RYRAR and RCR3 (the RYRAR control
  66  * register used to control RYRCNT/RYRAR compare) varies considerably
  67  * across various parts, occasionally being mapped in to a completely
  68  * unrelated address space. For proper RYRAR support a separate resource
  69  * would have to be handed off, but as this is purely optional in
  70  * practice, we simply opt not to support it, thereby keeping the code
  71  * quite a bit more simplified.
  72  */
  73
  74 /* ALARM Bits - or with BCD encoded value */
  75 #define AR_ENB          0x80    /* Enable for alarm cmp   */
  76
  77 /* Period Bits */
  78 #define PF_HP           0x100   /* Enable Half Period to support 8,32,128Hz */
  79 #define PF_COUNT        0x200   /* Half periodic counter */
  80 #define PF_OXS          0x400   /* Periodic One x Second */
  81 #define PF_KOU          0x800   /* Kernel or User periodic request 1=kernel */
  82 #define PF_MASK         0xf00
  83
  84 /* RCR1 Bits */
  85 #define RCR1_CF         0x80    /* Carry Flag             */
  86 #define RCR1_CIE        0x10    /* Carry Interrupt Enable */
  87 #define RCR1_AIE        0x08    /* Alarm Interrupt Enable */
  88 #define RCR1_AF         0x01    /* Alarm Flag             */
  89
  90 /* RCR2 Bits */
  91 #define RCR2_PEF        0x80    /* PEriodic interrupt Flag */
  92 #define RCR2_PESMASK    0x70    /* Periodic interrupt Set  */
  93 #define RCR2_RTCEN      0x08    /* ENable RTC              */
  94 #define RCR2_ADJ        0x04    /* ADJustment (30-second)  */
  95 #define RCR2_RESET      0x02    /* Reset bit               */
  96 #define RCR2_START      0x01    /* Start bit               */
  97
  98 struct sh_rtc {
  99         void __iomem            *regbase;
 100         unsigned long           regsize;
 101         struct resource         *res;
 102         int                     alarm_irq;
 103         int                     periodic_irq;
 104         int                     carry_irq;
 105         struct clk              *clk;
 106         struct rtc_device       *rtc_dev;
 107         spinlock_t              lock;
 108         unsigned long           capabilities;   /* See asm/rtc.h for cap bits */
 109         unsigned short          periodic_freq;
 110 };
 111
 112 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
 113 {
 114         unsigned int tmp, pending;
 115
 116         tmp = readb(rtc->regbase + RCR1);
 117         pending = tmp & RCR1_CF;
 118         tmp &= ~RCR1_CF;
 119         writeb(tmp, rtc->regbase + RCR1);
 120
 121         /* Users have requested One x Second IRQ */
 122         if (pending && rtc->periodic_freq & PF_OXS)
 123                 rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
 124
 125         return pending;
 126 }
 127
 128 static int __sh_rtc_alarm(struct sh_rtc *rtc)
 129 {
 130         unsigned int tmp, pending;
 131
 132         tmp = readb(rtc->regbase + RCR1);
 133         pending = tmp & RCR1_AF;
 134         tmp &= ~(RCR1_AF | RCR1_AIE);
 135         writeb(tmp, rtc->regbase + RCR1);
 136
 137         if (pending)
 138                 rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
 139
 140         return pending;
 141 }
 142
 143 static int __sh_rtc_periodic(struct sh_rtc *rtc)
 144 {
 145         struct rtc_device *rtc_dev = rtc->rtc_dev;
 146         struct rtc_task *irq_task;
 147         unsigned int tmp, pending;
 148
 149         tmp = readb(rtc->regbase + RCR2);
 150         pending = tmp & RCR2_PEF;
 151         tmp &= ~RCR2_PEF;
 152         writeb(tmp, rtc->regbase + RCR2);
 153
 154         if (!pending)
 155                 return 0;
 156
 157         /* Half period enabled than one skipped and the next notified */
 158         if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
 159                 rtc->periodic_freq &= ~PF_COUNT;
 160         else {
 161                 if (rtc->periodic_freq & PF_HP)
 162                         rtc->periodic_freq |= PF_COUNT;
 163                 if (rtc->periodic_freq & PF_KOU) {
 164                         spin_lock(&rtc_dev->irq_task_lock);
 165                         irq_task = rtc_dev->irq_task;
 166                         if (irq_task)
 167                                 irq_task->func(irq_task->private_data);
 168                         spin_unlock(&rtc_dev->irq_task_lock);
 169                 } else
 170                         rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
 171         }
 172
 173         return pending;
 174 }
 175
 176 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
 177 {
 178         struct sh_rtc *rtc = dev_id;
 179         int ret;
 180
 181         spin_lock(&rtc->lock);
 182         ret = __sh_rtc_interrupt(rtc);
 183         spin_unlock(&rtc->lock);
 184
 185         return IRQ_RETVAL(ret);
 186 }
 187
 188 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
 189 {
 190         struct sh_rtc *rtc = dev_id;
 191         int ret;
 192
 193         spin_lock(&rtc->lock);
 194         ret = __sh_rtc_alarm(rtc);
 195         spin_unlock(&rtc->lock);
 196
 197         return IRQ_RETVAL(ret);
 198 }
 199
 200 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
 201 {
 202         struct sh_rtc *rtc = dev_id;
 203         int ret;
 204
 205         spin_lock(&rtc->lock);
 206         ret = __sh_rtc_periodic(rtc);
 207         spin_unlock(&rtc->lock);
 208
 209         return IRQ_RETVAL(ret);
 210 }
 211
 212 static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
 213 {
 214         struct sh_rtc *rtc = dev_id;
 215         int ret;
 216
 217         spin_lock(&rtc->lock);
 218         ret = __sh_rtc_interrupt(rtc);
 219         ret |= __sh_rtc_alarm(rtc);
 220         ret |= __sh_rtc_periodic(rtc);
 221         spin_unlock(&rtc->lock);
 222
 223         return IRQ_RETVAL(ret);
 224 }
 225
 226 static int sh_rtc_irq_set_state(struct device *dev, int enable)
 227 {
 228         struct sh_rtc *rtc = dev_get_drvdata(dev);
 229         unsigned int tmp;
 230
 231         spin_lock_irq(&rtc->lock);
 232
 233         tmp = readb(rtc->regbase + RCR2);
 234
 235         if (enable) {
 236                 rtc->periodic_freq |= PF_KOU;
 237                 tmp &= ~RCR2_PEF;       /* Clear PES bit */
 238                 tmp |= (rtc->periodic_freq & ~PF_HP);   /* Set PES2-0 */
 239         } else {
 240                 rtc->periodic_freq &= ~PF_KOU;
 241                 tmp &= ~(RCR2_PESMASK | RCR2_PEF);
 242         }
 243
 244         writeb(tmp, rtc->regbase + RCR2);
 245
 246         spin_unlock_irq(&rtc->lock);
 247
 248         return 0;
 249 }
 250
 251 static int sh_rtc_irq_set_freq(struct device *dev, int freq)
 252 {
 253         struct sh_rtc *rtc = dev_get_drvdata(dev);
 254         int tmp, ret = 0;
 255
 256         spin_lock_irq(&rtc->lock);
 257         tmp = rtc->periodic_freq & PF_MASK;
 258
 259         switch (freq) {
 260         case 0:
 261                 rtc->periodic_freq = 0x00;
 262                 break;
 263         case 1:
 264                 rtc->periodic_freq = 0x60;
 265                 break;
 266         case 2:
 267                 rtc->periodic_freq = 0x50;
 268                 break;
 269         case 4:
 270                 rtc->periodic_freq = 0x40;
 271                 break;
 272         case 8:
 273                 rtc->periodic_freq = 0x30 | PF_HP;
 274                 break;
 275         case 16:
 276                 rtc->periodic_freq = 0x30;
 277                 break;
 278         case 32:
 279                 rtc->periodic_freq = 0x20 | PF_HP;
 280                 break;
 281         case 64:
 282                 rtc->periodic_freq = 0x20;
 283                 break;
 284         case 128:
 285                 rtc->periodic_freq = 0x10 | PF_HP;
 286                 break;
 287         case 256:
 288                 rtc->periodic_freq = 0x10;
 289                 break;
 290         default:
 291                 ret = -ENOTSUPP;
 292         }
 293
 294         if (ret == 0)
 295                 rtc->periodic_freq |= tmp;
 296
 297         spin_unlock_irq(&rtc->lock);
 298         return ret;
 299 }
 300
 301 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
 302 {
 303         struct sh_rtc *rtc = dev_get_drvdata(dev);
 304         unsigned int tmp;
 305
 306         spin_lock_irq(&rtc->lock);
 307
 308         tmp = readb(rtc->regbase + RCR1);
 309
 310         if (enable)
 311                 tmp |= RCR1_AIE;
 312         else
 313                 tmp &= ~RCR1_AIE;
 314
 315         writeb(tmp, rtc->regbase + RCR1);
 316
 317         spin_unlock_irq(&rtc->lock);
 318 }
 319
 320 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
 321 {
 322         struct sh_rtc *rtc = dev_get_drvdata(dev);
 323         unsigned int tmp;
 324
 325         tmp = readb(rtc->regbase + RCR1);
 326         seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
 327
 328         tmp = readb(rtc->regbase + RCR2);
 329         seq_printf(seq, "periodic_IRQ\t: %s\n",
 330                    (tmp & RCR2_PESMASK) ? "yes" : "no");
 331
 332         return 0;
 333 }
 334
 335 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
 336 {
 337         struct sh_rtc *rtc = dev_get_drvdata(dev);
 338         unsigned int tmp;
 339
 340         spin_lock_irq(&rtc->lock);
 341
 342         tmp = readb(rtc->regbase + RCR1);
 343
 344         if (!enable)
 345                 tmp &= ~RCR1_CIE;
 346         else
 347                 tmp |= RCR1_CIE;
 348
 349         writeb(tmp, rtc->regbase + RCR1);
 350
 351         spin_unlock_irq(&rtc->lock);
 352 }
 353
 354 static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 355 {
 356         sh_rtc_setaie(dev, enabled);
 357         return 0;
 358 }
 359
 360 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
 361 {
 362         struct platform_device *pdev = to_platform_device(dev);
 363         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 364         unsigned int sec128, sec2, yr, yr100, cf_bit;
 365
 366         do {
 367                 unsigned int tmp;
 368
 369                 spin_lock_irq(&rtc->lock);
 370
 371                 tmp = readb(rtc->regbase + RCR1);
 372                 tmp &= ~RCR1_CF; /* Clear CF-bit */
 373                 tmp |= RCR1_CIE;
 374                 writeb(tmp, rtc->regbase + RCR1);
 375
 376                 sec128 = readb(rtc->regbase + R64CNT);
 377
 378                 tm->tm_sec      = bcd2bin(readb(rtc->regbase + RSECCNT));
 379                 tm->tm_min      = bcd2bin(readb(rtc->regbase + RMINCNT));
 380                 tm->tm_hour     = bcd2bin(readb(rtc->regbase + RHRCNT));
 381                 tm->tm_wday     = bcd2bin(readb(rtc->regbase + RWKCNT));
 382                 tm->tm_mday     = bcd2bin(readb(rtc->regbase + RDAYCNT));
 383                 tm->tm_mon      = bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
 384
 385                 if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
 386                         yr  = readw(rtc->regbase + RYRCNT);
 387                         yr100 = bcd2bin(yr >> 8);
 388                         yr &= 0xff;
 389                 } else {
 390                         yr  = readb(rtc->regbase + RYRCNT);
 391                         yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
 392                 }
 393
 394                 tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
 395
 396                 sec2 = readb(rtc->regbase + R64CNT);
 397                 cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
 398
 399                 spin_unlock_irq(&rtc->lock);
 400         } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
 401
 402 #if RTC_BIT_INVERTED != 0
 403         if ((sec128 & RTC_BIT_INVERTED))
 404                 tm->tm_sec--;
 405 #endif
 406
 407         /* only keep the carry interrupt enabled if UIE is on */
 408         if (!(rtc->periodic_freq & PF_OXS))
 409                 sh_rtc_setcie(dev, 0);
 410
 411         dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 412                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 413                 __func__,
 414                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 415                 tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
 416
 417         return rtc_valid_tm(tm);
 418 }
 419
 420 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
 421 {
 422         struct platform_device *pdev = to_platform_device(dev);
 423         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 424         unsigned int tmp;
 425         int year;
 426
 427         spin_lock_irq(&rtc->lock);
 428
 429         /* Reset pre-scaler & stop RTC */
 430         tmp = readb(rtc->regbase + RCR2);
 431         tmp |= RCR2_RESET;
 432         tmp &= ~RCR2_START;
 433         writeb(tmp, rtc->regbase + RCR2);
 434
 435         writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
 436         writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
 437         writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
 438         writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
 439         writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
 440         writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
 441
 442         if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
 443                 year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
 444                         bin2bcd(tm->tm_year % 100);
 445                 writew(year, rtc->regbase + RYRCNT);
 446         } else {
 447                 year = tm->tm_year % 100;
 448                 writeb(bin2bcd(year), rtc->regbase + RYRCNT);
 449         }
 450
 451         /* Start RTC */
 452         tmp = readb(rtc->regbase + RCR2);
 453         tmp &= ~RCR2_RESET;
 454         tmp |= RCR2_RTCEN | RCR2_START;
 455         writeb(tmp, rtc->regbase + RCR2);
 456
 457         spin_unlock_irq(&rtc->lock);
 458
 459         return 0;
 460 }
 461
 462 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
 463 {
 464         unsigned int byte;
 465         int value = 0xff;       /* return 0xff for ignored values */
 466
 467         byte = readb(rtc->regbase + reg_off);
 468         if (byte & AR_ENB) {
 469                 byte &= ~AR_ENB;        /* strip the enable bit */
 470                 value = bcd2bin(byte);
 471         }
 472
 473         return value;
 474 }
 475
 476 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 477 {
 478         struct platform_device *pdev = to_platform_device(dev);
 479         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 480         struct rtc_time *tm = &wkalrm->time;
 481
 482         spin_lock_irq(&rtc->lock);
 483
 484         tm->tm_sec      = sh_rtc_read_alarm_value(rtc, RSECAR);
 485         tm->tm_min      = sh_rtc_read_alarm_value(rtc, RMINAR);
 486         tm->tm_hour     = sh_rtc_read_alarm_value(rtc, RHRAR);
 487         tm->tm_wday     = sh_rtc_read_alarm_value(rtc, RWKAR);
 488         tm->tm_mday     = sh_rtc_read_alarm_value(rtc, RDAYAR);
 489         tm->tm_mon      = sh_rtc_read_alarm_value(rtc, RMONAR);
 490         if (tm->tm_mon > 0)
 491                 tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
 492
 493         wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
 494
 495         spin_unlock_irq(&rtc->lock);
 496
 497         return 0;
 498 }
 499
 500 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
 501                                             int value, int reg_off)
 502 {
 503         /* < 0 for a value that is ignored */
 504         if (value < 0)
 505                 writeb(0, rtc->regbase + reg_off);
 506         else
 507                 writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
 508 }
 509
 510 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 511 {
 512         struct platform_device *pdev = to_platform_device(dev);
 513         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 514         unsigned int rcr1;
 515         struct rtc_time *tm = &wkalrm->time;
 516         int mon;
 517
 518         spin_lock_irq(&rtc->lock);
 519
 520         /* disable alarm interrupt and clear the alarm flag */
 521         rcr1 = readb(rtc->regbase + RCR1);
 522         rcr1 &= ~(RCR1_AF | RCR1_AIE);
 523         writeb(rcr1, rtc->regbase + RCR1);
 524
 525         /* set alarm time */
 526         sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
 527         sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
 528         sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
 529         sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
 530         sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
 531         mon = tm->tm_mon;
 532         if (mon >= 0)
 533                 mon += 1;
 534         sh_rtc_write_alarm_value(rtc, mon, RMONAR);
 535
 536         if (wkalrm->enabled) {
 537                 rcr1 |= RCR1_AIE;
 538                 writeb(rcr1, rtc->regbase + RCR1);
 539         }
 540
 541         spin_unlock_irq(&rtc->lock);
 542
 543         return 0;
 544 }
 545
 546 static const struct rtc_class_ops sh_rtc_ops = {
 547         .read_time      = sh_rtc_read_time,
 548         .set_time       = sh_rtc_set_time,
 549         .read_alarm     = sh_rtc_read_alarm,
 550         .set_alarm      = sh_rtc_set_alarm,
 551         .proc           = sh_rtc_proc,
 552         .alarm_irq_enable = sh_rtc_alarm_irq_enable,
 553 };
 554
 555 static int __init sh_rtc_probe(struct platform_device *pdev)
 556 {
 557         struct sh_rtc *rtc;
 558         struct resource *res;
 559         struct rtc_time r;
 560         char clk_name[6];
 561         int clk_id, ret;
 562
 563         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
 564         if (unlikely(!rtc))
 565                 return -ENOMEM;
 566
 567         spin_lock_init(&rtc->lock);
 568
 569         /* get periodic/carry/alarm irqs */
 570         ret = platform_get_irq(pdev, 0);
 571         if (unlikely(ret <= 0)) {
 572                 dev_err(&pdev->dev, "No IRQ resource\n");
 573                 return -ENOENT;
 574         }
 575
 576         rtc->periodic_irq = ret;
 577         rtc->carry_irq = platform_get_irq(pdev, 1);
 578         rtc->alarm_irq = platform_get_irq(pdev, 2);
 579
 580         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 581         if (!res)
 582                 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 583         if (unlikely(res == NULL)) {
 584                 dev_err(&pdev->dev, "No IO resource\n");
 585                 return -ENOENT;
 586         }
 587
 588         rtc->regsize = resource_size(res);
 589
 590         rtc->res = devm_request_mem_region(&pdev->dev, res->start,
 591                                         rtc->regsize, pdev->name);
 592         if (unlikely(!rtc->res))
 593                 return -EBUSY;
 594
 595         rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start,
 596                                         rtc->regsize);
 597         if (unlikely(!rtc->regbase))
 598                 return -EINVAL;
 599
 600         if (!pdev->dev.of_node) {
 601                 clk_id = pdev->id;
 602                 /* With a single device, the clock id is still "rtc0" */
 603                 if (clk_id < 0)
 604                         clk_id = 0;
 605
 606                 snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
 607         } else
 608                 snprintf(clk_name, sizeof(clk_name), "fck");
 609
 610         rtc->clk = devm_clk_get(&pdev->dev, clk_name);
 611         if (IS_ERR(rtc->clk)) {
 612                 /*
 613                  * No error handling for rtc->clk intentionally, not all
 614                  * platforms will have a unique clock for the RTC, and
 615                  * the clk API can handle the struct clk pointer being
 616                  * NULL.
 617                  */
 618                 rtc->clk = NULL;
 619         }
 620
 621         clk_enable(rtc->clk);
 622
 623         rtc->capabilities = RTC_DEF_CAPABILITIES;
 624
 625 #ifdef CONFIG_SUPERH
 626         if (dev_get_platdata(&pdev->dev)) {
 627                 struct sh_rtc_platform_info *pinfo =
 628                         dev_get_platdata(&pdev->dev);
 629
 630                 /*
 631                  * Some CPUs have special capabilities in addition to the
 632                  * default set. Add those in here.
 633                  */
 634                 rtc->capabilities |= pinfo->capabilities;
 635         }
 636 #endif
 637
 638         if (rtc->carry_irq <= 0) {
 639                 /* register shared periodic/carry/alarm irq */
 640                 ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
 641                                 sh_rtc_shared, 0, "sh-rtc", rtc);
 642                 if (unlikely(ret)) {
 643                         dev_err(&pdev->dev,
 644                                 "request IRQ failed with %d, IRQ %d\n", ret,
 645                                 rtc->periodic_irq);
 646                         goto err_unmap;
 647                 }
 648         } else {
 649                 /* register periodic/carry/alarm irqs */
 650                 ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
 651                                 sh_rtc_periodic, 0, "sh-rtc period", rtc);
 652                 if (unlikely(ret)) {
 653                         dev_err(&pdev->dev,
 654                                 "request period IRQ failed with %d, IRQ %d\n",
 655                                 ret, rtc->periodic_irq);
 656                         goto err_unmap;
 657                 }
 658
 659                 ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
 660                                 sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
 661                 if (unlikely(ret)) {
 662                         dev_err(&pdev->dev,
 663                                 "request carry IRQ failed with %d, IRQ %d\n",
 664                                 ret, rtc->carry_irq);
 665                         goto err_unmap;
 666                 }
 667
 668                 ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
 669                                 sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
 670                 if (unlikely(ret)) {
 671                         dev_err(&pdev->dev,
 672                                 "request alarm IRQ failed with %d, IRQ %d\n",
 673                                 ret, rtc->alarm_irq);
 674                         goto err_unmap;
 675                 }
 676         }
 677
 678         platform_set_drvdata(pdev, rtc);
 679
 680         /* everything disabled by default */
 681         sh_rtc_irq_set_freq(&pdev->dev, 0);
 682         sh_rtc_irq_set_state(&pdev->dev, 0);
 683         sh_rtc_setaie(&pdev->dev, 0);
 684         sh_rtc_setcie(&pdev->dev, 0);
 685
 686         rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
 687                                            &sh_rtc_ops, THIS_MODULE);
 688         if (IS_ERR(rtc->rtc_dev)) {
 689                 ret = PTR_ERR(rtc->rtc_dev);
 690                 goto err_unmap;
 691         }
 692
 693         rtc->rtc_dev->max_user_freq = 256;
 694
 695         /* reset rtc to epoch 0 if time is invalid */
 696         if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
 697                 rtc_time_to_tm(0, &r);
 698                 rtc_set_time(rtc->rtc_dev, &r);
 699         }
 700
 701         device_init_wakeup(&pdev->dev, 1);
 702         return 0;
 703
 704 err_unmap:
 705         clk_disable(rtc->clk);
 706
 707         return ret;
 708 }
 709
 710 static int __exit sh_rtc_remove(struct platform_device *pdev)
 711 {
 712         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 713
 714         sh_rtc_irq_set_state(&pdev->dev, 0);
 715
 716         sh_rtc_setaie(&pdev->dev, 0);
 717         sh_rtc_setcie(&pdev->dev, 0);
 718
 719         clk_disable(rtc->clk);
 720
 721         return 0;
 722 }
 723
 724 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
 725 {
 726         struct platform_device *pdev = to_platform_device(dev);
 727         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 728
 729         irq_set_irq_wake(rtc->periodic_irq, enabled);
 730
 731         if (rtc->carry_irq > 0) {
 732                 irq_set_irq_wake(rtc->carry_irq, enabled);
 733                 irq_set_irq_wake(rtc->alarm_irq, enabled);
 734         }
 735 }
 736
 737 static int __maybe_unused sh_rtc_suspend(struct device *dev)
 738 {
 739         if (device_may_wakeup(dev))
 740                 sh_rtc_set_irq_wake(dev, 1);
 741
 742         return 0;
 743 }
 744
 745 static int __maybe_unused sh_rtc_resume(struct device *dev)
 746 {
 747         if (device_may_wakeup(dev))
 748                 sh_rtc_set_irq_wake(dev, 0);
 749
 750         return 0;
 751 }
 752
 753 static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume);
 754
 755 static const struct of_device_id sh_rtc_of_match[] = {
 756         { .compatible = "renesas,sh-rtc", },
 757         { /* sentinel */ }
 758 };
 759 MODULE_DEVICE_TABLE(of, sh_rtc_of_match);
 760
 761 static struct platform_driver sh_rtc_platform_driver = {
 762         .driver         = {
 763                 .name   = DRV_NAME,
 764                 .pm     = &sh_rtc_pm_ops,
 765                 .of_match_table = sh_rtc_of_match,
 766         },
 767         .remove         = __exit_p(sh_rtc_remove),
 768 };
 769
 770 module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe);
 771
 772 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
 773 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
 774               "Jamie Lenehan <lenehan@twibble.org>, "
 775               "Angelo Castello <angelo.castello@st.com>");
 776 MODULE_LICENSE("GPL");
 777 MODULE_ALIAS("platform:" DRV_NAME);