drivers/clocksource/sh_cmt.c

   1 /*
   2  * SuperH Timer Support - CMT
   3  *
   4  *  Copyright (C) 2008 Magnus Damm
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/ioport.h>
  25 #include <linux/io.h>
  26 #include <linux/clk.h>
  27 #include <linux/irq.h>
  28 #include <linux/err.h>
  29 #include <linux/delay.h>
  30 #include <linux/clocksource.h>
  31 #include <linux/clockchips.h>
  32 #include <linux/sh_timer.h>
  33 #include <linux/slab.h>
  34 #include <linux/module.h>
  35 #include <linux/pm_domain.h>
  36 #include <linux/pm_runtime.h>
  37
  38 struct sh_cmt_priv {
  39         void __iomem *mapbase;
  40         void __iomem *mapbase_str;
  41         struct clk *clk;
  42         unsigned long width; /* 16 or 32 bit version of hardware block */
  43         unsigned long overflow_bit;
  44         unsigned long clear_bits;
  45         struct irqaction irqaction;
  46         struct platform_device *pdev;
  47
  48         unsigned long flags;
  49         unsigned long match_value;
  50         unsigned long next_match_value;
  51         unsigned long max_match_value;
  52         unsigned long rate;
  53         raw_spinlock_t lock;
  54         struct clock_event_device ced;
  55         struct clocksource cs;
  56         unsigned long total_cycles;
  57         bool cs_enabled;
  58
  59         /* callbacks for CMSTR and CMCSR access */
  60         unsigned long (*read_control)(void __iomem *base, unsigned long offs);
  61         void (*write_control)(void __iomem *base, unsigned long offs,
  62                               unsigned long value);
  63
  64         /* callbacks for CMCNT and CMCOR access */
  65         unsigned long (*read_count)(void __iomem *base, unsigned long offs);
  66         void (*write_count)(void __iomem *base, unsigned long offs,
  67                             unsigned long value);
  68 };
  69
  70 /* Examples of supported CMT timer register layouts and I/O access widths:
  71  *
  72  * "16-bit counter and 16-bit control" as found on sh7263:
  73  * CMSTR 0xfffec000 16-bit
  74  * CMCSR 0xfffec002 16-bit
  75  * CMCNT 0xfffec004 16-bit
  76  * CMCOR 0xfffec006 16-bit
  77  *
  78  * "32-bit counter and 16-bit control" as found on sh7372, sh73a0, r8a7740:
  79  * CMSTR 0xffca0000 16-bit
  80  * CMCSR 0xffca0060 16-bit
  81  * CMCNT 0xffca0064 32-bit
  82  * CMCOR 0xffca0068 32-bit
  83  *
  84  * "32-bit counter and 32-bit control" as found on r8a73a4 and r8a7790:
  85  * CMSTR 0xffca0500 32-bit
  86  * CMCSR 0xffca0510 32-bit
  87  * CMCNT 0xffca0514 32-bit
  88  * CMCOR 0xffca0518 32-bit
  89  */
  90
  91 static unsigned long sh_cmt_read16(void __iomem *base, unsigned long offs)
  92 {
  93         return ioread16(base + (offs << 1));
  94 }
  95
  96 static unsigned long sh_cmt_read32(void __iomem *base, unsigned long offs)
  97 {
  98         return ioread32(base + (offs << 2));
  99 }
 100
 101 static void sh_cmt_write16(void __iomem *base, unsigned long offs,
 102                            unsigned long value)
 103 {
 104         iowrite16(value, base + (offs << 1));
 105 }
 106
 107 static void sh_cmt_write32(void __iomem *base, unsigned long offs,
 108                            unsigned long value)
 109 {
 110         iowrite32(value, base + (offs << 2));
 111 }
 112
 113 #define CMCSR 0 /* channel register */
 114 #define CMCNT 1 /* channel register */
 115 #define CMCOR 2 /* channel register */
 116
 117 static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_priv *p)
 118 {
 119         return p->read_control(p->mapbase_str, 0);
 120 }
 121
 122 static inline unsigned long sh_cmt_read_cmcsr(struct sh_cmt_priv *p)
 123 {
 124         return p->read_control(p->mapbase, CMCSR);
 125 }
 126
 127 static inline unsigned long sh_cmt_read_cmcnt(struct sh_cmt_priv *p)
 128 {
 129         return p->read_count(p->mapbase, CMCNT);
 130 }
 131
 132 static inline void sh_cmt_write_cmstr(struct sh_cmt_priv *p,
 133                                       unsigned long value)
 134 {
 135         p->write_control(p->mapbase_str, 0, value);
 136 }
 137
 138 static inline void sh_cmt_write_cmcsr(struct sh_cmt_priv *p,
 139                                       unsigned long value)
 140 {
 141         p->write_control(p->mapbase, CMCSR, value);
 142 }
 143
 144 static inline void sh_cmt_write_cmcnt(struct sh_cmt_priv *p,
 145                                       unsigned long value)
 146 {
 147         p->write_count(p->mapbase, CMCNT, value);
 148 }
 149
 150 static inline void sh_cmt_write_cmcor(struct sh_cmt_priv *p,
 151                                       unsigned long value)
 152 {
 153         p->write_count(p->mapbase, CMCOR, value);
 154 }
 155
 156 static unsigned long sh_cmt_get_counter(struct sh_cmt_priv *p,
 157                                         int *has_wrapped)
 158 {
 159         unsigned long v1, v2, v3;
 160         int o1, o2;
 161
 162         o1 = sh_cmt_read_cmcsr(p) & p->overflow_bit;
 163
 164         /* Make sure the timer value is stable. Stolen from acpi_pm.c */
 165         do {
 166                 o2 = o1;
 167                 v1 = sh_cmt_read_cmcnt(p);
 168                 v2 = sh_cmt_read_cmcnt(p);
 169                 v3 = sh_cmt_read_cmcnt(p);
 170                 o1 = sh_cmt_read_cmcsr(p) & p->overflow_bit;
 171         } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
 172                           || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
 173
 174         *has_wrapped = o1;
 175         return v2;
 176 }
 177
 178 static DEFINE_RAW_SPINLOCK(sh_cmt_lock);
 179
 180 static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
 181 {
 182         struct sh_timer_config *cfg = p->pdev->dev.platform_data;
 183         unsigned long flags, value;
 184
 185         /* start stop register shared by multiple timer channels */
 186         raw_spin_lock_irqsave(&sh_cmt_lock, flags);
 187         value = sh_cmt_read_cmstr(p);
 188
 189         if (start)
 190                 value |= 1 << cfg->timer_bit;
 191         else
 192                 value &= ~(1 << cfg->timer_bit);
 193
 194         sh_cmt_write_cmstr(p, value);
 195         raw_spin_unlock_irqrestore(&sh_cmt_lock, flags);
 196 }
 197
 198 static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate)
 199 {
 200         int k, ret;
 201
 202         pm_runtime_get_sync(&p->pdev->dev);
 203         dev_pm_syscore_device(&p->pdev->dev, true);
 204
 205         /* enable clock */
 206         ret = clk_enable(p->clk);
 207         if (ret) {
 208                 dev_err(&p->pdev->dev, "cannot enable clock\n");
 209                 goto err0;
 210         }
 211
 212         /* make sure channel is disabled */
 213         sh_cmt_start_stop_ch(p, 0);
 214
 215         /* configure channel, periodic mode and maximum timeout */
 216         if (p->width == 16) {
 217                 *rate = clk_get_rate(p->clk) / 512;
 218                 sh_cmt_write_cmcsr(p, 0x43);
 219         } else {
 220                 *rate = clk_get_rate(p->clk) / 8;
 221                 sh_cmt_write_cmcsr(p, 0x01a4);
 222         }
 223
 224         sh_cmt_write_cmcor(p, 0xffffffff);
 225         sh_cmt_write_cmcnt(p, 0);
 226
 227         /*
 228          * According to the sh73a0 user's manual, as CMCNT can be operated
 229          * only by the RCLK (Pseudo 32 KHz), there's one restriction on
 230          * modifying CMCNT register; two RCLK cycles are necessary before
 231          * this register is either read or any modification of the value
 232          * it holds is reflected in the LSI's actual operation.
 233          *
 234          * While at it, we're supposed to clear out the CMCNT as of this
 235          * moment, so make sure it's processed properly here.  This will
 236          * take RCLKx2 at maximum.
 237          */
 238         for (k = 0; k < 100; k++) {
 239                 if (!sh_cmt_read_cmcnt(p))
 240                         break;
 241                 udelay(1);
 242         }
 243
 244         if (sh_cmt_read_cmcnt(p)) {
 245                 dev_err(&p->pdev->dev, "cannot clear CMCNT\n");
 246                 ret = -ETIMEDOUT;
 247                 goto err1;
 248         }
 249
 250         /* enable channel */
 251         sh_cmt_start_stop_ch(p, 1);
 252         return 0;
 253  err1:
 254         /* stop clock */
 255         clk_disable(p->clk);
 256
 257  err0:
 258         return ret;
 259 }
 260
 261 static void sh_cmt_disable(struct sh_cmt_priv *p)
 262 {
 263         /* disable channel */
 264         sh_cmt_start_stop_ch(p, 0);
 265
 266         /* disable interrupts in CMT block */
 267         sh_cmt_write_cmcsr(p, 0);
 268
 269         /* stop clock */
 270         clk_disable(p->clk);
 271
 272         dev_pm_syscore_device(&p->pdev->dev, false);
 273         pm_runtime_put(&p->pdev->dev);
 274 }
 275
 276 /* private flags */
 277 #define FLAG_CLOCKEVENT (1 << 0)
 278 #define FLAG_CLOCKSOURCE (1 << 1)
 279 #define FLAG_REPROGRAM (1 << 2)
 280 #define FLAG_SKIPEVENT (1 << 3)
 281 #define FLAG_IRQCONTEXT (1 << 4)
 282
 283 static void sh_cmt_clock_event_program_verify(struct sh_cmt_priv *p,
 284                                               int absolute)
 285 {
 286         unsigned long new_match;
 287         unsigned long value = p->next_match_value;
 288         unsigned long delay = 0;
 289         unsigned long now = 0;
 290         int has_wrapped;
 291
 292         now = sh_cmt_get_counter(p, &has_wrapped);
 293         p->flags |= FLAG_REPROGRAM; /* force reprogram */
 294
 295         if (has_wrapped) {
 296                 /* we're competing with the interrupt handler.
 297                  *  -> let the interrupt handler reprogram the timer.
 298                  *  -> interrupt number two handles the event.
 299                  */
 300                 p->flags |= FLAG_SKIPEVENT;
 301                 return;
 302         }
 303
 304         if (absolute)
 305                 now = 0;
 306
 307         do {
 308                 /* reprogram the timer hardware,
 309                  * but don't save the new match value yet.
 310                  */
 311                 new_match = now + value + delay;
 312                 if (new_match > p->max_match_value)
 313                         new_match = p->max_match_value;
 314
 315                 sh_cmt_write_cmcor(p, new_match);
 316
 317                 now = sh_cmt_get_counter(p, &has_wrapped);
 318                 if (has_wrapped && (new_match > p->match_value)) {
 319                         /* we are changing to a greater match value,
 320                          * so this wrap must be caused by the counter
 321                          * matching the old value.
 322                          * -> first interrupt reprograms the timer.
 323                          * -> interrupt number two handles the event.
 324                          */
 325                         p->flags |= FLAG_SKIPEVENT;
 326                         break;
 327                 }
 328
 329                 if (has_wrapped) {
 330                         /* we are changing to a smaller match value,
 331                          * so the wrap must be caused by the counter
 332                          * matching the new value.
 333                          * -> save programmed match value.
 334                          * -> let isr handle the event.
 335                          */
 336                         p->match_value = new_match;
 337                         break;
 338                 }
 339
 340                 /* be safe: verify hardware settings */
 341                 if (now < new_match) {
 342                         /* timer value is below match value, all good.
 343                          * this makes sure we won't miss any match events.
 344                          * -> save programmed match value.
 345                          * -> let isr handle the event.
 346                          */
 347                         p->match_value = new_match;
 348                         break;
 349                 }
 350
 351                 /* the counter has reached a value greater
 352                  * than our new match value. and since the
 353                  * has_wrapped flag isn't set we must have
 354                  * programmed a too close event.
 355                  * -> increase delay and retry.
 356                  */
 357                 if (delay)
 358                         delay <<= 1;
 359                 else
 360                         delay = 1;
 361
 362                 if (!delay)
 363                         dev_warn(&p->pdev->dev, "too long delay\n");
 364
 365         } while (delay);
 366 }
 367
 368 static void __sh_cmt_set_next(struct sh_cmt_priv *p, unsigned long delta)
 369 {
 370         if (delta > p->max_match_value)
 371                 dev_warn(&p->pdev->dev, "delta out of range\n");
 372
 373         p->next_match_value = delta;
 374         sh_cmt_clock_event_program_verify(p, 0);
 375 }
 376
 377 static void sh_cmt_set_next(struct sh_cmt_priv *p, unsigned long delta)
 378 {
 379         unsigned long flags;
 380
 381         raw_spin_lock_irqsave(&p->lock, flags);
 382         __sh_cmt_set_next(p, delta);
 383         raw_spin_unlock_irqrestore(&p->lock, flags);
 384 }
 385
 386 static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
 387 {
 388         struct sh_cmt_priv *p = dev_id;
 389
 390         /* clear flags */
 391         sh_cmt_write_cmcsr(p, sh_cmt_read_cmcsr(p) & p->clear_bits);
 392
 393         /* update clock source counter to begin with if enabled
 394          * the wrap flag should be cleared by the timer specific
 395          * isr before we end up here.
 396          */
 397         if (p->flags & FLAG_CLOCKSOURCE)
 398                 p->total_cycles += p->match_value + 1;
 399
 400         if (!(p->flags & FLAG_REPROGRAM))
 401                 p->next_match_value = p->max_match_value;
 402
 403         p->flags |= FLAG_IRQCONTEXT;
 404
 405         if (p->flags & FLAG_CLOCKEVENT) {
 406                 if (!(p->flags & FLAG_SKIPEVENT)) {
 407                         if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT) {
 408                                 p->next_match_value = p->max_match_value;
 409                                 p->flags |= FLAG_REPROGRAM;
 410                         }
 411
 412                         p->ced.event_handler(&p->ced);
 413                 }
 414         }
 415
 416         p->flags &= ~FLAG_SKIPEVENT;
 417
 418         if (p->flags & FLAG_REPROGRAM) {
 419                 p->flags &= ~FLAG_REPROGRAM;
 420                 sh_cmt_clock_event_program_verify(p, 1);
 421
 422                 if (p->flags & FLAG_CLOCKEVENT)
 423                         if ((p->ced.mode == CLOCK_EVT_MODE_SHUTDOWN)
 424                             || (p->match_value == p->next_match_value))
 425                                 p->flags &= ~FLAG_REPROGRAM;
 426         }
 427
 428         p->flags &= ~FLAG_IRQCONTEXT;
 429
 430         return IRQ_HANDLED;
 431 }
 432
 433 static int sh_cmt_start(struct sh_cmt_priv *p, unsigned long flag)
 434 {
 435         int ret = 0;
 436         unsigned long flags;
 437
 438         raw_spin_lock_irqsave(&p->lock, flags);
 439
 440         if (!(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
 441                 ret = sh_cmt_enable(p, &p->rate);
 442
 443         if (ret)
 444                 goto out;
 445         p->flags |= flag;
 446
 447         /* setup timeout if no clockevent */
 448         if ((flag == FLAG_CLOCKSOURCE) && (!(p->flags & FLAG_CLOCKEVENT)))
 449                 __sh_cmt_set_next(p, p->max_match_value);
 450  out:
 451         raw_spin_unlock_irqrestore(&p->lock, flags);
 452
 453         return ret;
 454 }
 455
 456 static void sh_cmt_stop(struct sh_cmt_priv *p, unsigned long flag)
 457 {
 458         unsigned long flags;
 459         unsigned long f;
 460
 461         raw_spin_lock_irqsave(&p->lock, flags);
 462
 463         f = p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
 464         p->flags &= ~flag;
 465
 466         if (f && !(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
 467                 sh_cmt_disable(p);
 468
 469         /* adjust the timeout to maximum if only clocksource left */
 470         if ((flag == FLAG_CLOCKEVENT) && (p->flags & FLAG_CLOCKSOURCE))
 471                 __sh_cmt_set_next(p, p->max_match_value);
 472
 473         raw_spin_unlock_irqrestore(&p->lock, flags);
 474 }
 475
 476 static struct sh_cmt_priv *cs_to_sh_cmt(struct clocksource *cs)
 477 {
 478         return container_of(cs, struct sh_cmt_priv, cs);
 479 }
 480
 481 static cycle_t sh_cmt_clocksource_read(struct clocksource *cs)
 482 {
 483         struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
 484         unsigned long flags, raw;
 485         unsigned long value;
 486         int has_wrapped;
 487
 488         raw_spin_lock_irqsave(&p->lock, flags);
 489         value = p->total_cycles;
 490         raw = sh_cmt_get_counter(p, &has_wrapped);
 491
 492         if (unlikely(has_wrapped))
 493                 raw += p->match_value + 1;
 494         raw_spin_unlock_irqrestore(&p->lock, flags);
 495
 496         return value + raw;
 497 }
 498
 499 static int sh_cmt_clocksource_enable(struct clocksource *cs)
 500 {
 501         int ret;
 502         struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
 503
 504         WARN_ON(p->cs_enabled);
 505
 506         p->total_cycles = 0;
 507
 508         ret = sh_cmt_start(p, FLAG_CLOCKSOURCE);
 509         if (!ret) {
 510                 __clocksource_updatefreq_hz(cs, p->rate);
 511                 p->cs_enabled = true;
 512         }
 513         return ret;
 514 }
 515
 516 static void sh_cmt_clocksource_disable(struct clocksource *cs)
 517 {
 518         struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
 519
 520         WARN_ON(!p->cs_enabled);
 521
 522         sh_cmt_stop(p, FLAG_CLOCKSOURCE);
 523         p->cs_enabled = false;
 524 }
 525
 526 static void sh_cmt_clocksource_suspend(struct clocksource *cs)
 527 {
 528         struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
 529
 530         sh_cmt_stop(p, FLAG_CLOCKSOURCE);
 531         pm_genpd_syscore_poweroff(&p->pdev->dev);
 532 }
 533
 534 static void sh_cmt_clocksource_resume(struct clocksource *cs)
 535 {
 536         struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
 537
 538         pm_genpd_syscore_poweron(&p->pdev->dev);
 539         sh_cmt_start(p, FLAG_CLOCKSOURCE);
 540 }
 541
 542 static int sh_cmt_register_clocksource(struct sh_cmt_priv *p,
 543                                        char *name, unsigned long rating)
 544 {
 545         struct clocksource *cs = &p->cs;
 546
 547         cs->name = name;
 548         cs->rating = rating;
 549         cs->read = sh_cmt_clocksource_read;
 550         cs->enable = sh_cmt_clocksource_enable;
 551         cs->disable = sh_cmt_clocksource_disable;
 552         cs->suspend = sh_cmt_clocksource_suspend;
 553         cs->resume = sh_cmt_clocksource_resume;
 554         cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
 555         cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
 556
 557         dev_info(&p->pdev->dev, "used as clock source\n");
 558
 559         /* Register with dummy 1 Hz value, gets updated in ->enable() */
 560         clocksource_register_hz(cs, 1);
 561         return 0;
 562 }
 563
 564 static struct sh_cmt_priv *ced_to_sh_cmt(struct clock_event_device *ced)
 565 {
 566         return container_of(ced, struct sh_cmt_priv, ced);
 567 }
 568
 569 static void sh_cmt_clock_event_start(struct sh_cmt_priv *p, int periodic)
 570 {
 571         struct clock_event_device *ced = &p->ced;
 572
 573         sh_cmt_start(p, FLAG_CLOCKEVENT);
 574
 575         /* TODO: calculate good shift from rate and counter bit width */
 576
 577         ced->shift = 32;
 578         ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
 579         ced->max_delta_ns = clockevent_delta2ns(p->max_match_value, ced);
 580         ced->min_delta_ns = clockevent_delta2ns(0x1f, ced);
 581
 582         if (periodic)
 583                 sh_cmt_set_next(p, ((p->rate + HZ/2) / HZ) - 1);
 584         else
 585                 sh_cmt_set_next(p, p->max_match_value);
 586 }
 587
 588 static void sh_cmt_clock_event_mode(enum clock_event_mode mode,
 589                                     struct clock_event_device *ced)
 590 {
 591         struct sh_cmt_priv *p = ced_to_sh_cmt(ced);
 592
 593         /* deal with old setting first */
 594         switch (ced->mode) {
 595         case CLOCK_EVT_MODE_PERIODIC:
 596         case CLOCK_EVT_MODE_ONESHOT:
 597                 sh_cmt_stop(p, FLAG_CLOCKEVENT);
 598                 break;
 599         default:
 600                 break;
 601         }
 602
 603         switch (mode) {
 604         case CLOCK_EVT_MODE_PERIODIC:
 605                 dev_info(&p->pdev->dev, "used for periodic clock events\n");
 606                 sh_cmt_clock_event_start(p, 1);
 607                 break;
 608         case CLOCK_EVT_MODE_ONESHOT:
 609                 dev_info(&p->pdev->dev, "used for oneshot clock events\n");
 610                 sh_cmt_clock_event_start(p, 0);
 611                 break;
 612         case CLOCK_EVT_MODE_SHUTDOWN:
 613         case CLOCK_EVT_MODE_UNUSED:
 614                 sh_cmt_stop(p, FLAG_CLOCKEVENT);
 615                 break;
 616         default:
 617                 break;
 618         }
 619 }
 620
 621 static int sh_cmt_clock_event_next(unsigned long delta,
 622                                    struct clock_event_device *ced)
 623 {
 624         struct sh_cmt_priv *p = ced_to_sh_cmt(ced);
 625
 626         BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT);
 627         if (likely(p->flags & FLAG_IRQCONTEXT))
 628                 p->next_match_value = delta - 1;
 629         else
 630                 sh_cmt_set_next(p, delta - 1);
 631
 632         return 0;
 633 }
 634
 635 static void sh_cmt_clock_event_suspend(struct clock_event_device *ced)
 636 {
 637         pm_genpd_syscore_poweroff(&ced_to_sh_cmt(ced)->pdev->dev);
 638 }
 639
 640 static void sh_cmt_clock_event_resume(struct clock_event_device *ced)
 641 {
 642         pm_genpd_syscore_poweron(&ced_to_sh_cmt(ced)->pdev->dev);
 643 }
 644
 645 static void sh_cmt_register_clockevent(struct sh_cmt_priv *p,
 646                                        char *name, unsigned long rating)
 647 {
 648         struct clock_event_device *ced = &p->ced;
 649
 650         memset(ced, 0, sizeof(*ced));
 651
 652         ced->name = name;
 653         ced->features = CLOCK_EVT_FEAT_PERIODIC;
 654         ced->features |= CLOCK_EVT_FEAT_ONESHOT;
 655         ced->rating = rating;
 656         ced->cpumask = cpumask_of(0);
 657         ced->set_next_event = sh_cmt_clock_event_next;
 658         ced->set_mode = sh_cmt_clock_event_mode;
 659         ced->suspend = sh_cmt_clock_event_suspend;
 660         ced->resume = sh_cmt_clock_event_resume;
 661
 662         dev_info(&p->pdev->dev, "used for clock events\n");
 663         clockevents_register_device(ced);
 664 }
 665
 666 static int sh_cmt_register(struct sh_cmt_priv *p, char *name,
 667                            unsigned long clockevent_rating,
 668                            unsigned long clocksource_rating)
 669 {
 670         if (clockevent_rating)
 671                 sh_cmt_register_clockevent(p, name, clockevent_rating);
 672
 673         if (clocksource_rating)
 674                 sh_cmt_register_clocksource(p, name, clocksource_rating);
 675
 676         return 0;
 677 }
 678
 679 static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev)
 680 {
 681         struct sh_timer_config *cfg = pdev->dev.platform_data;
 682         struct resource *res, *res2;
 683         int irq, ret;
 684         ret = -ENXIO;
 685
 686         memset(p, 0, sizeof(*p));
 687         p->pdev = pdev;
 688
 689         if (!cfg) {
 690                 dev_err(&p->pdev->dev, "missing platform data\n");
 691                 goto err0;
 692         }
 693
 694         res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0);
 695         if (!res) {
 696                 dev_err(&p->pdev->dev, "failed to get I/O memory\n");
 697                 goto err0;
 698         }
 699
 700         /* optional resource for the shared timer start/stop register */
 701         res2 = platform_get_resource(p->pdev, IORESOURCE_MEM, 1);
 702
 703         irq = platform_get_irq(p->pdev, 0);
 704         if (irq < 0) {
 705                 dev_err(&p->pdev->dev, "failed to get irq\n");
 706                 goto err0;
 707         }
 708
 709         /* map memory, let mapbase point to our channel */
 710         p->mapbase = ioremap_nocache(res->start, resource_size(res));
 711         if (p->mapbase == NULL) {
 712                 dev_err(&p->pdev->dev, "failed to remap I/O memory\n");
 713                 goto err0;
 714         }
 715
 716         /* map second resource for CMSTR */
 717         p->mapbase_str = ioremap_nocache(res2 ? res2->start :
 718                                          res->start - cfg->channel_offset,
 719                                          res2 ? resource_size(res2) : 2);
 720         if (p->mapbase_str == NULL) {
 721                 dev_err(&p->pdev->dev, "failed to remap I/O second memory\n");
 722                 goto err1;
 723         }
 724
 725         /* request irq using setup_irq() (too early for request_irq()) */
 726         p->irqaction.name = dev_name(&p->pdev->dev);
 727         p->irqaction.handler = sh_cmt_interrupt;
 728         p->irqaction.dev_id = p;
 729         p->irqaction.flags = IRQF_DISABLED | IRQF_TIMER | \
 730                              IRQF_IRQPOLL  | IRQF_NOBALANCING;
 731
 732         /* get hold of clock */
 733         p->clk = clk_get(&p->pdev->dev, "cmt_fck");
 734         if (IS_ERR(p->clk)) {
 735                 dev_err(&p->pdev->dev, "cannot get clock\n");
 736                 ret = PTR_ERR(p->clk);
 737                 goto err2;
 738         }
 739
 740         if (res2 && (resource_size(res2) == 4)) {
 741                 /* assume both CMSTR and CMCSR to be 32-bit */
 742                 p->read_control = sh_cmt_read32;
 743                 p->write_control = sh_cmt_write32;
 744         } else {
 745                 p->read_control = sh_cmt_read16;
 746                 p->write_control = sh_cmt_write16;
 747         }
 748
 749         if (resource_size(res) == 6) {
 750                 p->width = 16;
 751                 p->read_count = sh_cmt_read16;
 752                 p->write_count = sh_cmt_write16;
 753                 p->overflow_bit = 0x80;
 754                 p->clear_bits = ~0x80;
 755         } else {
 756                 p->width = 32;
 757                 p->read_count = sh_cmt_read32;
 758                 p->write_count = sh_cmt_write32;
 759                 p->overflow_bit = 0x8000;
 760                 p->clear_bits = ~0xc000;
 761         }
 762
 763         if (p->width == (sizeof(p->max_match_value) * 8))
 764                 p->max_match_value = ~0;
 765         else
 766                 p->max_match_value = (1 << p->width) - 1;
 767
 768         p->match_value = p->max_match_value;
 769         raw_spin_lock_init(&p->lock);
 770
 771         ret = sh_cmt_register(p, (char *)dev_name(&p->pdev->dev),
 772                               cfg->clockevent_rating,
 773                               cfg->clocksource_rating);
 774         if (ret) {
 775                 dev_err(&p->pdev->dev, "registration failed\n");
 776                 goto err3;
 777         }
 778         p->cs_enabled = false;
 779
 780         ret = setup_irq(irq, &p->irqaction);
 781         if (ret) {
 782                 dev_err(&p->pdev->dev, "failed to request irq %d\n", irq);
 783                 goto err3;
 784         }
 785
 786         platform_set_drvdata(pdev, p);
 787
 788         return 0;
 789 err3:
 790         clk_put(p->clk);
 791 err2:
 792         iounmap(p->mapbase_str);
 793 err1:
 794         iounmap(p->mapbase);
 795 err0:
 796         return ret;
 797 }
 798
 799 static int sh_cmt_probe(struct platform_device *pdev)
 800 {
 801         struct sh_cmt_priv *p = platform_get_drvdata(pdev);
 802         struct sh_timer_config *cfg = pdev->dev.platform_data;
 803         int ret;
 804
 805         if (!is_early_platform_device(pdev)) {
 806                 pm_runtime_set_active(&pdev->dev);
 807                 pm_runtime_enable(&pdev->dev);
 808         }
 809
 810         if (p) {
 811                 dev_info(&pdev->dev, "kept as earlytimer\n");
 812                 goto out;
 813         }
 814
 815         p = kmalloc(sizeof(*p), GFP_KERNEL);
 816         if (p == NULL) {
 817                 dev_err(&pdev->dev, "failed to allocate driver data\n");
 818                 return -ENOMEM;
 819         }
 820
 821         ret = sh_cmt_setup(p, pdev);
 822         if (ret) {
 823                 kfree(p);
 824                 pm_runtime_idle(&pdev->dev);
 825                 return ret;
 826         }
 827         if (is_early_platform_device(pdev))
 828                 return 0;
 829
 830  out:
 831         if (cfg->clockevent_rating || cfg->clocksource_rating)
 832                 pm_runtime_irq_safe(&pdev->dev);
 833         else
 834                 pm_runtime_idle(&pdev->dev);
 835
 836         return 0;
 837 }
 838
 839 static int sh_cmt_remove(struct platform_device *pdev)
 840 {
 841         return -EBUSY; /* cannot unregister clockevent and clocksource */
 842 }
 843
 844 static struct platform_driver sh_cmt_device_driver = {
 845         .probe          = sh_cmt_probe,
 846         .remove         = sh_cmt_remove,
 847         .driver         = {
 848                 .name   = "sh_cmt",
 849         }
 850 };
 851
 852 static int __init sh_cmt_init(void)
 853 {
 854         return platform_driver_register(&sh_cmt_device_driver);
 855 }
 856
 857 static void __exit sh_cmt_exit(void)
 858 {
 859         platform_driver_unregister(&sh_cmt_device_driver);
 860 }
 861
 862 early_platform_init("earlytimer", &sh_cmt_device_driver);
 863 subsys_initcall(sh_cmt_init);
 864 module_exit(sh_cmt_exit);
 865
 866 MODULE_AUTHOR("Magnus Damm");
 867 MODULE_DESCRIPTION("SuperH CMT Timer Driver");
 868 MODULE_LICENSE("GPL v2");