drivers/clocksource/exynos_mct.c

   1 /* linux/arch/arm/mach-exynos4/mct.c
   2  *
   3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com
   5  *
   6  * EXYNOS4 MCT(Multi-Core Timer) support
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11 */
  12
  13 #include <linux/sched.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/irq.h>
  16 #include <linux/err.h>
  17 #include <linux/clk.h>
  18 #include <linux/clockchips.h>
  19 #include <linux/cpu.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/delay.h>
  22 #include <linux/percpu.h>
  23 #include <linux/of.h>
  24 #include <linux/of_irq.h>
  25 #include <linux/of_address.h>
  26 #include <linux/clocksource.h>
  27 #include <linux/sched_clock.h>
  28
  29 #define EXYNOS4_MCTREG(x)               (x)
  30 #define EXYNOS4_MCT_G_CNT_L             EXYNOS4_MCTREG(0x100)
  31 #define EXYNOS4_MCT_G_CNT_U             EXYNOS4_MCTREG(0x104)
  32 #define EXYNOS4_MCT_G_CNT_WSTAT         EXYNOS4_MCTREG(0x110)
  33 #define EXYNOS4_MCT_G_COMP0_L           EXYNOS4_MCTREG(0x200)
  34 #define EXYNOS4_MCT_G_COMP0_U           EXYNOS4_MCTREG(0x204)
  35 #define EXYNOS4_MCT_G_COMP0_ADD_INCR    EXYNOS4_MCTREG(0x208)
  36 #define EXYNOS4_MCT_G_TCON              EXYNOS4_MCTREG(0x240)
  37 #define EXYNOS4_MCT_G_INT_CSTAT         EXYNOS4_MCTREG(0x244)
  38 #define EXYNOS4_MCT_G_INT_ENB           EXYNOS4_MCTREG(0x248)
  39 #define EXYNOS4_MCT_G_WSTAT             EXYNOS4_MCTREG(0x24C)
  40 #define _EXYNOS4_MCT_L_BASE             EXYNOS4_MCTREG(0x300)
  41 #define EXYNOS4_MCT_L_BASE(x)           (_EXYNOS4_MCT_L_BASE + (0x100 * x))
  42 #define EXYNOS4_MCT_L_MASK              (0xffffff00)
  43
  44 #define MCT_L_TCNTB_OFFSET              (0x00)
  45 #define MCT_L_ICNTB_OFFSET              (0x08)
  46 #define MCT_L_TCON_OFFSET               (0x20)
  47 #define MCT_L_INT_CSTAT_OFFSET          (0x30)
  48 #define MCT_L_INT_ENB_OFFSET            (0x34)
  49 #define MCT_L_WSTAT_OFFSET              (0x40)
  50 #define MCT_G_TCON_START                (1 << 8)
  51 #define MCT_G_TCON_COMP0_AUTO_INC       (1 << 1)
  52 #define MCT_G_TCON_COMP0_ENABLE         (1 << 0)
  53 #define MCT_L_TCON_INTERVAL_MODE        (1 << 2)
  54 #define MCT_L_TCON_INT_START            (1 << 1)
  55 #define MCT_L_TCON_TIMER_START          (1 << 0)
  56
  57 #define TICK_BASE_CNT   1
  58
  59 enum {
  60         MCT_INT_SPI,
  61         MCT_INT_PPI
  62 };
  63
  64 enum {
  65         MCT_G0_IRQ,
  66         MCT_G1_IRQ,
  67         MCT_G2_IRQ,
  68         MCT_G3_IRQ,
  69         MCT_L0_IRQ,
  70         MCT_L1_IRQ,
  71         MCT_L2_IRQ,
  72         MCT_L3_IRQ,
  73         MCT_L4_IRQ,
  74         MCT_L5_IRQ,
  75         MCT_L6_IRQ,
  76         MCT_L7_IRQ,
  77         MCT_NR_IRQS,
  78 };
  79
  80 static void __iomem *reg_base;
  81 static unsigned long clk_rate;
  82 static unsigned int mct_int_type;
  83 static int mct_irqs[MCT_NR_IRQS];
  84
  85 struct mct_clock_event_device {
  86         struct clock_event_device evt;
  87         unsigned long base;
  88         char name[10];
  89 };
  90
  91 static void exynos4_mct_write(unsigned int value, unsigned long offset)
  92 {
  93         unsigned long stat_addr;
  94         u32 mask;
  95         u32 i;
  96
  97         writel_relaxed(value, reg_base + offset);
  98
  99         if (likely(offset >= EXYNOS4_MCT_L_BASE(0))) {
 100                 stat_addr = (offset & EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET;
 101                 switch (offset & ~EXYNOS4_MCT_L_MASK) {
 102                 case MCT_L_TCON_OFFSET:
 103                         mask = 1 << 3;          /* L_TCON write status */
 104                         break;
 105                 case MCT_L_ICNTB_OFFSET:
 106                         mask = 1 << 1;          /* L_ICNTB write status */
 107                         break;
 108                 case MCT_L_TCNTB_OFFSET:
 109                         mask = 1 << 0;          /* L_TCNTB write status */
 110                         break;
 111                 default:
 112                         return;
 113                 }
 114         } else {
 115                 switch (offset) {
 116                 case EXYNOS4_MCT_G_TCON:
 117                         stat_addr = EXYNOS4_MCT_G_WSTAT;
 118                         mask = 1 << 16;         /* G_TCON write status */
 119                         break;
 120                 case EXYNOS4_MCT_G_COMP0_L:
 121                         stat_addr = EXYNOS4_MCT_G_WSTAT;
 122                         mask = 1 << 0;          /* G_COMP0_L write status */
 123                         break;
 124                 case EXYNOS4_MCT_G_COMP0_U:
 125                         stat_addr = EXYNOS4_MCT_G_WSTAT;
 126                         mask = 1 << 1;          /* G_COMP0_U write status */
 127                         break;
 128                 case EXYNOS4_MCT_G_COMP0_ADD_INCR:
 129                         stat_addr = EXYNOS4_MCT_G_WSTAT;
 130                         mask = 1 << 2;          /* G_COMP0_ADD_INCR w status */
 131                         break;
 132                 case EXYNOS4_MCT_G_CNT_L:
 133                         stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
 134                         mask = 1 << 0;          /* G_CNT_L write status */
 135                         break;
 136                 case EXYNOS4_MCT_G_CNT_U:
 137                         stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
 138                         mask = 1 << 1;          /* G_CNT_U write status */
 139                         break;
 140                 default:
 141                         return;
 142                 }
 143         }
 144
 145         /* Wait maximum 1 ms until written values are applied */
 146         for (i = 0; i < loops_per_jiffy / 1000 * HZ; i++)
 147                 if (readl_relaxed(reg_base + stat_addr) & mask) {
 148                         writel_relaxed(mask, reg_base + stat_addr);
 149                         return;
 150                 }
 151
 152         panic("MCT hangs after writing %d (offset:0x%lx)\n", value, offset);
 153 }
 154
 155 /* Clocksource handling */
 156 static void exynos4_mct_frc_start(void)
 157 {
 158         u32 reg;
 159
 160         reg = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
 161         reg |= MCT_G_TCON_START;
 162         exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON);
 163 }
 164
 165 /**
 166  * exynos4_read_count_64 - Read all 64-bits of the global counter
 167  *
 168  * This will read all 64-bits of the global counter taking care to make sure
 169  * that the upper and lower half match.  Note that reading the MCT can be quite
 170  * slow (hundreds of nanoseconds) so you should use the 32-bit (lower half
 171  * only) version when possible.
 172  *
 173  * Returns the number of cycles in the global counter.
 174  */
 175 static u64 exynos4_read_count_64(void)
 176 {
 177         unsigned int lo, hi;
 178         u32 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
 179
 180         do {
 181                 hi = hi2;
 182                 lo = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
 183                 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
 184         } while (hi != hi2);
 185
 186         return ((cycle_t)hi << 32) | lo;
 187 }
 188
 189 /**
 190  * exynos4_read_count_32 - Read the lower 32-bits of the global counter
 191  *
 192  * This will read just the lower 32-bits of the global counter.  This is marked
 193  * as notrace so it can be used by the scheduler clock.
 194  *
 195  * Returns the number of cycles in the global counter (lower 32 bits).
 196  */
 197 static u32 notrace exynos4_read_count_32(void)
 198 {
 199         return readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
 200 }
 201
 202 static cycle_t exynos4_frc_read(struct clocksource *cs)
 203 {
 204         return exynos4_read_count_32();
 205 }
 206
 207 static void exynos4_frc_resume(struct clocksource *cs)
 208 {
 209         exynos4_mct_frc_start();
 210 }
 211
 212 static struct clocksource mct_frc = {
 213         .name           = "mct-frc",
 214         .rating         = 400,
 215         .read           = exynos4_frc_read,
 216         .mask           = CLOCKSOURCE_MASK(32),
 217         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 218         .resume         = exynos4_frc_resume,
 219 };
 220
 221 static u64 notrace exynos4_read_sched_clock(void)
 222 {
 223         return exynos4_read_count_32();
 224 }
 225
 226 static struct delay_timer exynos4_delay_timer;
 227
 228 static cycles_t exynos4_read_current_timer(void)
 229 {
 230         BUILD_BUG_ON_MSG(sizeof(cycles_t) != sizeof(u32),
 231                          "cycles_t needs to move to 32-bit for ARM64 usage");
 232         return exynos4_read_count_32();
 233 }
 234
 235 static int __init exynos4_clocksource_init(void)
 236 {
 237         exynos4_mct_frc_start();
 238
 239         exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer;
 240         exynos4_delay_timer.freq = clk_rate;
 241         register_current_timer_delay(&exynos4_delay_timer);
 242
 243         if (clocksource_register_hz(&mct_frc, clk_rate))
 244                 panic("%s: can't register clocksource\n", mct_frc.name);
 245
 246         sched_clock_register(exynos4_read_sched_clock, 32, clk_rate);
 247
 248         return 0;
 249 }
 250
 251 static void exynos4_mct_comp0_stop(void)
 252 {
 253         unsigned int tcon;
 254
 255         tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
 256         tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
 257
 258         exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON);
 259         exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB);
 260 }
 261
 262 static void exynos4_mct_comp0_start(bool periodic, unsigned long cycles)
 263 {
 264         unsigned int tcon;
 265         cycle_t comp_cycle;
 266
 267         tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
 268
 269         if (periodic) {
 270                 tcon |= MCT_G_TCON_COMP0_AUTO_INC;
 271                 exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
 272         }
 273
 274         comp_cycle = exynos4_read_count_64() + cycles;
 275         exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
 276         exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
 277
 278         exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB);
 279
 280         tcon |= MCT_G_TCON_COMP0_ENABLE;
 281         exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON);
 282 }
 283
 284 static int exynos4_comp_set_next_event(unsigned long cycles,
 285                                        struct clock_event_device *evt)
 286 {
 287         exynos4_mct_comp0_start(false, cycles);
 288
 289         return 0;
 290 }
 291
 292 static int mct_set_state_shutdown(struct clock_event_device *evt)
 293 {
 294         exynos4_mct_comp0_stop();
 295         return 0;
 296 }
 297
 298 static int mct_set_state_periodic(struct clock_event_device *evt)
 299 {
 300         unsigned long cycles_per_jiffy;
 301
 302         cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
 303                             >> evt->shift);
 304         exynos4_mct_comp0_stop();
 305         exynos4_mct_comp0_start(true, cycles_per_jiffy);
 306         return 0;
 307 }
 308
 309 static struct clock_event_device mct_comp_device = {
 310         .name                   = "mct-comp",
 311         .features               = CLOCK_EVT_FEAT_PERIODIC |
 312                                   CLOCK_EVT_FEAT_ONESHOT,
 313         .rating                 = 250,
 314         .set_next_event         = exynos4_comp_set_next_event,
 315         .set_state_periodic     = mct_set_state_periodic,
 316         .set_state_shutdown     = mct_set_state_shutdown,
 317         .set_state_oneshot      = mct_set_state_shutdown,
 318         .set_state_oneshot_stopped = mct_set_state_shutdown,
 319         .tick_resume            = mct_set_state_shutdown,
 320 };
 321
 322 static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
 323 {
 324         struct clock_event_device *evt = dev_id;
 325
 326         exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT);
 327
 328         evt->event_handler(evt);
 329
 330         return IRQ_HANDLED;
 331 }
 332
 333 static struct irqaction mct_comp_event_irq = {
 334         .name           = "mct_comp_irq",
 335         .flags          = IRQF_TIMER | IRQF_IRQPOLL,
 336         .handler        = exynos4_mct_comp_isr,
 337         .dev_id         = &mct_comp_device,
 338 };
 339
 340 static int exynos4_clockevent_init(void)
 341 {
 342         mct_comp_device.cpumask = cpumask_of(0);
 343         clockevents_config_and_register(&mct_comp_device, clk_rate,
 344                                         0xf, 0xffffffff);
 345         setup_irq(mct_irqs[MCT_G0_IRQ], &mct_comp_event_irq);
 346
 347         return 0;
 348 }
 349
 350 static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
 351
 352 /* Clock event handling */
 353 static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
 354 {
 355         unsigned long tmp;
 356         unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
 357         unsigned long offset = mevt->base + MCT_L_TCON_OFFSET;
 358
 359         tmp = readl_relaxed(reg_base + offset);
 360         if (tmp & mask) {
 361                 tmp &= ~mask;
 362                 exynos4_mct_write(tmp, offset);
 363         }
 364 }
 365
 366 static void exynos4_mct_tick_start(unsigned long cycles,
 367                                    struct mct_clock_event_device *mevt)
 368 {
 369         unsigned long tmp;
 370
 371         exynos4_mct_tick_stop(mevt);
 372
 373         tmp = (1 << 31) | cycles;       /* MCT_L_UPDATE_ICNTB */
 374
 375         /* update interrupt count buffer */
 376         exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
 377
 378         /* enable MCT tick interrupt */
 379         exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET);
 380
 381         tmp = readl_relaxed(reg_base + mevt->base + MCT_L_TCON_OFFSET);
 382         tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
 383                MCT_L_TCON_INTERVAL_MODE;
 384         exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
 385 }
 386
 387 static int exynos4_tick_set_next_event(unsigned long cycles,
 388                                        struct clock_event_device *evt)
 389 {
 390         struct mct_clock_event_device *mevt;
 391
 392         mevt = container_of(evt, struct mct_clock_event_device, evt);
 393         exynos4_mct_tick_start(cycles, mevt);
 394         return 0;
 395 }
 396
 397 static int set_state_shutdown(struct clock_event_device *evt)
 398 {
 399         struct mct_clock_event_device *mevt;
 400
 401         mevt = container_of(evt, struct mct_clock_event_device, evt);
 402         exynos4_mct_tick_stop(mevt);
 403         return 0;
 404 }
 405
 406 static int set_state_periodic(struct clock_event_device *evt)
 407 {
 408         struct mct_clock_event_device *mevt;
 409         unsigned long cycles_per_jiffy;
 410
 411         mevt = container_of(evt, struct mct_clock_event_device, evt);
 412         cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
 413                             >> evt->shift);
 414         exynos4_mct_tick_stop(mevt);
 415         exynos4_mct_tick_start(cycles_per_jiffy, mevt);
 416         return 0;
 417 }
 418
 419 static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
 420 {
 421         /*
 422          * This is for supporting oneshot mode.
 423          * Mct would generate interrupt periodically
 424          * without explicit stopping.
 425          */
 426         if (!clockevent_state_periodic(&mevt->evt))
 427                 exynos4_mct_tick_stop(mevt);
 428
 429         /* Clear the MCT tick interrupt */
 430         if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
 431                 exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
 432 }
 433
 434 static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
 435 {
 436         struct mct_clock_event_device *mevt = dev_id;
 437         struct clock_event_device *evt = &mevt->evt;
 438
 439         exynos4_mct_tick_clear(mevt);
 440
 441         evt->event_handler(evt);
 442
 443         return IRQ_HANDLED;
 444 }
 445
 446 static int exynos4_mct_starting_cpu(unsigned int cpu)
 447 {
 448         struct mct_clock_event_device *mevt =
 449                 per_cpu_ptr(&percpu_mct_tick, cpu);
 450         struct clock_event_device *evt = &mevt->evt;
 451
 452         mevt->base = EXYNOS4_MCT_L_BASE(cpu);
 453         snprintf(mevt->name, sizeof(mevt->name), "mct_tick%d", cpu);
 454
 455         evt->name = mevt->name;
 456         evt->cpumask = cpumask_of(cpu);
 457         evt->set_next_event = exynos4_tick_set_next_event;
 458         evt->set_state_periodic = set_state_periodic;
 459         evt->set_state_shutdown = set_state_shutdown;
 460         evt->set_state_oneshot = set_state_shutdown;
 461         evt->set_state_oneshot_stopped = set_state_shutdown;
 462         evt->tick_resume = set_state_shutdown;
 463         evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 464         evt->rating = 450;
 465
 466         exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
 467
 468         if (mct_int_type == MCT_INT_SPI) {
 469
 470                 if (evt->irq == -1)
 471                         return -EIO;
 472
 473                 irq_force_affinity(evt->irq, cpumask_of(cpu));
 474                 enable_irq(evt->irq);
 475         } else {
 476                 enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
 477         }
 478         clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
 479                                         0xf, 0x7fffffff);
 480
 481         return 0;
 482 }
 483
 484 static int exynos4_mct_dying_cpu(unsigned int cpu)
 485 {
 486         struct mct_clock_event_device *mevt =
 487                 per_cpu_ptr(&percpu_mct_tick, cpu);
 488         struct clock_event_device *evt = &mevt->evt;
 489
 490         evt->set_state_shutdown(evt);
 491         if (mct_int_type == MCT_INT_SPI) {
 492                 if (evt->irq != -1)
 493                         disable_irq_nosync(evt->irq);
 494         } else {
 495                 disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
 496         }
 497         return 0;
 498 }
 499
 500 static int __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
 501 {
 502         int err, cpu;
 503         struct clk *mct_clk, *tick_clk;
 504
 505         tick_clk = np ? of_clk_get_by_name(np, "fin_pll") :
 506                                 clk_get(NULL, "fin_pll");
 507         if (IS_ERR(tick_clk))
 508                 panic("%s: unable to determine tick clock rate\n", __func__);
 509         clk_rate = clk_get_rate(tick_clk);
 510
 511         mct_clk = np ? of_clk_get_by_name(np, "mct") : clk_get(NULL, "mct");
 512         if (IS_ERR(mct_clk))
 513                 panic("%s: unable to retrieve mct clock instance\n", __func__);
 514         clk_prepare_enable(mct_clk);
 515
 516         reg_base = base;
 517         if (!reg_base)
 518                 panic("%s: unable to ioremap mct address space\n", __func__);
 519
 520         if (mct_int_type == MCT_INT_PPI) {
 521
 522                 err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
 523                                          exynos4_mct_tick_isr, "MCT",
 524                                          &percpu_mct_tick);
 525                 WARN(err, "MCT: can't request IRQ %d (%d)\n",
 526                      mct_irqs[MCT_L0_IRQ], err);
 527         } else {
 528                 for_each_possible_cpu(cpu) {
 529                         int mct_irq = mct_irqs[MCT_L0_IRQ + cpu];
 530                         struct mct_clock_event_device *pcpu_mevt =
 531                                 per_cpu_ptr(&percpu_mct_tick, cpu);
 532
 533                         pcpu_mevt->evt.irq = -1;
 534
 535                         irq_set_status_flags(mct_irq, IRQ_NOAUTOEN);
 536                         if (request_irq(mct_irq,
 537                                         exynos4_mct_tick_isr,
 538                                         IRQF_TIMER | IRQF_NOBALANCING,
 539                                         pcpu_mevt->name, pcpu_mevt)) {
 540                                 pr_err("exynos-mct: cannot register IRQ (cpu%d)\n",
 541                                                                         cpu);
 542
 543                                 continue;
 544                         }
 545                         pcpu_mevt->evt.irq = mct_irq;
 546                 }
 547         }
 548
 549         /* Install hotplug callbacks which configure the timer on this CPU */
 550         err = cpuhp_setup_state(CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
 551                                 "AP_EXYNOS4_MCT_TIMER_STARTING",
 552                                 exynos4_mct_starting_cpu,
 553                                 exynos4_mct_dying_cpu);
 554         if (err)
 555                 goto out_irq;
 556
 557         return 0;
 558
 559 out_irq:
 560         free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
 561         return err;
 562 }
 563
 564 static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
 565 {
 566         u32 nr_irqs, i;
 567         int ret;
 568
 569         mct_int_type = int_type;
 570
 571         /* This driver uses only one global timer interrupt */
 572         mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
 573
 574         /*
 575          * Find out the number of local irqs specified. The local
 576          * timer irqs are specified after the four global timer
 577          * irqs are specified.
 578          */
 579 #ifdef CONFIG_OF
 580         nr_irqs = of_irq_count(np);
 581 #else
 582         nr_irqs = 0;
 583 #endif
 584         for (i = MCT_L0_IRQ; i < nr_irqs; i++)
 585                 mct_irqs[i] = irq_of_parse_and_map(np, i);
 586
 587         ret = exynos4_timer_resources(np, of_iomap(np, 0));
 588         if (ret)
 589                 return ret;
 590
 591         ret = exynos4_clocksource_init();
 592         if (ret)
 593                 return ret;
 594
 595         return exynos4_clockevent_init();
 596 }
 597
 598
 599 static int __init mct_init_spi(struct device_node *np)
 600 {
 601         return mct_init_dt(np, MCT_INT_SPI);
 602 }
 603
 604 static int __init mct_init_ppi(struct device_node *np)
 605 {
 606         return mct_init_dt(np, MCT_INT_PPI);
 607 }
 608 CLOCKSOURCE_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
 609 CLOCKSOURCE_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);