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 void __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
 249 static void exynos4_mct_comp0_stop(void)
 250 {
 251         unsigned int tcon;
 252
 253         tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
 254         tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
 255
 256         exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON);
 257         exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB);
 258 }
 259
 260 static void exynos4_mct_comp0_start(bool periodic, unsigned long cycles)
 261 {
 262         unsigned int tcon;
 263         cycle_t comp_cycle;
 264
 265         tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
 266
 267         if (periodic) {
 268                 tcon |= MCT_G_TCON_COMP0_AUTO_INC;
 269                 exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
 270         }
 271
 272         comp_cycle = exynos4_read_count_64() + cycles;
 273         exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
 274         exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
 275
 276         exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB);
 277
 278         tcon |= MCT_G_TCON_COMP0_ENABLE;
 279         exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON);
 280 }
 281
 282 static int exynos4_comp_set_next_event(unsigned long cycles,
 283                                        struct clock_event_device *evt)
 284 {
 285         exynos4_mct_comp0_start(false, cycles);
 286
 287         return 0;
 288 }
 289
 290 static int mct_set_state_shutdown(struct clock_event_device *evt)
 291 {
 292         exynos4_mct_comp0_stop();
 293         return 0;
 294 }
 295
 296 static int mct_set_state_periodic(struct clock_event_device *evt)
 297 {
 298         unsigned long cycles_per_jiffy;
 299
 300         cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
 301                             >> evt->shift);
 302         exynos4_mct_comp0_stop();
 303         exynos4_mct_comp0_start(true, cycles_per_jiffy);
 304         return 0;
 305 }
 306
 307 static struct clock_event_device mct_comp_device = {
 308         .name                   = "mct-comp",
 309         .features               = CLOCK_EVT_FEAT_PERIODIC |
 310                                   CLOCK_EVT_FEAT_ONESHOT,
 311         .rating                 = 250,
 312         .set_next_event         = exynos4_comp_set_next_event,
 313         .set_state_periodic     = mct_set_state_periodic,
 314         .set_state_shutdown     = mct_set_state_shutdown,
 315         .set_state_oneshot      = mct_set_state_shutdown,
 316         .tick_resume            = mct_set_state_shutdown,
 317 };
 318
 319 static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
 320 {
 321         struct clock_event_device *evt = dev_id;
 322
 323         exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT);
 324
 325         evt->event_handler(evt);
 326
 327         return IRQ_HANDLED;
 328 }
 329
 330 static struct irqaction mct_comp_event_irq = {
 331         .name           = "mct_comp_irq",
 332         .flags          = IRQF_TIMER | IRQF_IRQPOLL,
 333         .handler        = exynos4_mct_comp_isr,
 334         .dev_id         = &mct_comp_device,
 335 };
 336
 337 static void exynos4_clockevent_init(void)
 338 {
 339         mct_comp_device.cpumask = cpumask_of(0);
 340         clockevents_config_and_register(&mct_comp_device, clk_rate,
 341                                         0xf, 0xffffffff);
 342         setup_irq(mct_irqs[MCT_G0_IRQ], &mct_comp_event_irq);
 343 }
 344
 345 static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
 346
 347 /* Clock event handling */
 348 static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
 349 {
 350         unsigned long tmp;
 351         unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
 352         unsigned long offset = mevt->base + MCT_L_TCON_OFFSET;
 353
 354         tmp = readl_relaxed(reg_base + offset);
 355         if (tmp & mask) {
 356                 tmp &= ~mask;
 357                 exynos4_mct_write(tmp, offset);
 358         }
 359 }
 360
 361 static void exynos4_mct_tick_start(unsigned long cycles,
 362                                    struct mct_clock_event_device *mevt)
 363 {
 364         unsigned long tmp;
 365
 366         exynos4_mct_tick_stop(mevt);
 367
 368         tmp = (1 << 31) | cycles;       /* MCT_L_UPDATE_ICNTB */
 369
 370         /* update interrupt count buffer */
 371         exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
 372
 373         /* enable MCT tick interrupt */
 374         exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET);
 375
 376         tmp = readl_relaxed(reg_base + mevt->base + MCT_L_TCON_OFFSET);
 377         tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
 378                MCT_L_TCON_INTERVAL_MODE;
 379         exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
 380 }
 381
 382 static int exynos4_tick_set_next_event(unsigned long cycles,
 383                                        struct clock_event_device *evt)
 384 {
 385         struct mct_clock_event_device *mevt;
 386
 387         mevt = container_of(evt, struct mct_clock_event_device, evt);
 388         exynos4_mct_tick_start(cycles, mevt);
 389         return 0;
 390 }
 391
 392 static int set_state_shutdown(struct clock_event_device *evt)
 393 {
 394         struct mct_clock_event_device *mevt;
 395
 396         mevt = container_of(evt, struct mct_clock_event_device, evt);
 397         exynos4_mct_tick_stop(mevt);
 398         return 0;
 399 }
 400
 401 static int set_state_periodic(struct clock_event_device *evt)
 402 {
 403         struct mct_clock_event_device *mevt;
 404         unsigned long cycles_per_jiffy;
 405
 406         mevt = container_of(evt, struct mct_clock_event_device, evt);
 407         cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
 408                             >> evt->shift);
 409         exynos4_mct_tick_stop(mevt);
 410         exynos4_mct_tick_start(cycles_per_jiffy, mevt);
 411         return 0;
 412 }
 413
 414 static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
 415 {
 416         /*
 417          * This is for supporting oneshot mode.
 418          * Mct would generate interrupt periodically
 419          * without explicit stopping.
 420          */
 421         if (!clockevent_state_periodic(&mevt->evt))
 422                 exynos4_mct_tick_stop(mevt);
 423
 424         /* Clear the MCT tick interrupt */
 425         if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
 426                 exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
 427 }
 428
 429 static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
 430 {
 431         struct mct_clock_event_device *mevt = dev_id;
 432         struct clock_event_device *evt = &mevt->evt;
 433
 434         exynos4_mct_tick_clear(mevt);
 435
 436         evt->event_handler(evt);
 437
 438         return IRQ_HANDLED;
 439 }
 440
 441 static int exynos4_local_timer_setup(struct mct_clock_event_device *mevt)
 442 {
 443         struct clock_event_device *evt = &mevt->evt;
 444         unsigned int cpu = smp_processor_id();
 445
 446         mevt->base = EXYNOS4_MCT_L_BASE(cpu);
 447         snprintf(mevt->name, sizeof(mevt->name), "mct_tick%d", cpu);
 448
 449         evt->name = mevt->name;
 450         evt->cpumask = cpumask_of(cpu);
 451         evt->set_next_event = exynos4_tick_set_next_event;
 452         evt->set_state_periodic = set_state_periodic;
 453         evt->set_state_shutdown = set_state_shutdown;
 454         evt->set_state_oneshot = set_state_shutdown;
 455         evt->tick_resume = set_state_shutdown;
 456         evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 457         evt->rating = 450;
 458
 459         exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
 460
 461         if (mct_int_type == MCT_INT_SPI) {
 462
 463                 if (evt->irq == -1)
 464                         return -EIO;
 465
 466                 irq_force_affinity(evt->irq, cpumask_of(cpu));
 467                 enable_irq(evt->irq);
 468         } else {
 469                 enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
 470         }
 471         clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
 472                                         0xf, 0x7fffffff);
 473
 474         return 0;
 475 }
 476
 477 static void exynos4_local_timer_stop(struct mct_clock_event_device *mevt)
 478 {
 479         struct clock_event_device *evt = &mevt->evt;
 480
 481         evt->set_state_shutdown(evt);
 482         if (mct_int_type == MCT_INT_SPI) {
 483                 if (evt->irq != -1)
 484                         disable_irq_nosync(evt->irq);
 485         } else {
 486                 disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
 487         }
 488 }
 489
 490 static int exynos4_mct_cpu_notify(struct notifier_block *self,
 491                                            unsigned long action, void *hcpu)
 492 {
 493         struct mct_clock_event_device *mevt;
 494
 495         /*
 496          * Grab cpu pointer in each case to avoid spurious
 497          * preemptible warnings
 498          */
 499         switch (action & ~CPU_TASKS_FROZEN) {
 500         case CPU_STARTING:
 501                 mevt = this_cpu_ptr(&percpu_mct_tick);
 502                 exynos4_local_timer_setup(mevt);
 503                 break;
 504         case CPU_DYING:
 505                 mevt = this_cpu_ptr(&percpu_mct_tick);
 506                 exynos4_local_timer_stop(mevt);
 507                 break;
 508         }
 509
 510         return NOTIFY_OK;
 511 }
 512
 513 static struct notifier_block exynos4_mct_cpu_nb = {
 514         .notifier_call = exynos4_mct_cpu_notify,
 515 };
 516
 517 static void __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
 518 {
 519         int err, cpu;
 520         struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
 521         struct clk *mct_clk, *tick_clk;
 522
 523         tick_clk = np ? of_clk_get_by_name(np, "fin_pll") :
 524                                 clk_get(NULL, "fin_pll");
 525         if (IS_ERR(tick_clk))
 526                 panic("%s: unable to determine tick clock rate\n", __func__);
 527         clk_rate = clk_get_rate(tick_clk);
 528
 529         mct_clk = np ? of_clk_get_by_name(np, "mct") : clk_get(NULL, "mct");
 530         if (IS_ERR(mct_clk))
 531                 panic("%s: unable to retrieve mct clock instance\n", __func__);
 532         clk_prepare_enable(mct_clk);
 533
 534         reg_base = base;
 535         if (!reg_base)
 536                 panic("%s: unable to ioremap mct address space\n", __func__);
 537
 538         if (mct_int_type == MCT_INT_PPI) {
 539
 540                 err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
 541                                          exynos4_mct_tick_isr, "MCT",
 542                                          &percpu_mct_tick);
 543                 WARN(err, "MCT: can't request IRQ %d (%d)\n",
 544                      mct_irqs[MCT_L0_IRQ], err);
 545         } else {
 546                 for_each_possible_cpu(cpu) {
 547                         int mct_irq = mct_irqs[MCT_L0_IRQ + cpu];
 548                         struct mct_clock_event_device *pcpu_mevt =
 549                                 per_cpu_ptr(&percpu_mct_tick, cpu);
 550
 551                         pcpu_mevt->evt.irq = -1;
 552
 553                         irq_set_status_flags(mct_irq, IRQ_NOAUTOEN);
 554                         if (request_irq(mct_irq,
 555                                         exynos4_mct_tick_isr,
 556                                         IRQF_TIMER | IRQF_NOBALANCING,
 557                                         pcpu_mevt->name, pcpu_mevt)) {
 558                                 pr_err("exynos-mct: cannot register IRQ (cpu%d)\n",
 559                                                                         cpu);
 560
 561                                 continue;
 562                         }
 563                         pcpu_mevt->evt.irq = mct_irq;
 564                 }
 565         }
 566
 567         err = register_cpu_notifier(&exynos4_mct_cpu_nb);
 568         if (err)
 569                 goto out_irq;
 570
 571         /* Immediately configure the timer on the boot CPU */
 572         exynos4_local_timer_setup(mevt);
 573         return;
 574
 575 out_irq:
 576         free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
 577 }
 578
 579 static void __init mct_init_dt(struct device_node *np, unsigned int int_type)
 580 {
 581         u32 nr_irqs, i;
 582
 583         mct_int_type = int_type;
 584
 585         /* This driver uses only one global timer interrupt */
 586         mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
 587
 588         /*
 589          * Find out the number of local irqs specified. The local
 590          * timer irqs are specified after the four global timer
 591          * irqs are specified.
 592          */
 593 #ifdef CONFIG_OF
 594         nr_irqs = of_irq_count(np);
 595 #else
 596         nr_irqs = 0;
 597 #endif
 598         for (i = MCT_L0_IRQ; i < nr_irqs; i++)
 599                 mct_irqs[i] = irq_of_parse_and_map(np, i);
 600
 601         exynos4_timer_resources(np, of_iomap(np, 0));
 602         exynos4_clocksource_init();
 603         exynos4_clockevent_init();
 604 }
 605
 606
 607 static void __init mct_init_spi(struct device_node *np)
 608 {
 609         return mct_init_dt(np, MCT_INT_SPI);
 610 }
 611
 612 static void __init mct_init_ppi(struct device_node *np)
 613 {
 614         return mct_init_dt(np, MCT_INT_PPI);
 615 }
 616 CLOCKSOURCE_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
 617 CLOCKSOURCE_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);