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         __raw_writel(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 (__raw_readl(reg_base + stat_addr) & mask) {
 148                         __raw_writel(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 = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
 161         reg |= MCT_G_TCON_START;
 162         exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON);
 163 }
 164
 165 static cycle_t exynos4_frc_read(struct clocksource *cs)
 166 {
 167         unsigned int lo, hi;
 168         u32 hi2 = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_U);
 169
 170         do {
 171                 hi = hi2;
 172                 lo = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_L);
 173                 hi2 = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_U);
 174         } while (hi != hi2);
 175
 176         return ((cycle_t)hi << 32) | lo;
 177 }
 178
 179 static void exynos4_frc_resume(struct clocksource *cs)
 180 {
 181         exynos4_mct_frc_start();
 182 }
 183
 184 struct clocksource mct_frc = {
 185         .name           = "mct-frc",
 186         .rating         = 400,
 187         .read           = exynos4_frc_read,
 188         .mask           = CLOCKSOURCE_MASK(64),
 189         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 190         .resume         = exynos4_frc_resume,
 191 };
 192
 193 static u64 notrace exynos4_read_sched_clock(void)
 194 {
 195         return exynos4_frc_read(&mct_frc);
 196 }
 197
 198 static void __init exynos4_clocksource_init(void)
 199 {
 200         exynos4_mct_frc_start();
 201
 202         if (clocksource_register_hz(&mct_frc, clk_rate))
 203                 panic("%s: can't register clocksource\n", mct_frc.name);
 204
 205         sched_clock_register(exynos4_read_sched_clock, 64, clk_rate);
 206 }
 207
 208 static void exynos4_mct_comp0_stop(void)
 209 {
 210         unsigned int tcon;
 211
 212         tcon = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
 213         tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
 214
 215         exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON);
 216         exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB);
 217 }
 218
 219 static void exynos4_mct_comp0_start(enum clock_event_mode mode,
 220                                     unsigned long cycles)
 221 {
 222         unsigned int tcon;
 223         cycle_t comp_cycle;
 224
 225         tcon = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
 226
 227         if (mode == CLOCK_EVT_MODE_PERIODIC) {
 228                 tcon |= MCT_G_TCON_COMP0_AUTO_INC;
 229                 exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
 230         }
 231
 232         comp_cycle = exynos4_frc_read(&mct_frc) + cycles;
 233         exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
 234         exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
 235
 236         exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB);
 237
 238         tcon |= MCT_G_TCON_COMP0_ENABLE;
 239         exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON);
 240 }
 241
 242 static int exynos4_comp_set_next_event(unsigned long cycles,
 243                                        struct clock_event_device *evt)
 244 {
 245         exynos4_mct_comp0_start(evt->mode, cycles);
 246
 247         return 0;
 248 }
 249
 250 static void exynos4_comp_set_mode(enum clock_event_mode mode,
 251                                   struct clock_event_device *evt)
 252 {
 253         unsigned long cycles_per_jiffy;
 254         exynos4_mct_comp0_stop();
 255
 256         switch (mode) {
 257         case CLOCK_EVT_MODE_PERIODIC:
 258                 cycles_per_jiffy =
 259                         (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
 260                 exynos4_mct_comp0_start(mode, cycles_per_jiffy);
 261                 break;
 262
 263         case CLOCK_EVT_MODE_ONESHOT:
 264         case CLOCK_EVT_MODE_UNUSED:
 265         case CLOCK_EVT_MODE_SHUTDOWN:
 266         case CLOCK_EVT_MODE_RESUME:
 267                 break;
 268         }
 269 }
 270
 271 static struct clock_event_device mct_comp_device = {
 272         .name           = "mct-comp",
 273         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 274         .rating         = 250,
 275         .set_next_event = exynos4_comp_set_next_event,
 276         .set_mode       = exynos4_comp_set_mode,
 277 };
 278
 279 static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
 280 {
 281         struct clock_event_device *evt = dev_id;
 282
 283         exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT);
 284
 285         evt->event_handler(evt);
 286
 287         return IRQ_HANDLED;
 288 }
 289
 290 static struct irqaction mct_comp_event_irq = {
 291         .name           = "mct_comp_irq",
 292         .flags          = IRQF_TIMER | IRQF_IRQPOLL,
 293         .handler        = exynos4_mct_comp_isr,
 294         .dev_id         = &mct_comp_device,
 295 };
 296
 297 static void exynos4_clockevent_init(void)
 298 {
 299         mct_comp_device.cpumask = cpumask_of(0);
 300         clockevents_config_and_register(&mct_comp_device, clk_rate,
 301                                         0xf, 0xffffffff);
 302         setup_irq(mct_irqs[MCT_G0_IRQ], &mct_comp_event_irq);
 303 }
 304
 305 static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
 306
 307 /* Clock event handling */
 308 static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
 309 {
 310         unsigned long tmp;
 311         unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
 312         unsigned long offset = mevt->base + MCT_L_TCON_OFFSET;
 313
 314         tmp = __raw_readl(reg_base + offset);
 315         if (tmp & mask) {
 316                 tmp &= ~mask;
 317                 exynos4_mct_write(tmp, offset);
 318         }
 319 }
 320
 321 static void exynos4_mct_tick_start(unsigned long cycles,
 322                                    struct mct_clock_event_device *mevt)
 323 {
 324         unsigned long tmp;
 325
 326         exynos4_mct_tick_stop(mevt);
 327
 328         tmp = (1 << 31) | cycles;       /* MCT_L_UPDATE_ICNTB */
 329
 330         /* update interrupt count buffer */
 331         exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
 332
 333         /* enable MCT tick interrupt */
 334         exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET);
 335
 336         tmp = __raw_readl(reg_base + mevt->base + MCT_L_TCON_OFFSET);
 337         tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
 338                MCT_L_TCON_INTERVAL_MODE;
 339         exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
 340 }
 341
 342 static int exynos4_tick_set_next_event(unsigned long cycles,
 343                                        struct clock_event_device *evt)
 344 {
 345         struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
 346
 347         exynos4_mct_tick_start(cycles, mevt);
 348
 349         return 0;
 350 }
 351
 352 static inline void exynos4_tick_set_mode(enum clock_event_mode mode,
 353                                          struct clock_event_device *evt)
 354 {
 355         struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
 356         unsigned long cycles_per_jiffy;
 357
 358         exynos4_mct_tick_stop(mevt);
 359
 360         switch (mode) {
 361         case CLOCK_EVT_MODE_PERIODIC:
 362                 cycles_per_jiffy =
 363                         (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
 364                 exynos4_mct_tick_start(cycles_per_jiffy, mevt);
 365                 break;
 366
 367         case CLOCK_EVT_MODE_ONESHOT:
 368         case CLOCK_EVT_MODE_UNUSED:
 369         case CLOCK_EVT_MODE_SHUTDOWN:
 370         case CLOCK_EVT_MODE_RESUME:
 371                 break;
 372         }
 373 }
 374
 375 static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
 376 {
 377         struct clock_event_device *evt = &mevt->evt;
 378
 379         /*
 380          * This is for supporting oneshot mode.
 381          * Mct would generate interrupt periodically
 382          * without explicit stopping.
 383          */
 384         if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
 385                 exynos4_mct_tick_stop(mevt);
 386
 387         /* Clear the MCT tick interrupt */
 388         if (__raw_readl(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) {
 389                 exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
 390                 return 1;
 391         } else {
 392                 return 0;
 393         }
 394 }
 395
 396 static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
 397 {
 398         struct mct_clock_event_device *mevt = dev_id;
 399         struct clock_event_device *evt = &mevt->evt;
 400
 401         exynos4_mct_tick_clear(mevt);
 402
 403         evt->event_handler(evt);
 404
 405         return IRQ_HANDLED;
 406 }
 407
 408 static int exynos4_local_timer_setup(struct clock_event_device *evt)
 409 {
 410         struct mct_clock_event_device *mevt;
 411         unsigned int cpu = smp_processor_id();
 412
 413         mevt = container_of(evt, struct mct_clock_event_device, evt);
 414
 415         mevt->base = EXYNOS4_MCT_L_BASE(cpu);
 416         snprintf(mevt->name, sizeof(mevt->name), "mct_tick%d", cpu);
 417
 418         evt->name = mevt->name;
 419         evt->cpumask = cpumask_of(cpu);
 420         evt->set_next_event = exynos4_tick_set_next_event;
 421         evt->set_mode = exynos4_tick_set_mode;
 422         evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 423         evt->rating = 450;
 424
 425         exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
 426
 427         if (mct_int_type == MCT_INT_SPI) {
 428                 evt->irq = mct_irqs[MCT_L0_IRQ + cpu];
 429                 if (request_irq(evt->irq, exynos4_mct_tick_isr,
 430                                 IRQF_TIMER | IRQF_NOBALANCING,
 431                                 evt->name, mevt)) {
 432                         pr_err("exynos-mct: cannot register IRQ %d\n",
 433                                 evt->irq);
 434                         return -EIO;
 435                 }
 436                 irq_force_affinity(mct_irqs[MCT_L0_IRQ + cpu], cpumask_of(cpu));
 437         } else {
 438                 enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
 439         }
 440         clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
 441                                         0xf, 0x7fffffff);
 442
 443         return 0;
 444 }
 445
 446 static void exynos4_local_timer_stop(struct clock_event_device *evt)
 447 {
 448         evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
 449         if (mct_int_type == MCT_INT_SPI)
 450                 free_irq(evt->irq, this_cpu_ptr(&percpu_mct_tick));
 451         else
 452                 disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
 453 }
 454
 455 static int exynos4_mct_cpu_notify(struct notifier_block *self,
 456                                            unsigned long action, void *hcpu)
 457 {
 458         struct mct_clock_event_device *mevt;
 459
 460         /*
 461          * Grab cpu pointer in each case to avoid spurious
 462          * preemptible warnings
 463          */
 464         switch (action & ~CPU_TASKS_FROZEN) {
 465         case CPU_STARTING:
 466                 mevt = this_cpu_ptr(&percpu_mct_tick);
 467                 exynos4_local_timer_setup(&mevt->evt);
 468                 break;
 469         case CPU_DYING:
 470                 mevt = this_cpu_ptr(&percpu_mct_tick);
 471                 exynos4_local_timer_stop(&mevt->evt);
 472                 break;
 473         }
 474
 475         return NOTIFY_OK;
 476 }
 477
 478 static struct notifier_block exynos4_mct_cpu_nb = {
 479         .notifier_call = exynos4_mct_cpu_notify,
 480 };
 481
 482 static void __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
 483 {
 484         int err;
 485         struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
 486         struct clk *mct_clk, *tick_clk;
 487
 488         tick_clk = np ? of_clk_get_by_name(np, "fin_pll") :
 489                                 clk_get(NULL, "fin_pll");
 490         if (IS_ERR(tick_clk))
 491                 panic("%s: unable to determine tick clock rate\n", __func__);
 492         clk_rate = clk_get_rate(tick_clk);
 493
 494         mct_clk = np ? of_clk_get_by_name(np, "mct") : clk_get(NULL, "mct");
 495         if (IS_ERR(mct_clk))
 496                 panic("%s: unable to retrieve mct clock instance\n", __func__);
 497         clk_prepare_enable(mct_clk);
 498
 499         reg_base = base;
 500         if (!reg_base)
 501                 panic("%s: unable to ioremap mct address space\n", __func__);
 502
 503         if (mct_int_type == MCT_INT_PPI) {
 504
 505                 err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
 506                                          exynos4_mct_tick_isr, "MCT",
 507                                          &percpu_mct_tick);
 508                 WARN(err, "MCT: can't request IRQ %d (%d)\n",
 509                      mct_irqs[MCT_L0_IRQ], err);
 510         } else {
 511                 irq_set_affinity(mct_irqs[MCT_L0_IRQ], cpumask_of(0));
 512         }
 513
 514         err = register_cpu_notifier(&exynos4_mct_cpu_nb);
 515         if (err)
 516                 goto out_irq;
 517
 518         /* Immediately configure the timer on the boot CPU */
 519         exynos4_local_timer_setup(&mevt->evt);
 520         return;
 521
 522 out_irq:
 523         free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
 524 }
 525
 526 void __init mct_init(void __iomem *base, int irq_g0, int irq_l0, int irq_l1)
 527 {
 528         mct_irqs[MCT_G0_IRQ] = irq_g0;
 529         mct_irqs[MCT_L0_IRQ] = irq_l0;
 530         mct_irqs[MCT_L1_IRQ] = irq_l1;
 531         mct_int_type = MCT_INT_SPI;
 532
 533         exynos4_timer_resources(NULL, base);
 534         exynos4_clocksource_init();
 535         exynos4_clockevent_init();
 536 }
 537
 538 static void __init mct_init_dt(struct device_node *np, unsigned int int_type)
 539 {
 540         u32 nr_irqs, i;
 541
 542         mct_int_type = int_type;
 543
 544         /* This driver uses only one global timer interrupt */
 545         mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
 546
 547         /*
 548          * Find out the number of local irqs specified. The local
 549          * timer irqs are specified after the four global timer
 550          * irqs are specified.
 551          */
 552 #ifdef CONFIG_OF
 553         nr_irqs = of_irq_count(np);
 554 #else
 555         nr_irqs = 0;
 556 #endif
 557         for (i = MCT_L0_IRQ; i < nr_irqs; i++)
 558                 mct_irqs[i] = irq_of_parse_and_map(np, i);
 559
 560         exynos4_timer_resources(np, of_iomap(np, 0));
 561         exynos4_clocksource_init();
 562         exynos4_clockevent_init();
 563 }
 564
 565
 566 static void __init mct_init_spi(struct device_node *np)
 567 {
 568         return mct_init_dt(np, MCT_INT_SPI);
 569 }
 570
 571 static void __init mct_init_ppi(struct device_node *np)
 572 {
 573         return mct_init_dt(np, MCT_INT_PPI);
 574 }
 575 CLOCKSOURCE_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
 576 CLOCKSOURCE_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);