arch/arm/mach-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/platform_device.h>
  20 #include <linux/delay.h>
  21 #include <linux/percpu.h>
  22 #include <linux/of.h>
  23
  24 #include <asm/arch_timer.h>
  25 #include <asm/localtimer.h>
  26
  27 #include <plat/cpu.h>
  28
  29 #include <mach/map.h>
  30 #include <mach/irqs.h>
  31 #include <mach/regs-mct.h>
  32 #include <asm/mach/time.h>
  33
  34 #define TICK_BASE_CNT   1
  35
  36 enum {
  37         MCT_INT_SPI,
  38         MCT_INT_PPI
  39 };
  40
  41 static unsigned long clk_rate;
  42 static unsigned int mct_int_type;
  43
  44 struct mct_clock_event_device {
  45         struct clock_event_device *evt;
  46         void __iomem *base;
  47         char name[10];
  48 };
  49
  50 static void exynos4_mct_write(unsigned int value, void *addr)
  51 {
  52         void __iomem *stat_addr;
  53         u32 mask;
  54         u32 i;
  55
  56         __raw_writel(value, addr);
  57
  58         if (likely(addr >= EXYNOS4_MCT_L_BASE(0))) {
  59                 u32 base = (u32) addr & EXYNOS4_MCT_L_MASK;
  60                 switch ((u32) addr & ~EXYNOS4_MCT_L_MASK) {
  61                 case (u32) MCT_L_TCON_OFFSET:
  62                         stat_addr = (void __iomem *) base + MCT_L_WSTAT_OFFSET;
  63                         mask = 1 << 3;          /* L_TCON write status */
  64                         break;
  65                 case (u32) MCT_L_ICNTB_OFFSET:
  66                         stat_addr = (void __iomem *) base + MCT_L_WSTAT_OFFSET;
  67                         mask = 1 << 1;          /* L_ICNTB write status */
  68                         break;
  69                 case (u32) MCT_L_TCNTB_OFFSET:
  70                         stat_addr = (void __iomem *) base + MCT_L_WSTAT_OFFSET;
  71                         mask = 1 << 0;          /* L_TCNTB write status */
  72                         break;
  73                 default:
  74                         return;
  75                 }
  76         } else {
  77                 switch ((u32) addr) {
  78                 case (u32) EXYNOS4_MCT_G_TCON:
  79                         stat_addr = EXYNOS4_MCT_G_WSTAT;
  80                         mask = 1 << 16;         /* G_TCON write status */
  81                         break;
  82                 case (u32) EXYNOS4_MCT_G_COMP0_L:
  83                         stat_addr = EXYNOS4_MCT_G_WSTAT;
  84                         mask = 1 << 0;          /* G_COMP0_L write status */
  85                         break;
  86                 case (u32) EXYNOS4_MCT_G_COMP0_U:
  87                         stat_addr = EXYNOS4_MCT_G_WSTAT;
  88                         mask = 1 << 1;          /* G_COMP0_U write status */
  89                         break;
  90                 case (u32) EXYNOS4_MCT_G_COMP0_ADD_INCR:
  91                         stat_addr = EXYNOS4_MCT_G_WSTAT;
  92                         mask = 1 << 2;          /* G_COMP0_ADD_INCR w status */
  93                         break;
  94                 case (u32) EXYNOS4_MCT_G_CNT_L:
  95                         stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
  96                         mask = 1 << 0;          /* G_CNT_L write status */
  97                         break;
  98                 case (u32) EXYNOS4_MCT_G_CNT_U:
  99                         stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
 100                         mask = 1 << 1;          /* G_CNT_U write status */
 101                         break;
 102                 default:
 103                         return;
 104                 }
 105         }
 106
 107         /* Wait maximum 1 ms until written values are applied */
 108         for (i = 0; i < loops_per_jiffy / 1000 * HZ; i++)
 109                 if (__raw_readl(stat_addr) & mask) {
 110                         __raw_writel(mask, stat_addr);
 111                         return;
 112                 }
 113
 114         panic("MCT hangs after writing %d (addr:0x%08x)\n", value, (u32)addr);
 115 }
 116
 117 /* Clocksource handling */
 118 static void exynos4_mct_frc_start(u32 hi, u32 lo)
 119 {
 120         u32 reg;
 121
 122         exynos4_mct_write(lo, EXYNOS4_MCT_G_CNT_L);
 123         exynos4_mct_write(hi, EXYNOS4_MCT_G_CNT_U);
 124
 125         reg = __raw_readl(EXYNOS4_MCT_G_TCON);
 126         reg |= MCT_G_TCON_START;
 127         exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON);
 128 }
 129
 130 static cycle_t exynos4_frc_read(struct clocksource *cs)
 131 {
 132         unsigned int lo, hi;
 133         u32 hi2 = __raw_readl(EXYNOS4_MCT_G_CNT_U);
 134
 135         do {
 136                 hi = hi2;
 137                 lo = __raw_readl(EXYNOS4_MCT_G_CNT_L);
 138                 hi2 = __raw_readl(EXYNOS4_MCT_G_CNT_U);
 139         } while (hi != hi2);
 140
 141         return ((cycle_t)hi << 32) | lo;
 142 }
 143
 144 static void exynos4_frc_resume(struct clocksource *cs)
 145 {
 146         exynos4_mct_frc_start(0, 0);
 147 }
 148
 149 struct clocksource mct_frc = {
 150         .name           = "mct-frc",
 151         .rating         = 400,
 152         .read           = exynos4_frc_read,
 153         .mask           = CLOCKSOURCE_MASK(64),
 154         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 155         .resume         = exynos4_frc_resume,
 156 };
 157
 158 static void __init exynos4_clocksource_init(void)
 159 {
 160         exynos4_mct_frc_start(0, 0);
 161
 162         if (clocksource_register_hz(&mct_frc, clk_rate))
 163                 panic("%s: can't register clocksource\n", mct_frc.name);
 164 }
 165
 166 static void exynos4_mct_comp0_stop(void)
 167 {
 168         unsigned int tcon;
 169
 170         tcon = __raw_readl(EXYNOS4_MCT_G_TCON);
 171         tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
 172
 173         exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON);
 174         exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB);
 175 }
 176
 177 static void exynos4_mct_comp0_start(enum clock_event_mode mode,
 178                                     unsigned long cycles)
 179 {
 180         unsigned int tcon;
 181         cycle_t comp_cycle;
 182
 183         tcon = __raw_readl(EXYNOS4_MCT_G_TCON);
 184
 185         if (mode == CLOCK_EVT_MODE_PERIODIC) {
 186                 tcon |= MCT_G_TCON_COMP0_AUTO_INC;
 187                 exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
 188         }
 189
 190         comp_cycle = exynos4_frc_read(&mct_frc) + cycles;
 191         exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
 192         exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
 193
 194         exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB);
 195
 196         tcon |= MCT_G_TCON_COMP0_ENABLE;
 197         exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON);
 198 }
 199
 200 static int exynos4_comp_set_next_event(unsigned long cycles,
 201                                        struct clock_event_device *evt)
 202 {
 203         exynos4_mct_comp0_start(evt->mode, cycles);
 204
 205         return 0;
 206 }
 207
 208 static void exynos4_comp_set_mode(enum clock_event_mode mode,
 209                                   struct clock_event_device *evt)
 210 {
 211         unsigned long cycles_per_jiffy;
 212         exynos4_mct_comp0_stop();
 213
 214         switch (mode) {
 215         case CLOCK_EVT_MODE_PERIODIC:
 216                 cycles_per_jiffy =
 217                         (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
 218                 exynos4_mct_comp0_start(mode, cycles_per_jiffy);
 219                 break;
 220
 221         case CLOCK_EVT_MODE_ONESHOT:
 222         case CLOCK_EVT_MODE_UNUSED:
 223         case CLOCK_EVT_MODE_SHUTDOWN:
 224         case CLOCK_EVT_MODE_RESUME:
 225                 break;
 226         }
 227 }
 228
 229 static struct clock_event_device mct_comp_device = {
 230         .name           = "mct-comp",
 231         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 232         .rating         = 250,
 233         .set_next_event = exynos4_comp_set_next_event,
 234         .set_mode       = exynos4_comp_set_mode,
 235 };
 236
 237 static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
 238 {
 239         struct clock_event_device *evt = dev_id;
 240
 241         exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT);
 242
 243         evt->event_handler(evt);
 244
 245         return IRQ_HANDLED;
 246 }
 247
 248 static struct irqaction mct_comp_event_irq = {
 249         .name           = "mct_comp_irq",
 250         .flags          = IRQF_TIMER | IRQF_IRQPOLL,
 251         .handler        = exynos4_mct_comp_isr,
 252         .dev_id         = &mct_comp_device,
 253 };
 254
 255 static void exynos4_clockevent_init(void)
 256 {
 257         mct_comp_device.cpumask = cpumask_of(0);
 258         clockevents_config_and_register(&mct_comp_device, clk_rate,
 259                                         0xf, 0xffffffff);
 260
 261         if (soc_is_exynos5250())
 262                 setup_irq(EXYNOS5_IRQ_MCT_G0, &mct_comp_event_irq);
 263         else
 264                 setup_irq(EXYNOS4_IRQ_MCT_G0, &mct_comp_event_irq);
 265 }
 266
 267 #ifdef CONFIG_LOCAL_TIMERS
 268
 269 static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
 270
 271 /* Clock event handling */
 272 static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
 273 {
 274         unsigned long tmp;
 275         unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
 276         void __iomem *addr = mevt->base + MCT_L_TCON_OFFSET;
 277
 278         tmp = __raw_readl(addr);
 279         if (tmp & mask) {
 280                 tmp &= ~mask;
 281                 exynos4_mct_write(tmp, addr);
 282         }
 283 }
 284
 285 static void exynos4_mct_tick_start(unsigned long cycles,
 286                                    struct mct_clock_event_device *mevt)
 287 {
 288         unsigned long tmp;
 289
 290         exynos4_mct_tick_stop(mevt);
 291
 292         tmp = (1 << 31) | cycles;       /* MCT_L_UPDATE_ICNTB */
 293
 294         /* update interrupt count buffer */
 295         exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
 296
 297         /* enable MCT tick interrupt */
 298         exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET);
 299
 300         tmp = __raw_readl(mevt->base + MCT_L_TCON_OFFSET);
 301         tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
 302                MCT_L_TCON_INTERVAL_MODE;
 303         exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
 304 }
 305
 306 static int exynos4_tick_set_next_event(unsigned long cycles,
 307                                        struct clock_event_device *evt)
 308 {
 309         struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
 310
 311         exynos4_mct_tick_start(cycles, mevt);
 312
 313         return 0;
 314 }
 315
 316 static inline void exynos4_tick_set_mode(enum clock_event_mode mode,
 317                                          struct clock_event_device *evt)
 318 {
 319         struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
 320         unsigned long cycles_per_jiffy;
 321
 322         exynos4_mct_tick_stop(mevt);
 323
 324         switch (mode) {
 325         case CLOCK_EVT_MODE_PERIODIC:
 326                 cycles_per_jiffy =
 327                         (((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
 328                 exynos4_mct_tick_start(cycles_per_jiffy, mevt);
 329                 break;
 330
 331         case CLOCK_EVT_MODE_ONESHOT:
 332         case CLOCK_EVT_MODE_UNUSED:
 333         case CLOCK_EVT_MODE_SHUTDOWN:
 334         case CLOCK_EVT_MODE_RESUME:
 335                 break;
 336         }
 337 }
 338
 339 static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
 340 {
 341         struct clock_event_device *evt = mevt->evt;
 342
 343         /*
 344          * This is for supporting oneshot mode.
 345          * Mct would generate interrupt periodically
 346          * without explicit stopping.
 347          */
 348         if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
 349                 exynos4_mct_tick_stop(mevt);
 350
 351         /* Clear the MCT tick interrupt */
 352         if (__raw_readl(mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) {
 353                 exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
 354                 return 1;
 355         } else {
 356                 return 0;
 357         }
 358 }
 359
 360 static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
 361 {
 362         struct mct_clock_event_device *mevt = dev_id;
 363         struct clock_event_device *evt = mevt->evt;
 364
 365         exynos4_mct_tick_clear(mevt);
 366
 367         evt->event_handler(evt);
 368
 369         return IRQ_HANDLED;
 370 }
 371
 372 static struct irqaction mct_tick0_event_irq = {
 373         .name           = "mct_tick0_irq",
 374         .flags          = IRQF_TIMER | IRQF_NOBALANCING,
 375         .handler        = exynos4_mct_tick_isr,
 376 };
 377
 378 static struct irqaction mct_tick1_event_irq = {
 379         .name           = "mct_tick1_irq",
 380         .flags          = IRQF_TIMER | IRQF_NOBALANCING,
 381         .handler        = exynos4_mct_tick_isr,
 382 };
 383
 384 static int __cpuinit exynos4_local_timer_setup(struct clock_event_device *evt)
 385 {
 386         struct mct_clock_event_device *mevt;
 387         unsigned int cpu = smp_processor_id();
 388         int mct_lx_irq;
 389
 390         mevt = this_cpu_ptr(&percpu_mct_tick);
 391         mevt->evt = evt;
 392
 393         mevt->base = EXYNOS4_MCT_L_BASE(cpu);
 394         sprintf(mevt->name, "mct_tick%d", cpu);
 395
 396         evt->name = mevt->name;
 397         evt->cpumask = cpumask_of(cpu);
 398         evt->set_next_event = exynos4_tick_set_next_event;
 399         evt->set_mode = exynos4_tick_set_mode;
 400         evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
 401         evt->rating = 450;
 402         clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
 403                                         0xf, 0x7fffffff);
 404
 405         exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
 406
 407         if (mct_int_type == MCT_INT_SPI) {
 408                 if (cpu == 0) {
 409                         mct_lx_irq = soc_is_exynos4210() ? EXYNOS4_IRQ_MCT_L0 :
 410                                                 EXYNOS5_IRQ_MCT_L0;
 411                         mct_tick0_event_irq.dev_id = mevt;
 412                         evt->irq = mct_lx_irq;
 413                         setup_irq(mct_lx_irq, &mct_tick0_event_irq);
 414                 } else {
 415                         mct_lx_irq = soc_is_exynos4210() ? EXYNOS4_IRQ_MCT_L1 :
 416                                                 EXYNOS5_IRQ_MCT_L1;
 417                         mct_tick1_event_irq.dev_id = mevt;
 418                         evt->irq = mct_lx_irq;
 419                         setup_irq(mct_lx_irq, &mct_tick1_event_irq);
 420                         irq_set_affinity(mct_lx_irq, cpumask_of(1));
 421                 }
 422         } else {
 423                 enable_percpu_irq(EXYNOS_IRQ_MCT_LOCALTIMER, 0);
 424         }
 425
 426         return 0;
 427 }
 428
 429 static void exynos4_local_timer_stop(struct clock_event_device *evt)
 430 {
 431         unsigned int cpu = smp_processor_id();
 432         evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
 433         if (mct_int_type == MCT_INT_SPI)
 434                 if (cpu == 0)
 435                         remove_irq(evt->irq, &mct_tick0_event_irq);
 436                 else
 437                         remove_irq(evt->irq, &mct_tick1_event_irq);
 438         else
 439                 disable_percpu_irq(EXYNOS_IRQ_MCT_LOCALTIMER);
 440 }
 441
 442 static struct local_timer_ops exynos4_mct_tick_ops __cpuinitdata = {
 443         .setup  = exynos4_local_timer_setup,
 444         .stop   = exynos4_local_timer_stop,
 445 };
 446 #endif /* CONFIG_LOCAL_TIMERS */
 447
 448 static void __init exynos4_timer_resources(void)
 449 {
 450         struct clk *mct_clk;
 451         mct_clk = clk_get(NULL, "xtal");
 452
 453         clk_rate = clk_get_rate(mct_clk);
 454
 455 #ifdef CONFIG_LOCAL_TIMERS
 456         if (mct_int_type == MCT_INT_PPI) {
 457                 int err;
 458
 459                 err = request_percpu_irq(EXYNOS_IRQ_MCT_LOCALTIMER,
 460                                          exynos4_mct_tick_isr, "MCT",
 461                                          &percpu_mct_tick);
 462                 WARN(err, "MCT: can't request IRQ %d (%d)\n",
 463                      EXYNOS_IRQ_MCT_LOCALTIMER, err);
 464         }
 465
 466         local_timer_register(&exynos4_mct_tick_ops);
 467 #endif /* CONFIG_LOCAL_TIMERS */
 468 }
 469
 470 void __init exynos4_timer_init(void)
 471 {
 472         if (soc_is_exynos5440()) {
 473                 arch_timer_of_register();
 474                 return;
 475         }
 476
 477         if ((soc_is_exynos4210()) || (soc_is_exynos5250()))
 478                 mct_int_type = MCT_INT_SPI;
 479         else
 480                 mct_int_type = MCT_INT_PPI;
 481
 482         exynos4_timer_resources();
 483         exynos4_clocksource_init();
 484         exynos4_clockevent_init();
 485 }