drivers/clocksource/arm_arch_timer.c

   1 /*
   2  *  linux/drivers/clocksource/arm_arch_timer.c
   3  *
   4  *  Copyright (C) 2011 ARM Ltd.
   5  *  All Rights Reserved
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/device.h>
  14 #include <linux/smp.h>
  15 #include <linux/cpu.h>
  16 #include <linux/cpu_pm.h>
  17 #include <linux/clockchips.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/of_irq.h>
  20 #include <linux/of_address.h>
  21 #include <linux/io.h>
  22 #include <linux/slab.h>
  23 #include <linux/sched_clock.h>
  24
  25 #include <asm/arch_timer.h>
  26 #include <asm/virt.h>
  27
  28 #include <clocksource/arm_arch_timer.h>
  29
  30 #define CNTTIDR         0x08
  31 #define CNTTIDR_VIRT(n) (BIT(1) << ((n) * 4))
  32
  33 #define CNTVCT_LO       0x08
  34 #define CNTVCT_HI       0x0c
  35 #define CNTFRQ          0x10
  36 #define CNTP_TVAL       0x28
  37 #define CNTP_CTL        0x2c
  38 #define CNTV_TVAL       0x38
  39 #define CNTV_CTL        0x3c
  40
  41 #define ARCH_CP15_TIMER BIT(0)
  42 #define ARCH_MEM_TIMER  BIT(1)
  43 static unsigned arch_timers_present __initdata;
  44
  45 static void __iomem *arch_counter_base;
  46
  47 struct arch_timer {
  48         void __iomem *base;
  49         struct clock_event_device evt;
  50 };
  51
  52 #define to_arch_timer(e) container_of(e, struct arch_timer, evt)
  53
  54 static u32 arch_timer_rate;
  55
  56 enum ppi_nr {
  57         PHYS_SECURE_PPI,
  58         PHYS_NONSECURE_PPI,
  59         VIRT_PPI,
  60         HYP_PPI,
  61         MAX_TIMER_PPI
  62 };
  63
  64 static int arch_timer_ppi[MAX_TIMER_PPI];
  65
  66 static struct clock_event_device __percpu *arch_timer_evt;
  67
  68 static bool arch_timer_use_virtual = true;
  69 static bool arch_timer_c3stop;
  70 static bool arch_timer_mem_use_virtual;
  71
  72 /*
  73  * Architected system timer support.
  74  */
  75
  76 static __always_inline
  77 void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val,
  78                           struct clock_event_device *clk)
  79 {
  80         if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
  81                 struct arch_timer *timer = to_arch_timer(clk);
  82                 switch (reg) {
  83                 case ARCH_TIMER_REG_CTRL:
  84                         writel_relaxed(val, timer->base + CNTP_CTL);
  85                         break;
  86                 case ARCH_TIMER_REG_TVAL:
  87                         writel_relaxed(val, timer->base + CNTP_TVAL);
  88                         break;
  89                 }
  90         } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
  91                 struct arch_timer *timer = to_arch_timer(clk);
  92                 switch (reg) {
  93                 case ARCH_TIMER_REG_CTRL:
  94                         writel_relaxed(val, timer->base + CNTV_CTL);
  95                         break;
  96                 case ARCH_TIMER_REG_TVAL:
  97                         writel_relaxed(val, timer->base + CNTV_TVAL);
  98                         break;
  99                 }
 100         } else {
 101                 arch_timer_reg_write_cp15(access, reg, val);
 102         }
 103 }
 104
 105 static __always_inline
 106 u32 arch_timer_reg_read(int access, enum arch_timer_reg reg,
 107                         struct clock_event_device *clk)
 108 {
 109         u32 val;
 110
 111         if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
 112                 struct arch_timer *timer = to_arch_timer(clk);
 113                 switch (reg) {
 114                 case ARCH_TIMER_REG_CTRL:
 115                         val = readl_relaxed(timer->base + CNTP_CTL);
 116                         break;
 117                 case ARCH_TIMER_REG_TVAL:
 118                         val = readl_relaxed(timer->base + CNTP_TVAL);
 119                         break;
 120                 }
 121         } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
 122                 struct arch_timer *timer = to_arch_timer(clk);
 123                 switch (reg) {
 124                 case ARCH_TIMER_REG_CTRL:
 125                         val = readl_relaxed(timer->base + CNTV_CTL);
 126                         break;
 127                 case ARCH_TIMER_REG_TVAL:
 128                         val = readl_relaxed(timer->base + CNTV_TVAL);
 129                         break;
 130                 }
 131         } else {
 132                 val = arch_timer_reg_read_cp15(access, reg);
 133         }
 134
 135         return val;
 136 }
 137
 138 static __always_inline irqreturn_t timer_handler(const int access,
 139                                         struct clock_event_device *evt)
 140 {
 141         unsigned long ctrl;
 142
 143         ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, evt);
 144         if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
 145                 ctrl |= ARCH_TIMER_CTRL_IT_MASK;
 146                 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, evt);
 147                 evt->event_handler(evt);
 148                 return IRQ_HANDLED;
 149         }
 150
 151         return IRQ_NONE;
 152 }
 153
 154 static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
 155 {
 156         struct clock_event_device *evt = dev_id;
 157
 158         return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
 159 }
 160
 161 static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
 162 {
 163         struct clock_event_device *evt = dev_id;
 164
 165         return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
 166 }
 167
 168 static irqreturn_t arch_timer_handler_phys_mem(int irq, void *dev_id)
 169 {
 170         struct clock_event_device *evt = dev_id;
 171
 172         return timer_handler(ARCH_TIMER_MEM_PHYS_ACCESS, evt);
 173 }
 174
 175 static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id)
 176 {
 177         struct clock_event_device *evt = dev_id;
 178
 179         return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt);
 180 }
 181
 182 static __always_inline void timer_set_mode(const int access, int mode,
 183                                   struct clock_event_device *clk)
 184 {
 185         unsigned long ctrl;
 186         switch (mode) {
 187         case CLOCK_EVT_MODE_UNUSED:
 188         case CLOCK_EVT_MODE_SHUTDOWN:
 189                 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
 190                 ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
 191                 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
 192                 break;
 193         default:
 194                 break;
 195         }
 196 }
 197
 198 static void arch_timer_set_mode_virt(enum clock_event_mode mode,
 199                                      struct clock_event_device *clk)
 200 {
 201         timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode, clk);
 202 }
 203
 204 static void arch_timer_set_mode_phys(enum clock_event_mode mode,
 205                                      struct clock_event_device *clk)
 206 {
 207         timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode, clk);
 208 }
 209
 210 static void arch_timer_set_mode_virt_mem(enum clock_event_mode mode,
 211                                          struct clock_event_device *clk)
 212 {
 213         timer_set_mode(ARCH_TIMER_MEM_VIRT_ACCESS, mode, clk);
 214 }
 215
 216 static void arch_timer_set_mode_phys_mem(enum clock_event_mode mode,
 217                                          struct clock_event_device *clk)
 218 {
 219         timer_set_mode(ARCH_TIMER_MEM_PHYS_ACCESS, mode, clk);
 220 }
 221
 222 static __always_inline void set_next_event(const int access, unsigned long evt,
 223                                            struct clock_event_device *clk)
 224 {
 225         unsigned long ctrl;
 226         ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
 227         ctrl |= ARCH_TIMER_CTRL_ENABLE;
 228         ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
 229         arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt, clk);
 230         arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
 231 }
 232
 233 static int arch_timer_set_next_event_virt(unsigned long evt,
 234                                           struct clock_event_device *clk)
 235 {
 236         set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
 237         return 0;
 238 }
 239
 240 static int arch_timer_set_next_event_phys(unsigned long evt,
 241                                           struct clock_event_device *clk)
 242 {
 243         set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
 244         return 0;
 245 }
 246
 247 static int arch_timer_set_next_event_virt_mem(unsigned long evt,
 248                                               struct clock_event_device *clk)
 249 {
 250         set_next_event(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk);
 251         return 0;
 252 }
 253
 254 static int arch_timer_set_next_event_phys_mem(unsigned long evt,
 255                                               struct clock_event_device *clk)
 256 {
 257         set_next_event(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
 258         return 0;
 259 }
 260
 261 static void __arch_timer_setup(unsigned type,
 262                                struct clock_event_device *clk)
 263 {
 264         clk->features = CLOCK_EVT_FEAT_ONESHOT;
 265
 266         if (type == ARCH_CP15_TIMER) {
 267                 if (arch_timer_c3stop)
 268                         clk->features |= CLOCK_EVT_FEAT_C3STOP;
 269                 clk->name = "arch_sys_timer";
 270                 clk->rating = 450;
 271                 clk->cpumask = cpumask_of(smp_processor_id());
 272                 if (arch_timer_use_virtual) {
 273                         clk->irq = arch_timer_ppi[VIRT_PPI];
 274                         clk->set_mode = arch_timer_set_mode_virt;
 275                         clk->set_next_event = arch_timer_set_next_event_virt;
 276                 } else {
 277                         clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
 278                         clk->set_mode = arch_timer_set_mode_phys;
 279                         clk->set_next_event = arch_timer_set_next_event_phys;
 280                 }
 281         } else {
 282                 clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
 283                 clk->name = "arch_mem_timer";
 284                 clk->rating = 400;
 285                 clk->cpumask = cpu_all_mask;
 286                 if (arch_timer_mem_use_virtual) {
 287                         clk->set_mode = arch_timer_set_mode_virt_mem;
 288                         clk->set_next_event =
 289                                 arch_timer_set_next_event_virt_mem;
 290                 } else {
 291                         clk->set_mode = arch_timer_set_mode_phys_mem;
 292                         clk->set_next_event =
 293                                 arch_timer_set_next_event_phys_mem;
 294                 }
 295         }
 296
 297         clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, clk);
 298
 299         clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff);
 300 }
 301
 302 static void arch_timer_configure_evtstream(void)
 303 {
 304         int evt_stream_div, pos;
 305
 306         /* Find the closest power of two to the divisor */
 307         evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ;
 308         pos = fls(evt_stream_div);
 309         if (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))
 310                 pos--;
 311         /* enable event stream */
 312         arch_timer_evtstrm_enable(min(pos, 15));
 313 }
 314
 315 static int arch_timer_setup(struct clock_event_device *clk)
 316 {
 317         __arch_timer_setup(ARCH_CP15_TIMER, clk);
 318
 319         if (arch_timer_use_virtual)
 320                 enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
 321         else {
 322                 enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
 323                 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
 324                         enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
 325         }
 326
 327         arch_counter_set_user_access();
 328         if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM))
 329                 arch_timer_configure_evtstream();
 330
 331         return 0;
 332 }
 333
 334 static void
 335 arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np)
 336 {
 337         /* Who has more than one independent system counter? */
 338         if (arch_timer_rate)
 339                 return;
 340
 341         /* Try to determine the frequency from the device tree or CNTFRQ */
 342         if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
 343                 if (cntbase)
 344                         arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
 345                 else
 346                         arch_timer_rate = arch_timer_get_cntfrq();
 347         }
 348
 349         /* Check the timer frequency. */
 350         if (arch_timer_rate == 0)
 351                 pr_warn("Architected timer frequency not available\n");
 352 }
 353
 354 static void arch_timer_banner(unsigned type)
 355 {
 356         pr_info("Architected %s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n",
 357                      type & ARCH_CP15_TIMER ? "cp15" : "",
 358                      type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ?  " and " : "",
 359                      type & ARCH_MEM_TIMER ? "mmio" : "",
 360                      (unsigned long)arch_timer_rate / 1000000,
 361                      (unsigned long)(arch_timer_rate / 10000) % 100,
 362                      type & ARCH_CP15_TIMER ?
 363                         arch_timer_use_virtual ? "virt" : "phys" :
 364                         "",
 365                      type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ?  "/" : "",
 366                      type & ARCH_MEM_TIMER ?
 367                         arch_timer_mem_use_virtual ? "virt" : "phys" :
 368                         "");
 369 }
 370
 371 u32 arch_timer_get_rate(void)
 372 {
 373         return arch_timer_rate;
 374 }
 375
 376 static u64 arch_counter_get_cntvct_mem(void)
 377 {
 378         u32 vct_lo, vct_hi, tmp_hi;
 379
 380         do {
 381                 vct_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
 382                 vct_lo = readl_relaxed(arch_counter_base + CNTVCT_LO);
 383                 tmp_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
 384         } while (vct_hi != tmp_hi);
 385
 386         return ((u64) vct_hi << 32) | vct_lo;
 387 }
 388
 389 /*
 390  * Default to cp15 based access because arm64 uses this function for
 391  * sched_clock() before DT is probed and the cp15 method is guaranteed
 392  * to exist on arm64. arm doesn't use this before DT is probed so even
 393  * if we don't have the cp15 accessors we won't have a problem.
 394  */
 395 u64 (*arch_timer_read_counter)(void) = arch_counter_get_cntvct;
 396
 397 static cycle_t arch_counter_read(struct clocksource *cs)
 398 {
 399         return arch_timer_read_counter();
 400 }
 401
 402 static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
 403 {
 404         return arch_timer_read_counter();
 405 }
 406
 407 static struct clocksource clocksource_counter = {
 408         .name   = "arch_sys_counter",
 409         .rating = 400,
 410         .read   = arch_counter_read,
 411         .mask   = CLOCKSOURCE_MASK(56),
 412         .flags  = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
 413 };
 414
 415 static struct cyclecounter cyclecounter = {
 416         .read   = arch_counter_read_cc,
 417         .mask   = CLOCKSOURCE_MASK(56),
 418 };
 419
 420 static struct timecounter timecounter;
 421
 422 struct timecounter *arch_timer_get_timecounter(void)
 423 {
 424         return &timecounter;
 425 }
 426
 427 static void __init arch_counter_register(unsigned type)
 428 {
 429         u64 start_count;
 430
 431         /* Register the CP15 based counter if we have one */
 432         if (type & ARCH_CP15_TIMER)
 433                 arch_timer_read_counter = arch_counter_get_cntvct;
 434         else
 435                 arch_timer_read_counter = arch_counter_get_cntvct_mem;
 436
 437         start_count = arch_timer_read_counter();
 438         clocksource_register_hz(&clocksource_counter, arch_timer_rate);
 439         cyclecounter.mult = clocksource_counter.mult;
 440         cyclecounter.shift = clocksource_counter.shift;
 441         timecounter_init(&timecounter, &cyclecounter, start_count);
 442
 443         /* 56 bits minimum, so we assume worst case rollover */
 444         sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate);
 445 }
 446
 447 static void arch_timer_stop(struct clock_event_device *clk)
 448 {
 449         pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
 450                  clk->irq, smp_processor_id());
 451
 452         if (arch_timer_use_virtual)
 453                 disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
 454         else {
 455                 disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
 456                 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
 457                         disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
 458         }
 459
 460         clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
 461 }
 462
 463 static int arch_timer_cpu_notify(struct notifier_block *self,
 464                                            unsigned long action, void *hcpu)
 465 {
 466         /*
 467          * Grab cpu pointer in each case to avoid spurious
 468          * preemptible warnings
 469          */
 470         switch (action & ~CPU_TASKS_FROZEN) {
 471         case CPU_STARTING:
 472                 arch_timer_setup(this_cpu_ptr(arch_timer_evt));
 473                 break;
 474         case CPU_DYING:
 475                 arch_timer_stop(this_cpu_ptr(arch_timer_evt));
 476                 break;
 477         }
 478
 479         return NOTIFY_OK;
 480 }
 481
 482 static struct notifier_block arch_timer_cpu_nb = {
 483         .notifier_call = arch_timer_cpu_notify,
 484 };
 485
 486 #ifdef CONFIG_CPU_PM
 487 static unsigned int saved_cntkctl;
 488 static int arch_timer_cpu_pm_notify(struct notifier_block *self,
 489                                     unsigned long action, void *hcpu)
 490 {
 491         if (action == CPU_PM_ENTER)
 492                 saved_cntkctl = arch_timer_get_cntkctl();
 493         else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT)
 494                 arch_timer_set_cntkctl(saved_cntkctl);
 495         return NOTIFY_OK;
 496 }
 497
 498 static struct notifier_block arch_timer_cpu_pm_notifier = {
 499         .notifier_call = arch_timer_cpu_pm_notify,
 500 };
 501
 502 static int __init arch_timer_cpu_pm_init(void)
 503 {
 504         return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
 505 }
 506 #else
 507 static int __init arch_timer_cpu_pm_init(void)
 508 {
 509         return 0;
 510 }
 511 #endif
 512
 513 static int __init arch_timer_register(void)
 514 {
 515         int err;
 516         int ppi;
 517
 518         arch_timer_evt = alloc_percpu(struct clock_event_device);
 519         if (!arch_timer_evt) {
 520                 err = -ENOMEM;
 521                 goto out;
 522         }
 523
 524         if (arch_timer_use_virtual) {
 525                 ppi = arch_timer_ppi[VIRT_PPI];
 526                 err = request_percpu_irq(ppi, arch_timer_handler_virt,
 527                                          "arch_timer", arch_timer_evt);
 528         } else {
 529                 ppi = arch_timer_ppi[PHYS_SECURE_PPI];
 530                 err = request_percpu_irq(ppi, arch_timer_handler_phys,
 531                                          "arch_timer", arch_timer_evt);
 532                 if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
 533                         ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
 534                         err = request_percpu_irq(ppi, arch_timer_handler_phys,
 535                                                  "arch_timer", arch_timer_evt);
 536                         if (err)
 537                                 free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
 538                                                 arch_timer_evt);
 539                 }
 540         }
 541
 542         if (err) {
 543                 pr_err("arch_timer: can't register interrupt %d (%d)\n",
 544                        ppi, err);
 545                 goto out_free;
 546         }
 547
 548         err = register_cpu_notifier(&arch_timer_cpu_nb);
 549         if (err)
 550                 goto out_free_irq;
 551
 552         err = arch_timer_cpu_pm_init();
 553         if (err)
 554                 goto out_unreg_notify;
 555
 556         /* Immediately configure the timer on the boot CPU */
 557         arch_timer_setup(this_cpu_ptr(arch_timer_evt));
 558
 559         return 0;
 560
 561 out_unreg_notify:
 562         unregister_cpu_notifier(&arch_timer_cpu_nb);
 563 out_free_irq:
 564         if (arch_timer_use_virtual)
 565                 free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
 566         else {
 567                 free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
 568                                 arch_timer_evt);
 569                 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
 570                         free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
 571                                         arch_timer_evt);
 572         }
 573
 574 out_free:
 575         free_percpu(arch_timer_evt);
 576 out:
 577         return err;
 578 }
 579
 580 static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
 581 {
 582         int ret;
 583         irq_handler_t func;
 584         struct arch_timer *t;
 585
 586         t = kzalloc(sizeof(*t), GFP_KERNEL);
 587         if (!t)
 588                 return -ENOMEM;
 589
 590         t->base = base;
 591         t->evt.irq = irq;
 592         __arch_timer_setup(ARCH_MEM_TIMER, &t->evt);
 593
 594         if (arch_timer_mem_use_virtual)
 595                 func = arch_timer_handler_virt_mem;
 596         else
 597                 func = arch_timer_handler_phys_mem;
 598
 599         ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt);
 600         if (ret) {
 601                 pr_err("arch_timer: Failed to request mem timer irq\n");
 602                 kfree(t);
 603         }
 604
 605         return ret;
 606 }
 607
 608 static const struct of_device_id arch_timer_of_match[] __initconst = {
 609         { .compatible   = "arm,armv7-timer",    },
 610         { .compatible   = "arm,armv8-timer",    },
 611         {},
 612 };
 613
 614 static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
 615         { .compatible   = "arm,armv7-timer-mem", },
 616         {},
 617 };
 618
 619 static void __init arch_timer_common_init(void)
 620 {
 621         unsigned mask = ARCH_CP15_TIMER | ARCH_MEM_TIMER;
 622
 623         /* Wait until both nodes are probed if we have two timers */
 624         if ((arch_timers_present & mask) != mask) {
 625                 if (of_find_matching_node(NULL, arch_timer_mem_of_match) &&
 626                                 !(arch_timers_present & ARCH_MEM_TIMER))
 627                         return;
 628                 if (of_find_matching_node(NULL, arch_timer_of_match) &&
 629                                 !(arch_timers_present & ARCH_CP15_TIMER))
 630                         return;
 631         }
 632
 633         arch_timer_banner(arch_timers_present);
 634         arch_counter_register(arch_timers_present);
 635         arch_timer_arch_init();
 636 }
 637
 638 static void __init arch_timer_init(struct device_node *np)
 639 {
 640         int i;
 641
 642         if (arch_timers_present & ARCH_CP15_TIMER) {
 643                 pr_warn("arch_timer: multiple nodes in dt, skipping\n");
 644                 return;
 645         }
 646
 647         arch_timers_present |= ARCH_CP15_TIMER;
 648         for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
 649                 arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
 650         arch_timer_detect_rate(NULL, np);
 651
 652         /*
 653          * If HYP mode is available, we know that the physical timer
 654          * has been configured to be accessible from PL1. Use it, so
 655          * that a guest can use the virtual timer instead.
 656          *
 657          * If no interrupt provided for virtual timer, we'll have to
 658          * stick to the physical timer. It'd better be accessible...
 659          */
 660         if (is_hyp_mode_available() || !arch_timer_ppi[VIRT_PPI]) {
 661                 arch_timer_use_virtual = false;
 662
 663                 if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
 664                     !arch_timer_ppi[PHYS_NONSECURE_PPI]) {
 665                         pr_warn("arch_timer: No interrupt available, giving up\n");
 666                         return;
 667                 }
 668         }
 669
 670         arch_timer_c3stop = !of_property_read_bool(np, "always-on");
 671
 672         arch_timer_register();
 673         arch_timer_common_init();
 674 }
 675 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init);
 676 CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init);
 677
 678 static void __init arch_timer_mem_init(struct device_node *np)
 679 {
 680         struct device_node *frame, *best_frame = NULL;
 681         void __iomem *cntctlbase, *base;
 682         unsigned int irq;
 683         u32 cnttidr;
 684
 685         arch_timers_present |= ARCH_MEM_TIMER;
 686         cntctlbase = of_iomap(np, 0);
 687         if (!cntctlbase) {
 688                 pr_err("arch_timer: Can't find CNTCTLBase\n");
 689                 return;
 690         }
 691
 692         cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
 693         iounmap(cntctlbase);
 694
 695         /*
 696          * Try to find a virtual capable frame. Otherwise fall back to a
 697          * physical capable frame.
 698          */
 699         for_each_available_child_of_node(np, frame) {
 700                 int n;
 701
 702                 if (of_property_read_u32(frame, "frame-number", &n)) {
 703                         pr_err("arch_timer: Missing frame-number\n");
 704                         of_node_put(best_frame);
 705                         of_node_put(frame);
 706                         return;
 707                 }
 708
 709                 if (cnttidr & CNTTIDR_VIRT(n)) {
 710                         of_node_put(best_frame);
 711                         best_frame = frame;
 712                         arch_timer_mem_use_virtual = true;
 713                         break;
 714                 }
 715                 of_node_put(best_frame);
 716                 best_frame = of_node_get(frame);
 717         }
 718
 719         base = arch_counter_base = of_iomap(best_frame, 0);
 720         if (!base) {
 721                 pr_err("arch_timer: Can't map frame's registers\n");
 722                 of_node_put(best_frame);
 723                 return;
 724         }
 725
 726         if (arch_timer_mem_use_virtual)
 727                 irq = irq_of_parse_and_map(best_frame, 1);
 728         else
 729                 irq = irq_of_parse_and_map(best_frame, 0);
 730         of_node_put(best_frame);
 731         if (!irq) {
 732                 pr_err("arch_timer: Frame missing %s irq",
 733                        arch_timer_mem_use_virtual ? "virt" : "phys");
 734                 return;
 735         }
 736
 737         arch_timer_detect_rate(base, np);
 738         arch_timer_mem_register(base, irq);
 739         arch_timer_common_init();
 740 }
 741 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
 742                        arch_timer_mem_init);