drivers/clocksource/timer-ti-dm-systimer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 #include <linux/clk.h>
   3 #include <linux/clocksource.h>
   4 #include <linux/clockchips.h>
   5 #include <linux/cpuhotplug.h>
   6 #include <linux/interrupt.h>
   7 #include <linux/io.h>
   8 #include <linux/iopoll.h>
   9 #include <linux/err.h>
  10 #include <linux/of.h>
  11 #include <linux/of_address.h>
  12 #include <linux/of_irq.h>
  13 #include <linux/sched_clock.h>
  14
  15 #include <linux/clk/clk-conf.h>
  16
  17 #include <clocksource/timer-ti-dm.h>
  18 #include <dt-bindings/bus/ti-sysc.h>
  19
  20 /* For type1, set SYSC_OMAP2_CLOCKACTIVITY for fck off on idle, l4 clock on */
  21 #define DMTIMER_TYPE1_ENABLE    ((1 << 9) | (SYSC_IDLE_SMART << 3) | \
  22                                  SYSC_OMAP2_ENAWAKEUP | SYSC_OMAP2_AUTOIDLE)
  23 #define DMTIMER_TYPE1_DISABLE   (SYSC_OMAP2_SOFTRESET | SYSC_OMAP2_AUTOIDLE)
  24 #define DMTIMER_TYPE2_ENABLE    (SYSC_IDLE_SMART_WKUP << 2)
  25 #define DMTIMER_RESET_WAIT      100000
  26
  27 #define DMTIMER_INST_DONT_CARE  ~0U
  28
  29 static int counter_32k;
  30 static u32 clocksource;
  31 static u32 clockevent;
  32
  33 /*
  34  * Subset of the timer registers we use. Note that the register offsets
  35  * depend on the timer revision detected.
  36  */
  37 struct dmtimer_systimer {
  38         void __iomem *base;
  39         u8 sysc;
  40         u8 irq_stat;
  41         u8 irq_ena;
  42         u8 pend;
  43         u8 load;
  44         u8 counter;
  45         u8 ctrl;
  46         u8 wakeup;
  47         u8 ifctrl;
  48         struct clk *fck;
  49         struct clk *ick;
  50         unsigned long rate;
  51 };
  52
  53 struct dmtimer_clockevent {
  54         struct clock_event_device dev;
  55         struct dmtimer_systimer t;
  56         u32 period;
  57 };
  58
  59 struct dmtimer_clocksource {
  60         struct clocksource dev;
  61         struct dmtimer_systimer t;
  62         unsigned int loadval;
  63 };
  64
  65 /* Assumes v1 ip if bits [31:16] are zero */
  66 static bool dmtimer_systimer_revision1(struct dmtimer_systimer *t)
  67 {
  68         u32 tidr = readl_relaxed(t->base);
  69
  70         return !(tidr >> 16);
  71 }
  72
  73 static void dmtimer_systimer_enable(struct dmtimer_systimer *t)
  74 {
  75         u32 val;
  76
  77         if (dmtimer_systimer_revision1(t))
  78                 val = DMTIMER_TYPE1_ENABLE;
  79         else
  80                 val = DMTIMER_TYPE2_ENABLE;
  81
  82         writel_relaxed(val, t->base + t->sysc);
  83 }
  84
  85 static void dmtimer_systimer_disable(struct dmtimer_systimer *t)
  86 {
  87         if (!dmtimer_systimer_revision1(t))
  88                 return;
  89
  90         writel_relaxed(DMTIMER_TYPE1_DISABLE, t->base + t->sysc);
  91 }
  92
  93 static int __init dmtimer_systimer_type1_reset(struct dmtimer_systimer *t)
  94 {
  95         void __iomem *syss = t->base + OMAP_TIMER_V1_SYS_STAT_OFFSET;
  96         int ret;
  97         u32 l;
  98
  99         dmtimer_systimer_enable(t);
 100         writel_relaxed(BIT(1) | BIT(2), t->base + t->ifctrl);
 101         ret = readl_poll_timeout_atomic(syss, l, l & BIT(0), 100,
 102                                         DMTIMER_RESET_WAIT);
 103
 104         return ret;
 105 }
 106
 107 /* Note we must use io_base instead of func_base for type2 OCP regs */
 108 static int __init dmtimer_systimer_type2_reset(struct dmtimer_systimer *t)
 109 {
 110         void __iomem *sysc = t->base + t->sysc;
 111         u32 l;
 112
 113         dmtimer_systimer_enable(t);
 114         l = readl_relaxed(sysc);
 115         l |= BIT(0);
 116         writel_relaxed(l, sysc);
 117
 118         return readl_poll_timeout_atomic(sysc, l, !(l & BIT(0)), 100,
 119                                          DMTIMER_RESET_WAIT);
 120 }
 121
 122 static int __init dmtimer_systimer_reset(struct dmtimer_systimer *t)
 123 {
 124         int ret;
 125
 126         if (dmtimer_systimer_revision1(t))
 127                 ret = dmtimer_systimer_type1_reset(t);
 128         else
 129                 ret = dmtimer_systimer_type2_reset(t);
 130         if (ret < 0) {
 131                 pr_err("%s failed with %i\n", __func__, ret);
 132
 133                 return ret;
 134         }
 135
 136         return 0;
 137 }
 138
 139 static const struct of_device_id counter_match_table[] = {
 140         { .compatible = "ti,omap-counter32k" },
 141         { /* Sentinel */ },
 142 };
 143
 144 /*
 145  * Check if the SoC als has a usable working 32 KiHz counter. The 32 KiHz
 146  * counter is handled by timer-ti-32k, but we need to detect it as it
 147  * affects the preferred dmtimer system timer configuration. There is
 148  * typically no use for a dmtimer clocksource if the 32 KiHz counter is
 149  * present, except on am437x as described below.
 150  */
 151 static void __init dmtimer_systimer_check_counter32k(void)
 152 {
 153         struct device_node *np;
 154
 155         if (counter_32k)
 156                 return;
 157
 158         np = of_find_matching_node(NULL, counter_match_table);
 159         if (!np) {
 160                 counter_32k = -ENODEV;
 161
 162                 return;
 163         }
 164
 165         if (of_device_is_available(np))
 166                 counter_32k = 1;
 167         else
 168                 counter_32k = -ENODEV;
 169
 170         of_node_put(np);
 171 }
 172
 173 static const struct of_device_id dmtimer_match_table[] = {
 174         { .compatible = "ti,omap2420-timer", },
 175         { .compatible = "ti,omap3430-timer", },
 176         { .compatible = "ti,omap4430-timer", },
 177         { .compatible = "ti,omap5430-timer", },
 178         { .compatible = "ti,am335x-timer", },
 179         { .compatible = "ti,am335x-timer-1ms", },
 180         { .compatible = "ti,dm814-timer", },
 181         { .compatible = "ti,dm816-timer", },
 182         { /* Sentinel */ },
 183 };
 184
 185 /*
 186  * Checks that system timers are configured to not reset and idle during
 187  * the generic timer-ti-dm device driver probe. And that the system timer
 188  * source clocks are properly configured. Also, let's not hog any DSP and
 189  * PWM capable timers unnecessarily as system timers.
 190  */
 191 static bool __init dmtimer_is_preferred(struct device_node *np)
 192 {
 193         if (!of_device_is_available(np))
 194                 return false;
 195
 196         if (!of_property_read_bool(np->parent,
 197                                    "ti,no-reset-on-init"))
 198                 return false;
 199
 200         if (!of_property_read_bool(np->parent, "ti,no-idle"))
 201                 return false;
 202
 203         /* Secure gptimer12 is always clocked with a fixed source */
 204         if (!of_property_read_bool(np, "ti,timer-secure")) {
 205                 if (!of_property_present(np, "assigned-clocks"))
 206                         return false;
 207
 208                 if (!of_property_present(np, "assigned-clock-parents"))
 209                         return false;
 210         }
 211
 212         if (of_property_read_bool(np, "ti,timer-dsp"))
 213                 return false;
 214
 215         if (of_property_read_bool(np, "ti,timer-pwm"))
 216                 return false;
 217
 218         return true;
 219 }
 220
 221 /*
 222  * Finds the first available usable always-on timer, and assigns it to either
 223  * clockevent or clocksource depending if the counter_32k is available on the
 224  * SoC or not.
 225  *
 226  * Some omap3 boards with unreliable oscillator must not use the counter_32k
 227  * or dmtimer1 with 32 KiHz source. Additionally, the boards with unreliable
 228  * oscillator should really set counter_32k as disabled, and delete dmtimer1
 229  * ti,always-on property, but let's not count on it. For these quirky cases,
 230  * we prefer using the always-on secure dmtimer12 with the internal 32 KiHz
 231  * clock as the clocksource, and any available dmtimer as clockevent.
 232  *
 233  * For am437x, we are using am335x style dmtimer clocksource. It is unclear
 234  * if this quirk handling is really needed, but let's change it separately
 235  * based on testing as it might cause side effects.
 236  */
 237 static void __init dmtimer_systimer_assign_alwon(void)
 238 {
 239         struct device_node *np;
 240         u32 pa = 0;
 241         bool quirk_unreliable_oscillator = false;
 242
 243         /* Quirk unreliable 32 KiHz oscillator with incomplete dts */
 244         if (of_machine_is_compatible("ti,omap3-beagle-ab4")) {
 245                 quirk_unreliable_oscillator = true;
 246                 counter_32k = -ENODEV;
 247         }
 248
 249         /* Quirk am437x using am335x style dmtimer clocksource */
 250         if (of_machine_is_compatible("ti,am43"))
 251                 counter_32k = -ENODEV;
 252
 253         for_each_matching_node(np, dmtimer_match_table) {
 254                 struct resource res;
 255                 if (!dmtimer_is_preferred(np))
 256                         continue;
 257
 258                 if (!of_property_read_bool(np, "ti,timer-alwon"))
 259                         continue;
 260
 261                 if (of_address_to_resource(np, 0, &res))
 262                         continue;
 263
 264                 pa = res.start;
 265
 266                 /* Quirky omap3 boards must use dmtimer12 */
 267                 if (quirk_unreliable_oscillator && pa == 0x48318000)
 268                         continue;
 269
 270                 of_node_put(np);
 271                 break;
 272         }
 273
 274         /* Usually no need for dmtimer clocksource if we have counter32 */
 275         if (counter_32k >= 0) {
 276                 clockevent = pa;
 277                 clocksource = 0;
 278         } else {
 279                 clocksource = pa;
 280                 clockevent = DMTIMER_INST_DONT_CARE;
 281         }
 282 }
 283
 284 /* Finds the first usable dmtimer, used for the don't care case */
 285 static u32 __init dmtimer_systimer_find_first_available(void)
 286 {
 287         struct device_node *np;
 288         u32 pa = 0;
 289
 290         for_each_matching_node(np, dmtimer_match_table) {
 291                 struct resource res;
 292                 if (!dmtimer_is_preferred(np))
 293                         continue;
 294
 295                 if (of_address_to_resource(np, 0, &res))
 296                         continue;
 297
 298                 if (res.start == clocksource || res.start == clockevent)
 299                         continue;
 300
 301                 pa = res.start;
 302                 of_node_put(np);
 303                 break;
 304         }
 305
 306         return pa;
 307 }
 308
 309 /* Selects the best clocksource and clockevent to use */
 310 static void __init dmtimer_systimer_select_best(void)
 311 {
 312         dmtimer_systimer_check_counter32k();
 313         dmtimer_systimer_assign_alwon();
 314
 315         if (clockevent == DMTIMER_INST_DONT_CARE)
 316                 clockevent = dmtimer_systimer_find_first_available();
 317
 318         pr_debug("%s: counter_32k: %i clocksource: %08x clockevent: %08x\n",
 319                  __func__, counter_32k, clocksource, clockevent);
 320 }
 321
 322 /* Interface clocks are only available on some SoCs variants */
 323 static int __init dmtimer_systimer_init_clock(struct dmtimer_systimer *t,
 324                                               struct device_node *np,
 325                                               const char *name,
 326                                               unsigned long *rate)
 327 {
 328         struct clk *clock;
 329         unsigned long r;
 330         bool is_ick = false;
 331         int error;
 332
 333         is_ick = !strncmp(name, "ick", 3);
 334
 335         clock = of_clk_get_by_name(np, name);
 336         if ((PTR_ERR(clock) == -EINVAL) && is_ick)
 337                 return 0;
 338         else if (IS_ERR(clock))
 339                 return PTR_ERR(clock);
 340
 341         error = clk_prepare_enable(clock);
 342         if (error)
 343                 return error;
 344
 345         r = clk_get_rate(clock);
 346         if (!r) {
 347                 clk_disable_unprepare(clock);
 348                 return -ENODEV;
 349         }
 350
 351         if (is_ick)
 352                 t->ick = clock;
 353         else
 354                 t->fck = clock;
 355
 356         *rate = r;
 357
 358         return 0;
 359 }
 360
 361 static int __init dmtimer_systimer_setup(struct device_node *np,
 362                                          struct dmtimer_systimer *t)
 363 {
 364         unsigned long rate;
 365         u8 regbase;
 366         int error;
 367
 368         if (!of_device_is_compatible(np->parent, "ti,sysc"))
 369                 return -EINVAL;
 370
 371         t->base = of_iomap(np, 0);
 372         if (!t->base)
 373                 return -ENXIO;
 374
 375         /*
 376          * Enable optional assigned-clock-parents configured at the timer
 377          * node level. For regular device drivers, this is done automatically
 378          * by bus related code such as platform_drv_probe().
 379          */
 380         error = of_clk_set_defaults(np, false);
 381         if (error < 0)
 382                 pr_err("%s: clock source init failed: %i\n", __func__, error);
 383
 384         /* For ti-sysc, we have timer clocks at the parent module level */
 385         error = dmtimer_systimer_init_clock(t, np->parent, "fck", &rate);
 386         if (error)
 387                 goto err_unmap;
 388
 389         t->rate = rate;
 390
 391         error = dmtimer_systimer_init_clock(t, np->parent, "ick", &rate);
 392         if (error)
 393                 goto err_unmap;
 394
 395         if (dmtimer_systimer_revision1(t)) {
 396                 t->irq_stat = OMAP_TIMER_V1_STAT_OFFSET;
 397                 t->irq_ena = OMAP_TIMER_V1_INT_EN_OFFSET;
 398                 t->pend = _OMAP_TIMER_WRITE_PEND_OFFSET;
 399                 regbase = 0;
 400         } else {
 401                 t->irq_stat = OMAP_TIMER_V2_IRQSTATUS;
 402                 t->irq_ena = OMAP_TIMER_V2_IRQENABLE_SET;
 403                 regbase = OMAP_TIMER_V2_FUNC_OFFSET;
 404                 t->pend = regbase + _OMAP_TIMER_WRITE_PEND_OFFSET;
 405         }
 406
 407         t->sysc = OMAP_TIMER_OCP_CFG_OFFSET;
 408         t->load = regbase + _OMAP_TIMER_LOAD_OFFSET;
 409         t->counter = regbase + _OMAP_TIMER_COUNTER_OFFSET;
 410         t->ctrl = regbase + _OMAP_TIMER_CTRL_OFFSET;
 411         t->wakeup = regbase + _OMAP_TIMER_WAKEUP_EN_OFFSET;
 412         t->ifctrl = regbase + _OMAP_TIMER_IF_CTRL_OFFSET;
 413
 414         dmtimer_systimer_reset(t);
 415         dmtimer_systimer_enable(t);
 416         pr_debug("dmtimer rev %08x sysc %08x\n", readl_relaxed(t->base),
 417                  readl_relaxed(t->base + t->sysc));
 418
 419         return 0;
 420
 421 err_unmap:
 422         iounmap(t->base);
 423
 424         return error;
 425 }
 426
 427 /* Clockevent */
 428 static struct dmtimer_clockevent *
 429 to_dmtimer_clockevent(struct clock_event_device *clockevent)
 430 {
 431         return container_of(clockevent, struct dmtimer_clockevent, dev);
 432 }
 433
 434 static irqreturn_t dmtimer_clockevent_interrupt(int irq, void *data)
 435 {
 436         struct dmtimer_clockevent *clkevt = data;
 437         struct dmtimer_systimer *t = &clkevt->t;
 438
 439         writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_stat);
 440         clkevt->dev.event_handler(&clkevt->dev);
 441
 442         return IRQ_HANDLED;
 443 }
 444
 445 static int dmtimer_set_next_event(unsigned long cycles,
 446                                   struct clock_event_device *evt)
 447 {
 448         struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);
 449         struct dmtimer_systimer *t = &clkevt->t;
 450         void __iomem *pend = t->base + t->pend;
 451
 452         while (readl_relaxed(pend) & WP_TCRR)
 453                 cpu_relax();
 454         writel_relaxed(0xffffffff - cycles, t->base + t->counter);
 455
 456         while (readl_relaxed(pend) & WP_TCLR)
 457                 cpu_relax();
 458         writel_relaxed(OMAP_TIMER_CTRL_ST, t->base + t->ctrl);
 459
 460         return 0;
 461 }
 462
 463 static int dmtimer_clockevent_shutdown(struct clock_event_device *evt)
 464 {
 465         struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);
 466         struct dmtimer_systimer *t = &clkevt->t;
 467         void __iomem *ctrl = t->base + t->ctrl;
 468         u32 l;
 469
 470         l = readl_relaxed(ctrl);
 471         if (l & OMAP_TIMER_CTRL_ST) {
 472                 l &= ~BIT(0);
 473                 writel_relaxed(l, ctrl);
 474                 /* Flush posted write */
 475                 l = readl_relaxed(ctrl);
 476                 /*  Wait for functional clock period x 3.5 */
 477                 udelay(3500000 / t->rate + 1);
 478         }
 479         writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_stat);
 480
 481         return 0;
 482 }
 483
 484 static int dmtimer_set_periodic(struct clock_event_device *evt)
 485 {
 486         struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);
 487         struct dmtimer_systimer *t = &clkevt->t;
 488         void __iomem *pend = t->base + t->pend;
 489
 490         dmtimer_clockevent_shutdown(evt);
 491
 492         /* Looks like we need to first set the load value separately */
 493         while (readl_relaxed(pend) & WP_TLDR)
 494                 cpu_relax();
 495         writel_relaxed(clkevt->period, t->base + t->load);
 496
 497         while (readl_relaxed(pend) & WP_TCRR)
 498                 cpu_relax();
 499         writel_relaxed(clkevt->period, t->base + t->counter);
 500
 501         while (readl_relaxed(pend) & WP_TCLR)
 502                 cpu_relax();
 503         writel_relaxed(OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
 504                        t->base + t->ctrl);
 505
 506         return 0;
 507 }
 508
 509 static void omap_clockevent_idle(struct clock_event_device *evt)
 510 {
 511         struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);
 512         struct dmtimer_systimer *t = &clkevt->t;
 513
 514         dmtimer_systimer_disable(t);
 515         clk_disable(t->fck);
 516 }
 517
 518 static void omap_clockevent_unidle(struct clock_event_device *evt)
 519 {
 520         struct dmtimer_clockevent *clkevt = to_dmtimer_clockevent(evt);
 521         struct dmtimer_systimer *t = &clkevt->t;
 522         int error;
 523
 524         error = clk_enable(t->fck);
 525         if (error)
 526                 pr_err("could not enable timer fck on resume: %i\n", error);
 527
 528         dmtimer_systimer_enable(t);
 529         writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_ena);
 530         writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->wakeup);
 531 }
 532
 533 static int __init dmtimer_clkevt_init_common(struct dmtimer_clockevent *clkevt,
 534                                              struct device_node *np,
 535                                              unsigned int features,
 536                                              const struct cpumask *cpumask,
 537                                              const char *name,
 538                                              int rating)
 539 {
 540         struct clock_event_device *dev;
 541         struct dmtimer_systimer *t;
 542         int error;
 543
 544         t = &clkevt->t;
 545         dev = &clkevt->dev;
 546
 547         /*
 548          * We mostly use cpuidle_coupled with ARM local timers for runtime,
 549          * so there's probably no use for CLOCK_EVT_FEAT_DYNIRQ here.
 550          */
 551         dev->features = features;
 552         dev->rating = rating;
 553         dev->set_next_event = dmtimer_set_next_event;
 554         dev->set_state_shutdown = dmtimer_clockevent_shutdown;
 555         dev->set_state_periodic = dmtimer_set_periodic;
 556         dev->set_state_oneshot = dmtimer_clockevent_shutdown;
 557         dev->set_state_oneshot_stopped = dmtimer_clockevent_shutdown;
 558         dev->tick_resume = dmtimer_clockevent_shutdown;
 559         dev->cpumask = cpumask;
 560
 561         dev->irq = irq_of_parse_and_map(np, 0);
 562         if (!dev->irq)
 563                 return -ENXIO;
 564
 565         error = dmtimer_systimer_setup(np, &clkevt->t);
 566         if (error)
 567                 return error;
 568
 569         clkevt->period = 0xffffffff - DIV_ROUND_CLOSEST(t->rate, HZ);
 570
 571         /*
 572          * For clock-event timers we never read the timer counter and
 573          * so we are not impacted by errata i103 and i767. Therefore,
 574          * we can safely ignore this errata for clock-event timers.
 575          */
 576         writel_relaxed(OMAP_TIMER_CTRL_POSTED, t->base + t->ifctrl);
 577
 578         error = request_irq(dev->irq, dmtimer_clockevent_interrupt,
 579                             IRQF_TIMER, name, clkevt);
 580         if (error)
 581                 goto err_out_unmap;
 582
 583         writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_ena);
 584         writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->wakeup);
 585
 586         pr_info("TI gptimer %s: %s%lu Hz at %pOF\n",
 587                 name, of_property_read_bool(np, "ti,timer-alwon") ?
 588                 "always-on " : "", t->rate, np->parent);
 589
 590         return 0;
 591
 592 err_out_unmap:
 593         iounmap(t->base);
 594
 595         return error;
 596 }
 597
 598 static int __init dmtimer_clockevent_init(struct device_node *np)
 599 {
 600         struct dmtimer_clockevent *clkevt;
 601         int error;
 602
 603         clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
 604         if (!clkevt)
 605                 return -ENOMEM;
 606
 607         error = dmtimer_clkevt_init_common(clkevt, np,
 608                                            CLOCK_EVT_FEAT_PERIODIC |
 609                                            CLOCK_EVT_FEAT_ONESHOT,
 610                                            cpu_possible_mask, "clockevent",
 611                                            300);
 612         if (error)
 613                 goto err_out_free;
 614
 615         clockevents_config_and_register(&clkevt->dev, clkevt->t.rate,
 616                                         3, /* Timer internal resync latency */
 617                                         0xffffffff);
 618
 619         if (of_machine_is_compatible("ti,am33xx") ||
 620             of_machine_is_compatible("ti,am43")) {
 621                 clkevt->dev.suspend = omap_clockevent_idle;
 622                 clkevt->dev.resume = omap_clockevent_unidle;
 623         }
 624
 625         return 0;
 626
 627 err_out_free:
 628         kfree(clkevt);
 629
 630         return error;
 631 }
 632
 633 /* Dmtimer as percpu timer. See dra7 ARM architected timer wrap erratum i940 */
 634 static DEFINE_PER_CPU(struct dmtimer_clockevent, dmtimer_percpu_timer);
 635
 636 static int __init dmtimer_percpu_timer_init(struct device_node *np, int cpu)
 637 {
 638         struct dmtimer_clockevent *clkevt;
 639         int error;
 640
 641         if (!cpu_possible(cpu))
 642                 return -EINVAL;
 643
 644         if (!of_property_read_bool(np->parent, "ti,no-reset-on-init") ||
 645             !of_property_read_bool(np->parent, "ti,no-idle"))
 646                 pr_warn("Incomplete dtb for percpu dmtimer %pOF\n", np->parent);
 647
 648         clkevt = per_cpu_ptr(&dmtimer_percpu_timer, cpu);
 649
 650         error = dmtimer_clkevt_init_common(clkevt, np, CLOCK_EVT_FEAT_ONESHOT,
 651                                            cpumask_of(cpu), "percpu-dmtimer",
 652                                            500);
 653         if (error)
 654                 return error;
 655
 656         return 0;
 657 }
 658
 659 /* See TRM for timer internal resynch latency */
 660 static int omap_dmtimer_starting_cpu(unsigned int cpu)
 661 {
 662         struct dmtimer_clockevent *clkevt = per_cpu_ptr(&dmtimer_percpu_timer, cpu);
 663         struct clock_event_device *dev = &clkevt->dev;
 664         struct dmtimer_systimer *t = &clkevt->t;
 665
 666         clockevents_config_and_register(dev, t->rate, 3, ULONG_MAX);
 667         irq_force_affinity(dev->irq, cpumask_of(cpu));
 668
 669         return 0;
 670 }
 671
 672 static int __init dmtimer_percpu_timer_startup(void)
 673 {
 674         struct dmtimer_clockevent *clkevt = per_cpu_ptr(&dmtimer_percpu_timer, 0);
 675         struct dmtimer_systimer *t = &clkevt->t;
 676
 677         if (t->sysc) {
 678                 cpuhp_setup_state(CPUHP_AP_TI_GP_TIMER_STARTING,
 679                                   "clockevents/omap/gptimer:starting",
 680                                   omap_dmtimer_starting_cpu, NULL);
 681         }
 682
 683         return 0;
 684 }
 685 subsys_initcall(dmtimer_percpu_timer_startup);
 686
 687 static int __init dmtimer_percpu_quirk_init(struct device_node *np, u32 pa)
 688 {
 689         struct device_node *arm_timer __free(device_node) =
 690                 of_find_compatible_node(NULL, NULL, "arm,armv7-timer");
 691
 692         if (of_device_is_available(arm_timer)) {
 693                 pr_warn_once("ARM architected timer wrap issue i940 detected\n");
 694                 return 0;
 695         }
 696
 697         if (pa == 0x4882c000)           /* dra7 dmtimer15 */
 698                 return dmtimer_percpu_timer_init(np, 0);
 699         else if (pa == 0x4882e000)      /* dra7 dmtimer16 */
 700                 return dmtimer_percpu_timer_init(np, 1);
 701
 702         return 0;
 703 }
 704
 705 /* Clocksource */
 706 static struct dmtimer_clocksource *
 707 to_dmtimer_clocksource(struct clocksource *cs)
 708 {
 709         return container_of(cs, struct dmtimer_clocksource, dev);
 710 }
 711
 712 static u64 dmtimer_clocksource_read_cycles(struct clocksource *cs)
 713 {
 714         struct dmtimer_clocksource *clksrc = to_dmtimer_clocksource(cs);
 715         struct dmtimer_systimer *t = &clksrc->t;
 716
 717         return (u64)readl_relaxed(t->base + t->counter);
 718 }
 719
 720 static void __iomem *dmtimer_sched_clock_counter;
 721
 722 static u64 notrace dmtimer_read_sched_clock(void)
 723 {
 724         return readl_relaxed(dmtimer_sched_clock_counter);
 725 }
 726
 727 static void dmtimer_clocksource_suspend(struct clocksource *cs)
 728 {
 729         struct dmtimer_clocksource *clksrc = to_dmtimer_clocksource(cs);
 730         struct dmtimer_systimer *t = &clksrc->t;
 731
 732         clksrc->loadval = readl_relaxed(t->base + t->counter);
 733         dmtimer_systimer_disable(t);
 734         clk_disable(t->fck);
 735 }
 736
 737 static void dmtimer_clocksource_resume(struct clocksource *cs)
 738 {
 739         struct dmtimer_clocksource *clksrc = to_dmtimer_clocksource(cs);
 740         struct dmtimer_systimer *t = &clksrc->t;
 741         int error;
 742
 743         error = clk_enable(t->fck);
 744         if (error)
 745                 pr_err("could not enable timer fck on resume: %i\n", error);
 746
 747         dmtimer_systimer_enable(t);
 748         writel_relaxed(clksrc->loadval, t->base + t->counter);
 749         writel_relaxed(OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR,
 750                        t->base + t->ctrl);
 751 }
 752
 753 static int __init dmtimer_clocksource_init(struct device_node *np)
 754 {
 755         struct dmtimer_clocksource *clksrc;
 756         struct dmtimer_systimer *t;
 757         struct clocksource *dev;
 758         int error;
 759
 760         clksrc = kzalloc(sizeof(*clksrc), GFP_KERNEL);
 761         if (!clksrc)
 762                 return -ENOMEM;
 763
 764         dev = &clksrc->dev;
 765         t = &clksrc->t;
 766
 767         error = dmtimer_systimer_setup(np, t);
 768         if (error)
 769                 goto err_out_free;
 770
 771         dev->name = "dmtimer";
 772         dev->rating = 300;
 773         dev->read = dmtimer_clocksource_read_cycles;
 774         dev->mask = CLOCKSOURCE_MASK(32);
 775         dev->flags = CLOCK_SOURCE_IS_CONTINUOUS;
 776
 777         /* Unlike for clockevent, legacy code sets suspend only for am4 */
 778         if (of_machine_is_compatible("ti,am43")) {
 779                 dev->suspend = dmtimer_clocksource_suspend;
 780                 dev->resume = dmtimer_clocksource_resume;
 781         }
 782
 783         writel_relaxed(0, t->base + t->counter);
 784         writel_relaxed(OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR,
 785                        t->base + t->ctrl);
 786
 787         pr_info("TI gptimer clocksource: %s%pOF\n",
 788                 of_property_read_bool(np, "ti,timer-alwon") ?
 789                 "always-on " : "", np->parent);
 790
 791         if (!dmtimer_sched_clock_counter) {
 792                 dmtimer_sched_clock_counter = t->base + t->counter;
 793                 sched_clock_register(dmtimer_read_sched_clock, 32, t->rate);
 794         }
 795
 796         if (clocksource_register_hz(dev, t->rate))
 797                 pr_err("Could not register clocksource %pOF\n", np);
 798
 799         return 0;
 800
 801 err_out_free:
 802         kfree(clksrc);
 803
 804         return -ENODEV;
 805 }
 806
 807 /*
 808  * To detect between a clocksource and clockevent, we assume the device tree
 809  * has no interrupts configured for a clocksource timer.
 810  */
 811 static int __init dmtimer_systimer_init(struct device_node *np)
 812 {
 813         struct resource res;
 814         u32 pa;
 815
 816         /* One time init for the preferred timer configuration */
 817         if (!clocksource && !clockevent)
 818                 dmtimer_systimer_select_best();
 819
 820         if (!clocksource && !clockevent) {
 821                 pr_err("%s: unable to detect system timers, update dtb?\n",
 822                        __func__);
 823
 824                 return -EINVAL;
 825         }
 826
 827
 828         of_address_to_resource(np, 0, &res);
 829         pa = (u32)res.start;
 830         if (!pa)
 831                 return -EINVAL;
 832
 833         if (counter_32k <= 0 && clocksource == pa)
 834                 return dmtimer_clocksource_init(np);
 835
 836         if (clockevent == pa)
 837                 return dmtimer_clockevent_init(np);
 838
 839         if (of_machine_is_compatible("ti,dra7"))
 840                 return dmtimer_percpu_quirk_init(np, pa);
 841
 842         return 0;
 843 }
 844
 845 TIMER_OF_DECLARE(systimer_omap2, "ti,omap2420-timer", dmtimer_systimer_init);
 846 TIMER_OF_DECLARE(systimer_omap3, "ti,omap3430-timer", dmtimer_systimer_init);
 847 TIMER_OF_DECLARE(systimer_omap4, "ti,omap4430-timer", dmtimer_systimer_init);
 848 TIMER_OF_DECLARE(systimer_omap5, "ti,omap5430-timer", dmtimer_systimer_init);
 849 TIMER_OF_DECLARE(systimer_am33x, "ti,am335x-timer", dmtimer_systimer_init);
 850 TIMER_OF_DECLARE(systimer_am3ms, "ti,am335x-timer-1ms", dmtimer_systimer_init);
 851 TIMER_OF_DECLARE(systimer_dm814, "ti,dm814-timer", dmtimer_systimer_init);
 852 TIMER_OF_DECLARE(systimer_dm816, "ti,dm816-timer", dmtimer_systimer_init);