arch/arm/mach-omap2/timer.c

   1 /*
   2  * linux/arch/arm/mach-omap2/timer.c
   3  *
   4  * OMAP2 GP timer support.
   5  *
   6  * Copyright (C) 2009 Nokia Corporation
   7  *
   8  * Update to use new clocksource/clockevent layers
   9  * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
  10  * Copyright (C) 2007 MontaVista Software, Inc.
  11  *
  12  * Original driver:
  13  * Copyright (C) 2005 Nokia Corporation
  14  * Author: Paul Mundt <paul.mundt@nokia.com>
  15  *         Juha Yrjölä <juha.yrjola@nokia.com>
  16  * OMAP Dual-mode timer framework support by Timo Teras
  17  *
  18  * Some parts based off of TI's 24xx code:
  19  *
  20  * Copyright (C) 2004-2009 Texas Instruments, Inc.
  21  *
  22  * Roughly modelled after the OMAP1 MPU timer code.
  23  * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
  24  *
  25  * This file is subject to the terms and conditions of the GNU General Public
  26  * License. See the file "COPYING" in the main directory of this archive
  27  * for more details.
  28  */
  29 #include <linux/init.h>
  30 #include <linux/time.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/err.h>
  33 #include <linux/clk.h>
  34 #include <linux/delay.h>
  35 #include <linux/irq.h>
  36 #include <linux/clocksource.h>
  37 #include <linux/clockchips.h>
  38 #include <linux/slab.h>
  39 #include <linux/of.h>
  40 #include <linux/of_address.h>
  41 #include <linux/of_irq.h>
  42 #include <linux/platform_device.h>
  43 #include <linux/platform_data/dmtimer-omap.h>
  44 #include <linux/sched_clock.h>
  45
  46 #include <asm/mach/time.h>
  47 #include <asm/smp_twd.h>
  48
  49 #include "omap_hwmod.h"
  50 #include "omap_device.h"
  51 #include <plat/counter-32k.h>
  52 #include <plat/dmtimer.h>
  53 #include "omap-pm.h"
  54
  55 #include "soc.h"
  56 #include "common.h"
  57 #include "control.h"
  58 #include "powerdomain.h"
  59 #include "omap-secure.h"
  60
  61 #define REALTIME_COUNTER_BASE                           0x48243200
  62 #define INCREMENTER_NUMERATOR_OFFSET                    0x10
  63 #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET           0x14
  64 #define NUMERATOR_DENUMERATOR_MASK                      0xfffff000
  65
  66 /* Clockevent code */
  67
  68 static struct omap_dm_timer clkev;
  69 static struct clock_event_device clockevent_gpt;
  70
  71 #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
  72 static unsigned long arch_timer_freq;
  73
  74 void set_cntfreq(void)
  75 {
  76         omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
  77 }
  78 #endif
  79
  80 static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
  81 {
  82         struct clock_event_device *evt = &clockevent_gpt;
  83
  84         __omap_dm_timer_write_status(&clkev, OMAP_TIMER_INT_OVERFLOW);
  85
  86         evt->event_handler(evt);
  87         return IRQ_HANDLED;
  88 }
  89
  90 static struct irqaction omap2_gp_timer_irq = {
  91         .name           = "gp_timer",
  92         .flags          = IRQF_TIMER | IRQF_IRQPOLL,
  93         .handler        = omap2_gp_timer_interrupt,
  94 };
  95
  96 static int omap2_gp_timer_set_next_event(unsigned long cycles,
  97                                          struct clock_event_device *evt)
  98 {
  99         __omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
 100                                    0xffffffff - cycles, OMAP_TIMER_POSTED);
 101
 102         return 0;
 103 }
 104
 105 static int omap2_gp_timer_shutdown(struct clock_event_device *evt)
 106 {
 107         __omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
 108         return 0;
 109 }
 110
 111 static int omap2_gp_timer_set_periodic(struct clock_event_device *evt)
 112 {
 113         u32 period;
 114
 115         __omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
 116
 117         period = clkev.rate / HZ;
 118         period -= 1;
 119         /* Looks like we need to first set the load value separately */
 120         __omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG, 0xffffffff - period,
 121                               OMAP_TIMER_POSTED);
 122         __omap_dm_timer_load_start(&clkev,
 123                                    OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
 124                                    0xffffffff - period, OMAP_TIMER_POSTED);
 125         return 0;
 126 }
 127
 128 static struct clock_event_device clockevent_gpt = {
 129         .features               = CLOCK_EVT_FEAT_PERIODIC |
 130                                   CLOCK_EVT_FEAT_ONESHOT,
 131         .rating                 = 300,
 132         .set_next_event         = omap2_gp_timer_set_next_event,
 133         .set_state_shutdown     = omap2_gp_timer_shutdown,
 134         .set_state_periodic     = omap2_gp_timer_set_periodic,
 135         .set_state_oneshot      = omap2_gp_timer_shutdown,
 136         .tick_resume            = omap2_gp_timer_shutdown,
 137 };
 138
 139 static struct property device_disabled = {
 140         .name = "status",
 141         .length = sizeof("disabled"),
 142         .value = "disabled",
 143 };
 144
 145 static const struct of_device_id omap_timer_match[] __initconst = {
 146         { .compatible = "ti,omap2420-timer", },
 147         { .compatible = "ti,omap3430-timer", },
 148         { .compatible = "ti,omap4430-timer", },
 149         { .compatible = "ti,omap5430-timer", },
 150         { .compatible = "ti,dm814-timer", },
 151         { .compatible = "ti,dm816-timer", },
 152         { .compatible = "ti,am335x-timer", },
 153         { .compatible = "ti,am335x-timer-1ms", },
 154         { }
 155 };
 156
 157 /**
 158  * omap_get_timer_dt - get a timer using device-tree
 159  * @match       - device-tree match structure for matching a device type
 160  * @property    - optional timer property to match
 161  *
 162  * Helper function to get a timer during early boot using device-tree for use
 163  * as kernel system timer. Optionally, the property argument can be used to
 164  * select a timer with a specific property. Once a timer is found then mark
 165  * the timer node in device-tree as disabled, to prevent the kernel from
 166  * registering this timer as a platform device and so no one else can use it.
 167  */
 168 static struct device_node * __init omap_get_timer_dt(const struct of_device_id *match,
 169                                                      const char *property)
 170 {
 171         struct device_node *np;
 172
 173         for_each_matching_node(np, match) {
 174                 if (!of_device_is_available(np))
 175                         continue;
 176
 177                 if (property && !of_get_property(np, property, NULL))
 178                         continue;
 179
 180                 if (!property && (of_get_property(np, "ti,timer-alwon", NULL) ||
 181                                   of_get_property(np, "ti,timer-dsp", NULL) ||
 182                                   of_get_property(np, "ti,timer-pwm", NULL) ||
 183                                   of_get_property(np, "ti,timer-secure", NULL)))
 184                         continue;
 185
 186                 of_add_property(np, &device_disabled);
 187                 return np;
 188         }
 189
 190         return NULL;
 191 }
 192
 193 /**
 194  * omap_dmtimer_init - initialisation function when device tree is used
 195  *
 196  * For secure OMAP3 devices, timers with device type "timer-secure" cannot
 197  * be used by the kernel as they are reserved. Therefore, to prevent the
 198  * kernel registering these devices remove them dynamically from the device
 199  * tree on boot.
 200  */
 201 static void __init omap_dmtimer_init(void)
 202 {
 203         struct device_node *np;
 204
 205         if (!cpu_is_omap34xx())
 206                 return;
 207
 208         /* If we are a secure device, remove any secure timer nodes */
 209         if ((omap_type() != OMAP2_DEVICE_TYPE_GP)) {
 210                 np = omap_get_timer_dt(omap_timer_match, "ti,timer-secure");
 211                 of_node_put(np);
 212         }
 213 }
 214
 215 /**
 216  * omap_dm_timer_get_errata - get errata flags for a timer
 217  *
 218  * Get the timer errata flags that are specific to the OMAP device being used.
 219  */
 220 static u32 __init omap_dm_timer_get_errata(void)
 221 {
 222         if (cpu_is_omap24xx())
 223                 return 0;
 224
 225         return OMAP_TIMER_ERRATA_I103_I767;
 226 }
 227
 228 static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
 229                                          const char *fck_source,
 230                                          const char *property,
 231                                          const char **timer_name,
 232                                          int posted)
 233 {
 234         char name[10]; /* 10 = sizeof("gptXX_Xck0") */
 235         const char *oh_name = NULL;
 236         struct device_node *np;
 237         struct omap_hwmod *oh;
 238         struct resource irq, mem;
 239         struct clk *src;
 240         int r = 0;
 241
 242         if (of_have_populated_dt()) {
 243                 np = omap_get_timer_dt(omap_timer_match, property);
 244                 if (!np)
 245                         return -ENODEV;
 246
 247                 of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
 248                 if (!oh_name)
 249                         return -ENODEV;
 250
 251                 timer->irq = irq_of_parse_and_map(np, 0);
 252                 if (!timer->irq)
 253                         return -ENXIO;
 254
 255                 timer->io_base = of_iomap(np, 0);
 256
 257                 of_node_put(np);
 258         } else {
 259                 if (omap_dm_timer_reserve_systimer(timer->id))
 260                         return -ENODEV;
 261
 262                 sprintf(name, "timer%d", timer->id);
 263                 oh_name = name;
 264         }
 265
 266         oh = omap_hwmod_lookup(oh_name);
 267         if (!oh)
 268                 return -ENODEV;
 269
 270         *timer_name = oh->name;
 271
 272         if (!of_have_populated_dt()) {
 273                 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL,
 274                                                    &irq);
 275                 if (r)
 276                         return -ENXIO;
 277                 timer->irq = irq.start;
 278
 279                 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL,
 280                                                    &mem);
 281                 if (r)
 282                         return -ENXIO;
 283
 284                 /* Static mapping, never released */
 285                 timer->io_base = ioremap(mem.start, mem.end - mem.start);
 286         }
 287
 288         if (!timer->io_base)
 289                 return -ENXIO;
 290
 291         /* After the dmtimer is using hwmod these clocks won't be needed */
 292         timer->fclk = clk_get(NULL, omap_hwmod_get_main_clk(oh));
 293         if (IS_ERR(timer->fclk))
 294                 return PTR_ERR(timer->fclk);
 295
 296         src = clk_get(NULL, fck_source);
 297         if (IS_ERR(src))
 298                 return PTR_ERR(src);
 299
 300         WARN(clk_set_parent(timer->fclk, src) < 0,
 301              "Cannot set timer parent clock, no PLL clock driver?");
 302
 303         clk_put(src);
 304
 305         omap_hwmod_setup_one(oh_name);
 306         omap_hwmod_enable(oh);
 307         __omap_dm_timer_init_regs(timer);
 308
 309         if (posted)
 310                 __omap_dm_timer_enable_posted(timer);
 311
 312         /* Check that the intended posted configuration matches the actual */
 313         if (posted != timer->posted)
 314                 return -EINVAL;
 315
 316         timer->rate = clk_get_rate(timer->fclk);
 317         timer->reserved = 1;
 318
 319         return r;
 320 }
 321
 322 static void __init omap2_gp_clockevent_init(int gptimer_id,
 323                                                 const char *fck_source,
 324                                                 const char *property)
 325 {
 326         int res;
 327
 328         clkev.id = gptimer_id;
 329         clkev.errata = omap_dm_timer_get_errata();
 330
 331         /*
 332          * For clock-event timers we never read the timer counter and
 333          * so we are not impacted by errata i103 and i767. Therefore,
 334          * we can safely ignore this errata for clock-event timers.
 335          */
 336         __omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);
 337
 338         res = omap_dm_timer_init_one(&clkev, fck_source, property,
 339                                      &clockevent_gpt.name, OMAP_TIMER_POSTED);
 340         BUG_ON(res);
 341
 342         omap2_gp_timer_irq.dev_id = &clkev;
 343         setup_irq(clkev.irq, &omap2_gp_timer_irq);
 344
 345         __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
 346
 347         clockevent_gpt.cpumask = cpu_possible_mask;
 348         clockevent_gpt.irq = omap_dm_timer_get_irq(&clkev);
 349         clockevents_config_and_register(&clockevent_gpt, clkev.rate,
 350                                         3, /* Timer internal resynch latency */
 351                                         0xffffffff);
 352
 353         pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt.name,
 354                 clkev.rate);
 355 }
 356
 357 /* Clocksource code */
 358 static struct omap_dm_timer clksrc;
 359 static bool use_gptimer_clksrc __initdata;
 360
 361 /*
 362  * clocksource
 363  */
 364 static cycle_t clocksource_read_cycles(struct clocksource *cs)
 365 {
 366         return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
 367                                                      OMAP_TIMER_NONPOSTED);
 368 }
 369
 370 static struct clocksource clocksource_gpt = {
 371         .rating         = 300,
 372         .read           = clocksource_read_cycles,
 373         .mask           = CLOCKSOURCE_MASK(32),
 374         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 375 };
 376
 377 static u64 notrace dmtimer_read_sched_clock(void)
 378 {
 379         if (clksrc.reserved)
 380                 return __omap_dm_timer_read_counter(&clksrc,
 381                                                     OMAP_TIMER_NONPOSTED);
 382
 383         return 0;
 384 }
 385
 386 static const struct of_device_id omap_counter_match[] __initconst = {
 387         { .compatible = "ti,omap-counter32k", },
 388         { }
 389 };
 390
 391 /* Setup free-running counter for clocksource */
 392 static int __init __maybe_unused omap2_sync32k_clocksource_init(void)
 393 {
 394         int ret;
 395         struct device_node *np = NULL;
 396         struct omap_hwmod *oh;
 397         void __iomem *vbase;
 398         const char *oh_name = "counter_32k";
 399
 400         /*
 401          * If device-tree is present, then search the DT blob
 402          * to see if the 32kHz counter is supported.
 403          */
 404         if (of_have_populated_dt()) {
 405                 np = omap_get_timer_dt(omap_counter_match, NULL);
 406                 if (!np)
 407                         return -ENODEV;
 408
 409                 of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
 410                 if (!oh_name)
 411                         return -ENODEV;
 412         }
 413
 414         /*
 415          * First check hwmod data is available for sync32k counter
 416          */
 417         oh = omap_hwmod_lookup(oh_name);
 418         if (!oh || oh->slaves_cnt == 0)
 419                 return -ENODEV;
 420
 421         omap_hwmod_setup_one(oh_name);
 422
 423         if (np) {
 424                 vbase = of_iomap(np, 0);
 425                 of_node_put(np);
 426         } else {
 427                 vbase = omap_hwmod_get_mpu_rt_va(oh);
 428         }
 429
 430         if (!vbase) {
 431                 pr_warn("%s: failed to get counter_32k resource\n", __func__);
 432                 return -ENXIO;
 433         }
 434
 435         ret = omap_hwmod_enable(oh);
 436         if (ret) {
 437                 pr_warn("%s: failed to enable counter_32k module (%d)\n",
 438                                                         __func__, ret);
 439                 return ret;
 440         }
 441
 442         ret = omap_init_clocksource_32k(vbase);
 443         if (ret) {
 444                 pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
 445                                                         __func__, ret);
 446                 omap_hwmod_idle(oh);
 447         }
 448
 449         return ret;
 450 }
 451
 452 static void __init omap2_gptimer_clocksource_init(int gptimer_id,
 453                                                   const char *fck_source,
 454                                                   const char *property)
 455 {
 456         int res;
 457
 458         clksrc.id = gptimer_id;
 459         clksrc.errata = omap_dm_timer_get_errata();
 460
 461         res = omap_dm_timer_init_one(&clksrc, fck_source, property,
 462                                      &clocksource_gpt.name,
 463                                      OMAP_TIMER_NONPOSTED);
 464         BUG_ON(res);
 465
 466         __omap_dm_timer_load_start(&clksrc,
 467                                    OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
 468                                    OMAP_TIMER_NONPOSTED);
 469         sched_clock_register(dmtimer_read_sched_clock, 32, clksrc.rate);
 470
 471         if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
 472                 pr_err("Could not register clocksource %s\n",
 473                         clocksource_gpt.name);
 474         else
 475                 pr_info("OMAP clocksource: %s at %lu Hz\n",
 476                         clocksource_gpt.name, clksrc.rate);
 477 }
 478
 479 #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
 480 /*
 481  * The realtime counter also called master counter, is a free-running
 482  * counter, which is related to real time. It produces the count used
 483  * by the CPU local timer peripherals in the MPU cluster. The timer counts
 484  * at a rate of 6.144 MHz. Because the device operates on different clocks
 485  * in different power modes, the master counter shifts operation between
 486  * clocks, adjusting the increment per clock in hardware accordingly to
 487  * maintain a constant count rate.
 488  */
 489 static void __init realtime_counter_init(void)
 490 {
 491         void __iomem *base;
 492         static struct clk *sys_clk;
 493         unsigned long rate;
 494         unsigned int reg;
 495         unsigned long long num, den;
 496
 497         base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
 498         if (!base) {
 499                 pr_err("%s: ioremap failed\n", __func__);
 500                 return;
 501         }
 502         sys_clk = clk_get(NULL, "sys_clkin");
 503         if (IS_ERR(sys_clk)) {
 504                 pr_err("%s: failed to get system clock handle\n", __func__);
 505                 iounmap(base);
 506                 return;
 507         }
 508
 509         rate = clk_get_rate(sys_clk);
 510
 511         if (soc_is_dra7xx()) {
 512                 /*
 513                  * Errata i856 says the 32.768KHz crystal does not start at
 514                  * power on, so the CPU falls back to an emulated 32KHz clock
 515                  * based on sysclk / 610 instead. This causes the master counter
 516                  * frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
 517                  * (OR sysclk * 75 / 244)
 518                  *
 519                  * This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
 520                  * Of course any board built without a populated 32.768KHz
 521                  * crystal would also need this fix even if the CPU is fixed
 522                  * later.
 523                  *
 524                  * Either case can be detected by using the two speedselect bits
 525                  * If they are not 0, then the 32.768KHz clock driving the
 526                  * coarse counter that corrects the fine counter every time it
 527                  * ticks is actually rate/610 rather than 32.768KHz and we
 528                  * should compensate to avoid the 570ppm (at 20MHz, much worse
 529                  * at other rates) too fast system time.
 530                  */
 531                 reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
 532                 if (reg & DRA7_SPEEDSELECT_MASK) {
 533                         num = 75;
 534                         den = 244;
 535                         goto sysclk1_based;
 536                 }
 537         }
 538
 539         /* Numerator/denumerator values refer TRM Realtime Counter section */
 540         switch (rate) {
 541         case 12000000:
 542                 num = 64;
 543                 den = 125;
 544                 break;
 545         case 13000000:
 546                 num = 768;
 547                 den = 1625;
 548                 break;
 549         case 19200000:
 550                 num = 8;
 551                 den = 25;
 552                 break;
 553         case 20000000:
 554                 num = 192;
 555                 den = 625;
 556                 break;
 557         case 26000000:
 558                 num = 384;
 559                 den = 1625;
 560                 break;
 561         case 27000000:
 562                 num = 256;
 563                 den = 1125;
 564                 break;
 565         case 38400000:
 566         default:
 567                 /* Program it for 38.4 MHz */
 568                 num = 4;
 569                 den = 25;
 570                 break;
 571         }
 572
 573 sysclk1_based:
 574         /* Program numerator and denumerator registers */
 575         reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
 576                         NUMERATOR_DENUMERATOR_MASK;
 577         reg |= num;
 578         writel_relaxed(reg, base + INCREMENTER_NUMERATOR_OFFSET);
 579
 580         reg = readl_relaxed(base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET) &
 581                         NUMERATOR_DENUMERATOR_MASK;
 582         reg |= den;
 583         writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
 584
 585         arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
 586         set_cntfreq();
 587
 588         iounmap(base);
 589 }
 590 #else
 591 static inline void __init realtime_counter_init(void)
 592 {}
 593 #endif
 594
 595 #define OMAP_SYS_GP_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop,   \
 596                                clksrc_nr, clksrc_src, clksrc_prop)      \
 597 void __init omap##name##_gptimer_timer_init(void)                       \
 598 {                                                                       \
 599         omap_clk_init();                                        \
 600         omap_dmtimer_init();                                            \
 601         omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop);    \
 602         omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src,         \
 603                                         clksrc_prop);                   \
 604 }
 605
 606 #define OMAP_SYS_32K_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop,  \
 607                                 clksrc_nr, clksrc_src, clksrc_prop)     \
 608 void __init omap##name##_sync32k_timer_init(void)               \
 609 {                                                                       \
 610         omap_clk_init();                                        \
 611         omap_dmtimer_init();                                            \
 612         omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop);    \
 613         /* Enable the use of clocksource="gp_timer" kernel parameter */ \
 614         if (use_gptimer_clksrc)                                         \
 615                 omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src, \
 616                                                 clksrc_prop);           \
 617         else                                                            \
 618                 omap2_sync32k_clocksource_init();                       \
 619 }
 620
 621 #ifdef CONFIG_ARCH_OMAP2
 622 OMAP_SYS_32K_TIMER_INIT(2, 1, "timer_32k_ck", "ti,timer-alwon",
 623                         2, "timer_sys_ck", NULL);
 624 #endif /* CONFIG_ARCH_OMAP2 */
 625
 626 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX)
 627 OMAP_SYS_32K_TIMER_INIT(3, 1, "timer_32k_ck", "ti,timer-alwon",
 628                         2, "timer_sys_ck", NULL);
 629 OMAP_SYS_32K_TIMER_INIT(3_secure, 12, "secure_32k_fck", "ti,timer-secure",
 630                         2, "timer_sys_ck", NULL);
 631 #endif /* CONFIG_ARCH_OMAP3 */
 632
 633 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) || \
 634         defined(CONFIG_SOC_AM43XX)
 635 OMAP_SYS_GP_TIMER_INIT(3, 2, "timer_sys_ck", NULL,
 636                        1, "timer_sys_ck", "ti,timer-alwon");
 637 #endif
 638
 639 #if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) || \
 640         defined(CONFIG_SOC_DRA7XX)
 641 static OMAP_SYS_32K_TIMER_INIT(4, 1, "timer_32k_ck", "ti,timer-alwon",
 642                                2, "sys_clkin_ck", NULL);
 643 #endif
 644
 645 #ifdef CONFIG_ARCH_OMAP4
 646 #ifdef CONFIG_HAVE_ARM_TWD
 647 void __init omap4_local_timer_init(void)
 648 {
 649         omap4_sync32k_timer_init();
 650         clocksource_probe();
 651 }
 652 #else
 653 void __init omap4_local_timer_init(void)
 654 {
 655         omap4_sync32k_timer_init();
 656 }
 657 #endif /* CONFIG_HAVE_ARM_TWD */
 658 #endif /* CONFIG_ARCH_OMAP4 */
 659
 660 #if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
 661 void __init omap5_realtime_timer_init(void)
 662 {
 663         omap4_sync32k_timer_init();
 664         realtime_counter_init();
 665
 666         clocksource_probe();
 667 }
 668 #endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
 669
 670 /**
 671  * omap_timer_init - build and register timer device with an
 672  * associated timer hwmod
 673  * @oh: timer hwmod pointer to be used to build timer device
 674  * @user:       parameter that can be passed from calling hwmod API
 675  *
 676  * Called by omap_hwmod_for_each_by_class to register each of the timer
 677  * devices present in the system. The number of timer devices is known
 678  * by parsing through the hwmod database for a given class name. At the
 679  * end of function call memory is allocated for timer device and it is
 680  * registered to the framework ready to be proved by the driver.
 681  */
 682 static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
 683 {
 684         int id;
 685         int ret = 0;
 686         char *name = "omap_timer";
 687         struct dmtimer_platform_data *pdata;
 688         struct platform_device *pdev;
 689         struct omap_timer_capability_dev_attr *timer_dev_attr;
 690
 691         pr_debug("%s: %s\n", __func__, oh->name);
 692
 693         /* on secure device, do not register secure timer */
 694         timer_dev_attr = oh->dev_attr;
 695         if (omap_type() != OMAP2_DEVICE_TYPE_GP && timer_dev_attr)
 696                 if (timer_dev_attr->timer_capability == OMAP_TIMER_SECURE)
 697                         return ret;
 698
 699         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 700         if (!pdata) {
 701                 pr_err("%s: No memory for [%s]\n", __func__, oh->name);
 702                 return -ENOMEM;
 703         }
 704
 705         /*
 706          * Extract the IDs from name field in hwmod database
 707          * and use the same for constructing ids' for the
 708          * timer devices. In a way, we are avoiding usage of
 709          * static variable witin the function to do the same.
 710          * CAUTION: We have to be careful and make sure the
 711          * name in hwmod database does not change in which case
 712          * we might either make corresponding change here or
 713          * switch back static variable mechanism.
 714          */
 715         sscanf(oh->name, "timer%2d", &id);
 716
 717         if (timer_dev_attr)
 718                 pdata->timer_capability = timer_dev_attr->timer_capability;
 719
 720         pdata->timer_errata = omap_dm_timer_get_errata();
 721         pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
 722
 723         pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata));
 724
 725         if (IS_ERR(pdev)) {
 726                 pr_err("%s: Can't build omap_device for %s: %s.\n",
 727                         __func__, name, oh->name);
 728                 ret = -EINVAL;
 729         }
 730
 731         kfree(pdata);
 732
 733         return ret;
 734 }
 735
 736 /**
 737  * omap2_dm_timer_init - top level regular device initialization
 738  *
 739  * Uses dedicated hwmod api to parse through hwmod database for
 740  * given class name and then build and register the timer device.
 741  */
 742 static int __init omap2_dm_timer_init(void)
 743 {
 744         int ret;
 745
 746         /* If dtb is there, the devices will be created dynamically */
 747         if (of_have_populated_dt())
 748                 return -ENODEV;
 749
 750         ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
 751         if (unlikely(ret)) {
 752                 pr_err("%s: device registration failed.\n", __func__);
 753                 return -EINVAL;
 754         }
 755
 756         return 0;
 757 }
 758 omap_arch_initcall(omap2_dm_timer_init);
 759
 760 /**
 761  * omap2_override_clocksource - clocksource override with user configuration
 762  *
 763  * Allows user to override default clocksource, using kernel parameter
 764  *   clocksource="gp_timer"     (For all OMAP2PLUS architectures)
 765  *
 766  * Note that, here we are using same standard kernel parameter "clocksource=",
 767  * and not introducing any OMAP specific interface.
 768  */
 769 static int __init omap2_override_clocksource(char *str)
 770 {
 771         if (!str)
 772                 return 0;
 773         /*
 774          * For OMAP architecture, we only have two options
 775          *    - sync_32k (default)
 776          *    - gp_timer (sys_clk based)
 777          */
 778         if (!strcmp(str, "gp_timer"))
 779                 use_gptimer_clksrc = true;
 780
 781         return 0;
 782 }
 783 early_param("clocksource", omap2_override_clocksource);