linux/arch/arm/mach-omap2/timer.c
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   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
  68static struct omap_dm_timer clkev;
  69static struct clock_event_device clockevent_gpt;
  70
  71#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
  72static unsigned long arch_timer_freq;
  73
  74void set_cntfreq(void)
  75{
  76        omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
  77}
  78#endif
  79
  80static 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
  90static struct irqaction omap2_gp_timer_irq = {
  91        .name           = "gp_timer",
  92        .flags          = IRQF_TIMER | IRQF_IRQPOLL,
  93        .handler        = omap2_gp_timer_interrupt,
  94};
  95
  96static 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
 105static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
 106                                    struct clock_event_device *evt)
 107{
 108        u32 period;
 109
 110        __omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
 111
 112        switch (mode) {
 113        case CLOCK_EVT_MODE_PERIODIC:
 114                period = clkev.rate / HZ;
 115                period -= 1;
 116                /* Looks like we need to first set the load value separately */
 117                __omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG,
 118                                      0xffffffff - period, OMAP_TIMER_POSTED);
 119                __omap_dm_timer_load_start(&clkev,
 120                                        OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
 121                                        0xffffffff - period, OMAP_TIMER_POSTED);
 122                break;
 123        case CLOCK_EVT_MODE_ONESHOT:
 124                break;
 125        case CLOCK_EVT_MODE_UNUSED:
 126        case CLOCK_EVT_MODE_SHUTDOWN:
 127        case CLOCK_EVT_MODE_RESUME:
 128                break;
 129        }
 130}
 131
 132static struct clock_event_device clockevent_gpt = {
 133        .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 134        .rating         = 300,
 135        .set_next_event = omap2_gp_timer_set_next_event,
 136        .set_mode       = omap2_gp_timer_set_mode,
 137};
 138
 139static struct property device_disabled = {
 140        .name = "status",
 141        .length = sizeof("disabled"),
 142        .value = "disabled",
 143};
 144
 145static 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 */
 168static 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 */
 201static 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                if (np)
 212                        of_node_put(np);
 213        }
 214}
 215
 216/**
 217 * omap_dm_timer_get_errata - get errata flags for a timer
 218 *
 219 * Get the timer errata flags that are specific to the OMAP device being used.
 220 */
 221static u32 __init omap_dm_timer_get_errata(void)
 222{
 223        if (cpu_is_omap24xx())
 224                return 0;
 225
 226        return OMAP_TIMER_ERRATA_I103_I767;
 227}
 228
 229static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
 230                                         const char *fck_source,
 231                                         const char *property,
 232                                         const char **timer_name,
 233                                         int posted)
 234{
 235        char name[10]; /* 10 = sizeof("gptXX_Xck0") */
 236        const char *oh_name = NULL;
 237        struct device_node *np;
 238        struct omap_hwmod *oh;
 239        struct resource irq, mem;
 240        struct clk *src;
 241        int r = 0;
 242
 243        if (of_have_populated_dt()) {
 244                np = omap_get_timer_dt(omap_timer_match, property);
 245                if (!np)
 246                        return -ENODEV;
 247
 248                of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
 249                if (!oh_name)
 250                        return -ENODEV;
 251
 252                timer->irq = irq_of_parse_and_map(np, 0);
 253                if (!timer->irq)
 254                        return -ENXIO;
 255
 256                timer->io_base = of_iomap(np, 0);
 257
 258                of_node_put(np);
 259        } else {
 260                if (omap_dm_timer_reserve_systimer(timer->id))
 261                        return -ENODEV;
 262
 263                sprintf(name, "timer%d", timer->id);
 264                oh_name = name;
 265        }
 266
 267        oh = omap_hwmod_lookup(oh_name);
 268        if (!oh)
 269                return -ENODEV;
 270
 271        *timer_name = oh->name;
 272
 273        if (!of_have_populated_dt()) {
 274                r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL,
 275                                                   &irq);
 276                if (r)
 277                        return -ENXIO;
 278                timer->irq = irq.start;
 279
 280                r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL,
 281                                                   &mem);
 282                if (r)
 283                        return -ENXIO;
 284
 285                /* Static mapping, never released */
 286                timer->io_base = ioremap(mem.start, mem.end - mem.start);
 287        }
 288
 289        if (!timer->io_base)
 290                return -ENXIO;
 291
 292        /* After the dmtimer is using hwmod these clocks won't be needed */
 293        timer->fclk = clk_get(NULL, omap_hwmod_get_main_clk(oh));
 294        if (IS_ERR(timer->fclk))
 295                return PTR_ERR(timer->fclk);
 296
 297        src = clk_get(NULL, fck_source);
 298        if (IS_ERR(src))
 299                return PTR_ERR(src);
 300
 301        r = clk_set_parent(timer->fclk, src);
 302        if (r < 0) {
 303                pr_warn("%s: %s cannot set source\n", __func__, oh->name);
 304                clk_put(src);
 305                return r;
 306        }
 307
 308        clk_put(src);
 309
 310        omap_hwmod_setup_one(oh_name);
 311        omap_hwmod_enable(oh);
 312        __omap_dm_timer_init_regs(timer);
 313
 314        if (posted)
 315                __omap_dm_timer_enable_posted(timer);
 316
 317        /* Check that the intended posted configuration matches the actual */
 318        if (posted != timer->posted)
 319                return -EINVAL;
 320
 321        timer->rate = clk_get_rate(timer->fclk);
 322        timer->reserved = 1;
 323
 324        return r;
 325}
 326
 327static void __init omap2_gp_clockevent_init(int gptimer_id,
 328                                                const char *fck_source,
 329                                                const char *property)
 330{
 331        int res;
 332
 333        clkev.id = gptimer_id;
 334        clkev.errata = omap_dm_timer_get_errata();
 335
 336        /*
 337         * For clock-event timers we never read the timer counter and
 338         * so we are not impacted by errata i103 and i767. Therefore,
 339         * we can safely ignore this errata for clock-event timers.
 340         */
 341        __omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);
 342
 343        res = omap_dm_timer_init_one(&clkev, fck_source, property,
 344                                     &clockevent_gpt.name, OMAP_TIMER_POSTED);
 345        BUG_ON(res);
 346
 347        omap2_gp_timer_irq.dev_id = &clkev;
 348        setup_irq(clkev.irq, &omap2_gp_timer_irq);
 349
 350        __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
 351
 352        clockevent_gpt.cpumask = cpu_possible_mask;
 353        clockevent_gpt.irq = omap_dm_timer_get_irq(&clkev);
 354        clockevents_config_and_register(&clockevent_gpt, clkev.rate,
 355                                        3, /* Timer internal resynch latency */
 356                                        0xffffffff);
 357
 358        pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt.name,
 359                clkev.rate);
 360}
 361
 362/* Clocksource code */
 363static struct omap_dm_timer clksrc;
 364static bool use_gptimer_clksrc __initdata;
 365
 366/*
 367 * clocksource
 368 */
 369static cycle_t clocksource_read_cycles(struct clocksource *cs)
 370{
 371        return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
 372                                                     OMAP_TIMER_NONPOSTED);
 373}
 374
 375static struct clocksource clocksource_gpt = {
 376        .rating         = 300,
 377        .read           = clocksource_read_cycles,
 378        .mask           = CLOCKSOURCE_MASK(32),
 379        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 380};
 381
 382static u64 notrace dmtimer_read_sched_clock(void)
 383{
 384        if (clksrc.reserved)
 385                return __omap_dm_timer_read_counter(&clksrc,
 386                                                    OMAP_TIMER_NONPOSTED);
 387
 388        return 0;
 389}
 390
 391static const struct of_device_id omap_counter_match[] __initconst = {
 392        { .compatible = "ti,omap-counter32k", },
 393        { }
 394};
 395
 396/* Setup free-running counter for clocksource */
 397static int __init __maybe_unused omap2_sync32k_clocksource_init(void)
 398{
 399        int ret;
 400        struct device_node *np = NULL;
 401        struct omap_hwmod *oh;
 402        void __iomem *vbase;
 403        const char *oh_name = "counter_32k";
 404
 405        /*
 406         * If device-tree is present, then search the DT blob
 407         * to see if the 32kHz counter is supported.
 408         */
 409        if (of_have_populated_dt()) {
 410                np = omap_get_timer_dt(omap_counter_match, NULL);
 411                if (!np)
 412                        return -ENODEV;
 413
 414                of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
 415                if (!oh_name)
 416                        return -ENODEV;
 417        }
 418
 419        /*
 420         * First check hwmod data is available for sync32k counter
 421         */
 422        oh = omap_hwmod_lookup(oh_name);
 423        if (!oh || oh->slaves_cnt == 0)
 424                return -ENODEV;
 425
 426        omap_hwmod_setup_one(oh_name);
 427
 428        if (np) {
 429                vbase = of_iomap(np, 0);
 430                of_node_put(np);
 431        } else {
 432                vbase = omap_hwmod_get_mpu_rt_va(oh);
 433        }
 434
 435        if (!vbase) {
 436                pr_warn("%s: failed to get counter_32k resource\n", __func__);
 437                return -ENXIO;
 438        }
 439
 440        ret = omap_hwmod_enable(oh);
 441        if (ret) {
 442                pr_warn("%s: failed to enable counter_32k module (%d)\n",
 443                                                        __func__, ret);
 444                return ret;
 445        }
 446
 447        ret = omap_init_clocksource_32k(vbase);
 448        if (ret) {
 449                pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
 450                                                        __func__, ret);
 451                omap_hwmod_idle(oh);
 452        }
 453
 454        return ret;
 455}
 456
 457static void __init omap2_gptimer_clocksource_init(int gptimer_id,
 458                                                  const char *fck_source,
 459                                                  const char *property)
 460{
 461        int res;
 462
 463        clksrc.id = gptimer_id;
 464        clksrc.errata = omap_dm_timer_get_errata();
 465
 466        res = omap_dm_timer_init_one(&clksrc, fck_source, property,
 467                                     &clocksource_gpt.name,
 468                                     OMAP_TIMER_NONPOSTED);
 469        BUG_ON(res);
 470
 471        __omap_dm_timer_load_start(&clksrc,
 472                                   OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
 473                                   OMAP_TIMER_NONPOSTED);
 474        sched_clock_register(dmtimer_read_sched_clock, 32, clksrc.rate);
 475
 476        if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
 477                pr_err("Could not register clocksource %s\n",
 478                        clocksource_gpt.name);
 479        else
 480                pr_info("OMAP clocksource: %s at %lu Hz\n",
 481                        clocksource_gpt.name, clksrc.rate);
 482}
 483
 484#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
 485/*
 486 * The realtime counter also called master counter, is a free-running
 487 * counter, which is related to real time. It produces the count used
 488 * by the CPU local timer peripherals in the MPU cluster. The timer counts
 489 * at a rate of 6.144 MHz. Because the device operates on different clocks
 490 * in different power modes, the master counter shifts operation between
 491 * clocks, adjusting the increment per clock in hardware accordingly to
 492 * maintain a constant count rate.
 493 */
 494static void __init realtime_counter_init(void)
 495{
 496        void __iomem *base;
 497        static struct clk *sys_clk;
 498        unsigned long rate;
 499        unsigned int reg;
 500        unsigned long long num, den;
 501
 502        base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
 503        if (!base) {
 504                pr_err("%s: ioremap failed\n", __func__);
 505                return;
 506        }
 507        sys_clk = clk_get(NULL, "sys_clkin");
 508        if (IS_ERR(sys_clk)) {
 509                pr_err("%s: failed to get system clock handle\n", __func__);
 510                iounmap(base);
 511                return;
 512        }
 513
 514        rate = clk_get_rate(sys_clk);
 515
 516        if (soc_is_dra7xx()) {
 517                /*
 518                 * Errata i856 says the 32.768KHz crystal does not start at
 519                 * power on, so the CPU falls back to an emulated 32KHz clock
 520                 * based on sysclk / 610 instead. This causes the master counter
 521                 * frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
 522                 * (OR sysclk * 75 / 244)
 523                 *
 524                 * This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
 525                 * Of course any board built without a populated 32.768KHz
 526                 * crystal would also need this fix even if the CPU is fixed
 527                 * later.
 528                 *
 529                 * Either case can be detected by using the two speedselect bits
 530                 * If they are not 0, then the 32.768KHz clock driving the
 531                 * coarse counter that corrects the fine counter every time it
 532                 * ticks is actually rate/610 rather than 32.768KHz and we
 533                 * should compensate to avoid the 570ppm (at 20MHz, much worse
 534                 * at other rates) too fast system time.
 535                 */
 536                reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
 537                if (reg & DRA7_SPEEDSELECT_MASK) {
 538                        num = 75;
 539                        den = 244;
 540                        goto sysclk1_based;
 541                }
 542        }
 543
 544        /* Numerator/denumerator values refer TRM Realtime Counter section */
 545        switch (rate) {
 546        case 12000000:
 547                num = 64;
 548                den = 125;
 549                break;
 550        case 13000000:
 551                num = 768;
 552                den = 1625;
 553                break;
 554        case 19200000:
 555                num = 8;
 556                den = 25;
 557                break;
 558        case 20000000:
 559                num = 192;
 560                den = 625;
 561                break;
 562        case 26000000:
 563                num = 384;
 564                den = 1625;
 565                break;
 566        case 27000000:
 567                num = 256;
 568                den = 1125;
 569                break;
 570        case 38400000:
 571        default:
 572                /* Program it for 38.4 MHz */
 573                num = 4;
 574                den = 25;
 575                break;
 576        }
 577
 578sysclk1_based:
 579        /* Program numerator and denumerator registers */
 580        reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
 581                        NUMERATOR_DENUMERATOR_MASK;
 582        reg |= num;
 583        writel_relaxed(reg, base + INCREMENTER_NUMERATOR_OFFSET);
 584
 585        reg = readl_relaxed(base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET) &
 586                        NUMERATOR_DENUMERATOR_MASK;
 587        reg |= den;
 588        writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
 589
 590        arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
 591        set_cntfreq();
 592
 593        iounmap(base);
 594}
 595#else
 596static inline void __init realtime_counter_init(void)
 597{}
 598#endif
 599
 600#define OMAP_SYS_GP_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop,   \
 601                               clksrc_nr, clksrc_src, clksrc_prop)      \
 602void __init omap##name##_gptimer_timer_init(void)                       \
 603{                                                                       \
 604        omap_clk_init();                                        \
 605        omap_dmtimer_init();                                            \
 606        omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop);    \
 607        omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src,         \
 608                                        clksrc_prop);                   \
 609}
 610
 611#define OMAP_SYS_32K_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop,  \
 612                                clksrc_nr, clksrc_src, clksrc_prop)     \
 613void __init omap##name##_sync32k_timer_init(void)               \
 614{                                                                       \
 615        omap_clk_init();                                        \
 616        omap_dmtimer_init();                                            \
 617        omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop);    \
 618        /* Enable the use of clocksource="gp_timer" kernel parameter */ \
 619        if (use_gptimer_clksrc)                                         \
 620                omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src, \
 621                                                clksrc_prop);           \
 622        else                                                            \
 623                omap2_sync32k_clocksource_init();                       \
 624}
 625
 626#ifdef CONFIG_ARCH_OMAP2
 627OMAP_SYS_32K_TIMER_INIT(2, 1, "timer_32k_ck", "ti,timer-alwon",
 628                        2, "timer_sys_ck", NULL);
 629#endif /* CONFIG_ARCH_OMAP2 */
 630
 631#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX)
 632OMAP_SYS_32K_TIMER_INIT(3, 1, "timer_32k_ck", "ti,timer-alwon",
 633                        2, "timer_sys_ck", NULL);
 634OMAP_SYS_32K_TIMER_INIT(3_secure, 12, "secure_32k_fck", "ti,timer-secure",
 635                        2, "timer_sys_ck", NULL);
 636#endif /* CONFIG_ARCH_OMAP3 */
 637
 638#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) || \
 639        defined(CONFIG_SOC_AM43XX)
 640OMAP_SYS_GP_TIMER_INIT(3, 2, "timer_sys_ck", NULL,
 641                       1, "timer_sys_ck", "ti,timer-alwon");
 642#endif
 643
 644#if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) || \
 645        defined(CONFIG_SOC_DRA7XX)
 646static OMAP_SYS_32K_TIMER_INIT(4, 1, "timer_32k_ck", "ti,timer-alwon",
 647                               2, "sys_clkin_ck", NULL);
 648#endif
 649
 650#ifdef CONFIG_ARCH_OMAP4
 651#ifdef CONFIG_HAVE_ARM_TWD
 652static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, OMAP44XX_LOCAL_TWD_BASE, 29);
 653void __init omap4_local_timer_init(void)
 654{
 655        omap4_sync32k_timer_init();
 656        /* Local timers are not supprted on OMAP4430 ES1.0 */
 657        if (omap_rev() != OMAP4430_REV_ES1_0) {
 658                int err;
 659
 660                if (of_have_populated_dt()) {
 661                        clocksource_of_init();
 662                        return;
 663                }
 664
 665                err = twd_local_timer_register(&twd_local_timer);
 666                if (err)
 667                        pr_err("twd_local_timer_register failed %d\n", err);
 668        }
 669}
 670#else
 671void __init omap4_local_timer_init(void)
 672{
 673        omap4_sync32k_timer_init();
 674}
 675#endif /* CONFIG_HAVE_ARM_TWD */
 676#endif /* CONFIG_ARCH_OMAP4 */
 677
 678#if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
 679void __init omap5_realtime_timer_init(void)
 680{
 681        omap4_sync32k_timer_init();
 682        realtime_counter_init();
 683
 684        clocksource_of_init();
 685}
 686#endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
 687
 688/**
 689 * omap_timer_init - build and register timer device with an
 690 * associated timer hwmod
 691 * @oh: timer hwmod pointer to be used to build timer device
 692 * @user:       parameter that can be passed from calling hwmod API
 693 *
 694 * Called by omap_hwmod_for_each_by_class to register each of the timer
 695 * devices present in the system. The number of timer devices is known
 696 * by parsing through the hwmod database for a given class name. At the
 697 * end of function call memory is allocated for timer device and it is
 698 * registered to the framework ready to be proved by the driver.
 699 */
 700static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
 701{
 702        int id;
 703        int ret = 0;
 704        char *name = "omap_timer";
 705        struct dmtimer_platform_data *pdata;
 706        struct platform_device *pdev;
 707        struct omap_timer_capability_dev_attr *timer_dev_attr;
 708
 709        pr_debug("%s: %s\n", __func__, oh->name);
 710
 711        /* on secure device, do not register secure timer */
 712        timer_dev_attr = oh->dev_attr;
 713        if (omap_type() != OMAP2_DEVICE_TYPE_GP && timer_dev_attr)
 714                if (timer_dev_attr->timer_capability == OMAP_TIMER_SECURE)
 715                        return ret;
 716
 717        pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 718        if (!pdata) {
 719                pr_err("%s: No memory for [%s]\n", __func__, oh->name);
 720                return -ENOMEM;
 721        }
 722
 723        /*
 724         * Extract the IDs from name field in hwmod database
 725         * and use the same for constructing ids' for the
 726         * timer devices. In a way, we are avoiding usage of
 727         * static variable witin the function to do the same.
 728         * CAUTION: We have to be careful and make sure the
 729         * name in hwmod database does not change in which case
 730         * we might either make corresponding change here or
 731         * switch back static variable mechanism.
 732         */
 733        sscanf(oh->name, "timer%2d", &id);
 734
 735        if (timer_dev_attr)
 736                pdata->timer_capability = timer_dev_attr->timer_capability;
 737
 738        pdata->timer_errata = omap_dm_timer_get_errata();
 739        pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
 740
 741        pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata));
 742
 743        if (IS_ERR(pdev)) {
 744                pr_err("%s: Can't build omap_device for %s: %s.\n",
 745                        __func__, name, oh->name);
 746                ret = -EINVAL;
 747        }
 748
 749        kfree(pdata);
 750
 751        return ret;
 752}
 753
 754/**
 755 * omap2_dm_timer_init - top level regular device initialization
 756 *
 757 * Uses dedicated hwmod api to parse through hwmod database for
 758 * given class name and then build and register the timer device.
 759 */
 760static int __init omap2_dm_timer_init(void)
 761{
 762        int ret;
 763
 764        /* If dtb is there, the devices will be created dynamically */
 765        if (of_have_populated_dt())
 766                return -ENODEV;
 767
 768        ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
 769        if (unlikely(ret)) {
 770                pr_err("%s: device registration failed.\n", __func__);
 771                return -EINVAL;
 772        }
 773
 774        return 0;
 775}
 776omap_arch_initcall(omap2_dm_timer_init);
 777
 778/**
 779 * omap2_override_clocksource - clocksource override with user configuration
 780 *
 781 * Allows user to override default clocksource, using kernel parameter
 782 *   clocksource="gp_timer"     (For all OMAP2PLUS architectures)
 783 *
 784 * Note that, here we are using same standard kernel parameter "clocksource=",
 785 * and not introducing any OMAP specific interface.
 786 */
 787static int __init omap2_override_clocksource(char *str)
 788{
 789        if (!str)
 790                return 0;
 791        /*
 792         * For OMAP architecture, we only have two options
 793         *    - sync_32k (default)
 794         *    - gp_timer (sys_clk based)
 795         */
 796        if (!strcmp(str, "gp_timer"))
 797                use_gptimer_clksrc = true;
 798
 799        return 0;
 800}
 801early_param("clocksource", omap2_override_clocksource);
 802