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 "powerdomain.h"
  58
  59 #define REALTIME_COUNTER_BASE                           0x48243200
  60 #define INCREMENTER_NUMERATOR_OFFSET                    0x10
  61 #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET           0x14
  62 #define NUMERATOR_DENUMERATOR_MASK                      0xfffff000
  63
  64 /* Clockevent code */
  65
  66 static struct omap_dm_timer clkev;
  67 static struct clock_event_device clockevent_gpt;
  68
  69 static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
  70 {
  71         struct clock_event_device *evt = &clockevent_gpt;
  72
  73         __omap_dm_timer_write_status(&clkev, OMAP_TIMER_INT_OVERFLOW);
  74
  75         evt->event_handler(evt);
  76         return IRQ_HANDLED;
  77 }
  78
  79 static struct irqaction omap2_gp_timer_irq = {
  80         .name           = "gp_timer",
  81         .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
  82         .handler        = omap2_gp_timer_interrupt,
  83 };
  84
  85 static int omap2_gp_timer_set_next_event(unsigned long cycles,
  86                                          struct clock_event_device *evt)
  87 {
  88         __omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
  89                                    0xffffffff - cycles, OMAP_TIMER_POSTED);
  90
  91         return 0;
  92 }
  93
  94 static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
  95                                     struct clock_event_device *evt)
  96 {
  97         u32 period;
  98
  99         __omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
 100
 101         switch (mode) {
 102         case CLOCK_EVT_MODE_PERIODIC:
 103                 period = clkev.rate / HZ;
 104                 period -= 1;
 105                 /* Looks like we need to first set the load value separately */
 106                 __omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG,
 107                                       0xffffffff - period, OMAP_TIMER_POSTED);
 108                 __omap_dm_timer_load_start(&clkev,
 109                                         OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
 110                                         0xffffffff - period, OMAP_TIMER_POSTED);
 111                 break;
 112         case CLOCK_EVT_MODE_ONESHOT:
 113                 break;
 114         case CLOCK_EVT_MODE_UNUSED:
 115         case CLOCK_EVT_MODE_SHUTDOWN:
 116         case CLOCK_EVT_MODE_RESUME:
 117                 break;
 118         }
 119 }
 120
 121 static struct clock_event_device clockevent_gpt = {
 122         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 123         .rating         = 300,
 124         .set_next_event = omap2_gp_timer_set_next_event,
 125         .set_mode       = omap2_gp_timer_set_mode,
 126 };
 127
 128 static struct property device_disabled = {
 129         .name = "status",
 130         .length = sizeof("disabled"),
 131         .value = "disabled",
 132 };
 133
 134 static struct of_device_id omap_timer_match[] __initdata = {
 135         { .compatible = "ti,omap2420-timer", },
 136         { .compatible = "ti,omap3430-timer", },
 137         { .compatible = "ti,omap4430-timer", },
 138         { .compatible = "ti,omap5430-timer", },
 139         { .compatible = "ti,am335x-timer", },
 140         { .compatible = "ti,am335x-timer-1ms", },
 141         { }
 142 };
 143
 144 /**
 145  * omap_get_timer_dt - get a timer using device-tree
 146  * @match       - device-tree match structure for matching a device type
 147  * @property    - optional timer property to match
 148  *
 149  * Helper function to get a timer during early boot using device-tree for use
 150  * as kernel system timer. Optionally, the property argument can be used to
 151  * select a timer with a specific property. Once a timer is found then mark
 152  * the timer node in device-tree as disabled, to prevent the kernel from
 153  * registering this timer as a platform device and so no one else can use it.
 154  */
 155 static struct device_node * __init omap_get_timer_dt(struct of_device_id *match,
 156                                                      const char *property)
 157 {
 158         struct device_node *np;
 159
 160         for_each_matching_node(np, match) {
 161                 if (!of_device_is_available(np))
 162                         continue;
 163
 164                 if (property && !of_get_property(np, property, NULL))
 165                         continue;
 166
 167                 if (!property && (of_get_property(np, "ti,timer-alwon", NULL) ||
 168                                   of_get_property(np, "ti,timer-dsp", NULL) ||
 169                                   of_get_property(np, "ti,timer-pwm", NULL) ||
 170                                   of_get_property(np, "ti,timer-secure", NULL)))
 171                         continue;
 172
 173                 of_add_property(np, &device_disabled);
 174                 return np;
 175         }
 176
 177         return NULL;
 178 }
 179
 180 /**
 181  * omap_dmtimer_init - initialisation function when device tree is used
 182  *
 183  * For secure OMAP3 devices, timers with device type "timer-secure" cannot
 184  * be used by the kernel as they are reserved. Therefore, to prevent the
 185  * kernel registering these devices remove them dynamically from the device
 186  * tree on boot.
 187  */
 188 static void __init omap_dmtimer_init(void)
 189 {
 190         struct device_node *np;
 191
 192         if (!cpu_is_omap34xx())
 193                 return;
 194
 195         /* If we are a secure device, remove any secure timer nodes */
 196         if ((omap_type() != OMAP2_DEVICE_TYPE_GP)) {
 197                 np = omap_get_timer_dt(omap_timer_match, "ti,timer-secure");
 198                 if (np)
 199                         of_node_put(np);
 200         }
 201 }
 202
 203 /**
 204  * omap_dm_timer_get_errata - get errata flags for a timer
 205  *
 206  * Get the timer errata flags that are specific to the OMAP device being used.
 207  */
 208 static u32 __init omap_dm_timer_get_errata(void)
 209 {
 210         if (cpu_is_omap24xx())
 211                 return 0;
 212
 213         return OMAP_TIMER_ERRATA_I103_I767;
 214 }
 215
 216 static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
 217                                          const char *fck_source,
 218                                          const char *property,
 219                                          const char **timer_name,
 220                                          int posted)
 221 {
 222         char name[10]; /* 10 = sizeof("gptXX_Xck0") */
 223         const char *oh_name = NULL;
 224         struct device_node *np;
 225         struct omap_hwmod *oh;
 226         struct resource irq, mem;
 227         struct clk *src;
 228         int r = 0;
 229
 230         if (of_have_populated_dt()) {
 231                 np = omap_get_timer_dt(omap_timer_match, property);
 232                 if (!np)
 233                         return -ENODEV;
 234
 235                 of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
 236                 if (!oh_name)
 237                         return -ENODEV;
 238
 239                 timer->irq = irq_of_parse_and_map(np, 0);
 240                 if (!timer->irq)
 241                         return -ENXIO;
 242
 243                 timer->io_base = of_iomap(np, 0);
 244
 245                 of_node_put(np);
 246         } else {
 247                 if (omap_dm_timer_reserve_systimer(timer->id))
 248                         return -ENODEV;
 249
 250                 sprintf(name, "timer%d", timer->id);
 251                 oh_name = name;
 252         }
 253
 254         oh = omap_hwmod_lookup(oh_name);
 255         if (!oh)
 256                 return -ENODEV;
 257
 258         *timer_name = oh->name;
 259
 260         if (!of_have_populated_dt()) {
 261                 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL,
 262                                                    &irq);
 263                 if (r)
 264                         return -ENXIO;
 265                 timer->irq = irq.start;
 266
 267                 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL,
 268                                                    &mem);
 269                 if (r)
 270                         return -ENXIO;
 271
 272                 /* Static mapping, never released */
 273                 timer->io_base = ioremap(mem.start, mem.end - mem.start);
 274         }
 275
 276         if (!timer->io_base)
 277                 return -ENXIO;
 278
 279         /* After the dmtimer is using hwmod these clocks won't be needed */
 280         timer->fclk = clk_get(NULL, omap_hwmod_get_main_clk(oh));
 281         if (IS_ERR(timer->fclk))
 282                 return PTR_ERR(timer->fclk);
 283
 284         src = clk_get(NULL, fck_source);
 285         if (IS_ERR(src))
 286                 return PTR_ERR(src);
 287
 288         if (clk_get_parent(timer->fclk) != src) {
 289                 r = clk_set_parent(timer->fclk, src);
 290                 if (r < 0) {
 291                         pr_warn("%s: %s cannot set source\n", __func__,
 292                                 oh->name);
 293                         clk_put(src);
 294                         return r;
 295                 }
 296         }
 297
 298         clk_put(src);
 299
 300         omap_hwmod_setup_one(oh_name);
 301         omap_hwmod_enable(oh);
 302         __omap_dm_timer_init_regs(timer);
 303
 304         if (posted)
 305                 __omap_dm_timer_enable_posted(timer);
 306
 307         /* Check that the intended posted configuration matches the actual */
 308         if (posted != timer->posted)
 309                 return -EINVAL;
 310
 311         timer->rate = clk_get_rate(timer->fclk);
 312         timer->reserved = 1;
 313
 314         return r;
 315 }
 316
 317 static void __init omap2_gp_clockevent_init(int gptimer_id,
 318                                                 const char *fck_source,
 319                                                 const char *property)
 320 {
 321         int res;
 322
 323         clkev.id = gptimer_id;
 324         clkev.errata = omap_dm_timer_get_errata();
 325
 326         /*
 327          * For clock-event timers we never read the timer counter and
 328          * so we are not impacted by errata i103 and i767. Therefore,
 329          * we can safely ignore this errata for clock-event timers.
 330          */
 331         __omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);
 332
 333         res = omap_dm_timer_init_one(&clkev, fck_source, property,
 334                                      &clockevent_gpt.name, OMAP_TIMER_POSTED);
 335         BUG_ON(res);
 336
 337         omap2_gp_timer_irq.dev_id = &clkev;
 338         setup_irq(clkev.irq, &omap2_gp_timer_irq);
 339
 340         __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
 341
 342         clockevent_gpt.cpumask = cpu_possible_mask;
 343         clockevent_gpt.irq = omap_dm_timer_get_irq(&clkev);
 344         clockevents_config_and_register(&clockevent_gpt, clkev.rate,
 345                                         3, /* Timer internal resynch latency */
 346                                         0xffffffff);
 347
 348         pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt.name,
 349                 clkev.rate);
 350 }
 351
 352 /* Clocksource code */
 353 static struct omap_dm_timer clksrc;
 354 static bool use_gptimer_clksrc;
 355
 356 /*
 357  * clocksource
 358  */
 359 static cycle_t clocksource_read_cycles(struct clocksource *cs)
 360 {
 361         return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
 362                                                      OMAP_TIMER_NONPOSTED);
 363 }
 364
 365 static struct clocksource clocksource_gpt = {
 366         .rating         = 300,
 367         .read           = clocksource_read_cycles,
 368         .mask           = CLOCKSOURCE_MASK(32),
 369         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 370 };
 371
 372 static u32 notrace dmtimer_read_sched_clock(void)
 373 {
 374         if (clksrc.reserved)
 375                 return __omap_dm_timer_read_counter(&clksrc,
 376                                                     OMAP_TIMER_NONPOSTED);
 377
 378         return 0;
 379 }
 380
 381 static struct of_device_id omap_counter_match[] __initdata = {
 382         { .compatible = "ti,omap-counter32k", },
 383         { }
 384 };
 385
 386 /* Setup free-running counter for clocksource */
 387 static int __init __maybe_unused omap2_sync32k_clocksource_init(void)
 388 {
 389         int ret;
 390         struct device_node *np = NULL;
 391         struct omap_hwmod *oh;
 392         void __iomem *vbase;
 393         const char *oh_name = "counter_32k";
 394
 395         /*
 396          * If device-tree is present, then search the DT blob
 397          * to see if the 32kHz counter is supported.
 398          */
 399         if (of_have_populated_dt()) {
 400                 np = omap_get_timer_dt(omap_counter_match, NULL);
 401                 if (!np)
 402                         return -ENODEV;
 403
 404                 of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
 405                 if (!oh_name)
 406                         return -ENODEV;
 407         }
 408
 409         /*
 410          * First check hwmod data is available for sync32k counter
 411          */
 412         oh = omap_hwmod_lookup(oh_name);
 413         if (!oh || oh->slaves_cnt == 0)
 414                 return -ENODEV;
 415
 416         omap_hwmod_setup_one(oh_name);
 417
 418         if (np) {
 419                 vbase = of_iomap(np, 0);
 420                 of_node_put(np);
 421         } else {
 422                 vbase = omap_hwmod_get_mpu_rt_va(oh);
 423         }
 424
 425         if (!vbase) {
 426                 pr_warn("%s: failed to get counter_32k resource\n", __func__);
 427                 return -ENXIO;
 428         }
 429
 430         ret = omap_hwmod_enable(oh);
 431         if (ret) {
 432                 pr_warn("%s: failed to enable counter_32k module (%d)\n",
 433                                                         __func__, ret);
 434                 return ret;
 435         }
 436
 437         ret = omap_init_clocksource_32k(vbase);
 438         if (ret) {
 439                 pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
 440                                                         __func__, ret);
 441                 omap_hwmod_idle(oh);
 442         }
 443
 444         return ret;
 445 }
 446
 447 static void __init omap2_gptimer_clocksource_init(int gptimer_id,
 448                                                   const char *fck_source,
 449                                                   const char *property)
 450 {
 451         int res;
 452
 453         clksrc.id = gptimer_id;
 454         clksrc.errata = omap_dm_timer_get_errata();
 455
 456         res = omap_dm_timer_init_one(&clksrc, fck_source, property,
 457                                      &clocksource_gpt.name,
 458                                      OMAP_TIMER_NONPOSTED);
 459         BUG_ON(res);
 460
 461         __omap_dm_timer_load_start(&clksrc,
 462                                    OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
 463                                    OMAP_TIMER_NONPOSTED);
 464         setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
 465
 466         if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
 467                 pr_err("Could not register clocksource %s\n",
 468                         clocksource_gpt.name);
 469         else
 470                 pr_info("OMAP clocksource: %s at %lu Hz\n",
 471                         clocksource_gpt.name, clksrc.rate);
 472 }
 473
 474 #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
 475 /*
 476  * The realtime counter also called master counter, is a free-running
 477  * counter, which is related to real time. It produces the count used
 478  * by the CPU local timer peripherals in the MPU cluster. The timer counts
 479  * at a rate of 6.144 MHz. Because the device operates on different clocks
 480  * in different power modes, the master counter shifts operation between
 481  * clocks, adjusting the increment per clock in hardware accordingly to
 482  * maintain a constant count rate.
 483  */
 484 static void __init realtime_counter_init(void)
 485 {
 486         void __iomem *base;
 487         static struct clk *sys_clk;
 488         unsigned long rate;
 489         unsigned int reg, num, den;
 490
 491         base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
 492         if (!base) {
 493                 pr_err("%s: ioremap failed\n", __func__);
 494                 return;
 495         }
 496         sys_clk = clk_get(NULL, "sys_clkin");
 497         if (IS_ERR(sys_clk)) {
 498                 pr_err("%s: failed to get system clock handle\n", __func__);
 499                 iounmap(base);
 500                 return;
 501         }
 502
 503         rate = clk_get_rate(sys_clk);
 504         /* Numerator/denumerator values refer TRM Realtime Counter section */
 505         switch (rate) {
 506         case 1200000:
 507                 num = 64;
 508                 den = 125;
 509                 break;
 510         case 1300000:
 511                 num = 768;
 512                 den = 1625;
 513                 break;
 514         case 19200000:
 515                 num = 8;
 516                 den = 25;
 517                 break;
 518         case 2600000:
 519                 num = 384;
 520                 den = 1625;
 521                 break;
 522         case 2700000:
 523                 num = 256;
 524                 den = 1125;
 525                 break;
 526         case 38400000:
 527         default:
 528                 /* Program it for 38.4 MHz */
 529                 num = 4;
 530                 den = 25;
 531                 break;
 532         }
 533
 534         /* Program numerator and denumerator registers */
 535         reg = __raw_readl(base + INCREMENTER_NUMERATOR_OFFSET) &
 536                         NUMERATOR_DENUMERATOR_MASK;
 537         reg |= num;
 538         __raw_writel(reg, base + INCREMENTER_NUMERATOR_OFFSET);
 539
 540         reg = __raw_readl(base + INCREMENTER_NUMERATOR_OFFSET) &
 541                         NUMERATOR_DENUMERATOR_MASK;
 542         reg |= den;
 543         __raw_writel(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
 544
 545         iounmap(base);
 546 }
 547 #else
 548 static inline void __init realtime_counter_init(void)
 549 {}
 550 #endif
 551
 552 #define OMAP_SYS_GP_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop,   \
 553                                clksrc_nr, clksrc_src, clksrc_prop)      \
 554 void __init omap##name##_gptimer_timer_init(void)                       \
 555 {                                                                       \
 556         if (omap_clk_init)                                              \
 557                 omap_clk_init();                                        \
 558         omap_dmtimer_init();                                            \
 559         omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop);    \
 560         omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src,         \
 561                                         clksrc_prop);                   \
 562 }
 563
 564 #define OMAP_SYS_32K_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop,  \
 565                                 clksrc_nr, clksrc_src, clksrc_prop)     \
 566 void __init omap##name##_sync32k_timer_init(void)               \
 567 {                                                                       \
 568         if (omap_clk_init)                                              \
 569                 omap_clk_init();                                        \
 570         omap_dmtimer_init();                                            \
 571         omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop);    \
 572         /* Enable the use of clocksource="gp_timer" kernel parameter */ \
 573         if (use_gptimer_clksrc)                                         \
 574                 omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src, \
 575                                                 clksrc_prop);           \
 576         else                                                            \
 577                 omap2_sync32k_clocksource_init();                       \
 578 }
 579
 580 #ifdef CONFIG_ARCH_OMAP2
 581 OMAP_SYS_32K_TIMER_INIT(2, 1, "timer_32k_ck", "ti,timer-alwon",
 582                         2, "timer_sys_ck", NULL);
 583 #endif /* CONFIG_ARCH_OMAP2 */
 584
 585 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX)
 586 OMAP_SYS_32K_TIMER_INIT(3, 1, "timer_32k_ck", "ti,timer-alwon",
 587                         2, "timer_sys_ck", NULL);
 588 OMAP_SYS_32K_TIMER_INIT(3_secure, 12, "secure_32k_fck", "ti,timer-secure",
 589                         2, "timer_sys_ck", NULL);
 590 #endif /* CONFIG_ARCH_OMAP3 */
 591
 592 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX)
 593 OMAP_SYS_GP_TIMER_INIT(3, 2, "timer_sys_ck", NULL,
 594                        1, "timer_sys_ck", "ti,timer-alwon");
 595 #endif
 596
 597 #if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5)
 598 static OMAP_SYS_32K_TIMER_INIT(4, 1, "timer_32k_ck", "ti,timer-alwon",
 599                                2, "sys_clkin_ck", NULL);
 600 #endif
 601
 602 #ifdef CONFIG_ARCH_OMAP4
 603 #ifdef CONFIG_LOCAL_TIMERS
 604 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, OMAP44XX_LOCAL_TWD_BASE, 29);
 605 void __init omap4_local_timer_init(void)
 606 {
 607         omap4_sync32k_timer_init();
 608         /* Local timers are not supprted on OMAP4430 ES1.0 */
 609         if (omap_rev() != OMAP4430_REV_ES1_0) {
 610                 int err;
 611
 612                 if (of_have_populated_dt()) {
 613                         clocksource_of_init();
 614                         return;
 615                 }
 616
 617                 err = twd_local_timer_register(&twd_local_timer);
 618                 if (err)
 619                         pr_err("twd_local_timer_register failed %d\n", err);
 620         }
 621 }
 622 #else /* CONFIG_LOCAL_TIMERS */
 623 void __init omap4_local_timer_init(void)
 624 {
 625         omap4_sync32k_timer_init();
 626 }
 627 #endif /* CONFIG_LOCAL_TIMERS */
 628 #endif /* CONFIG_ARCH_OMAP4 */
 629
 630 #ifdef CONFIG_SOC_OMAP5
 631 void __init omap5_realtime_timer_init(void)
 632 {
 633         omap4_sync32k_timer_init();
 634         realtime_counter_init();
 635
 636         clocksource_of_init();
 637 }
 638 #endif /* CONFIG_SOC_OMAP5 */
 639
 640 /**
 641  * omap_timer_init - build and register timer device with an
 642  * associated timer hwmod
 643  * @oh: timer hwmod pointer to be used to build timer device
 644  * @user:       parameter that can be passed from calling hwmod API
 645  *
 646  * Called by omap_hwmod_for_each_by_class to register each of the timer
 647  * devices present in the system. The number of timer devices is known
 648  * by parsing through the hwmod database for a given class name. At the
 649  * end of function call memory is allocated for timer device and it is
 650  * registered to the framework ready to be proved by the driver.
 651  */
 652 static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
 653 {
 654         int id;
 655         int ret = 0;
 656         char *name = "omap_timer";
 657         struct dmtimer_platform_data *pdata;
 658         struct platform_device *pdev;
 659         struct omap_timer_capability_dev_attr *timer_dev_attr;
 660
 661         pr_debug("%s: %s\n", __func__, oh->name);
 662
 663         /* on secure device, do not register secure timer */
 664         timer_dev_attr = oh->dev_attr;
 665         if (omap_type() != OMAP2_DEVICE_TYPE_GP && timer_dev_attr)
 666                 if (timer_dev_attr->timer_capability == OMAP_TIMER_SECURE)
 667                         return ret;
 668
 669         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 670         if (!pdata) {
 671                 pr_err("%s: No memory for [%s]\n", __func__, oh->name);
 672                 return -ENOMEM;
 673         }
 674
 675         /*
 676          * Extract the IDs from name field in hwmod database
 677          * and use the same for constructing ids' for the
 678          * timer devices. In a way, we are avoiding usage of
 679          * static variable witin the function to do the same.
 680          * CAUTION: We have to be careful and make sure the
 681          * name in hwmod database does not change in which case
 682          * we might either make corresponding change here or
 683          * switch back static variable mechanism.
 684          */
 685         sscanf(oh->name, "timer%2d", &id);
 686
 687         if (timer_dev_attr)
 688                 pdata->timer_capability = timer_dev_attr->timer_capability;
 689
 690         pdata->timer_errata = omap_dm_timer_get_errata();
 691         pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
 692
 693         pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata));
 694
 695         if (IS_ERR(pdev)) {
 696                 pr_err("%s: Can't build omap_device for %s: %s.\n",
 697                         __func__, name, oh->name);
 698                 ret = -EINVAL;
 699         }
 700
 701         kfree(pdata);
 702
 703         return ret;
 704 }
 705
 706 /**
 707  * omap2_dm_timer_init - top level regular device initialization
 708  *
 709  * Uses dedicated hwmod api to parse through hwmod database for
 710  * given class name and then build and register the timer device.
 711  */
 712 static int __init omap2_dm_timer_init(void)
 713 {
 714         int ret;
 715
 716         /* If dtb is there, the devices will be created dynamically */
 717         if (of_have_populated_dt())
 718                 return -ENODEV;
 719
 720         ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
 721         if (unlikely(ret)) {
 722                 pr_err("%s: device registration failed.\n", __func__);
 723                 return -EINVAL;
 724         }
 725
 726         return 0;
 727 }
 728 omap_arch_initcall(omap2_dm_timer_init);
 729
 730 /**
 731  * omap2_override_clocksource - clocksource override with user configuration
 732  *
 733  * Allows user to override default clocksource, using kernel parameter
 734  *   clocksource="gp_timer"     (For all OMAP2PLUS architectures)
 735  *
 736  * Note that, here we are using same standard kernel parameter "clocksource=",
 737  * and not introducing any OMAP specific interface.
 738  */
 739 static int __init omap2_override_clocksource(char *str)
 740 {
 741         if (!str)
 742                 return 0;
 743         /*
 744          * For OMAP architecture, we only have two options
 745          *    - sync_32k (default)
 746          *    - gp_timer (sys_clk based)
 747          */
 748         if (!strcmp(str, "gp_timer"))
 749                 use_gptimer_clksrc = true;
 750
 751         return 0;
 752 }
 753 early_param("clocksource", omap2_override_clocksource);