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