2 * linux/arch/arm/mach-omap2/timer.c
4 * OMAP2 GP timer support.
6 * Copyright (C) 2009 Nokia Corporation
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.
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
18 * Some parts based off of TI's 24xx code:
20 * Copyright (C) 2004-2009 Texas Instruments, Inc.
22 * Roughly modelled after the OMAP1 MPU timer code.
23 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
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
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>
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>
46 #include <asm/mach/time.h>
47 #include <asm/smp_twd.h>
49 #include "omap_hwmod.h"
50 #include "omap_device.h"
51 #include <plat/counter-32k.h>
52 #include <plat/dmtimer.h>
58 #include "powerdomain.h"
59 #include "omap-secure.h"
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
68 static struct omap_dm_timer clkev;
69 static struct clock_event_device clockevent_gpt;
71 #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
72 static unsigned long arch_timer_freq;
74 void set_cntfreq(void)
76 omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
80 static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
82 struct clock_event_device *evt = &clockevent_gpt;
84 __omap_dm_timer_write_status(&clkev, OMAP_TIMER_INT_OVERFLOW);
86 evt->event_handler(evt);
90 static struct irqaction omap2_gp_timer_irq = {
92 .flags = IRQF_TIMER | IRQF_IRQPOLL,
93 .handler = omap2_gp_timer_interrupt,
96 static int omap2_gp_timer_set_next_event(unsigned long cycles,
97 struct clock_event_device *evt)
99 __omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
100 0xffffffff - cycles, OMAP_TIMER_POSTED);
105 static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
106 struct clock_event_device *evt)
110 __omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
113 case CLOCK_EVT_MODE_PERIODIC:
114 period = clkev.rate / HZ;
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);
123 case CLOCK_EVT_MODE_ONESHOT:
125 case CLOCK_EVT_MODE_UNUSED:
126 case CLOCK_EVT_MODE_SHUTDOWN:
127 case CLOCK_EVT_MODE_RESUME:
132 static struct clock_event_device clockevent_gpt = {
133 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
135 .set_next_event = omap2_gp_timer_set_next_event,
136 .set_mode = omap2_gp_timer_set_mode,
139 static struct property device_disabled = {
141 .length = sizeof("disabled"),
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,am335x-timer", },
151 { .compatible = "ti,am335x-timer-1ms", },
156 * omap_get_timer_dt - get a timer using device-tree
157 * @match - device-tree match structure for matching a device type
158 * @property - optional timer property to match
160 * Helper function to get a timer during early boot using device-tree for use
161 * as kernel system timer. Optionally, the property argument can be used to
162 * select a timer with a specific property. Once a timer is found then mark
163 * the timer node in device-tree as disabled, to prevent the kernel from
164 * registering this timer as a platform device and so no one else can use it.
166 static struct device_node * __init omap_get_timer_dt(const struct of_device_id *match,
167 const char *property)
169 struct device_node *np;
171 for_each_matching_node(np, match) {
172 if (!of_device_is_available(np))
175 if (property && !of_get_property(np, property, NULL))
178 if (!property && (of_get_property(np, "ti,timer-alwon", NULL) ||
179 of_get_property(np, "ti,timer-dsp", NULL) ||
180 of_get_property(np, "ti,timer-pwm", NULL) ||
181 of_get_property(np, "ti,timer-secure", NULL)))
184 of_add_property(np, &device_disabled);
192 * omap_dmtimer_init - initialisation function when device tree is used
194 * For secure OMAP3 devices, timers with device type "timer-secure" cannot
195 * be used by the kernel as they are reserved. Therefore, to prevent the
196 * kernel registering these devices remove them dynamically from the device
199 static void __init omap_dmtimer_init(void)
201 struct device_node *np;
203 if (!cpu_is_omap34xx())
206 /* If we are a secure device, remove any secure timer nodes */
207 if ((omap_type() != OMAP2_DEVICE_TYPE_GP)) {
208 np = omap_get_timer_dt(omap_timer_match, "ti,timer-secure");
215 * omap_dm_timer_get_errata - get errata flags for a timer
217 * Get the timer errata flags that are specific to the OMAP device being used.
219 static u32 __init omap_dm_timer_get_errata(void)
221 if (cpu_is_omap24xx())
224 return OMAP_TIMER_ERRATA_I103_I767;
227 static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
228 const char *fck_source,
229 const char *property,
230 const char **timer_name,
233 char name[10]; /* 10 = sizeof("gptXX_Xck0") */
234 const char *oh_name = NULL;
235 struct device_node *np;
236 struct omap_hwmod *oh;
237 struct resource irq, mem;
241 if (of_have_populated_dt()) {
242 np = omap_get_timer_dt(omap_timer_match, property);
246 of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
250 timer->irq = irq_of_parse_and_map(np, 0);
254 timer->io_base = of_iomap(np, 0);
258 if (omap_dm_timer_reserve_systimer(timer->id))
261 sprintf(name, "timer%d", timer->id);
265 oh = omap_hwmod_lookup(oh_name);
269 *timer_name = oh->name;
271 if (!of_have_populated_dt()) {
272 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL,
276 timer->irq = irq.start;
278 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL,
283 /* Static mapping, never released */
284 timer->io_base = ioremap(mem.start, mem.end - mem.start);
290 /* After the dmtimer is using hwmod these clocks won't be needed */
291 timer->fclk = clk_get(NULL, omap_hwmod_get_main_clk(oh));
292 if (IS_ERR(timer->fclk))
293 return PTR_ERR(timer->fclk);
295 src = clk_get(NULL, fck_source);
299 if (clk_get_parent(timer->fclk) != src) {
300 r = clk_set_parent(timer->fclk, src);
302 pr_warn("%s: %s cannot set source\n", __func__,
311 omap_hwmod_setup_one(oh_name);
312 omap_hwmod_enable(oh);
313 __omap_dm_timer_init_regs(timer);
316 __omap_dm_timer_enable_posted(timer);
318 /* Check that the intended posted configuration matches the actual */
319 if (posted != timer->posted)
322 timer->rate = clk_get_rate(timer->fclk);
328 static void __init omap2_gp_clockevent_init(int gptimer_id,
329 const char *fck_source,
330 const char *property)
334 clkev.id = gptimer_id;
335 clkev.errata = omap_dm_timer_get_errata();
338 * For clock-event timers we never read the timer counter and
339 * so we are not impacted by errata i103 and i767. Therefore,
340 * we can safely ignore this errata for clock-event timers.
342 __omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);
344 res = omap_dm_timer_init_one(&clkev, fck_source, property,
345 &clockevent_gpt.name, OMAP_TIMER_POSTED);
348 omap2_gp_timer_irq.dev_id = &clkev;
349 setup_irq(clkev.irq, &omap2_gp_timer_irq);
351 __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
353 clockevent_gpt.cpumask = cpu_possible_mask;
354 clockevent_gpt.irq = omap_dm_timer_get_irq(&clkev);
355 clockevents_config_and_register(&clockevent_gpt, clkev.rate,
356 3, /* Timer internal resynch latency */
359 pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt.name,
363 /* Clocksource code */
364 static struct omap_dm_timer clksrc;
365 static bool use_gptimer_clksrc __initdata;
370 static cycle_t clocksource_read_cycles(struct clocksource *cs)
372 return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
373 OMAP_TIMER_NONPOSTED);
376 static struct clocksource clocksource_gpt = {
378 .read = clocksource_read_cycles,
379 .mask = CLOCKSOURCE_MASK(32),
380 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
383 static u64 notrace dmtimer_read_sched_clock(void)
386 return __omap_dm_timer_read_counter(&clksrc,
387 OMAP_TIMER_NONPOSTED);
392 static const struct of_device_id omap_counter_match[] __initconst = {
393 { .compatible = "ti,omap-counter32k", },
397 /* Setup free-running counter for clocksource */
398 static int __init __maybe_unused omap2_sync32k_clocksource_init(void)
401 struct device_node *np = NULL;
402 struct omap_hwmod *oh;
404 const char *oh_name = "counter_32k";
407 * If device-tree is present, then search the DT blob
408 * to see if the 32kHz counter is supported.
410 if (of_have_populated_dt()) {
411 np = omap_get_timer_dt(omap_counter_match, NULL);
415 of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
421 * First check hwmod data is available for sync32k counter
423 oh = omap_hwmod_lookup(oh_name);
424 if (!oh || oh->slaves_cnt == 0)
427 omap_hwmod_setup_one(oh_name);
430 vbase = of_iomap(np, 0);
433 vbase = omap_hwmod_get_mpu_rt_va(oh);
437 pr_warn("%s: failed to get counter_32k resource\n", __func__);
441 ret = omap_hwmod_enable(oh);
443 pr_warn("%s: failed to enable counter_32k module (%d)\n",
448 ret = omap_init_clocksource_32k(vbase);
450 pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
458 static void __init omap2_gptimer_clocksource_init(int gptimer_id,
459 const char *fck_source,
460 const char *property)
464 clksrc.id = gptimer_id;
465 clksrc.errata = omap_dm_timer_get_errata();
467 res = omap_dm_timer_init_one(&clksrc, fck_source, property,
468 &clocksource_gpt.name,
469 OMAP_TIMER_NONPOSTED);
472 __omap_dm_timer_load_start(&clksrc,
473 OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
474 OMAP_TIMER_NONPOSTED);
475 sched_clock_register(dmtimer_read_sched_clock, 32, clksrc.rate);
477 if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
478 pr_err("Could not register clocksource %s\n",
479 clocksource_gpt.name);
481 pr_info("OMAP clocksource: %s at %lu Hz\n",
482 clocksource_gpt.name, clksrc.rate);
485 #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
487 * The realtime counter also called master counter, is a free-running
488 * counter, which is related to real time. It produces the count used
489 * by the CPU local timer peripherals in the MPU cluster. The timer counts
490 * at a rate of 6.144 MHz. Because the device operates on different clocks
491 * in different power modes, the master counter shifts operation between
492 * clocks, adjusting the increment per clock in hardware accordingly to
493 * maintain a constant count rate.
495 static void __init realtime_counter_init(void)
498 static struct clk *sys_clk;
501 unsigned long long num, den;
503 base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
505 pr_err("%s: ioremap failed\n", __func__);
508 sys_clk = clk_get(NULL, "sys_clkin");
509 if (IS_ERR(sys_clk)) {
510 pr_err("%s: failed to get system clock handle\n", __func__);
515 rate = clk_get_rate(sys_clk);
517 if (soc_is_dra7xx()) {
519 * Errata i856 says the 32.768KHz crystal does not start at
520 * power on, so the CPU falls back to an emulated 32KHz clock
521 * based on sysclk / 610 instead. This causes the master counter
522 * frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
523 * (OR sysclk * 75 / 244)
525 * This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
526 * Of course any board built without a populated 32.768KHz
527 * crystal would also need this fix even if the CPU is fixed
530 * Either case can be detected by using the two speedselect bits
531 * If they are not 0, then the 32.768KHz clock driving the
532 * coarse counter that corrects the fine counter every time it
533 * ticks is actually rate/610 rather than 32.768KHz and we
534 * should compensate to avoid the 570ppm (at 20MHz, much worse
535 * at other rates) too fast system time.
537 reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
538 if (reg & DRA7_SPEEDSELECT_MASK) {
545 /* Numerator/denumerator values refer TRM Realtime Counter section */
573 /* Program it for 38.4 MHz */
580 /* Program numerator and denumerator registers */
581 reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
582 NUMERATOR_DENUMERATOR_MASK;
584 writel_relaxed(reg, base + INCREMENTER_NUMERATOR_OFFSET);
586 reg = readl_relaxed(base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET) &
587 NUMERATOR_DENUMERATOR_MASK;
589 writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
591 arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
597 static inline void __init realtime_counter_init(void)
601 #define OMAP_SYS_GP_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop, \
602 clksrc_nr, clksrc_src, clksrc_prop) \
603 void __init omap##name##_gptimer_timer_init(void) \
606 omap_dmtimer_init(); \
607 omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop); \
608 omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src, \
612 #define OMAP_SYS_32K_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop, \
613 clksrc_nr, clksrc_src, clksrc_prop) \
614 void __init omap##name##_sync32k_timer_init(void) \
617 omap_dmtimer_init(); \
618 omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop); \
619 /* Enable the use of clocksource="gp_timer" kernel parameter */ \
620 if (use_gptimer_clksrc) \
621 omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src, \
624 omap2_sync32k_clocksource_init(); \
627 #ifdef CONFIG_ARCH_OMAP2
628 OMAP_SYS_32K_TIMER_INIT(2, 1, "timer_32k_ck", "ti,timer-alwon",
629 2, "timer_sys_ck", NULL);
630 #endif /* CONFIG_ARCH_OMAP2 */
632 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX)
633 OMAP_SYS_32K_TIMER_INIT(3, 1, "timer_32k_ck", "ti,timer-alwon",
634 2, "timer_sys_ck", NULL);
635 OMAP_SYS_32K_TIMER_INIT(3_secure, 12, "secure_32k_fck", "ti,timer-secure",
636 2, "timer_sys_ck", NULL);
637 #endif /* CONFIG_ARCH_OMAP3 */
639 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) || \
640 defined(CONFIG_SOC_AM43XX)
641 OMAP_SYS_GP_TIMER_INIT(3, 2, "timer_sys_ck", NULL,
642 1, "timer_sys_ck", "ti,timer-alwon");
645 #if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) || \
646 defined(CONFIG_SOC_DRA7XX)
647 static OMAP_SYS_32K_TIMER_INIT(4, 1, "timer_32k_ck", "ti,timer-alwon",
648 2, "sys_clkin_ck", NULL);
651 #ifdef CONFIG_ARCH_OMAP4
652 #ifdef CONFIG_HAVE_ARM_TWD
653 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, OMAP44XX_LOCAL_TWD_BASE, 29);
654 void __init omap4_local_timer_init(void)
656 omap4_sync32k_timer_init();
657 /* Local timers are not supprted on OMAP4430 ES1.0 */
658 if (omap_rev() != OMAP4430_REV_ES1_0) {
661 if (of_have_populated_dt()) {
662 clocksource_of_init();
666 err = twd_local_timer_register(&twd_local_timer);
668 pr_err("twd_local_timer_register failed %d\n", err);
672 void __init omap4_local_timer_init(void)
674 omap4_sync32k_timer_init();
676 #endif /* CONFIG_HAVE_ARM_TWD */
677 #endif /* CONFIG_ARCH_OMAP4 */
679 #if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
680 void __init omap5_realtime_timer_init(void)
682 omap4_sync32k_timer_init();
683 realtime_counter_init();
685 clocksource_of_init();
687 #endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
690 * omap_timer_init - build and register timer device with an
691 * associated timer hwmod
692 * @oh: timer hwmod pointer to be used to build timer device
693 * @user: parameter that can be passed from calling hwmod API
695 * Called by omap_hwmod_for_each_by_class to register each of the timer
696 * devices present in the system. The number of timer devices is known
697 * by parsing through the hwmod database for a given class name. At the
698 * end of function call memory is allocated for timer device and it is
699 * registered to the framework ready to be proved by the driver.
701 static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
705 char *name = "omap_timer";
706 struct dmtimer_platform_data *pdata;
707 struct platform_device *pdev;
708 struct omap_timer_capability_dev_attr *timer_dev_attr;
710 pr_debug("%s: %s\n", __func__, oh->name);
712 /* on secure device, do not register secure timer */
713 timer_dev_attr = oh->dev_attr;
714 if (omap_type() != OMAP2_DEVICE_TYPE_GP && timer_dev_attr)
715 if (timer_dev_attr->timer_capability == OMAP_TIMER_SECURE)
718 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
720 pr_err("%s: No memory for [%s]\n", __func__, oh->name);
725 * Extract the IDs from name field in hwmod database
726 * and use the same for constructing ids' for the
727 * timer devices. In a way, we are avoiding usage of
728 * static variable witin the function to do the same.
729 * CAUTION: We have to be careful and make sure the
730 * name in hwmod database does not change in which case
731 * we might either make corresponding change here or
732 * switch back static variable mechanism.
734 sscanf(oh->name, "timer%2d", &id);
737 pdata->timer_capability = timer_dev_attr->timer_capability;
739 pdata->timer_errata = omap_dm_timer_get_errata();
740 pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
742 pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata));
745 pr_err("%s: Can't build omap_device for %s: %s.\n",
746 __func__, name, oh->name);
756 * omap2_dm_timer_init - top level regular device initialization
758 * Uses dedicated hwmod api to parse through hwmod database for
759 * given class name and then build and register the timer device.
761 static int __init omap2_dm_timer_init(void)
765 /* If dtb is there, the devices will be created dynamically */
766 if (of_have_populated_dt())
769 ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
771 pr_err("%s: device registration failed.\n", __func__);
777 omap_arch_initcall(omap2_dm_timer_init);
780 * omap2_override_clocksource - clocksource override with user configuration
782 * Allows user to override default clocksource, using kernel parameter
783 * clocksource="gp_timer" (For all OMAP2PLUS architectures)
785 * Note that, here we are using same standard kernel parameter "clocksource=",
786 * and not introducing any OMAP specific interface.
788 static int __init omap2_override_clocksource(char *str)
793 * For OMAP architecture, we only have two options
794 * - sync_32k (default)
795 * - gp_timer (sys_clk based)
797 if (!strcmp(str, "gp_timer"))
798 use_gptimer_clksrc = true;
802 early_param("clocksource", omap2_override_clocksource);