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 int omap2_gp_timer_shutdown(struct clock_event_device *evt)
107 __omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
111 static int omap2_gp_timer_set_periodic(struct clock_event_device *evt)
115 __omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
117 period = clkev.rate / HZ;
119 /* Looks like we need to first set the load value separately */
120 __omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG, 0xffffffff - period,
122 __omap_dm_timer_load_start(&clkev,
123 OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
124 0xffffffff - period, OMAP_TIMER_POSTED);
128 static struct clock_event_device clockevent_gpt = {
129 .features = CLOCK_EVT_FEAT_PERIODIC |
130 CLOCK_EVT_FEAT_ONESHOT,
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,
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,dm814-timer", },
151 { .compatible = "ti,dm816-timer", },
152 { .compatible = "ti,am335x-timer", },
153 { .compatible = "ti,am335x-timer-1ms", },
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
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.
168 static struct device_node * __init omap_get_timer_dt(const struct of_device_id *match,
169 const char *property)
171 struct device_node *np;
173 for_each_matching_node(np, match) {
174 if (!of_device_is_available(np))
177 if (property && !of_get_property(np, property, NULL))
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)))
186 of_add_property(np, &device_disabled);
194 * omap_dmtimer_init - initialisation function when device tree is used
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
201 static void __init omap_dmtimer_init(void)
203 struct device_node *np;
205 if (!cpu_is_omap34xx())
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");
216 * omap_dm_timer_get_errata - get errata flags for a timer
218 * Get the timer errata flags that are specific to the OMAP device being used.
220 static u32 __init omap_dm_timer_get_errata(void)
222 if (cpu_is_omap24xx())
225 return OMAP_TIMER_ERRATA_I103_I767;
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,
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;
242 if (of_have_populated_dt()) {
243 np = omap_get_timer_dt(omap_timer_match, property);
247 of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
251 timer->irq = irq_of_parse_and_map(np, 0);
255 timer->io_base = of_iomap(np, 0);
259 if (omap_dm_timer_reserve_systimer(timer->id))
262 sprintf(name, "timer%d", timer->id);
266 oh = omap_hwmod_lookup(oh_name);
270 *timer_name = oh->name;
272 if (!of_have_populated_dt()) {
273 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL,
277 timer->irq = irq.start;
279 r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL,
284 /* Static mapping, never released */
285 timer->io_base = ioremap(mem.start, mem.end - mem.start);
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);
296 src = clk_get(NULL, fck_source);
300 r = clk_set_parent(timer->fclk, src);
302 pr_warn("%s: %s cannot set source\n", __func__, oh->name);
309 omap_hwmod_setup_one(oh_name);
310 omap_hwmod_enable(oh);
311 __omap_dm_timer_init_regs(timer);
314 __omap_dm_timer_enable_posted(timer);
316 /* Check that the intended posted configuration matches the actual */
317 if (posted != timer->posted)
320 timer->rate = clk_get_rate(timer->fclk);
326 static void __init omap2_gp_clockevent_init(int gptimer_id,
327 const char *fck_source,
328 const char *property)
332 clkev.id = gptimer_id;
333 clkev.errata = omap_dm_timer_get_errata();
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.
340 __omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);
342 res = omap_dm_timer_init_one(&clkev, fck_source, property,
343 &clockevent_gpt.name, OMAP_TIMER_POSTED);
346 omap2_gp_timer_irq.dev_id = &clkev;
347 setup_irq(clkev.irq, &omap2_gp_timer_irq);
349 __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
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 */
357 pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt.name,
361 /* Clocksource code */
362 static struct omap_dm_timer clksrc;
363 static bool use_gptimer_clksrc __initdata;
368 static cycle_t clocksource_read_cycles(struct clocksource *cs)
370 return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
371 OMAP_TIMER_NONPOSTED);
374 static struct clocksource clocksource_gpt = {
376 .read = clocksource_read_cycles,
377 .mask = CLOCKSOURCE_MASK(32),
378 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
381 static u64 notrace dmtimer_read_sched_clock(void)
384 return __omap_dm_timer_read_counter(&clksrc,
385 OMAP_TIMER_NONPOSTED);
390 static const struct of_device_id omap_counter_match[] __initconst = {
391 { .compatible = "ti,omap-counter32k", },
395 /* Setup free-running counter for clocksource */
396 static int __init __maybe_unused omap2_sync32k_clocksource_init(void)
399 struct device_node *np = NULL;
400 struct omap_hwmod *oh;
402 const char *oh_name = "counter_32k";
405 * If device-tree is present, then search the DT blob
406 * to see if the 32kHz counter is supported.
408 if (of_have_populated_dt()) {
409 np = omap_get_timer_dt(omap_counter_match, NULL);
413 of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
419 * First check hwmod data is available for sync32k counter
421 oh = omap_hwmod_lookup(oh_name);
422 if (!oh || oh->slaves_cnt == 0)
425 omap_hwmod_setup_one(oh_name);
428 vbase = of_iomap(np, 0);
431 vbase = omap_hwmod_get_mpu_rt_va(oh);
435 pr_warn("%s: failed to get counter_32k resource\n", __func__);
439 ret = omap_hwmod_enable(oh);
441 pr_warn("%s: failed to enable counter_32k module (%d)\n",
446 ret = omap_init_clocksource_32k(vbase);
448 pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
456 static void __init omap2_gptimer_clocksource_init(int gptimer_id,
457 const char *fck_source,
458 const char *property)
462 clksrc.id = gptimer_id;
463 clksrc.errata = omap_dm_timer_get_errata();
465 res = omap_dm_timer_init_one(&clksrc, fck_source, property,
466 &clocksource_gpt.name,
467 OMAP_TIMER_NONPOSTED);
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);
475 if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
476 pr_err("Could not register clocksource %s\n",
477 clocksource_gpt.name);
479 pr_info("OMAP clocksource: %s at %lu Hz\n",
480 clocksource_gpt.name, clksrc.rate);
483 #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
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.
493 static void __init realtime_counter_init(void)
496 static struct clk *sys_clk;
499 unsigned long long num, den;
501 base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
503 pr_err("%s: ioremap failed\n", __func__);
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__);
513 rate = clk_get_rate(sys_clk);
515 if (soc_is_dra7xx()) {
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)
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
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.
535 reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
536 if (reg & DRA7_SPEEDSELECT_MASK) {
543 /* Numerator/denumerator values refer TRM Realtime Counter section */
571 /* Program it for 38.4 MHz */
578 /* Program numerator and denumerator registers */
579 reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
580 NUMERATOR_DENUMERATOR_MASK;
582 writel_relaxed(reg, base + INCREMENTER_NUMERATOR_OFFSET);
584 reg = readl_relaxed(base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET) &
585 NUMERATOR_DENUMERATOR_MASK;
587 writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
589 arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
595 static inline void __init realtime_counter_init(void)
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) \
604 omap_dmtimer_init(); \
605 omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop); \
606 omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src, \
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) \
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, \
622 omap2_sync32k_clocksource_init(); \
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 */
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 */
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");
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);
649 #ifdef CONFIG_ARCH_OMAP4
650 #ifdef CONFIG_HAVE_ARM_TWD
651 void __init omap4_local_timer_init(void)
653 omap4_sync32k_timer_init();
654 clocksource_of_init();
657 void __init omap4_local_timer_init(void)
659 omap4_sync32k_timer_init();
661 #endif /* CONFIG_HAVE_ARM_TWD */
662 #endif /* CONFIG_ARCH_OMAP4 */
664 #if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
665 void __init omap5_realtime_timer_init(void)
667 omap4_sync32k_timer_init();
668 realtime_counter_init();
670 clocksource_of_init();
672 #endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
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
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.
686 static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
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;
695 pr_debug("%s: %s\n", __func__, oh->name);
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)
703 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
705 pr_err("%s: No memory for [%s]\n", __func__, oh->name);
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.
719 sscanf(oh->name, "timer%2d", &id);
722 pdata->timer_capability = timer_dev_attr->timer_capability;
724 pdata->timer_errata = omap_dm_timer_get_errata();
725 pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
727 pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata));
730 pr_err("%s: Can't build omap_device for %s: %s.\n",
731 __func__, name, oh->name);
741 * omap2_dm_timer_init - top level regular device initialization
743 * Uses dedicated hwmod api to parse through hwmod database for
744 * given class name and then build and register the timer device.
746 static int __init omap2_dm_timer_init(void)
750 /* If dtb is there, the devices will be created dynamically */
751 if (of_have_populated_dt())
754 ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
756 pr_err("%s: device registration failed.\n", __func__);
762 omap_arch_initcall(omap2_dm_timer_init);
765 * omap2_override_clocksource - clocksource override with user configuration
767 * Allows user to override default clocksource, using kernel parameter
768 * clocksource="gp_timer" (For all OMAP2PLUS architectures)
770 * Note that, here we are using same standard kernel parameter "clocksource=",
771 * and not introducing any OMAP specific interface.
773 static int __init omap2_override_clocksource(char *str)
778 * For OMAP architecture, we only have two options
779 * - sync_32k (default)
780 * - gp_timer (sys_clk based)
782 if (!strcmp(str, "gp_timer"))
783 use_gptimer_clksrc = true;
787 early_param("clocksource", omap2_override_clocksource);