summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap2/timer.c
blob: 5b385bb8aff9673b21b5f18edeab8d8114525180 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
/*
 * linux/arch/arm/mach-omap2/timer.c
 *
 * OMAP2 GP timer support.
 *
 * Copyright (C) 2009 Nokia Corporation
 *
 * Update to use new clocksource/clockevent layers
 * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
 * Copyright (C) 2007 MontaVista Software, Inc.
 *
 * Original driver:
 * Copyright (C) 2005 Nokia Corporation
 * Author: Paul Mundt <paul.mundt@nokia.com>
 *         Juha Yrjölä <juha.yrjola@nokia.com>
 * OMAP Dual-mode timer framework support by Timo Teras
 *
 * Some parts based off of TI's 24xx code:
 *
 * Copyright (C) 2004-2009 Texas Instruments, Inc.
 *
 * Roughly modelled after the OMAP1 MPU timer code.
 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/init.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/platform_data/dmtimer-omap.h>
#include <linux/sched_clock.h>

#include <asm/mach/time.h>
#include <asm/smp_twd.h>

#include "omap_hwmod.h"
#include "omap_device.h"
#include <plat/counter-32k.h>
#include <plat/dmtimer.h>
#include "omap-pm.h"

#include "soc.h"
#include "common.h"
#include "control.h"
#include "powerdomain.h"
#include "omap-secure.h"

#define REALTIME_COUNTER_BASE				0x48243200
#define INCREMENTER_NUMERATOR_OFFSET			0x10
#define INCREMENTER_DENUMERATOR_RELOAD_OFFSET		0x14
#define NUMERATOR_DENUMERATOR_MASK			0xfffff000

/* Clockevent code */

static struct omap_dm_timer clkev;
static struct clock_event_device clockevent_gpt;

#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
static unsigned long arch_timer_freq;

void set_cntfreq(void)
{
	omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
}
#endif

static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = &clockevent_gpt;

	__omap_dm_timer_write_status(&clkev, OMAP_TIMER_INT_OVERFLOW);

	evt->event_handler(evt);
	return IRQ_HANDLED;
}

static struct irqaction omap2_gp_timer_irq = {
	.name		= "gp_timer",
	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
	.handler	= omap2_gp_timer_interrupt,
};

static int omap2_gp_timer_set_next_event(unsigned long cycles,
					 struct clock_event_device *evt)
{
	__omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
				   0xffffffff - cycles, OMAP_TIMER_POSTED);

	return 0;
}

static int omap2_gp_timer_shutdown(struct clock_event_device *evt)
{
	__omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
	return 0;
}

static int omap2_gp_timer_set_periodic(struct clock_event_device *evt)
{
	u32 period;

	__omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);

	period = clkev.rate / HZ;
	period -= 1;
	/* Looks like we need to first set the load value separately */
	__omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG, 0xffffffff - period,
			      OMAP_TIMER_POSTED);
	__omap_dm_timer_load_start(&clkev,
				   OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
				   0xffffffff - period, OMAP_TIMER_POSTED);
	return 0;
}

static struct clock_event_device clockevent_gpt = {
	.features		= CLOCK_EVT_FEAT_PERIODIC |
				  CLOCK_EVT_FEAT_ONESHOT,
	.rating			= 300,
	.set_next_event		= omap2_gp_timer_set_next_event,
	.set_state_shutdown	= omap2_gp_timer_shutdown,
	.set_state_periodic	= omap2_gp_timer_set_periodic,
	.set_state_oneshot	= omap2_gp_timer_shutdown,
	.tick_resume		= omap2_gp_timer_shutdown,
};

static struct property device_disabled = {
	.name = "status",
	.length = sizeof("disabled"),
	.value = "disabled",
};

static const struct of_device_id omap_timer_match[] __initconst = {
	{ .compatible = "ti,omap2420-timer", },
	{ .compatible = "ti,omap3430-timer", },
	{ .compatible = "ti,omap4430-timer", },
	{ .compatible = "ti,omap5430-timer", },
	{ .compatible = "ti,dm814-timer", },
	{ .compatible = "ti,dm816-timer", },
	{ .compatible = "ti,am335x-timer", },
	{ .compatible = "ti,am335x-timer-1ms", },
	{ }
};

/**
 * omap_get_timer_dt - get a timer using device-tree
 * @match	- device-tree match structure for matching a device type
 * @property	- optional timer property to match
 *
 * Helper function to get a timer during early boot using device-tree for use
 * as kernel system timer. Optionally, the property argument can be used to
 * select a timer with a specific property. Once a timer is found then mark
 * the timer node in device-tree as disabled, to prevent the kernel from
 * registering this timer as a platform device and so no one else can use it.
 */
static struct device_node * __init omap_get_timer_dt(const struct of_device_id *match,
						     const char *property)
{
	struct device_node *np;

	for_each_matching_node(np, match) {
		if (!of_device_is_available(np))
			continue;

		if (property && !of_get_property(np, property, NULL))
			continue;

		if (!property && (of_get_property(np, "ti,timer-alwon", NULL) ||
				  of_get_property(np, "ti,timer-dsp", NULL) ||
				  of_get_property(np, "ti,timer-pwm", NULL) ||
				  of_get_property(np, "ti,timer-secure", NULL)))
			continue;

		if (!of_device_is_compatible(np, "ti,omap-counter32k"))
			of_add_property(np, &device_disabled);
		return np;
	}

	return NULL;
}

/**
 * omap_dmtimer_init - initialisation function when device tree is used
 *
 * For secure OMAP3/DRA7xx devices, timers with device type "timer-secure"
 * cannot be used by the kernel as they are reserved. Therefore, to prevent the
 * kernel registering these devices remove them dynamically from the device
 * tree on boot.
 */
static void __init omap_dmtimer_init(void)
{
	struct device_node *np;

	if (!cpu_is_omap34xx() && !soc_is_dra7xx())
		return;

	/* If we are a secure device, remove any secure timer nodes */
	if ((omap_type() != OMAP2_DEVICE_TYPE_GP)) {
		np = omap_get_timer_dt(omap_timer_match, "ti,timer-secure");
		of_node_put(np);
	}
}

/**
 * omap_dm_timer_get_errata - get errata flags for a timer
 *
 * Get the timer errata flags that are specific to the OMAP device being used.
 */
static u32 __init omap_dm_timer_get_errata(void)
{
	if (cpu_is_omap24xx())
		return 0;

	return OMAP_TIMER_ERRATA_I103_I767;
}

static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
					 const char *fck_source,
					 const char *property,
					 const char **timer_name,
					 int posted)
{
	char name[10]; /* 10 = sizeof("gptXX_Xck0") */
	const char *oh_name = NULL;
	struct device_node *np;
	struct omap_hwmod *oh;
	struct resource irq, mem;
	struct clk *src;
	int r = 0;

	if (of_have_populated_dt()) {
		np = omap_get_timer_dt(omap_timer_match, property);
		if (!np)
			return -ENODEV;

		of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
		if (!oh_name)
			return -ENODEV;

		timer->irq = irq_of_parse_and_map(np, 0);
		if (!timer->irq)
			return -ENXIO;

		timer->io_base = of_iomap(np, 0);

		of_node_put(np);
	} else {
		if (omap_dm_timer_reserve_systimer(timer->id))
			return -ENODEV;

		sprintf(name, "timer%d", timer->id);
		oh_name = name;
	}

	oh = omap_hwmod_lookup(oh_name);
	if (!oh)
		return -ENODEV;

	*timer_name = oh->name;

	if (!of_have_populated_dt()) {
		r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL,
						   &irq);
		if (r)
			return -ENXIO;
		timer->irq = irq.start;

		r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL,
						   &mem);
		if (r)
			return -ENXIO;

		/* Static mapping, never released */
		timer->io_base = ioremap(mem.start, mem.end - mem.start);
	}

	if (!timer->io_base)
		return -ENXIO;

	/* After the dmtimer is using hwmod these clocks won't be needed */
	timer->fclk = clk_get(NULL, omap_hwmod_get_main_clk(oh));
	if (IS_ERR(timer->fclk))
		return PTR_ERR(timer->fclk);

	src = clk_get(NULL, fck_source);
	if (IS_ERR(src))
		return PTR_ERR(src);

	WARN(clk_set_parent(timer->fclk, src) < 0,
	     "Cannot set timer parent clock, no PLL clock driver?");

	clk_put(src);

	omap_hwmod_setup_one(oh_name);
	omap_hwmod_enable(oh);
	__omap_dm_timer_init_regs(timer);

	if (posted)
		__omap_dm_timer_enable_posted(timer);

	/* Check that the intended posted configuration matches the actual */
	if (posted != timer->posted)
		return -EINVAL;

	timer->rate = clk_get_rate(timer->fclk);
	timer->reserved = 1;

	return r;
}

#if !defined(CONFIG_SMP) && defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
void tick_broadcast(const struct cpumask *mask)
{
}
#endif

static void __init omap2_gp_clockevent_init(int gptimer_id,
						const char *fck_source,
						const char *property)
{
	int res;

	clkev.id = gptimer_id;
	clkev.errata = omap_dm_timer_get_errata();

	/*
	 * For clock-event timers we never read the timer counter and
	 * so we are not impacted by errata i103 and i767. Therefore,
	 * we can safely ignore this errata for clock-event timers.
	 */
	__omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);

	res = omap_dm_timer_init_one(&clkev, fck_source, property,
				     &clockevent_gpt.name, OMAP_TIMER_POSTED);
	BUG_ON(res);

	omap2_gp_timer_irq.dev_id = &clkev;
	setup_irq(clkev.irq, &omap2_gp_timer_irq);

	__omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);

	clockevent_gpt.cpumask = cpu_possible_mask;
	clockevent_gpt.irq = omap_dm_timer_get_irq(&clkev);
	clockevents_config_and_register(&clockevent_gpt, clkev.rate,
					3, /* Timer internal resynch latency */
					0xffffffff);

	pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt.name,
		clkev.rate);
}

/* Clocksource code */
static struct omap_dm_timer clksrc;
static bool use_gptimer_clksrc __initdata;

/*
 * clocksource
 */
static cycle_t clocksource_read_cycles(struct clocksource *cs)
{
	return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
						     OMAP_TIMER_NONPOSTED);
}

static struct clocksource clocksource_gpt = {
	.rating		= 300,
	.read		= clocksource_read_cycles,
	.mask		= CLOCKSOURCE_MASK(32),
	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
};

static u64 notrace dmtimer_read_sched_clock(void)
{
	if (clksrc.reserved)
		return __omap_dm_timer_read_counter(&clksrc,
						    OMAP_TIMER_NONPOSTED);

	return 0;
}

static const struct of_device_id omap_counter_match[] __initconst = {
	{ .compatible = "ti,omap-counter32k", },
	{ }
};

/* Setup free-running counter for clocksource */
static int __init __maybe_unused omap2_sync32k_clocksource_init(void)
{
	int ret;
	struct device_node *np = NULL;
	struct omap_hwmod *oh;
	const char *oh_name = "counter_32k";

	/*
	 * If device-tree is present, then search the DT blob
	 * to see if the 32kHz counter is supported.
	 */
	if (of_have_populated_dt()) {
		np = omap_get_timer_dt(omap_counter_match, NULL);
		if (!np)
			return -ENODEV;

		of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
		if (!oh_name)
			return -ENODEV;
	}

	/*
	 * First check hwmod data is available for sync32k counter
	 */
	oh = omap_hwmod_lookup(oh_name);
	if (!oh || oh->slaves_cnt == 0)
		return -ENODEV;

	omap_hwmod_setup_one(oh_name);

	ret = omap_hwmod_enable(oh);
	if (ret) {
		pr_warn("%s: failed to enable counter_32k module (%d)\n",
							__func__, ret);
		return ret;
	}

	if (!of_have_populated_dt()) {
		void __iomem *vbase;

		vbase = omap_hwmod_get_mpu_rt_va(oh);

		ret = omap_init_clocksource_32k(vbase);
		if (ret) {
			pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
					__func__, ret);
			omap_hwmod_idle(oh);
		}
	}
	return ret;
}

static void __init omap2_gptimer_clocksource_init(int gptimer_id,
						  const char *fck_source,
						  const char *property)
{
	int res;

	clksrc.id = gptimer_id;
	clksrc.errata = omap_dm_timer_get_errata();

	res = omap_dm_timer_init_one(&clksrc, fck_source, property,
				     &clocksource_gpt.name,
				     OMAP_TIMER_NONPOSTED);
	BUG_ON(res);

	__omap_dm_timer_load_start(&clksrc,
				   OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
				   OMAP_TIMER_NONPOSTED);
	sched_clock_register(dmtimer_read_sched_clock, 32, clksrc.rate);

	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
		pr_err("Could not register clocksource %s\n",
			clocksource_gpt.name);
	else
		pr_info("OMAP clocksource: %s at %lu Hz\n",
			clocksource_gpt.name, clksrc.rate);
}

static void __init __omap_sync32k_timer_init(int clkev_nr, const char *clkev_src,
		const char *clkev_prop, int clksrc_nr, const char *clksrc_src,
		const char *clksrc_prop, bool gptimer)
{
	omap_clk_init();
	omap_dmtimer_init();
	omap2_gp_clockevent_init(clkev_nr, clkev_src, clkev_prop);

	/* Enable the use of clocksource="gp_timer" kernel parameter */
	if (use_gptimer_clksrc || gptimer)
		omap2_gptimer_clocksource_init(clksrc_nr, clksrc_src,
						clksrc_prop);
	else
		omap2_sync32k_clocksource_init();
}

void __init omap_init_time(void)
{
	__omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon",
			2, "timer_sys_ck", NULL, false);

	if (of_have_populated_dt())
		clocksource_probe();
}

#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX)
void __init omap3_secure_sync32k_timer_init(void)
{
	__omap_sync32k_timer_init(12, "secure_32k_fck", "ti,timer-secure",
			2, "timer_sys_ck", NULL, false);
}
#endif /* CONFIG_ARCH_OMAP3 */

#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX)
void __init omap3_gptimer_timer_init(void)
{
	__omap_sync32k_timer_init(2, "timer_sys_ck", NULL,
			1, "timer_sys_ck", "ti,timer-alwon", true);
}
#endif

#if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) ||		\
	defined(CONFIG_SOC_DRA7XX) || defined(CONFIG_SOC_AM43XX)
static void __init omap4_sync32k_timer_init(void)
{
	__omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon",
			2, "sys_clkin_ck", NULL, false);
}

void __init omap4_local_timer_init(void)
{
	omap4_sync32k_timer_init();
	clocksource_probe();
}
#endif

#if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)

/*
 * The realtime counter also called master counter, is a free-running
 * counter, which is related to real time. It produces the count used
 * by the CPU local timer peripherals in the MPU cluster. The timer counts
 * at a rate of 6.144 MHz. Because the device operates on different clocks
 * in different power modes, the master counter shifts operation between
 * clocks, adjusting the increment per clock in hardware accordingly to
 * maintain a constant count rate.
 */
static void __init realtime_counter_init(void)
{
#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
	void __iomem *base;
	static struct clk *sys_clk;
	unsigned long rate;
	unsigned int reg;
	unsigned long long num, den;

	base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
	if (!base) {
		pr_err("%s: ioremap failed\n", __func__);
		return;
	}
	sys_clk = clk_get(NULL, "sys_clkin");
	if (IS_ERR(sys_clk)) {
		pr_err("%s: failed to get system clock handle\n", __func__);
		iounmap(base);
		return;
	}

	rate = clk_get_rate(sys_clk);

	if (soc_is_dra7xx()) {
		/*
		 * Errata i856 says the 32.768KHz crystal does not start at
		 * power on, so the CPU falls back to an emulated 32KHz clock
		 * based on sysclk / 610 instead. This causes the master counter
		 * frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
		 * (OR sysclk * 75 / 244)
		 *
		 * This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
		 * Of course any board built without a populated 32.768KHz
		 * crystal would also need this fix even if the CPU is fixed
		 * later.
		 *
		 * Either case can be detected by using the two speedselect bits
		 * If they are not 0, then the 32.768KHz clock driving the
		 * coarse counter that corrects the fine counter every time it
		 * ticks is actually rate/610 rather than 32.768KHz and we
		 * should compensate to avoid the 570ppm (at 20MHz, much worse
		 * at other rates) too fast system time.
		 */
		reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
		if (reg & DRA7_SPEEDSELECT_MASK) {
			num = 75;
			den = 244;
			goto sysclk1_based;
		}
	}

	/* Numerator/denumerator values refer TRM Realtime Counter section */
	switch (rate) {
	case 12000000:
		num = 64;
		den = 125;
		break;
	case 13000000:
		num = 768;
		den = 1625;
		break;
	case 19200000:
		num = 8;
		den = 25;
		break;
	case 20000000:
		num = 192;
		den = 625;
		break;
	case 26000000:
		num = 384;
		den = 1625;
		break;
	case 27000000:
		num = 256;
		den = 1125;
		break;
	case 38400000:
	default:
		/* Program it for 38.4 MHz */
		num = 4;
		den = 25;
		break;
	}

sysclk1_based:
	/* Program numerator and denumerator registers */
	reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
			NUMERATOR_DENUMERATOR_MASK;
	reg |= num;
	writel_relaxed(reg, base + INCREMENTER_NUMERATOR_OFFSET);

	reg = readl_relaxed(base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET) &
			NUMERATOR_DENUMERATOR_MASK;
	reg |= den;
	writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);

	arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
	set_cntfreq();

	iounmap(base);
#endif
}

void __init omap5_realtime_timer_init(void)
{
	omap4_sync32k_timer_init();
	realtime_counter_init();

	clocksource_probe();
}
#endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */

/**
 * omap_timer_init - build and register timer device with an
 * associated timer hwmod
 * @oh:	timer hwmod pointer to be used to build timer device
 * @user:	parameter that can be passed from calling hwmod API
 *
 * Called by omap_hwmod_for_each_by_class to register each of the timer
 * devices present in the system. The number of timer devices is known
 * by parsing through the hwmod database for a given class name. At the
 * end of function call memory is allocated for timer device and it is
 * registered to the framework ready to be proved by the driver.
 */
static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
{
	int id;
	int ret = 0;
	char *name = "omap_timer";
	struct dmtimer_platform_data *pdata;
	struct platform_device *pdev;
	struct omap_timer_capability_dev_attr *timer_dev_attr;

	pr_debug("%s: %s\n", __func__, oh->name);

	/* on secure device, do not register secure timer */
	timer_dev_attr = oh->dev_attr;
	if (omap_type() != OMAP2_DEVICE_TYPE_GP && timer_dev_attr)
		if (timer_dev_attr->timer_capability == OMAP_TIMER_SECURE)
			return ret;

	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
		pr_err("%s: No memory for [%s]\n", __func__, oh->name);
		return -ENOMEM;
	}

	/*
	 * Extract the IDs from name field in hwmod database
	 * and use the same for constructing ids' for the
	 * timer devices. In a way, we are avoiding usage of
	 * static variable witin the function to do the same.
	 * CAUTION: We have to be careful and make sure the
	 * name in hwmod database does not change in which case
	 * we might either make corresponding change here or
	 * switch back static variable mechanism.
	 */
	sscanf(oh->name, "timer%2d", &id);

	if (timer_dev_attr)
		pdata->timer_capability = timer_dev_attr->timer_capability;

	pdata->timer_errata = omap_dm_timer_get_errata();
	pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;

	pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata));

	if (IS_ERR(pdev)) {
		pr_err("%s: Can't build omap_device for %s: %s.\n",
			__func__, name, oh->name);
		ret = -EINVAL;
	}

	kfree(pdata);

	return ret;
}

/**
 * omap2_dm_timer_init - top level regular device initialization
 *
 * Uses dedicated hwmod api to parse through hwmod database for
 * given class name and then build and register the timer device.
 */
static int __init omap2_dm_timer_init(void)
{
	int ret;

	/* If dtb is there, the devices will be created dynamically */
	if (of_have_populated_dt())
		return -ENODEV;

	ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
	if (unlikely(ret)) {
		pr_err("%s: device registration failed.\n", __func__);
		return -EINVAL;
	}

	return 0;
}
omap_arch_initcall(omap2_dm_timer_init);

/**
 * omap2_override_clocksource - clocksource override with user configuration
 *
 * Allows user to override default clocksource, using kernel parameter
 *   clocksource="gp_timer"	(For all OMAP2PLUS architectures)
 *
 * Note that, here we are using same standard kernel parameter "clocksource=",
 * and not introducing any OMAP specific interface.
 */
static int __init omap2_override_clocksource(char *str)
{
	if (!str)
		return 0;
	/*
	 * For OMAP architecture, we only have two options
	 *    - sync_32k (default)
	 *    - gp_timer (sys_clk based)
	 */
	if (!strcmp(str, "gp_timer"))
		use_gptimer_clksrc = true;

	return 0;
}
early_param("clocksource", omap2_override_clocksource);