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 /* Clockevent hwmod for am335x and am437x suspend */
72 static struct omap_hwmod
*clockevent_gpt_hwmod
;
74 #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
75 static unsigned long arch_timer_freq
;
77 void set_cntfreq(void)
79 omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX
, arch_timer_freq
);
83 static irqreturn_t
omap2_gp_timer_interrupt(int irq
, void *dev_id
)
85 struct clock_event_device
*evt
= &clockevent_gpt
;
87 __omap_dm_timer_write_status(&clkev
, OMAP_TIMER_INT_OVERFLOW
);
89 evt
->event_handler(evt
);
93 static struct irqaction omap2_gp_timer_irq
= {
95 .flags
= IRQF_TIMER
| IRQF_IRQPOLL
,
96 .handler
= omap2_gp_timer_interrupt
,
99 static int omap2_gp_timer_set_next_event(unsigned long cycles
,
100 struct clock_event_device
*evt
)
102 __omap_dm_timer_load_start(&clkev
, OMAP_TIMER_CTRL_ST
,
103 0xffffffff - cycles
, OMAP_TIMER_POSTED
);
108 static int omap2_gp_timer_shutdown(struct clock_event_device
*evt
)
110 __omap_dm_timer_stop(&clkev
, OMAP_TIMER_POSTED
, clkev
.rate
);
114 static int omap2_gp_timer_set_periodic(struct clock_event_device
*evt
)
118 __omap_dm_timer_stop(&clkev
, OMAP_TIMER_POSTED
, clkev
.rate
);
120 period
= clkev
.rate
/ HZ
;
122 /* Looks like we need to first set the load value separately */
123 __omap_dm_timer_write(&clkev
, OMAP_TIMER_LOAD_REG
, 0xffffffff - period
,
125 __omap_dm_timer_load_start(&clkev
,
126 OMAP_TIMER_CTRL_AR
| OMAP_TIMER_CTRL_ST
,
127 0xffffffff - period
, OMAP_TIMER_POSTED
);
131 static void omap_clkevt_idle(struct clock_event_device
*unused
)
133 if (!clockevent_gpt_hwmod
)
136 omap_hwmod_idle(clockevent_gpt_hwmod
);
139 static void omap_clkevt_unidle(struct clock_event_device
*unused
)
141 if (!clockevent_gpt_hwmod
)
144 omap_hwmod_enable(clockevent_gpt_hwmod
);
145 __omap_dm_timer_int_enable(&clkev
, OMAP_TIMER_INT_OVERFLOW
);
148 static struct clock_event_device clockevent_gpt
= {
149 .features
= CLOCK_EVT_FEAT_PERIODIC
|
150 CLOCK_EVT_FEAT_ONESHOT
,
152 .set_next_event
= omap2_gp_timer_set_next_event
,
153 .set_state_shutdown
= omap2_gp_timer_shutdown
,
154 .set_state_periodic
= omap2_gp_timer_set_periodic
,
155 .set_state_oneshot
= omap2_gp_timer_shutdown
,
156 .tick_resume
= omap2_gp_timer_shutdown
,
159 static struct property device_disabled
= {
161 .length
= sizeof("disabled"),
165 static const struct of_device_id omap_timer_match
[] __initconst
= {
166 { .compatible
= "ti,omap2420-timer", },
167 { .compatible
= "ti,omap3430-timer", },
168 { .compatible
= "ti,omap4430-timer", },
169 { .compatible
= "ti,omap5430-timer", },
170 { .compatible
= "ti,dm814-timer", },
171 { .compatible
= "ti,dm816-timer", },
172 { .compatible
= "ti,am335x-timer", },
173 { .compatible
= "ti,am335x-timer-1ms", },
178 * omap_get_timer_dt - get a timer using device-tree
179 * @match - device-tree match structure for matching a device type
180 * @property - optional timer property to match
182 * Helper function to get a timer during early boot using device-tree for use
183 * as kernel system timer. Optionally, the property argument can be used to
184 * select a timer with a specific property. Once a timer is found then mark
185 * the timer node in device-tree as disabled, to prevent the kernel from
186 * registering this timer as a platform device and so no one else can use it.
188 static struct device_node
* __init
omap_get_timer_dt(const struct of_device_id
*match
,
189 const char *property
)
191 struct device_node
*np
;
193 for_each_matching_node(np
, match
) {
194 if (!of_device_is_available(np
))
197 if (property
&& !of_get_property(np
, property
, NULL
))
200 if (!property
&& (of_get_property(np
, "ti,timer-alwon", NULL
) ||
201 of_get_property(np
, "ti,timer-dsp", NULL
) ||
202 of_get_property(np
, "ti,timer-pwm", NULL
) ||
203 of_get_property(np
, "ti,timer-secure", NULL
)))
206 if (!of_device_is_compatible(np
, "ti,omap-counter32k"))
207 of_add_property(np
, &device_disabled
);
215 * omap_dmtimer_init - initialisation function when device tree is used
217 * For secure OMAP3/DRA7xx devices, timers with device type "timer-secure"
218 * cannot be used by the kernel as they are reserved. Therefore, to prevent the
219 * kernel registering these devices remove them dynamically from the device
222 static void __init
omap_dmtimer_init(void)
224 struct device_node
*np
;
226 if (!cpu_is_omap34xx() && !soc_is_dra7xx())
229 /* If we are a secure device, remove any secure timer nodes */
230 if ((omap_type() != OMAP2_DEVICE_TYPE_GP
)) {
231 np
= omap_get_timer_dt(omap_timer_match
, "ti,timer-secure");
237 * omap_dm_timer_get_errata - get errata flags for a timer
239 * Get the timer errata flags that are specific to the OMAP device being used.
241 static u32 __init
omap_dm_timer_get_errata(void)
243 if (cpu_is_omap24xx())
246 return OMAP_TIMER_ERRATA_I103_I767
;
249 static int __init
omap_dm_timer_init_one(struct omap_dm_timer
*timer
,
250 const char *fck_source
,
251 const char *property
,
252 const char **timer_name
,
255 const char *oh_name
= NULL
;
256 struct device_node
*np
;
257 struct omap_hwmod
*oh
;
261 np
= omap_get_timer_dt(omap_timer_match
, property
);
265 of_property_read_string_index(np
, "ti,hwmods", 0, &oh_name
);
269 timer
->irq
= irq_of_parse_and_map(np
, 0);
273 timer
->io_base
= of_iomap(np
, 0);
275 timer
->fclk
= of_clk_get_by_name(np
, "fck");
279 oh
= omap_hwmod_lookup(oh_name
);
283 *timer_name
= oh
->name
;
288 omap_hwmod_setup_one(oh_name
);
290 /* After the dmtimer is using hwmod these clocks won't be needed */
291 if (IS_ERR_OR_NULL(timer
->fclk
))
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 WARN(clk_set_parent(timer
->fclk
, src
) < 0,
301 "Cannot set timer parent clock, no PLL clock driver?");
305 omap_hwmod_enable(oh
);
306 __omap_dm_timer_init_regs(timer
);
309 __omap_dm_timer_enable_posted(timer
);
311 /* Check that the intended posted configuration matches the actual */
312 if (posted
!= timer
->posted
)
315 timer
->rate
= clk_get_rate(timer
->fclk
);
321 #if !defined(CONFIG_SMP) && defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
322 void tick_broadcast(const struct cpumask
*mask
)
327 static void __init
omap2_gp_clockevent_init(int gptimer_id
,
328 const char *fck_source
,
329 const char *property
)
333 clkev
.id
= gptimer_id
;
334 clkev
.errata
= omap_dm_timer_get_errata();
337 * For clock-event timers we never read the timer counter and
338 * so we are not impacted by errata i103 and i767. Therefore,
339 * we can safely ignore this errata for clock-event timers.
341 __omap_dm_timer_override_errata(&clkev
, OMAP_TIMER_ERRATA_I103_I767
);
343 res
= omap_dm_timer_init_one(&clkev
, fck_source
, property
,
344 &clockevent_gpt
.name
, OMAP_TIMER_POSTED
);
347 omap2_gp_timer_irq
.dev_id
= &clkev
;
348 setup_irq(clkev
.irq
, &omap2_gp_timer_irq
);
350 __omap_dm_timer_int_enable(&clkev
, OMAP_TIMER_INT_OVERFLOW
);
352 clockevent_gpt
.cpumask
= cpu_possible_mask
;
353 clockevent_gpt
.irq
= omap_dm_timer_get_irq(&clkev
);
354 clockevents_config_and_register(&clockevent_gpt
, clkev
.rate
,
355 3, /* Timer internal resynch latency */
358 if (soc_is_am33xx() || soc_is_am43xx()) {
359 clockevent_gpt
.suspend
= omap_clkevt_idle
;
360 clockevent_gpt
.resume
= omap_clkevt_unidle
;
362 clockevent_gpt_hwmod
=
363 omap_hwmod_lookup(clockevent_gpt
.name
);
366 pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt
.name
,
370 /* Clocksource code */
371 static struct omap_dm_timer clksrc
;
372 static bool use_gptimer_clksrc __initdata
;
377 static u64
clocksource_read_cycles(struct clocksource
*cs
)
379 return (u64
)__omap_dm_timer_read_counter(&clksrc
,
380 OMAP_TIMER_NONPOSTED
);
383 static struct clocksource clocksource_gpt
= {
385 .read
= clocksource_read_cycles
,
386 .mask
= CLOCKSOURCE_MASK(32),
387 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
390 static u64 notrace
dmtimer_read_sched_clock(void)
393 return __omap_dm_timer_read_counter(&clksrc
,
394 OMAP_TIMER_NONPOSTED
);
399 static const struct of_device_id omap_counter_match
[] __initconst
= {
400 { .compatible
= "ti,omap-counter32k", },
404 /* Setup free-running counter for clocksource */
405 static int __init __maybe_unused
omap2_sync32k_clocksource_init(void)
408 struct device_node
*np
= NULL
;
409 struct omap_hwmod
*oh
;
410 const char *oh_name
= "counter_32k";
413 * See if the 32kHz counter is supported.
415 np
= omap_get_timer_dt(omap_counter_match
, NULL
);
419 of_property_read_string_index(np
, "ti,hwmods", 0, &oh_name
);
424 * First check hwmod data is available for sync32k counter
426 oh
= omap_hwmod_lookup(oh_name
);
427 if (!oh
|| oh
->slaves_cnt
== 0)
430 omap_hwmod_setup_one(oh_name
);
432 ret
= omap_hwmod_enable(oh
);
434 pr_warn("%s: failed to enable counter_32k module (%d)\n",
442 static void __init
omap2_gptimer_clocksource_init(int gptimer_id
,
443 const char *fck_source
,
444 const char *property
)
448 clksrc
.id
= gptimer_id
;
449 clksrc
.errata
= omap_dm_timer_get_errata();
451 res
= omap_dm_timer_init_one(&clksrc
, fck_source
, property
,
452 &clocksource_gpt
.name
,
453 OMAP_TIMER_NONPOSTED
);
456 __omap_dm_timer_load_start(&clksrc
,
457 OMAP_TIMER_CTRL_ST
| OMAP_TIMER_CTRL_AR
, 0,
458 OMAP_TIMER_NONPOSTED
);
459 sched_clock_register(dmtimer_read_sched_clock
, 32, clksrc
.rate
);
461 if (clocksource_register_hz(&clocksource_gpt
, clksrc
.rate
))
462 pr_err("Could not register clocksource %s\n",
463 clocksource_gpt
.name
);
465 pr_info("OMAP clocksource: %s at %lu Hz\n",
466 clocksource_gpt
.name
, clksrc
.rate
);
469 static void __init
__omap_sync32k_timer_init(int clkev_nr
, const char *clkev_src
,
470 const char *clkev_prop
, int clksrc_nr
, const char *clksrc_src
,
471 const char *clksrc_prop
, bool gptimer
)
475 omap2_gp_clockevent_init(clkev_nr
, clkev_src
, clkev_prop
);
477 /* Enable the use of clocksource="gp_timer" kernel parameter */
478 if (use_gptimer_clksrc
|| gptimer
)
479 omap2_gptimer_clocksource_init(clksrc_nr
, clksrc_src
,
482 omap2_sync32k_clocksource_init();
485 void __init
omap_init_time(void)
487 __omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon",
488 2, "timer_sys_ck", NULL
, false);
493 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX)
494 void __init
omap3_secure_sync32k_timer_init(void)
496 __omap_sync32k_timer_init(12, "secure_32k_fck", "ti,timer-secure",
497 2, "timer_sys_ck", NULL
, false);
501 #endif /* CONFIG_ARCH_OMAP3 */
503 #if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) || \
504 defined(CONFIG_SOC_AM43XX)
505 void __init
omap3_gptimer_timer_init(void)
507 __omap_sync32k_timer_init(2, "timer_sys_ck", NULL
,
508 1, "timer_sys_ck", "ti,timer-alwon", true);
509 if (of_have_populated_dt())
514 #if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) || \
515 defined(CONFIG_SOC_DRA7XX)
516 static void __init
omap4_sync32k_timer_init(void)
518 __omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon",
519 2, "sys_clkin_ck", NULL
, false);
522 void __init
omap4_local_timer_init(void)
524 omap4_sync32k_timer_init();
529 #if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
532 * The realtime counter also called master counter, is a free-running
533 * counter, which is related to real time. It produces the count used
534 * by the CPU local timer peripherals in the MPU cluster. The timer counts
535 * at a rate of 6.144 MHz. Because the device operates on different clocks
536 * in different power modes, the master counter shifts operation between
537 * clocks, adjusting the increment per clock in hardware accordingly to
538 * maintain a constant count rate.
540 static void __init
realtime_counter_init(void)
542 #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
544 static struct clk
*sys_clk
;
547 unsigned long long num
, den
;
549 base
= ioremap(REALTIME_COUNTER_BASE
, SZ_32
);
551 pr_err("%s: ioremap failed\n", __func__
);
554 sys_clk
= clk_get(NULL
, "sys_clkin");
555 if (IS_ERR(sys_clk
)) {
556 pr_err("%s: failed to get system clock handle\n", __func__
);
561 rate
= clk_get_rate(sys_clk
);
563 if (soc_is_dra7xx()) {
565 * Errata i856 says the 32.768KHz crystal does not start at
566 * power on, so the CPU falls back to an emulated 32KHz clock
567 * based on sysclk / 610 instead. This causes the master counter
568 * frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
569 * (OR sysclk * 75 / 244)
571 * This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
572 * Of course any board built without a populated 32.768KHz
573 * crystal would also need this fix even if the CPU is fixed
576 * Either case can be detected by using the two speedselect bits
577 * If they are not 0, then the 32.768KHz clock driving the
578 * coarse counter that corrects the fine counter every time it
579 * ticks is actually rate/610 rather than 32.768KHz and we
580 * should compensate to avoid the 570ppm (at 20MHz, much worse
581 * at other rates) too fast system time.
583 reg
= omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP
);
584 if (reg
& DRA7_SPEEDSELECT_MASK
) {
591 /* Numerator/denumerator values refer TRM Realtime Counter section */
619 /* Program it for 38.4 MHz */
626 /* Program numerator and denumerator registers */
627 reg
= readl_relaxed(base
+ INCREMENTER_NUMERATOR_OFFSET
) &
628 NUMERATOR_DENUMERATOR_MASK
;
630 writel_relaxed(reg
, base
+ INCREMENTER_NUMERATOR_OFFSET
);
632 reg
= readl_relaxed(base
+ INCREMENTER_DENUMERATOR_RELOAD_OFFSET
) &
633 NUMERATOR_DENUMERATOR_MASK
;
635 writel_relaxed(reg
, base
+ INCREMENTER_DENUMERATOR_RELOAD_OFFSET
);
637 arch_timer_freq
= DIV_ROUND_UP_ULL(rate
* num
, den
);
644 void __init
omap5_realtime_timer_init(void)
646 omap4_sync32k_timer_init();
647 realtime_counter_init();
651 #endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
654 * omap2_override_clocksource - clocksource override with user configuration
656 * Allows user to override default clocksource, using kernel parameter
657 * clocksource="gp_timer" (For all OMAP2PLUS architectures)
659 * Note that, here we are using same standard kernel parameter "clocksource=",
660 * and not introducing any OMAP specific interface.
662 static int __init
omap2_override_clocksource(char *str
)
667 * For OMAP architecture, we only have two options
668 * - sync_32k (default)
669 * - gp_timer (sys_clk based)
671 if (!strcmp(str
, "gp_timer"))
672 use_gptimer_clksrc
= true;
676 early_param("clocksource", omap2_override_clocksource
);