1 /* time.c: UltraSparc timer and TOD clock support.
3 * Copyright (C) 1997, 2008 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
6 * Based largely on code which is:
8 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
11 #include <linux/errno.h>
12 #include <linux/module.h>
13 #include <linux/sched.h>
14 #include <linux/smp_lock.h>
15 #include <linux/kernel.h>
16 #include <linux/param.h>
17 #include <linux/string.h>
19 #include <linux/interrupt.h>
20 #include <linux/time.h>
21 #include <linux/timex.h>
22 #include <linux/init.h>
23 #include <linux/ioport.h>
24 #include <linux/mc146818rtc.h>
25 #include <linux/delay.h>
26 #include <linux/profile.h>
27 #include <linux/bcd.h>
28 #include <linux/jiffies.h>
29 #include <linux/cpufreq.h>
30 #include <linux/percpu.h>
31 #include <linux/miscdevice.h>
32 #include <linux/rtc.h>
33 #include <linux/rtc/m48t59.h>
34 #include <linux/kernel_stat.h>
35 #include <linux/clockchips.h>
36 #include <linux/clocksource.h>
37 #include <linux/of_device.h>
38 #include <linux/platform_device.h>
40 #include <asm/oplib.h>
41 #include <asm/timer.h>
45 #include <asm/starfire.h>
47 #include <asm/sections.h>
48 #include <asm/cpudata.h>
49 #include <asm/uaccess.h>
50 #include <asm/irq_regs.h>
54 DEFINE_SPINLOCK(rtc_lock);
56 #define TICK_PRIV_BIT (1UL << 63)
57 #define TICKCMP_IRQ_BIT (1UL << 63)
60 unsigned long profile_pc(struct pt_regs *regs)
62 unsigned long pc = instruction_pointer(regs);
64 if (in_lock_functions(pc))
65 return regs->u_regs[UREG_RETPC];
68 EXPORT_SYMBOL(profile_pc);
71 static void tick_disable_protection(void)
73 /* Set things up so user can access tick register for profiling
74 * purposes. Also workaround BB_ERRATA_1 by doing a dummy
75 * read back of %tick after writing it.
81 "1: rd %%tick, %%g2\n"
82 " add %%g2, 6, %%g2\n"
83 " andn %%g2, %0, %%g2\n"
84 " wrpr %%g2, 0, %%tick\n"
91 static void tick_disable_irq(void)
97 "1: wr %0, 0x0, %%tick_cmpr\n"
98 " rd %%tick_cmpr, %%g0"
100 : "r" (TICKCMP_IRQ_BIT));
103 static void tick_init_tick(void)
105 tick_disable_protection();
109 static unsigned long long tick_get_tick(void)
113 __asm__ __volatile__("rd %%tick, %0\n\t"
117 return ret & ~TICK_PRIV_BIT;
120 static int tick_add_compare(unsigned long adj)
122 unsigned long orig_tick, new_tick, new_compare;
124 __asm__ __volatile__("rd %%tick, %0"
127 orig_tick &= ~TICKCMP_IRQ_BIT;
129 /* Workaround for Spitfire Errata (#54 I think??), I discovered
130 * this via Sun BugID 4008234, mentioned in Solaris-2.5.1 patch
133 * On Blackbird writes to %tick_cmpr can fail, the
134 * workaround seems to be to execute the wr instruction
135 * at the start of an I-cache line, and perform a dummy
136 * read back from %tick_cmpr right after writing to it. -DaveM
138 __asm__ __volatile__("ba,pt %%xcc, 1f\n\t"
139 " add %1, %2, %0\n\t"
142 "wr %0, 0, %%tick_cmpr\n\t"
143 "rd %%tick_cmpr, %%g0\n\t"
145 : "r" (orig_tick), "r" (adj));
147 __asm__ __volatile__("rd %%tick, %0"
149 new_tick &= ~TICKCMP_IRQ_BIT;
151 return ((long)(new_tick - (orig_tick+adj))) > 0L;
154 static unsigned long tick_add_tick(unsigned long adj)
156 unsigned long new_tick;
158 /* Also need to handle Blackbird bug here too. */
159 __asm__ __volatile__("rd %%tick, %0\n\t"
161 "wrpr %0, 0, %%tick\n\t"
168 static struct sparc64_tick_ops tick_operations __read_mostly = {
170 .init_tick = tick_init_tick,
171 .disable_irq = tick_disable_irq,
172 .get_tick = tick_get_tick,
173 .add_tick = tick_add_tick,
174 .add_compare = tick_add_compare,
175 .softint_mask = 1UL << 0,
178 struct sparc64_tick_ops *tick_ops __read_mostly = &tick_operations;
179 EXPORT_SYMBOL(tick_ops);
181 static void stick_disable_irq(void)
183 __asm__ __volatile__(
184 "wr %0, 0x0, %%asr25"
186 : "r" (TICKCMP_IRQ_BIT));
189 static void stick_init_tick(void)
191 /* Writes to the %tick and %stick register are not
192 * allowed on sun4v. The Hypervisor controls that
195 if (tlb_type != hypervisor) {
196 tick_disable_protection();
199 /* Let the user get at STICK too. */
200 __asm__ __volatile__(
201 " rd %%asr24, %%g2\n"
202 " andn %%g2, %0, %%g2\n"
203 " wr %%g2, 0, %%asr24"
205 : "r" (TICK_PRIV_BIT)
212 static unsigned long long stick_get_tick(void)
216 __asm__ __volatile__("rd %%asr24, %0"
219 return ret & ~TICK_PRIV_BIT;
222 static unsigned long stick_add_tick(unsigned long adj)
224 unsigned long new_tick;
226 __asm__ __volatile__("rd %%asr24, %0\n\t"
228 "wr %0, 0, %%asr24\n\t"
235 static int stick_add_compare(unsigned long adj)
237 unsigned long orig_tick, new_tick;
239 __asm__ __volatile__("rd %%asr24, %0"
241 orig_tick &= ~TICKCMP_IRQ_BIT;
243 __asm__ __volatile__("wr %0, 0, %%asr25"
245 : "r" (orig_tick + adj));
247 __asm__ __volatile__("rd %%asr24, %0"
249 new_tick &= ~TICKCMP_IRQ_BIT;
251 return ((long)(new_tick - (orig_tick+adj))) > 0L;
254 static struct sparc64_tick_ops stick_operations __read_mostly = {
256 .init_tick = stick_init_tick,
257 .disable_irq = stick_disable_irq,
258 .get_tick = stick_get_tick,
259 .add_tick = stick_add_tick,
260 .add_compare = stick_add_compare,
261 .softint_mask = 1UL << 16,
264 /* On Hummingbird the STICK/STICK_CMPR register is implemented
265 * in I/O space. There are two 64-bit registers each, the
266 * first holds the low 32-bits of the value and the second holds
269 * Since STICK is constantly updating, we have to access it carefully.
271 * The sequence we use to read is:
274 * 3) read high again, if it rolled re-read both low and high again.
276 * Writing STICK safely is also tricky:
277 * 1) write low to zero
281 #define HBIRD_STICKCMP_ADDR 0x1fe0000f060UL
282 #define HBIRD_STICK_ADDR 0x1fe0000f070UL
284 static unsigned long __hbird_read_stick(void)
286 unsigned long ret, tmp1, tmp2, tmp3;
287 unsigned long addr = HBIRD_STICK_ADDR+8;
289 __asm__ __volatile__("ldxa [%1] %5, %2\n"
291 "sub %1, 0x8, %1\n\t"
292 "ldxa [%1] %5, %3\n\t"
293 "add %1, 0x8, %1\n\t"
294 "ldxa [%1] %5, %4\n\t"
296 "bne,a,pn %%xcc, 1b\n\t"
298 "sllx %4, 32, %4\n\t"
300 : "=&r" (ret), "=&r" (addr),
301 "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
302 : "i" (ASI_PHYS_BYPASS_EC_E), "1" (addr));
307 static void __hbird_write_stick(unsigned long val)
309 unsigned long low = (val & 0xffffffffUL);
310 unsigned long high = (val >> 32UL);
311 unsigned long addr = HBIRD_STICK_ADDR;
313 __asm__ __volatile__("stxa %%g0, [%0] %4\n\t"
314 "add %0, 0x8, %0\n\t"
315 "stxa %3, [%0] %4\n\t"
316 "sub %0, 0x8, %0\n\t"
319 : "0" (addr), "r" (low), "r" (high),
320 "i" (ASI_PHYS_BYPASS_EC_E));
323 static void __hbird_write_compare(unsigned long val)
325 unsigned long low = (val & 0xffffffffUL);
326 unsigned long high = (val >> 32UL);
327 unsigned long addr = HBIRD_STICKCMP_ADDR + 0x8UL;
329 __asm__ __volatile__("stxa %3, [%0] %4\n\t"
330 "sub %0, 0x8, %0\n\t"
333 : "0" (addr), "r" (low), "r" (high),
334 "i" (ASI_PHYS_BYPASS_EC_E));
337 static void hbtick_disable_irq(void)
339 __hbird_write_compare(TICKCMP_IRQ_BIT);
342 static void hbtick_init_tick(void)
344 tick_disable_protection();
346 /* XXX This seems to be necessary to 'jumpstart' Hummingbird
347 * XXX into actually sending STICK interrupts. I think because
348 * XXX of how we store %tick_cmpr in head.S this somehow resets the
349 * XXX {TICK + STICK} interrupt mux. -DaveM
351 __hbird_write_stick(__hbird_read_stick());
353 hbtick_disable_irq();
356 static unsigned long long hbtick_get_tick(void)
358 return __hbird_read_stick() & ~TICK_PRIV_BIT;
361 static unsigned long hbtick_add_tick(unsigned long adj)
365 val = __hbird_read_stick() + adj;
366 __hbird_write_stick(val);
371 static int hbtick_add_compare(unsigned long adj)
373 unsigned long val = __hbird_read_stick();
376 val &= ~TICKCMP_IRQ_BIT;
378 __hbird_write_compare(val);
380 val2 = __hbird_read_stick() & ~TICKCMP_IRQ_BIT;
382 return ((long)(val2 - val)) > 0L;
385 static struct sparc64_tick_ops hbtick_operations __read_mostly = {
387 .init_tick = hbtick_init_tick,
388 .disable_irq = hbtick_disable_irq,
389 .get_tick = hbtick_get_tick,
390 .add_tick = hbtick_add_tick,
391 .add_compare = hbtick_add_compare,
392 .softint_mask = 1UL << 0,
395 static unsigned long timer_ticks_per_nsec_quotient __read_mostly;
397 int update_persistent_clock(struct timespec now)
399 struct rtc_device *rtc = rtc_class_open("rtc0");
403 err = rtc_set_mmss(rtc, now.tv_sec);
404 rtc_class_close(rtc);
410 unsigned long cmos_regs;
411 EXPORT_SYMBOL(cmos_regs);
413 static struct resource rtc_cmos_resource;
415 static struct platform_device rtc_cmos_device = {
418 .resource = &rtc_cmos_resource,
422 static int __devinit rtc_probe(struct of_device *op, const struct of_device_id *match)
426 printk(KERN_INFO "%s: RTC regs at 0x%llx\n",
427 op->node->full_name, op->resource[0].start);
429 /* The CMOS RTC driver only accepts IORESOURCE_IO, so cons
430 * up a fake resource so that the probe works for all cases.
431 * When the RTC is behind an ISA bus it will have IORESOURCE_IO
432 * already, whereas when it's behind EBUS is will be IORESOURCE_MEM.
435 r = &rtc_cmos_resource;
436 r->flags = IORESOURCE_IO;
437 r->name = op->resource[0].name;
438 r->start = op->resource[0].start;
439 r->end = op->resource[0].end;
441 cmos_regs = op->resource[0].start;
442 return platform_device_register(&rtc_cmos_device);
445 static struct of_device_id __initdata rtc_match[] = {
448 .compatible = "m5819",
452 .compatible = "isa-m5819p",
456 .compatible = "isa-m5823p",
460 .compatible = "ds1287",
465 static struct of_platform_driver rtc_driver = {
466 .match_table = rtc_match,
473 static struct platform_device rtc_bq4802_device = {
474 .name = "rtc-bq4802",
479 static int __devinit bq4802_probe(struct of_device *op, const struct of_device_id *match)
482 printk(KERN_INFO "%s: BQ4802 regs at 0x%llx\n",
483 op->node->full_name, op->resource[0].start);
485 rtc_bq4802_device.resource = &op->resource[0];
486 return platform_device_register(&rtc_bq4802_device);
489 static struct of_device_id __initdata bq4802_match[] = {
492 .compatible = "bq4802",
497 static struct of_platform_driver bq4802_driver = {
498 .match_table = bq4802_match,
499 .probe = bq4802_probe,
505 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
507 struct platform_device *pdev = to_platform_device(dev);
508 void __iomem *regs = (void __iomem *) pdev->resource[0].start;
510 return readb(regs + ofs);
513 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
515 struct platform_device *pdev = to_platform_device(dev);
516 void __iomem *regs = (void __iomem *) pdev->resource[0].start;
518 writeb(val, regs + ofs);
521 static struct m48t59_plat_data m48t59_data = {
522 .read_byte = mostek_read_byte,
523 .write_byte = mostek_write_byte,
526 static struct platform_device m48t59_rtc = {
527 .name = "rtc-m48t59",
531 .platform_data = &m48t59_data,
535 static int __devinit mostek_probe(struct of_device *op, const struct of_device_id *match)
537 struct device_node *dp = op->node;
539 /* On an Enterprise system there can be multiple mostek clocks.
540 * We should only match the one that is on the central FHC bus.
542 if (!strcmp(dp->parent->name, "fhc") &&
543 strcmp(dp->parent->parent->name, "central") != 0)
546 printk(KERN_INFO "%s: Mostek regs at 0x%llx\n",
547 dp->full_name, op->resource[0].start);
549 m48t59_rtc.resource = &op->resource[0];
550 return platform_device_register(&m48t59_rtc);
553 static struct of_device_id __initdata mostek_match[] = {
560 static struct of_platform_driver mostek_driver = {
561 .match_table = mostek_match,
562 .probe = mostek_probe,
568 static struct platform_device rtc_sun4v_device = {
573 static struct platform_device rtc_starfire_device = {
574 .name = "rtc-starfire",
578 static int __init clock_init(void)
580 if (this_is_starfire)
581 return platform_device_register(&rtc_starfire_device);
583 if (tlb_type == hypervisor)
584 return platform_device_register(&rtc_sun4v_device);
586 (void) of_register_driver(&rtc_driver, &of_platform_bus_type);
587 (void) of_register_driver(&mostek_driver, &of_platform_bus_type);
588 (void) of_register_driver(&bq4802_driver, &of_platform_bus_type);
593 /* Must be after subsys_initcall() so that busses are probed. Must
594 * be before device_initcall() because things like the RTC driver
595 * need to see the clock registers.
597 fs_initcall(clock_init);
599 /* This is gets the master TICK_INT timer going. */
600 static unsigned long sparc64_init_timers(void)
602 struct device_node *dp;
605 dp = of_find_node_by_path("/");
606 if (tlb_type == spitfire) {
607 unsigned long ver, manuf, impl;
609 __asm__ __volatile__ ("rdpr %%ver, %0"
611 manuf = ((ver >> 48) & 0xffff);
612 impl = ((ver >> 32) & 0xffff);
613 if (manuf == 0x17 && impl == 0x13) {
614 /* Hummingbird, aka Ultra-IIe */
615 tick_ops = &hbtick_operations;
616 freq = of_getintprop_default(dp, "stick-frequency", 0);
618 tick_ops = &tick_operations;
619 freq = local_cpu_data().clock_tick;
622 tick_ops = &stick_operations;
623 freq = of_getintprop_default(dp, "stick-frequency", 0);
630 unsigned long clock_tick_ref;
631 unsigned int ref_freq;
633 static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };
635 unsigned long sparc64_get_clock_tick(unsigned int cpu)
637 struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
639 if (ft->clock_tick_ref)
640 return ft->clock_tick_ref;
641 return cpu_data(cpu).clock_tick;
643 EXPORT_SYMBOL(sparc64_get_clock_tick);
645 #ifdef CONFIG_CPU_FREQ
647 static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
650 struct cpufreq_freqs *freq = data;
651 unsigned int cpu = freq->cpu;
652 struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
655 ft->ref_freq = freq->old;
656 ft->clock_tick_ref = cpu_data(cpu).clock_tick;
658 if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
659 (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
660 (val == CPUFREQ_RESUMECHANGE)) {
661 cpu_data(cpu).clock_tick =
662 cpufreq_scale(ft->clock_tick_ref,
670 static struct notifier_block sparc64_cpufreq_notifier_block = {
671 .notifier_call = sparc64_cpufreq_notifier
674 static int __init register_sparc64_cpufreq_notifier(void)
677 cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
678 CPUFREQ_TRANSITION_NOTIFIER);
682 core_initcall(register_sparc64_cpufreq_notifier);
684 #endif /* CONFIG_CPU_FREQ */
686 static int sparc64_next_event(unsigned long delta,
687 struct clock_event_device *evt)
689 return tick_ops->add_compare(delta) ? -ETIME : 0;
692 static void sparc64_timer_setup(enum clock_event_mode mode,
693 struct clock_event_device *evt)
696 case CLOCK_EVT_MODE_ONESHOT:
697 case CLOCK_EVT_MODE_RESUME:
700 case CLOCK_EVT_MODE_SHUTDOWN:
701 tick_ops->disable_irq();
704 case CLOCK_EVT_MODE_PERIODIC:
705 case CLOCK_EVT_MODE_UNUSED:
711 static struct clock_event_device sparc64_clockevent = {
712 .features = CLOCK_EVT_FEAT_ONESHOT,
713 .set_mode = sparc64_timer_setup,
714 .set_next_event = sparc64_next_event,
719 static DEFINE_PER_CPU(struct clock_event_device, sparc64_events);
721 void timer_interrupt(int irq, struct pt_regs *regs)
723 struct pt_regs *old_regs = set_irq_regs(regs);
724 unsigned long tick_mask = tick_ops->softint_mask;
725 int cpu = smp_processor_id();
726 struct clock_event_device *evt = &per_cpu(sparc64_events, cpu);
728 clear_softint(tick_mask);
732 kstat_incr_irqs_this_cpu(0, irq_to_desc(0));
734 if (unlikely(!evt->event_handler)) {
736 "Spurious SPARC64 timer interrupt on cpu %d\n", cpu);
738 evt->event_handler(evt);
742 set_irq_regs(old_regs);
745 void __devinit setup_sparc64_timer(void)
747 struct clock_event_device *sevt;
748 unsigned long pstate;
750 /* Guarantee that the following sequences execute
753 __asm__ __volatile__("rdpr %%pstate, %0\n\t"
754 "wrpr %0, %1, %%pstate"
758 tick_ops->init_tick();
760 /* Restore PSTATE_IE. */
761 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
765 sevt = &__get_cpu_var(sparc64_events);
767 memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
768 sevt->cpumask = cpumask_of(smp_processor_id());
770 clockevents_register_device(sevt);
773 #define SPARC64_NSEC_PER_CYC_SHIFT 10UL
775 static struct clocksource clocksource_tick = {
777 .mask = CLOCKSOURCE_MASK(64),
779 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
782 static void __init setup_clockevent_multiplier(unsigned long hz)
784 unsigned long mult, shift = 32;
787 mult = div_sc(hz, NSEC_PER_SEC, shift);
788 if (mult && (mult >> 32UL) == 0UL)
794 sparc64_clockevent.shift = shift;
795 sparc64_clockevent.mult = mult;
798 static unsigned long tb_ticks_per_usec __read_mostly;
800 void __delay(unsigned long loops)
802 unsigned long bclock, now;
804 bclock = tick_ops->get_tick();
806 now = tick_ops->get_tick();
807 } while ((now-bclock) < loops);
809 EXPORT_SYMBOL(__delay);
811 void udelay(unsigned long usecs)
813 __delay(tb_ticks_per_usec * usecs);
815 EXPORT_SYMBOL(udelay);
817 static cycle_t clocksource_tick_read(struct clocksource *cs)
819 return tick_ops->get_tick();
822 void __init time_init(void)
824 unsigned long freq = sparc64_init_timers();
826 tb_ticks_per_usec = freq / USEC_PER_SEC;
828 timer_ticks_per_nsec_quotient =
829 clocksource_hz2mult(freq, SPARC64_NSEC_PER_CYC_SHIFT);
831 clocksource_tick.name = tick_ops->name;
832 clocksource_tick.mult =
833 clocksource_hz2mult(freq,
834 clocksource_tick.shift);
835 clocksource_tick.read = clocksource_tick_read;
837 printk("clocksource: mult[%x] shift[%d]\n",
838 clocksource_tick.mult, clocksource_tick.shift);
840 clocksource_register(&clocksource_tick);
842 sparc64_clockevent.name = tick_ops->name;
844 setup_clockevent_multiplier(freq);
846 sparc64_clockevent.max_delta_ns =
847 clockevent_delta2ns(0x7fffffffffffffffUL, &sparc64_clockevent);
848 sparc64_clockevent.min_delta_ns =
849 clockevent_delta2ns(0xF, &sparc64_clockevent);
851 printk("clockevent: mult[%lx] shift[%d]\n",
852 sparc64_clockevent.mult, sparc64_clockevent.shift);
854 setup_sparc64_timer();
857 unsigned long long sched_clock(void)
859 unsigned long ticks = tick_ops->get_tick();
861 return (ticks * timer_ticks_per_nsec_quotient)
862 >> SPARC64_NSEC_PER_CYC_SHIFT;
865 int __devinit read_current_timer(unsigned long *timer_val)
867 *timer_val = tick_ops->get_tick();