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;
180 static void stick_disable_irq(void)
182 __asm__ __volatile__(
183 "wr %0, 0x0, %%asr25"
185 : "r" (TICKCMP_IRQ_BIT));
188 static void stick_init_tick(void)
190 /* Writes to the %tick and %stick register are not
191 * allowed on sun4v. The Hypervisor controls that
194 if (tlb_type != hypervisor) {
195 tick_disable_protection();
198 /* Let the user get at STICK too. */
199 __asm__ __volatile__(
200 " rd %%asr24, %%g2\n"
201 " andn %%g2, %0, %%g2\n"
202 " wr %%g2, 0, %%asr24"
204 : "r" (TICK_PRIV_BIT)
211 static unsigned long long stick_get_tick(void)
215 __asm__ __volatile__("rd %%asr24, %0"
218 return ret & ~TICK_PRIV_BIT;
221 static unsigned long stick_add_tick(unsigned long adj)
223 unsigned long new_tick;
225 __asm__ __volatile__("rd %%asr24, %0\n\t"
227 "wr %0, 0, %%asr24\n\t"
234 static int stick_add_compare(unsigned long adj)
236 unsigned long orig_tick, new_tick;
238 __asm__ __volatile__("rd %%asr24, %0"
240 orig_tick &= ~TICKCMP_IRQ_BIT;
242 __asm__ __volatile__("wr %0, 0, %%asr25"
244 : "r" (orig_tick + adj));
246 __asm__ __volatile__("rd %%asr24, %0"
248 new_tick &= ~TICKCMP_IRQ_BIT;
250 return ((long)(new_tick - (orig_tick+adj))) > 0L;
253 static struct sparc64_tick_ops stick_operations __read_mostly = {
255 .init_tick = stick_init_tick,
256 .disable_irq = stick_disable_irq,
257 .get_tick = stick_get_tick,
258 .add_tick = stick_add_tick,
259 .add_compare = stick_add_compare,
260 .softint_mask = 1UL << 16,
263 /* On Hummingbird the STICK/STICK_CMPR register is implemented
264 * in I/O space. There are two 64-bit registers each, the
265 * first holds the low 32-bits of the value and the second holds
268 * Since STICK is constantly updating, we have to access it carefully.
270 * The sequence we use to read is:
273 * 3) read high again, if it rolled re-read both low and high again.
275 * Writing STICK safely is also tricky:
276 * 1) write low to zero
280 #define HBIRD_STICKCMP_ADDR 0x1fe0000f060UL
281 #define HBIRD_STICK_ADDR 0x1fe0000f070UL
283 static unsigned long __hbird_read_stick(void)
285 unsigned long ret, tmp1, tmp2, tmp3;
286 unsigned long addr = HBIRD_STICK_ADDR+8;
288 __asm__ __volatile__("ldxa [%1] %5, %2\n"
290 "sub %1, 0x8, %1\n\t"
291 "ldxa [%1] %5, %3\n\t"
292 "add %1, 0x8, %1\n\t"
293 "ldxa [%1] %5, %4\n\t"
295 "bne,a,pn %%xcc, 1b\n\t"
297 "sllx %4, 32, %4\n\t"
299 : "=&r" (ret), "=&r" (addr),
300 "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
301 : "i" (ASI_PHYS_BYPASS_EC_E), "1" (addr));
306 static void __hbird_write_stick(unsigned long val)
308 unsigned long low = (val & 0xffffffffUL);
309 unsigned long high = (val >> 32UL);
310 unsigned long addr = HBIRD_STICK_ADDR;
312 __asm__ __volatile__("stxa %%g0, [%0] %4\n\t"
313 "add %0, 0x8, %0\n\t"
314 "stxa %3, [%0] %4\n\t"
315 "sub %0, 0x8, %0\n\t"
318 : "0" (addr), "r" (low), "r" (high),
319 "i" (ASI_PHYS_BYPASS_EC_E));
322 static void __hbird_write_compare(unsigned long val)
324 unsigned long low = (val & 0xffffffffUL);
325 unsigned long high = (val >> 32UL);
326 unsigned long addr = HBIRD_STICKCMP_ADDR + 0x8UL;
328 __asm__ __volatile__("stxa %3, [%0] %4\n\t"
329 "sub %0, 0x8, %0\n\t"
332 : "0" (addr), "r" (low), "r" (high),
333 "i" (ASI_PHYS_BYPASS_EC_E));
336 static void hbtick_disable_irq(void)
338 __hbird_write_compare(TICKCMP_IRQ_BIT);
341 static void hbtick_init_tick(void)
343 tick_disable_protection();
345 /* XXX This seems to be necessary to 'jumpstart' Hummingbird
346 * XXX into actually sending STICK interrupts. I think because
347 * XXX of how we store %tick_cmpr in head.S this somehow resets the
348 * XXX {TICK + STICK} interrupt mux. -DaveM
350 __hbird_write_stick(__hbird_read_stick());
352 hbtick_disable_irq();
355 static unsigned long long hbtick_get_tick(void)
357 return __hbird_read_stick() & ~TICK_PRIV_BIT;
360 static unsigned long hbtick_add_tick(unsigned long adj)
364 val = __hbird_read_stick() + adj;
365 __hbird_write_stick(val);
370 static int hbtick_add_compare(unsigned long adj)
372 unsigned long val = __hbird_read_stick();
375 val &= ~TICKCMP_IRQ_BIT;
377 __hbird_write_compare(val);
379 val2 = __hbird_read_stick() & ~TICKCMP_IRQ_BIT;
381 return ((long)(val2 - val)) > 0L;
384 static struct sparc64_tick_ops hbtick_operations __read_mostly = {
386 .init_tick = hbtick_init_tick,
387 .disable_irq = hbtick_disable_irq,
388 .get_tick = hbtick_get_tick,
389 .add_tick = hbtick_add_tick,
390 .add_compare = hbtick_add_compare,
391 .softint_mask = 1UL << 0,
394 static unsigned long timer_ticks_per_nsec_quotient __read_mostly;
396 int update_persistent_clock(struct timespec now)
398 struct rtc_device *rtc = rtc_class_open("rtc0");
402 err = rtc_set_mmss(rtc, now.tv_sec);
403 rtc_class_close(rtc);
409 unsigned long cmos_regs;
410 EXPORT_SYMBOL(cmos_regs);
412 static struct resource rtc_cmos_resource;
414 static struct platform_device rtc_cmos_device = {
417 .resource = &rtc_cmos_resource,
421 static int __devinit rtc_probe(struct of_device *op, const struct of_device_id *match)
425 printk(KERN_INFO "%s: RTC regs at 0x%llx\n",
426 op->node->full_name, op->resource[0].start);
428 /* The CMOS RTC driver only accepts IORESOURCE_IO, so cons
429 * up a fake resource so that the probe works for all cases.
430 * When the RTC is behind an ISA bus it will have IORESOURCE_IO
431 * already, whereas when it's behind EBUS is will be IORESOURCE_MEM.
434 r = &rtc_cmos_resource;
435 r->flags = IORESOURCE_IO;
436 r->name = op->resource[0].name;
437 r->start = op->resource[0].start;
438 r->end = op->resource[0].end;
440 cmos_regs = op->resource[0].start;
441 return platform_device_register(&rtc_cmos_device);
444 static struct of_device_id __initdata rtc_match[] = {
447 .compatible = "m5819",
451 .compatible = "isa-m5819p",
455 .compatible = "isa-m5823p",
459 .compatible = "ds1287",
464 static struct of_platform_driver rtc_driver = {
465 .match_table = rtc_match,
472 static struct platform_device rtc_bq4802_device = {
473 .name = "rtc-bq4802",
478 static int __devinit bq4802_probe(struct of_device *op, const struct of_device_id *match)
481 printk(KERN_INFO "%s: BQ4802 regs at 0x%llx\n",
482 op->node->full_name, op->resource[0].start);
484 rtc_bq4802_device.resource = &op->resource[0];
485 return platform_device_register(&rtc_bq4802_device);
488 static struct of_device_id __initdata bq4802_match[] = {
491 .compatible = "bq4802",
496 static struct of_platform_driver bq4802_driver = {
497 .match_table = bq4802_match,
498 .probe = bq4802_probe,
504 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
506 struct platform_device *pdev = to_platform_device(dev);
507 void __iomem *regs = (void __iomem *) pdev->resource[0].start;
509 return readb(regs + ofs);
512 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
514 struct platform_device *pdev = to_platform_device(dev);
515 void __iomem *regs = (void __iomem *) pdev->resource[0].start;
517 writeb(val, regs + ofs);
520 static struct m48t59_plat_data m48t59_data = {
521 .read_byte = mostek_read_byte,
522 .write_byte = mostek_write_byte,
525 static struct platform_device m48t59_rtc = {
526 .name = "rtc-m48t59",
530 .platform_data = &m48t59_data,
534 static int __devinit mostek_probe(struct of_device *op, const struct of_device_id *match)
536 struct device_node *dp = op->node;
538 /* On an Enterprise system there can be multiple mostek clocks.
539 * We should only match the one that is on the central FHC bus.
541 if (!strcmp(dp->parent->name, "fhc") &&
542 strcmp(dp->parent->parent->name, "central") != 0)
545 printk(KERN_INFO "%s: Mostek regs at 0x%llx\n",
546 dp->full_name, op->resource[0].start);
548 m48t59_rtc.resource = &op->resource[0];
549 return platform_device_register(&m48t59_rtc);
552 static struct of_device_id __initdata mostek_match[] = {
559 static struct of_platform_driver mostek_driver = {
560 .match_table = mostek_match,
561 .probe = mostek_probe,
567 static struct platform_device rtc_sun4v_device = {
572 static struct platform_device rtc_starfire_device = {
573 .name = "rtc-starfire",
577 static int __init clock_init(void)
579 if (this_is_starfire)
580 return platform_device_register(&rtc_starfire_device);
582 if (tlb_type == hypervisor)
583 return platform_device_register(&rtc_sun4v_device);
585 (void) of_register_driver(&rtc_driver, &of_platform_bus_type);
586 (void) of_register_driver(&mostek_driver, &of_platform_bus_type);
587 (void) of_register_driver(&bq4802_driver, &of_platform_bus_type);
592 /* Must be after subsys_initcall() so that busses are probed. Must
593 * be before device_initcall() because things like the RTC driver
594 * need to see the clock registers.
596 fs_initcall(clock_init);
598 /* This is gets the master TICK_INT timer going. */
599 static unsigned long sparc64_init_timers(void)
601 struct device_node *dp;
604 dp = of_find_node_by_path("/");
605 if (tlb_type == spitfire) {
606 unsigned long ver, manuf, impl;
608 __asm__ __volatile__ ("rdpr %%ver, %0"
610 manuf = ((ver >> 48) & 0xffff);
611 impl = ((ver >> 32) & 0xffff);
612 if (manuf == 0x17 && impl == 0x13) {
613 /* Hummingbird, aka Ultra-IIe */
614 tick_ops = &hbtick_operations;
615 freq = of_getintprop_default(dp, "stick-frequency", 0);
617 tick_ops = &tick_operations;
618 freq = local_cpu_data().clock_tick;
621 tick_ops = &stick_operations;
622 freq = of_getintprop_default(dp, "stick-frequency", 0);
629 unsigned long clock_tick_ref;
630 unsigned int ref_freq;
632 static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };
634 unsigned long sparc64_get_clock_tick(unsigned int cpu)
636 struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
638 if (ft->clock_tick_ref)
639 return ft->clock_tick_ref;
640 return cpu_data(cpu).clock_tick;
643 #ifdef CONFIG_CPU_FREQ
645 static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
648 struct cpufreq_freqs *freq = data;
649 unsigned int cpu = freq->cpu;
650 struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
653 ft->ref_freq = freq->old;
654 ft->clock_tick_ref = cpu_data(cpu).clock_tick;
656 if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
657 (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
658 (val == CPUFREQ_RESUMECHANGE)) {
659 cpu_data(cpu).clock_tick =
660 cpufreq_scale(ft->clock_tick_ref,
668 static struct notifier_block sparc64_cpufreq_notifier_block = {
669 .notifier_call = sparc64_cpufreq_notifier
672 static int __init register_sparc64_cpufreq_notifier(void)
675 cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
676 CPUFREQ_TRANSITION_NOTIFIER);
680 core_initcall(register_sparc64_cpufreq_notifier);
682 #endif /* CONFIG_CPU_FREQ */
684 static int sparc64_next_event(unsigned long delta,
685 struct clock_event_device *evt)
687 return tick_ops->add_compare(delta) ? -ETIME : 0;
690 static void sparc64_timer_setup(enum clock_event_mode mode,
691 struct clock_event_device *evt)
694 case CLOCK_EVT_MODE_ONESHOT:
695 case CLOCK_EVT_MODE_RESUME:
698 case CLOCK_EVT_MODE_SHUTDOWN:
699 tick_ops->disable_irq();
702 case CLOCK_EVT_MODE_PERIODIC:
703 case CLOCK_EVT_MODE_UNUSED:
709 static struct clock_event_device sparc64_clockevent = {
710 .features = CLOCK_EVT_FEAT_ONESHOT,
711 .set_mode = sparc64_timer_setup,
712 .set_next_event = sparc64_next_event,
717 static DEFINE_PER_CPU(struct clock_event_device, sparc64_events);
719 void timer_interrupt(int irq, struct pt_regs *regs)
721 struct pt_regs *old_regs = set_irq_regs(regs);
722 unsigned long tick_mask = tick_ops->softint_mask;
723 int cpu = smp_processor_id();
724 struct clock_event_device *evt = &per_cpu(sparc64_events, cpu);
726 clear_softint(tick_mask);
730 kstat_this_cpu.irqs[0]++;
732 if (unlikely(!evt->event_handler)) {
734 "Spurious SPARC64 timer interrupt on cpu %d\n", cpu);
736 evt->event_handler(evt);
740 set_irq_regs(old_regs);
743 void __devinit setup_sparc64_timer(void)
745 struct clock_event_device *sevt;
746 unsigned long pstate;
748 /* Guarantee that the following sequences execute
751 __asm__ __volatile__("rdpr %%pstate, %0\n\t"
752 "wrpr %0, %1, %%pstate"
756 tick_ops->init_tick();
758 /* Restore PSTATE_IE. */
759 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
763 sevt = &__get_cpu_var(sparc64_events);
765 memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
766 sevt->cpumask = cpumask_of(smp_processor_id());
768 clockevents_register_device(sevt);
771 #define SPARC64_NSEC_PER_CYC_SHIFT 10UL
773 static struct clocksource clocksource_tick = {
775 .mask = CLOCKSOURCE_MASK(64),
777 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
780 static void __init setup_clockevent_multiplier(unsigned long hz)
782 unsigned long mult, shift = 32;
785 mult = div_sc(hz, NSEC_PER_SEC, shift);
786 if (mult && (mult >> 32UL) == 0UL)
792 sparc64_clockevent.shift = shift;
793 sparc64_clockevent.mult = mult;
796 static unsigned long tb_ticks_per_usec __read_mostly;
798 void __delay(unsigned long loops)
800 unsigned long bclock, now;
802 bclock = tick_ops->get_tick();
804 now = tick_ops->get_tick();
805 } while ((now-bclock) < loops);
807 EXPORT_SYMBOL(__delay);
809 void udelay(unsigned long usecs)
811 __delay(tb_ticks_per_usec * usecs);
813 EXPORT_SYMBOL(udelay);
815 void __init time_init(void)
817 unsigned long freq = sparc64_init_timers();
819 tb_ticks_per_usec = freq / USEC_PER_SEC;
821 timer_ticks_per_nsec_quotient =
822 clocksource_hz2mult(freq, SPARC64_NSEC_PER_CYC_SHIFT);
824 clocksource_tick.name = tick_ops->name;
825 clocksource_tick.mult =
826 clocksource_hz2mult(freq,
827 clocksource_tick.shift);
828 clocksource_tick.read = tick_ops->get_tick;
830 printk("clocksource: mult[%x] shift[%d]\n",
831 clocksource_tick.mult, clocksource_tick.shift);
833 clocksource_register(&clocksource_tick);
835 sparc64_clockevent.name = tick_ops->name;
837 setup_clockevent_multiplier(freq);
839 sparc64_clockevent.max_delta_ns =
840 clockevent_delta2ns(0x7fffffffffffffffUL, &sparc64_clockevent);
841 sparc64_clockevent.min_delta_ns =
842 clockevent_delta2ns(0xF, &sparc64_clockevent);
844 printk("clockevent: mult[%lx] shift[%d]\n",
845 sparc64_clockevent.mult, sparc64_clockevent.shift);
847 setup_sparc64_timer();
850 unsigned long long sched_clock(void)
852 unsigned long ticks = tick_ops->get_tick();
854 return (ticks * timer_ticks_per_nsec_quotient)
855 >> SPARC64_NSEC_PER_CYC_SHIFT;
858 int __devinit read_current_timer(unsigned long *timer_val)
860 *timer_val = tick_ops->get_tick();