1 /* $Id: time.c,v 1.60 2002/01/23 14:33:55 davem Exp $
2 * linux/arch/sparc/kernel/time.c
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
7 * Chris Davis (cdavis@cois.on.ca) 03/27/1998
8 * Added support for the intersil on the sun4/4200
10 * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
11 * Support for MicroSPARC-IIep, PCI CPU.
13 * This file handles the Sparc specific time handling details.
15 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
16 * "A Kernel Model for Precision Timekeeping" by Dave Mills
18 #include <linux/config.h>
19 #include <linux/errno.h>
20 #include <linux/module.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/param.h>
24 #include <linux/string.h>
26 #include <linux/interrupt.h>
27 #include <linux/time.h>
28 #include <linux/timex.h>
29 #include <linux/init.h>
30 #include <linux/pci.h>
31 #include <linux/ioport.h>
32 #include <linux/profile.h>
34 #include <asm/oplib.h>
35 #include <asm/segment.h>
36 #include <asm/timer.h>
37 #include <asm/mostek.h>
38 #include <asm/system.h>
41 #include <asm/idprom.h>
42 #include <asm/machines.h>
43 #include <asm/sun4paddr.h>
47 extern unsigned long wall_jiffies;
49 u64 jiffies_64 = INITIAL_JIFFIES;
51 EXPORT_SYMBOL(jiffies_64);
53 spinlock_t rtc_lock = SPIN_LOCK_UNLOCKED;
54 enum sparc_clock_type sp_clock_typ;
55 spinlock_t mostek_lock = SPIN_LOCK_UNLOCKED;
56 unsigned long mstk48t02_regs = 0UL;
57 static struct mostek48t08 *mstk48t08_regs = NULL;
58 static int set_rtc_mmss(unsigned long);
59 static int sbus_do_settimeofday(struct timespec *tv);
62 struct intersil *intersil_clock;
63 #define intersil_cmd(intersil_reg, intsil_cmd) intersil_reg->int_cmd_reg = \
66 #define intersil_intr(intersil_reg, intsil_cmd) intersil_reg->int_intr_reg = \
69 #define intersil_start(intersil_reg) intersil_cmd(intersil_reg, \
70 ( INTERSIL_START | INTERSIL_32K | INTERSIL_NORMAL | INTERSIL_24H |\
71 INTERSIL_INTR_ENABLE))
73 #define intersil_stop(intersil_reg) intersil_cmd(intersil_reg, \
74 ( INTERSIL_STOP | INTERSIL_32K | INTERSIL_NORMAL | INTERSIL_24H |\
75 INTERSIL_INTR_ENABLE))
77 #define intersil_read_intr(intersil_reg, towhere) towhere = \
78 intersil_reg->int_intr_reg
82 unsigned long profile_pc(struct pt_regs *regs)
84 extern char __copy_user_begin[], __copy_user_end[];
85 extern char __atomic_begin[], __atomic_end[];
86 extern char __bzero_begin[], __bzero_end[];
87 extern char __bitops_begin[], __bitops_end[];
89 unsigned long pc = regs->pc;
91 if (in_lock_functions(pc) ||
92 (pc >= (unsigned long) __copy_user_begin &&
93 pc < (unsigned long) __copy_user_end) ||
94 (pc >= (unsigned long) __atomic_begin &&
95 pc < (unsigned long) __atomic_end) ||
96 (pc >= (unsigned long) __bzero_begin &&
97 pc < (unsigned long) __bzero_end) ||
98 (pc >= (unsigned long) __bitops_begin &&
99 pc < (unsigned long) __bitops_end))
100 pc = regs->u_regs[UREG_RETPC];
104 __volatile__ unsigned int *master_l10_counter;
105 __volatile__ unsigned int *master_l10_limit;
108 * timer_interrupt() needs to keep up the real-time clock,
109 * as well as call the "do_timer()" routine every clocktick
112 #define TICK_SIZE (tick_nsec / 1000)
114 irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
116 /* last time the cmos clock got updated */
117 static long last_rtc_update;
120 profile_tick(CPU_PROFILING, regs);
123 /* Protect counter clear so that do_gettimeoffset works */
124 write_seqlock(&xtime_lock);
126 if((idprom->id_machtype == (SM_SUN4 | SM_4_260)) ||
127 (idprom->id_machtype == (SM_SUN4 | SM_4_110))) {
129 intersil_read_intr(intersil_clock, temp);
130 /* re-enable the irq */
138 /* Determine when to update the Mostek clock. */
139 if ((time_status & STA_UNSYNC) == 0 &&
140 xtime.tv_sec > last_rtc_update + 660 &&
141 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
142 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
143 if (set_rtc_mmss(xtime.tv_sec) == 0)
144 last_rtc_update = xtime.tv_sec;
146 last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
148 write_sequnlock(&xtime_lock);
153 /* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
154 static void __init kick_start_clock(void)
156 struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
160 prom_printf("CLOCK: Clock was stopped. Kick start ");
162 spin_lock_irq(&mostek_lock);
164 /* Turn on the kick start bit to start the oscillator. */
165 regs->creg |= MSTK_CREG_WRITE;
166 regs->sec &= ~MSTK_STOP;
167 regs->hour |= MSTK_KICK_START;
168 regs->creg &= ~MSTK_CREG_WRITE;
170 spin_unlock_irq(&mostek_lock);
172 /* Delay to allow the clock oscillator to start. */
173 sec = MSTK_REG_SEC(regs);
174 for (i = 0; i < 3; i++) {
175 while (sec == MSTK_REG_SEC(regs))
176 for (count = 0; count < 100000; count++)
183 spin_lock_irq(&mostek_lock);
185 /* Turn off kick start and set a "valid" time and date. */
186 regs->creg |= MSTK_CREG_WRITE;
187 regs->hour &= ~MSTK_KICK_START;
188 MSTK_SET_REG_SEC(regs,0);
189 MSTK_SET_REG_MIN(regs,0);
190 MSTK_SET_REG_HOUR(regs,0);
191 MSTK_SET_REG_DOW(regs,5);
192 MSTK_SET_REG_DOM(regs,1);
193 MSTK_SET_REG_MONTH(regs,8);
194 MSTK_SET_REG_YEAR(regs,1996 - MSTK_YEAR_ZERO);
195 regs->creg &= ~MSTK_CREG_WRITE;
197 spin_unlock_irq(&mostek_lock);
199 /* Ensure the kick start bit is off. If it isn't, turn it off. */
200 while (regs->hour & MSTK_KICK_START) {
201 prom_printf("CLOCK: Kick start still on!\n");
203 spin_lock_irq(&mostek_lock);
204 regs->creg |= MSTK_CREG_WRITE;
205 regs->hour &= ~MSTK_KICK_START;
206 regs->creg &= ~MSTK_CREG_WRITE;
207 spin_unlock_irq(&mostek_lock);
210 prom_printf("CLOCK: Kick start procedure successful.\n");
213 /* Return nonzero if the clock chip battery is low. */
214 static __inline__ int has_low_battery(void)
216 struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
217 unsigned char data1, data2;
219 spin_lock_irq(&mostek_lock);
220 data1 = regs->eeprom[0]; /* Read some data. */
221 regs->eeprom[0] = ~data1; /* Write back the complement. */
222 data2 = regs->eeprom[0]; /* Read back the complement. */
223 regs->eeprom[0] = data1; /* Restore the original value. */
224 spin_unlock_irq(&mostek_lock);
226 return (data1 == data2); /* Was the write blocked? */
229 /* Probe for the real time clock chip on Sun4 */
230 static __inline__ void sun4_clock_probe(void)
236 memset(&r, 0, sizeof(r));
237 if( idprom->id_machtype == (SM_SUN4 | SM_4_330) ) {
238 sp_clock_typ = MSTK48T02;
239 r.start = sun4_clock_physaddr;
240 mstk48t02_regs = sbus_ioremap(&r, 0,
241 sizeof(struct mostek48t02), NULL);
242 mstk48t08_regs = NULL; /* To catch weirdness */
243 intersil_clock = NULL; /* just in case */
245 /* Kick start the clock if it is completely stopped. */
246 if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
248 } else if( idprom->id_machtype == (SM_SUN4 | SM_4_260)) {
249 /* intersil setup code */
250 printk("Clock: INTERSIL at %8x ",sun4_clock_physaddr);
251 sp_clock_typ = INTERSIL;
252 r.start = sun4_clock_physaddr;
253 intersil_clock = (struct intersil *)
254 sbus_ioremap(&r, 0, sizeof(*intersil_clock), "intersil");
255 mstk48t02_regs = 0; /* just be sure */
256 mstk48t08_regs = NULL; /* ditto */
257 /* initialise the clock */
259 intersil_intr(intersil_clock,INTERSIL_INT_100HZ);
261 intersil_start(intersil_clock);
263 intersil_read_intr(intersil_clock, temp);
264 while (!(temp & 0x80))
265 intersil_read_intr(intersil_clock, temp);
267 intersil_read_intr(intersil_clock, temp);
268 while (!(temp & 0x80))
269 intersil_read_intr(intersil_clock, temp);
271 intersil_stop(intersil_clock);
277 /* Probe for the mostek real time clock chip. */
278 static __inline__ void clock_probe(void)
280 struct linux_prom_registers clk_reg[2];
282 register int node, cpuunit, bootbus;
285 cpuunit = bootbus = 0;
286 memset(&r, 0, sizeof(r));
288 /* Determine the correct starting PROM node for the probe. */
289 node = prom_getchild(prom_root_node);
290 switch (sparc_cpu_model) {
294 node = prom_getchild(prom_searchsiblings(node, "obio"));
297 node = prom_getchild(bootbus = prom_searchsiblings(prom_getchild(cpuunit = prom_searchsiblings(node, "cpu-unit")), "bootbus"));
300 prom_printf("CLOCK: Unsupported architecture!\n");
304 /* Find the PROM node describing the real time clock. */
305 sp_clock_typ = MSTK_INVALID;
306 node = prom_searchsiblings(node,"eeprom");
308 prom_printf("CLOCK: No clock found!\n");
312 /* Get the model name and setup everything up. */
314 prom_getstring(node, "model", model, sizeof(model));
315 if (strcmp(model, "mk48t02") == 0) {
316 sp_clock_typ = MSTK48T02;
317 if (prom_getproperty(node, "reg", (char *) clk_reg, sizeof(clk_reg)) == -1) {
318 prom_printf("clock_probe: FAILED!\n");
321 if (sparc_cpu_model == sun4d)
322 prom_apply_generic_ranges (bootbus, cpuunit, clk_reg, 1);
324 prom_apply_obio_ranges(clk_reg, 1);
325 /* Map the clock register io area read-only */
326 r.flags = clk_reg[0].which_io;
327 r.start = clk_reg[0].phys_addr;
328 mstk48t02_regs = sbus_ioremap(&r, 0,
329 sizeof(struct mostek48t02), "mk48t02");
330 mstk48t08_regs = NULL; /* To catch weirdness */
331 } else if (strcmp(model, "mk48t08") == 0) {
332 sp_clock_typ = MSTK48T08;
333 if(prom_getproperty(node, "reg", (char *) clk_reg,
334 sizeof(clk_reg)) == -1) {
335 prom_printf("clock_probe: FAILED!\n");
338 if (sparc_cpu_model == sun4d)
339 prom_apply_generic_ranges (bootbus, cpuunit, clk_reg, 1);
341 prom_apply_obio_ranges(clk_reg, 1);
342 /* Map the clock register io area read-only */
343 /* XXX r/o attribute is somewhere in r.flags */
344 r.flags = clk_reg[0].which_io;
345 r.start = clk_reg[0].phys_addr;
346 mstk48t08_regs = (struct mostek48t08 *) sbus_ioremap(&r, 0,
347 sizeof(struct mostek48t08), "mk48t08");
349 mstk48t02_regs = (unsigned long)&mstk48t08_regs->regs;
351 prom_printf("CLOCK: Unknown model name '%s'\n",model);
355 /* Report a low battery voltage condition. */
356 if (has_low_battery())
357 printk(KERN_CRIT "NVRAM: Low battery voltage!\n");
359 /* Kick start the clock if it is completely stopped. */
360 if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
364 void __init sbus_time_init(void)
366 unsigned int year, mon, day, hour, min, sec;
367 struct mostek48t02 *mregs;
371 struct intersil *iregs;
374 BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
382 sparc_init_timers(timer_interrupt);
385 if(idprom->id_machtype == (SM_SUN4 | SM_4_330)) {
387 mregs = (struct mostek48t02 *)mstk48t02_regs;
389 prom_printf("Something wrong, clock regs not mapped yet.\n");
392 spin_lock_irq(&mostek_lock);
393 mregs->creg |= MSTK_CREG_READ;
394 sec = MSTK_REG_SEC(mregs);
395 min = MSTK_REG_MIN(mregs);
396 hour = MSTK_REG_HOUR(mregs);
397 day = MSTK_REG_DOM(mregs);
398 mon = MSTK_REG_MONTH(mregs);
399 year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) );
400 xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
401 xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
402 set_normalized_timespec(&wall_to_monotonic,
403 -xtime.tv_sec, -xtime.tv_nsec);
404 mregs->creg &= ~MSTK_CREG_READ;
405 spin_unlock_irq(&mostek_lock);
407 } else if(idprom->id_machtype == (SM_SUN4 | SM_4_260) ) {
408 /* initialise the intersil on sun4 */
410 iregs=intersil_clock;
412 prom_printf("Something wrong, clock regs not mapped yet.\n");
416 intersil_intr(intersil_clock,INTERSIL_INT_100HZ);
418 intersil_stop(iregs);
419 intersil_read_intr(intersil_clock, temp);
421 temp = iregs->clk.int_csec;
423 sec = iregs->clk.int_sec;
424 min = iregs->clk.int_min;
425 hour = iregs->clk.int_hour;
426 day = iregs->clk.int_day;
427 mon = iregs->clk.int_month;
428 year = MSTK_CVT_YEAR(iregs->clk.int_year);
431 intersil_start(iregs);
433 xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
434 xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
435 set_normalized_timespec(&wall_to_monotonic,
436 -xtime.tv_sec, -xtime.tv_nsec);
437 printk("%u/%u/%u %u:%u:%u\n",day,mon,year,hour,min,sec);
441 /* Now that OBP ticker has been silenced, it is safe to enable IRQ. */
445 void __init time_init(void)
448 extern void pci_time_init(void);
449 if (pcic_present()) {
457 extern __inline__ unsigned long do_gettimeoffset(void)
459 return (*master_l10_counter >> 10) & 0x1fffff;
463 * Returns nanoseconds
464 * XXX This is a suboptimal implementation.
466 unsigned long long sched_clock(void)
468 return (unsigned long long)jiffies * (1000000000 / HZ);
471 /* Ok, my cute asm atomicity trick doesn't work anymore.
472 * There are just too many variables that need to be protected
473 * now (both members of xtime, wall_jiffies, et al.)
475 void do_gettimeofday(struct timeval *tv)
479 unsigned long usec, sec;
480 unsigned long max_ntp_tick = tick_usec - tickadj;
485 seq = read_seqbegin_irqsave(&xtime_lock, flags);
486 usec = do_gettimeoffset();
487 lost = jiffies - wall_jiffies;
490 * If time_adjust is negative then NTP is slowing the clock
491 * so make sure not to go into next possible interval.
492 * Better to lose some accuracy than have time go backwards..
494 if (unlikely(time_adjust < 0)) {
495 usec = min(usec, max_ntp_tick);
498 usec += lost * max_ntp_tick;
500 else if (unlikely(lost))
501 usec += lost * tick_usec;
504 usec += (xtime.tv_nsec / 1000);
505 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
507 while (usec >= 1000000) {
516 EXPORT_SYMBOL(do_gettimeofday);
518 int do_settimeofday(struct timespec *tv)
522 write_seqlock_irq(&xtime_lock);
523 ret = bus_do_settimeofday(tv);
524 write_sequnlock_irq(&xtime_lock);
529 EXPORT_SYMBOL(do_settimeofday);
531 static int sbus_do_settimeofday(struct timespec *tv)
533 time_t wtm_sec, sec = tv->tv_sec;
534 long wtm_nsec, nsec = tv->tv_nsec;
536 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
540 * This is revolting. We need to set "xtime" correctly. However, the
541 * value in this location is the value at the most recent update of
542 * wall time. Discover what correction gettimeofday() would have
543 * made, and then undo it!
545 nsec -= 1000 * (do_gettimeoffset() +
546 (jiffies - wall_jiffies) * (USEC_PER_SEC / HZ));
548 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
549 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
551 set_normalized_timespec(&xtime, sec, nsec);
552 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
554 time_adjust = 0; /* stop active adjtime() */
555 time_status |= STA_UNSYNC;
556 time_maxerror = NTP_PHASE_LIMIT;
557 time_esterror = NTP_PHASE_LIMIT;
562 * BUG: This routine does not handle hour overflow properly; it just
563 * sets the minutes. Usually you won't notice until after reboot!
565 static int set_rtc_mmss(unsigned long nowtime)
567 int real_seconds, real_minutes, mostek_minutes;
568 struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
571 struct intersil *iregs = intersil_clock;
575 /* Not having a register set can lead to trouble. */
581 temp = iregs->clk.int_csec;
583 mostek_minutes = iregs->clk.int_min;
585 real_seconds = nowtime % 60;
586 real_minutes = nowtime / 60;
587 if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
588 real_minutes += 30; /* correct for half hour time zone */
591 if (abs(real_minutes - mostek_minutes) < 30) {
592 intersil_stop(iregs);
593 iregs->clk.int_sec=real_seconds;
594 iregs->clk.int_min=real_minutes;
595 intersil_start(iregs);
598 "set_rtc_mmss: can't update from %d to %d\n",
599 mostek_minutes, real_minutes);
608 spin_lock_irqsave(&mostek_lock, flags);
609 /* Read the current RTC minutes. */
610 regs->creg |= MSTK_CREG_READ;
611 mostek_minutes = MSTK_REG_MIN(regs);
612 regs->creg &= ~MSTK_CREG_READ;
615 * since we're only adjusting minutes and seconds,
616 * don't interfere with hour overflow. This avoids
617 * messing with unknown time zones but requires your
618 * RTC not to be off by more than 15 minutes
620 real_seconds = nowtime % 60;
621 real_minutes = nowtime / 60;
622 if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
623 real_minutes += 30; /* correct for half hour time zone */
626 if (abs(real_minutes - mostek_minutes) < 30) {
627 regs->creg |= MSTK_CREG_WRITE;
628 MSTK_SET_REG_SEC(regs,real_seconds);
629 MSTK_SET_REG_MIN(regs,real_minutes);
630 regs->creg &= ~MSTK_CREG_WRITE;
631 spin_unlock_irqrestore(&mostek_lock, flags);
634 spin_unlock_irqrestore(&mostek_lock, flags);