1 /* linux/arch/sparc/kernel/time.c
3 * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
6 * Chris Davis (cdavis@cois.on.ca) 03/27/1998
7 * Added support for the intersil on the sun4/4200
9 * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
10 * Support for MicroSPARC-IIep, PCI CPU.
12 * This file handles the Sparc specific time handling details.
14 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
15 * "A Kernel Model for Precision Timekeeping" by Dave Mills
17 #include <linux/errno.h>
18 #include <linux/module.h>
19 #include <linux/sched.h>
20 #include <linux/kernel.h>
21 #include <linux/param.h>
22 #include <linux/string.h>
24 #include <linux/interrupt.h>
25 #include <linux/time.h>
26 #include <linux/rtc.h>
27 #include <linux/rtc/m48t59.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 <linux/of_device.h>
35 #include <linux/platform_device.h>
37 #include <asm/oplib.h>
38 #include <asm/timer.h>
39 #include <asm/system.h>
42 #include <asm/idprom.h>
43 #include <asm/machines.h>
46 #include <asm/irq_regs.h>
50 DEFINE_SPINLOCK(rtc_lock);
51 EXPORT_SYMBOL(rtc_lock);
53 static int set_rtc_mmss(unsigned long);
54 static int sbus_do_settimeofday(struct timespec *tv);
56 unsigned long profile_pc(struct pt_regs *regs)
58 extern char __copy_user_begin[], __copy_user_end[];
59 extern char __atomic_begin[], __atomic_end[];
60 extern char __bzero_begin[], __bzero_end[];
62 unsigned long pc = regs->pc;
64 if (in_lock_functions(pc) ||
65 (pc >= (unsigned long) __copy_user_begin &&
66 pc < (unsigned long) __copy_user_end) ||
67 (pc >= (unsigned long) __atomic_begin &&
68 pc < (unsigned long) __atomic_end) ||
69 (pc >= (unsigned long) __bzero_begin &&
70 pc < (unsigned long) __bzero_end))
71 pc = regs->u_regs[UREG_RETPC];
75 EXPORT_SYMBOL(profile_pc);
77 __volatile__ unsigned int *master_l10_counter;
80 * timer_interrupt() needs to keep up the real-time clock,
81 * as well as call the "do_timer()" routine every clocktick
84 #define TICK_SIZE (tick_nsec / 1000)
86 static irqreturn_t timer_interrupt(int dummy, void *dev_id)
88 /* last time the cmos clock got updated */
89 static long last_rtc_update;
92 profile_tick(CPU_PROFILING);
95 /* Protect counter clear so that do_gettimeoffset works */
96 write_seqlock(&xtime_lock);
102 /* Determine when to update the Mostek clock. */
104 xtime.tv_sec > last_rtc_update + 660 &&
105 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
106 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
107 if (set_rtc_mmss(xtime.tv_sec) == 0)
108 last_rtc_update = xtime.tv_sec;
110 last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
112 write_sequnlock(&xtime_lock);
115 update_process_times(user_mode(get_irq_regs()));
120 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
122 struct platform_device *pdev = to_platform_device(dev);
123 struct m48t59_plat_data *pdata = pdev->dev.platform_data;
125 return readb(pdata->ioaddr + ofs);
128 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
130 struct platform_device *pdev = to_platform_device(dev);
131 struct m48t59_plat_data *pdata = pdev->dev.platform_data;
133 writeb(val, pdata->ioaddr + ofs);
136 static struct m48t59_plat_data m48t59_data = {
137 .read_byte = mostek_read_byte,
138 .write_byte = mostek_write_byte,
141 /* resource is set at runtime */
142 static struct platform_device m48t59_rtc = {
143 .name = "rtc-m48t59",
147 .platform_data = &m48t59_data,
151 static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
153 struct device_node *dp = op->node;
154 const char *model = of_get_property(dp, "model", NULL);
159 m48t59_rtc.resource = &op->resource[0];
160 if (!strcmp(model, "mk48t02")) {
161 /* Map the clock register io area read-only */
162 m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
164 m48t59_data.type = M48T59RTC_TYPE_M48T02;
165 } else if (!strcmp(model, "mk48t08")) {
166 m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
168 m48t59_data.type = M48T59RTC_TYPE_M48T08;
172 if (platform_device_register(&m48t59_rtc) < 0)
173 printk(KERN_ERR "Registering RTC device failed\n");
178 static struct of_device_id __initdata clock_match[] = {
185 static struct of_platform_driver clock_driver = {
186 .match_table = clock_match,
187 .probe = clock_probe,
194 /* Probe for the mostek real time clock chip. */
195 static int __init clock_init(void)
197 return of_register_driver(&clock_driver, &of_platform_bus_type);
200 /* Must be after subsys_initcall() so that busses are probed. Must
201 * be before device_initcall() because things like the RTC driver
202 * need to see the clock registers.
204 fs_initcall(clock_init);
206 static void __init sbus_time_init(void)
209 BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
212 sparc_init_timers(timer_interrupt);
215 void __init time_init(void)
218 extern void pci_time_init(void);
219 if (pcic_present()) {
227 static inline unsigned long do_gettimeoffset(void)
229 unsigned long val = *master_l10_counter;
230 unsigned long usec = (val >> 10) & 0x1fffff;
233 if (val & 0x80000000)
234 usec += 1000000 / HZ;
239 /* Ok, my cute asm atomicity trick doesn't work anymore.
240 * There are just too many variables that need to be protected
241 * now (both members of xtime, et al.)
243 void do_gettimeofday(struct timeval *tv)
247 unsigned long usec, sec;
248 unsigned long max_ntp_tick = tick_usec - tickadj;
251 seq = read_seqbegin_irqsave(&xtime_lock, flags);
252 usec = do_gettimeoffset();
255 * If time_adjust is negative then NTP is slowing the clock
256 * so make sure not to go into next possible interval.
257 * Better to lose some accuracy than have time go backwards..
259 if (unlikely(time_adjust < 0))
260 usec = min(usec, max_ntp_tick);
263 usec += (xtime.tv_nsec / 1000);
264 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
266 while (usec >= 1000000) {
275 EXPORT_SYMBOL(do_gettimeofday);
277 int do_settimeofday(struct timespec *tv)
281 write_seqlock_irq(&xtime_lock);
282 ret = bus_do_settimeofday(tv);
283 write_sequnlock_irq(&xtime_lock);
288 EXPORT_SYMBOL(do_settimeofday);
290 static int sbus_do_settimeofday(struct timespec *tv)
292 time_t wtm_sec, sec = tv->tv_sec;
293 long wtm_nsec, nsec = tv->tv_nsec;
295 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
299 * This is revolting. We need to set "xtime" correctly. However, the
300 * value in this location is the value at the most recent update of
301 * wall time. Discover what correction gettimeofday() would have
302 * made, and then undo it!
304 nsec -= 1000 * do_gettimeoffset();
306 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
307 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
309 set_normalized_timespec(&xtime, sec, nsec);
310 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
316 static int set_rtc_mmss(unsigned long secs)
318 struct rtc_device *rtc = rtc_class_open("rtc0");
322 err = rtc_set_mmss(rtc, secs);
323 rtc_class_close(rtc);