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+/* linux/arch/sparc/kernel/time.c
+ *
+ * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
+ *
+ * Chris Davis (cdavis@cois.on.ca) 03/27/1998
+ * Added support for the intersil on the sun4/4200
+ *
+ * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
+ * Support for MicroSPARC-IIep, PCI CPU.
+ *
+ * This file handles the Sparc specific time handling details.
+ *
+ * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
+ * "A Kernel Model for Precision Timekeeping" by Dave Mills
+ */
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/rtc/m48t59.h>
+#include <linux/timex.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/ioport.h>
+#include <linux/profile.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#include <asm/oplib.h>
+#include <asm/timer.h>
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/io.h>
+#include <asm/idprom.h>
+#include <asm/machines.h>
+#include <asm/page.h>
+#include <asm/pcic.h>
+#include <asm/irq_regs.h>
+
+#include "irq.h"
+
+DEFINE_SPINLOCK(rtc_lock);
+static int set_rtc_mmss(unsigned long);
+static int sbus_do_settimeofday(struct timespec *tv);
+
+unsigned long profile_pc(struct pt_regs *regs)
+{
+ extern char __copy_user_begin[], __copy_user_end[];
+ extern char __atomic_begin[], __atomic_end[];
+ extern char __bzero_begin[], __bzero_end[];
+
+ unsigned long pc = regs->pc;
+
+ if (in_lock_functions(pc) ||
+ (pc >= (unsigned long) __copy_user_begin &&
+ pc < (unsigned long) __copy_user_end) ||
+ (pc >= (unsigned long) __atomic_begin &&
+ pc < (unsigned long) __atomic_end) ||
+ (pc >= (unsigned long) __bzero_begin &&
+ pc < (unsigned long) __bzero_end))
+ pc = regs->u_regs[UREG_RETPC];
+ return pc;
+}
+
+EXPORT_SYMBOL(profile_pc);
+
+__volatile__ unsigned int *master_l10_counter;
+
+/*
+ * timer_interrupt() needs to keep up the real-time clock,
+ * as well as call the "do_timer()" routine every clocktick
+ */
+
+#define TICK_SIZE (tick_nsec / 1000)
+
+static irqreturn_t timer_interrupt(int dummy, void *dev_id)
+{
+ /* last time the cmos clock got updated */
+ static long last_rtc_update;
+
+#ifndef CONFIG_SMP
+ profile_tick(CPU_PROFILING);
+#endif
+
+ /* Protect counter clear so that do_gettimeoffset works */
+ write_seqlock(&xtime_lock);
+
+ clear_clock_irq();
+
+ do_timer(1);
+
+ /* Determine when to update the Mostek clock. */
+ if (ntp_synced() &&
+ xtime.tv_sec > last_rtc_update + 660 &&
+ (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
+ (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
+ if (set_rtc_mmss(xtime.tv_sec) == 0)
+ last_rtc_update = xtime.tv_sec;
+ else
+ last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
+ }
+ write_sequnlock(&xtime_lock);
+
+#ifndef CONFIG_SMP
+ update_process_times(user_mode(get_irq_regs()));
+#endif
+ return IRQ_HANDLED;
+}
+
+static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = pdev->dev.platform_data;
+
+ return readb(pdata->ioaddr + ofs);
+}
+
+static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct m48t59_plat_data *pdata = pdev->dev.platform_data;
+
+ writeb(val, pdata->ioaddr + ofs);
+}
+
+static struct m48t59_plat_data m48t59_data = {
+ .read_byte = mostek_read_byte,
+ .write_byte = mostek_write_byte,
+};
+
+/* resource is set at runtime */
+static struct platform_device m48t59_rtc = {
+ .name = "rtc-m48t59",
+ .id = 0,
+ .num_resources = 1,
+ .dev = {
+ .platform_data = &m48t59_data,
+ },
+};
+
+static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
+{
+ struct device_node *dp = op->node;
+ const char *model = of_get_property(dp, "model", NULL);
+
+ if (!model)
+ return -ENODEV;
+
+ m48t59_rtc.resource = &op->resource[0];
+ if (!strcmp(model, "mk48t02")) {
+ /* Map the clock register io area read-only */
+ m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
+ 2048, "rtc-m48t59");
+ m48t59_data.type = M48T59RTC_TYPE_M48T02;
+ } else if (!strcmp(model, "mk48t08")) {
+ m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
+ 8192, "rtc-m48t59");
+ m48t59_data.type = M48T59RTC_TYPE_M48T08;
+ } else
+ return -ENODEV;
+
+ if (platform_device_register(&m48t59_rtc) < 0)
+ printk(KERN_ERR "Registering RTC device failed\n");
+
+ return 0;
+}
+
+static struct of_device_id __initdata clock_match[] = {
+ {
+ .name = "eeprom",
+ },
+ {},
+};
+
+static struct of_platform_driver clock_driver = {
+ .match_table = clock_match,
+ .probe = clock_probe,
+ .driver = {
+ .name = "rtc",
+ },
+};
+
+
+/* Probe for the mostek real time clock chip. */
+static int __init clock_init(void)
+{
+ return of_register_driver(&clock_driver, &of_platform_bus_type);
+}
+
+/* Must be after subsys_initcall() so that busses are probed. Must
+ * be before device_initcall() because things like the RTC driver
+ * need to see the clock registers.
+ */
+fs_initcall(clock_init);
+
+static void __init sbus_time_init(void)
+{
+
+ BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
+ btfixup();
+
+ sparc_init_timers(timer_interrupt);
+
+ /* Now that OBP ticker has been silenced, it is safe to enable IRQ. */
+ local_irq_enable();
+}
+
+void __init time_init(void)
+{
+#ifdef CONFIG_PCI
+ extern void pci_time_init(void);
+ if (pcic_present()) {
+ pci_time_init();
+ return;
+ }
+#endif
+ sbus_time_init();
+}
+
+static inline unsigned long do_gettimeoffset(void)
+{
+ unsigned long val = *master_l10_counter;
+ unsigned long usec = (val >> 10) & 0x1fffff;
+
+ /* Limit hit? */
+ if (val & 0x80000000)
+ usec += 1000000 / HZ;
+
+ return usec;
+}
+
+/* Ok, my cute asm atomicity trick doesn't work anymore.
+ * There are just too many variables that need to be protected
+ * now (both members of xtime, et al.)
+ */
+void do_gettimeofday(struct timeval *tv)
+{
+ unsigned long flags;
+ unsigned long seq;
+ unsigned long usec, sec;
+ unsigned long max_ntp_tick = tick_usec - tickadj;
+
+ do {
+ seq = read_seqbegin_irqsave(&xtime_lock, flags);
+ usec = do_gettimeoffset();
+
+ /*
+ * If time_adjust is negative then NTP is slowing the clock
+ * so make sure not to go into next possible interval.
+ * Better to lose some accuracy than have time go backwards..
+ */
+ if (unlikely(time_adjust < 0))
+ usec = min(usec, max_ntp_tick);
+
+ sec = xtime.tv_sec;
+ usec += (xtime.tv_nsec / 1000);
+ } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
+
+ while (usec >= 1000000) {
+ usec -= 1000000;
+ sec++;
+ }
+
+ tv->tv_sec = sec;
+ tv->tv_usec = usec;
+}
+
+EXPORT_SYMBOL(do_gettimeofday);
+
+int do_settimeofday(struct timespec *tv)
+{
+ int ret;
+
+ write_seqlock_irq(&xtime_lock);
+ ret = bus_do_settimeofday(tv);
+ write_sequnlock_irq(&xtime_lock);
+ clock_was_set();
+ return ret;
+}
+
+EXPORT_SYMBOL(do_settimeofday);
+
+static int sbus_do_settimeofday(struct timespec *tv)
+{
+ time_t wtm_sec, sec = tv->tv_sec;
+ long wtm_nsec, nsec = tv->tv_nsec;
+
+ if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+ return -EINVAL;
+
+ /*
+ * This is revolting. We need to set "xtime" correctly. However, the
+ * value in this location is the value at the most recent update of
+ * wall time. Discover what correction gettimeofday() would have
+ * made, and then undo it!
+ */
+ nsec -= 1000 * do_gettimeoffset();
+
+ wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+ wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+ set_normalized_timespec(&xtime, sec, nsec);
+ set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
+
+ ntp_clear();
+ return 0;
+}
+
+static int set_rtc_mmss(unsigned long secs)
+{
+ struct rtc_device *rtc = rtc_class_open("rtc0");
+ int err = -1;
+
+ if (rtc) {
+ err = rtc_set_mmss(rtc, secs);
+ rtc_class_close(rtc);
+ }
+
+ return err;
+}
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