patch-2.3.16 linux/arch/sh/kernel/time.c

• Lines: 226
• Date: Mon Aug 30 18:12:59 1999
• Orig file: v2.3.15/linux/arch/sh/kernel/time.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.15/linux/arch/sh/kernel/time.c linux/arch/sh/kernel/time.c
@@ -0,0 +1,225 @@
+/*
+ *  linux/arch/sh/kernel/time.c
+ *
+ *  Copyright (C) 1999  Niibe Yutaka
+ *
+ *  Some code taken from i386 version.
+ *    Copyright (C) 1991, 1992, 1995  Linus Torvalds
+ */
+
+#include <linux/errno.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/delay.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+
+#include <asm/processor.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/delay.h>
+
+#include <linux/timex.h>
+#include <linux/config.h>
+#include <linux/irq.h>
+
+#define TMU_TOCR	0xfffffe90	/* Byte access */
+#define TMU_TSTR	0xfffffe92	/* Byte access */
+
+#define TMU0_TCOR	0xfffffe94	/* Long access */
+#define TMU0_TCNT	0xfffffe98	/* Long access */
+#define TMU0_TCR	0xfffffe9c	/* Word access */
+
+#define TMU_TOCR_INIT	0x00
+#define TMU0_TCR_INIT	0x0020
+#define TMU_TSTR_INIT	1
+
+#define CLOCK_MHZ	(60/4)
+#define INTERVAL	37500 /* (1000000*CLOCK_MHZ/HZ/2) ??? */
+
+extern rwlock_t xtime_lock;
+#define TICK_SIZE tick
+
+void do_gettimeofday(struct timeval *tv)
+{
+	extern volatile unsigned long lost_ticks;
+	unsigned long flags;
+	unsigned long usec, sec;
+
+	read_lock_irqsave(&xtime_lock, flags);
+	usec = 0;
+	{
+		unsigned long lost = lost_ticks;
+		if (lost)
+			usec += lost * (1000000 / HZ);
+	}
+	sec = xtime.tv_sec;
+	usec += xtime.tv_usec;
+	read_unlock_irqrestore(&xtime_lock, flags);
+
+	while (usec >= 1000000) {
+		usec -= 1000000;
+		sec++;
+	}
+
+	tv->tv_sec = sec;
+	tv->tv_usec = usec;
+}
+
+void do_settimeofday(struct timeval *tv)
+{
+	write_lock_irq(&xtime_lock);
+	xtime = *tv;
+	time_adjust = 0;		/* stop active adjtime() */
+	time_status |= STA_UNSYNC;
+	time_maxerror = NTP_PHASE_LIMIT;
+	time_esterror = NTP_PHASE_LIMIT;
+	write_unlock_irq(&xtime_lock);
+}
+
+/*
+ */
+static int set_rtc_time(unsigned long nowtime)
+{
+/* XXX  should be implemented XXXXXXXXXX */
+	int retval = -1;
+
+	return retval;
+}
+
+/* last time the RTC clock got updated */
+static long last_rtc_update = 0;
+
+/*
+ * timer_interrupt() needs to keep up the real-time clock,
+ * as well as call the "do_timer()" routine every clocktick
+ */
+static inline void do_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	do_timer(regs);
+
+#if 0
+	if (!user_mode(regs))
+		sh_do_profile(regs->pc);
+#endif
+
+	/*
+	 * If we have an externally synchronized Linux clock, then update
+	 * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
+	 * called as close as possible to 500 ms before the new second starts.
+	 */
+	if ((time_status & STA_UNSYNC) == 0 &&
+	    xtime.tv_sec > last_rtc_update + 660 &&
+	    xtime.tv_usec >= 500000 - ((unsigned) tick) / 2 &&
+	    xtime.tv_usec <= 500000 + ((unsigned) tick) / 2) {
+		if (set_rtc_time(xtime.tv_sec) == 0)
+			last_rtc_update = xtime.tv_sec;
+		else
+			last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
+	}
+}
+
+/*
+ * This is the same as the above, except we _also_ save the current
+ * Time Stamp Counter value at the time of the timer interrupt, so that
+ * we later on can estimate the time of day more exactly.
+ */
+static void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	unsigned long __dummy;
+
+	/* Clear UNF bit */
+	asm volatile("mov.w	%1,%0\n\t"
+		     "and	%2,%0\n\t"
+		     "mov.w	%0,%1"
+		     : "=&z" (__dummy)
+		     : "m" (__m(TMU0_TCR)), "r" (~0x100));
+
+	/*
+	 * Here we are in the timer irq handler. We just have irqs locally
+	 * disabled but we don't know if the timer_bh is running on the other
+	 * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
+	 * the irq version of write_lock because as just said we have irq
+	 * locally disabled. -arca
+	 */
+	write_lock(&xtime_lock);
+
+	do_timer_interrupt(irq, NULL, regs);
+
+	write_unlock(&xtime_lock);
+}
+
+/* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
+ * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
+ * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
+ *
+ * [For the Julian calendar (which was used in Russia before 1917,
+ * Britain & colonies before 1752, anywhere else before 1582,
+ * and is still in use by some communities) leave out the
+ * -year/100+year/400 terms, and add 10.]
+ *
+ * This algorithm was first published by Gauss (I think).
+ *
+ * WARNING: this function will overflow on 2106-02-07 06:28:16 on
+ * machines were long is 32-bit! (However, as time_t is signed, we
+ * will already get problems at other places on 2038-01-19 03:14:08)
+ */
+static inline unsigned long mktime(unsigned int year, unsigned int mon,
+	unsigned int day, unsigned int hour,
+	unsigned int min, unsigned int sec)
+{
+	if (0 >= (int) (mon -= 2)) {	/* 1..12 -> 11,12,1..10 */
+		mon += 12;	/* Puts Feb last since it has leap day */
+		year -= 1;
+	}
+	return (((
+	    (unsigned long)(year/4 - year/100 + year/400 + 367*mon/12 + day) +
+	      year*365 - 719499
+	    )*24 + hour /* now have hours */
+	   )*60 + min /* now have minutes */
+	  )*60 + sec; /* finally seconds */
+}
+
+static unsigned long get_rtc_time(void)
+{
+/* XXX not implemented yet */
+	return 0;
+}
+
+static struct irqaction irq0  = { timer_interrupt, SA_INTERRUPT, 0, "timer", NULL, NULL};
+
+void __init time_init(void)
+{
+	unsigned long __dummy;
+
+	xtime.tv_sec = get_rtc_time();
+	xtime.tv_usec = 0;
+
+	set_ipr_data(TIMER_IRQ, TIMER_IRP_OFFSET, TIMER_PRIORITY);
+	setup_irq(TIMER_IRQ, &irq0);
+
+	/* Start TMU0 */
+	asm volatile("mov	%1,%0\n\t"
+		     "mov.b	%0,%2		! external clock input\n\t"
+		     "mov	%3,%0\n\t"
+		     "mov.w	%0,%4		! enable timer0 interrupt\n\t"
+		     "mov.l	%5,%6\n\t"
+		     "mov.l	%5,%7\n\t"
+		     "mov	%8,%0\n\t"
+		     "mov.b	%0,%9"
+		     : "=&z" (__dummy)
+		     : "i" (TMU_TOCR_INIT), "m" (__m(TMU_TOCR)),
+		       "i" (TMU0_TCR_INIT), "m" (__m(TMU0_TCR)),
+		       "r" (INTERVAL), "m" (__m(TMU0_TCOR)), "m" (__m(TMU0_TCNT)),
+		       "i" (TMU_TSTR_INIT), "m" (__m(TMU_TSTR)));
+#if 0
+	/* Start RTC */
+	asm volatile("");
+#endif
+}