patch-2.4.10 linux/arch/mips/philips/nino/time.c

• Lines: 217
• Date: Sun Sep 9 10:43:02 2001
• Orig file: v2.4.9/linux/arch/mips/philips/nino/time.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.9/linux/arch/mips/philips/nino/time.c linux/arch/mips/philips/nino/time.c
@@ -0,0 +1,216 @@
+/*
+ *  linux/arch/mips/philips/nino/time.c
+ *
+ *  Copyright (C) 1999 Harald Koerfgen
+ *  Copyright (C) 2000 Pavel Machek (pavel@suse.cz)
+ *  Copyright (C) 2001 Steven J. Hill (sjhill@realitydiluted.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  Time handling functinos for Philips Nino.
+ */
+#include <linux/errno.h>
+#include <linux/init.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/timex.h>
+#include <linux/delay.h>
+#include <asm/tx3912.h>
+
+extern volatile unsigned long wall_jiffies;
+extern rwlock_t xtime_lock;
+
+static struct timeval xbase;
+
+#define USECS_PER_JIFFY (1000000/HZ)
+
+/*
+ * Poll the Interrupt Status Registers
+ */
+#undef POLL_STATUS
+
+static unsigned long do_gettimeoffset(void)
+{
+    /*
+     * This is a kludge
+     */
+    return 0;
+}
+
+static
+void inline readRTC(unsigned long *high, unsigned long *low)
+{
+	/* read twice, and keep reading till we find two
+	 * the same pairs. This is needed in case the RTC
+	 * was updating its registers and we read a old
+	 * High but a new Low. */
+	do {
+		*high = RTChigh & RTC_HIGHMASK;
+		*low = RTClow;
+	} while (*high != (RTChigh & RTC_HIGHMASK) || RTClow!=*low);
+}
+
+/*
+ * This version of gettimeofday has near millisecond resolution.
+ */
+void do_gettimeofday(struct timeval *tv)
+{
+    unsigned long flags;
+    unsigned long high, low;
+
+    read_lock_irqsave(&xtime_lock, flags);
+    // 40 bit RTC, driven by 32khz source:
+    // +-----------+-----------------------------------------+
+    // | HHHH.HHHH | LLLL.LLLL.LLLL.LLLL.LMMM.MMMM.MMMM.MMMM |
+    // +-----------+-----------------------------------------+
+    readRTC(&high,&low);
+    tv->tv_sec  = (high << 17) | (low >> 15);
+    tv->tv_usec = (low % 32768) * 1953 / 64;
+    tv->tv_sec += xbase.tv_sec;
+    tv->tv_usec += xbase.tv_usec;
+
+    tv->tv_usec += do_gettimeoffset();
+
+    /*
+     * xtime is atomically updated in timer_bh. lost_ticks is
+     * nonzero if the timer bottom half hasnt executed yet.
+     */
+    if (jiffies - wall_jiffies)
+	tv->tv_usec += USECS_PER_JIFFY;
+
+    read_unlock_irqrestore(&xtime_lock, flags);
+
+    if (tv->tv_usec >= 1000000) {
+	tv->tv_usec -= 1000000;
+	tv->tv_sec++;
+    }
+}
+
+void do_settimeofday(struct timeval *tv)
+{
+    write_lock_irq(&xtime_lock);
+    /* This is revolting. We need to set the xtime.tv_usec
+     * correctly. However, the value in this location is
+     * is value at the last tick.
+     * Discover what correction gettimeofday
+     * would have done, and then undo it!
+     */
+    tv->tv_usec -= do_gettimeoffset();
+
+    if (tv->tv_usec < 0) {
+	tv->tv_usec += 1000000;
+	tv->tv_sec--;
+    }
+
+    /* reset RTC to 0 (real time is xbase + RTC) */
+    xbase = *tv;
+    RTCtimerControl |=  TIM_RTCCLEAR;
+    RTCtimerControl &= ~TIM_RTCCLEAR;
+    RTCalarmHigh = RTCalarmLow = ~0UL;
+
+    xtime = *tv;
+    time_state = TIME_BAD;
+    time_maxerror = MAXPHASE;
+    time_esterror = MAXPHASE;
+    write_unlock_irq(&xtime_lock);
+}
+
+static int set_rtc_mmss(unsigned long nowtime)
+{
+    int retval = 0;
+
+    return retval;
+}
+
+/* last time the cmos 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
+ */
+
+int do_write = 1;
+
+static void
+timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+#ifdef POLL_STATUS
+    static unsigned long old_IntStatus1 = 0;
+    static unsigned long old_IntStatus3 = 0;
+    static unsigned long old_IntStatus4 = 0;
+    static unsigned long old_IntStatus5 = 0;
+    static int counter = 0;
+    int i;
+
+    new_spircv = SPIData & 0xff;
+    if ((old_spircv != new_spircv) && (new_spircv != 0xff)) {
+	    printk( "SPIData changed: %x\n", new_spircv );
+    }
+    old_spircv = new_spircv;
+    if (do_write)
+	    SPIData = 0;
+#endif
+
+    if (!user_mode(regs)) {
+	if (prof_buffer && current->pid) {
+	    extern int _stext;
+	    unsigned long pc = regs->cp0_epc;
+
+	    pc -= (unsigned long) &_stext;
+	    pc >>= prof_shift;
+	    /*
+	     * Dont ignore out-of-bounds pc values silently,
+	     * put them into the last histogram slot, so if
+	     * present, they will show up as a sharp peak.
+	     */
+	    if (pc > prof_len - 1)
+		pc = prof_len - 1;
+		atomic_inc((atomic_t *) & prof_buffer[pc]);
+	    }
+    }
+
+    /*
+     * aaaand... action!
+     */
+    do_timer(regs);
+
+    /*
+     * If we have an externally syncronized Linux clock, then update
+     * CMOS 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_state != TIME_BAD && xtime.tv_sec > last_rtc_update + 660 &&
+	xtime.tv_usec > 500000 - (tick >> 1) &&
+	xtime.tv_usec < 500000 + (tick >> 1))
+    {
+	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 */
+    }
+}
+
+static struct irqaction irq0 = {timer_interrupt, SA_INTERRUPT, 0,
+ 			 "timer", NULL, NULL};
+
+void (*board_time_init) (struct irqaction * irq);
+
+int __init time_init(void)
+{
+    struct timeval starttime;
+
+    starttime.tv_sec = mktime(2000, 1, 1, 0, 0, 0);
+    starttime.tv_usec = 0;
+    do_settimeofday(&starttime);
+
+    board_time_init(&irq0);
+
+    return 0;
+}