[PATCH] arm26: replace arm32 time handling code with smaller version

ARM26 systems only have one possible clock, thus we can merge all this into
one source file and drop the ability to dynamically alter it.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/arm26/kernel/time-acorn.c

-/*
- *  linux/arch/arm/kernel/time-acorn.c
- *
- *  Copyright (c) 1996-2000 Russell King.
- *
- * 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.
- *
- *  Changelog:
- *   24-Sep-1996	RMK	Created
- *   10-Oct-1996	RMK	Brought up to date with arch-sa110eval
- *   04-Dec-1997	RMK	Updated for new arch/arm/time.c
- *   13-May-2003        IM      Brought over to ARM26
- */
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/init.h>
-
-#include <asm/hardware.h>
-#include <asm/io.h>
-#include <asm/irq.h>
-#include <asm/ioc.h>
-
-extern unsigned long (*gettimeoffset)(void);
-
-static unsigned long ioctime_gettimeoffset(void)
-{
-	unsigned int count1, count2, status;
-        long offset;
-
-        ioc_writeb (0, IOC_T0LATCH);
-        barrier ();
-        count1 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
-        barrier ();
-        status = ioc_readb(IOC_IRQREQA);
-        barrier ();
-        ioc_writeb (0, IOC_T0LATCH);
-        barrier ();
-        count2 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
-
-        offset = count2;
-        if (count2 < count1) {
-                /*
-                 * We have not had an interrupt between reading count1
-                 * and count2.
-                 */
-                if (status & (1 << 5))
-                        offset -= LATCH;
-        } else if (count2 > count1) {
-                /*
-                 * We have just had another interrupt between reading
-                 * count1 and count2.
-                 */
-                offset -= LATCH;
-        }
-
-        offset = (LATCH - offset) * (tick_nsec / 1000);
-        return (offset + LATCH/2) / LATCH;
-}
-
-void __init ioctime_init(void)
-{
-	ioc_writeb(LATCH & 255, IOC_T0LTCHL);
-	ioc_writeb(LATCH >> 8, IOC_T0LTCHH);
-	ioc_writeb(0, IOC_T0GO);
-
-	gettimeoffset = ioctime_gettimeoffset;
-}

arch/arm26/kernel/time.c

@@ -32,7 +32,7 @@
 #include <asm/hardware.h>
 #include <asm/io.h>
 #include <asm/irq.h>
-#include <asm/leds.h>
+#include <asm/ioc.h>
 
 u64 jiffies_64 = INITIAL_JIFFIES;
 
@@ -56,16 +56,53 @@ static int dummy_set_rtc(void)
  */
 int (*set_rtc)(void) = dummy_set_rtc;
 
-static unsigned long dummy_gettimeoffset(void)
+/*
+ * Get time offset based on IOCs timer.
+ * FIXME - if this is called with interrutps off, why the shennanigans
+ * below ?
+ */
+static unsigned long gettimeoffset(void)
 {
-	return 0;
+        unsigned int count1, count2, status;
+        long offset;
+
+        ioc_writeb (0, IOC_T0LATCH);
+        barrier ();
+        count1 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
+        barrier ();
+        status = ioc_readb(IOC_IRQREQA);
+        barrier ();
+        ioc_writeb (0, IOC_T0LATCH);
+        barrier ();
+        count2 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
+
+        offset = count2;
+        if (count2 < count1) {
+                /*
+                 * We have not had an interrupt between reading count1
+                 * and count2.
+                 */
+                if (status & (1 << 5))
+                        offset -= LATCH;
+        } else if (count2 > count1) {
+                /*
+                 * We have just had another interrupt between reading
+                 * count1 and count2.
+                 */
+                offset -= LATCH;
+        }
+
+        offset = (LATCH - offset) * (tick_nsec / 1000);
+        return (offset + LATCH/2) / LATCH;
 }
 
 /*
- * hook for getting the time offset.  Note that it is
- * always called with interrupts disabled.
+ * Scheduler clock - returns current time in nanosec units.
  */
-unsigned long (*gettimeoffset)(void) = dummy_gettimeoffset;
+unsigned long long sched_clock(void)
+{
+	return (unsigned long long)jiffies * (1000000000 / HZ);
+}
 
 static unsigned long next_rtc_update;
 
@@ -187,7 +224,10 @@ extern void ioctime_init(void);
  */
 void __init time_init(void)
 {
-        ioctime_init();
+	ioc_writeb(LATCH & 255, IOC_T0LTCHL);
+        ioc_writeb(LATCH >> 8, IOC_T0LTCHH);
+        ioc_writeb(0, IOC_T0GO);
+
 
         setup_irq(IRQ_TIMER, &timer_irq);
 }