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Diffstat (limited to 'arch/i386/kernel/timers/timer_pit.c')
-rw-r--r--arch/i386/kernel/timers/timer_pit.c177
1 files changed, 0 insertions, 177 deletions
diff --git a/arch/i386/kernel/timers/timer_pit.c b/arch/i386/kernel/timers/timer_pit.c
deleted file mode 100644
index b9b6bd56b9b..00000000000
--- a/arch/i386/kernel/timers/timer_pit.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/*
- * This code largely moved from arch/i386/kernel/time.c.
- * See comments there for proper credits.
- */
-
-#include <linux/spinlock.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/sysdev.h>
-#include <linux/timex.h>
-#include <asm/delay.h>
-#include <asm/mpspec.h>
-#include <asm/timer.h>
-#include <asm/smp.h>
-#include <asm/io.h>
-#include <asm/arch_hooks.h>
-#include <asm/i8253.h>
-
-#include "do_timer.h"
-#include "io_ports.h"
-
-static int count_p; /* counter in get_offset_pit() */
-
-static int __init init_pit(char* override)
-{
- /* check clock override */
- if (override[0] && strncmp(override,"pit",3))
- printk(KERN_ERR "Warning: clock= override failed. Defaulting "
- "to PIT\n");
- init_cpu_khz();
- count_p = LATCH;
- return 0;
-}
-
-static void mark_offset_pit(void)
-{
- /* nothing needed */
-}
-
-static unsigned long long monotonic_clock_pit(void)
-{
- return 0;
-}
-
-static void delay_pit(unsigned long loops)
-{
- int d0;
- __asm__ __volatile__(
- "\tjmp 1f\n"
- ".align 16\n"
- "1:\tjmp 2f\n"
- ".align 16\n"
- "2:\tdecl %0\n\tjns 2b"
- :"=&a" (d0)
- :"0" (loops));
-}
-
-
-/* This function must be called with xtime_lock held.
- * It was inspired by Steve McCanne's microtime-i386 for BSD. -- jrs
- *
- * However, the pc-audio speaker driver changes the divisor so that
- * it gets interrupted rather more often - it loads 64 into the
- * counter rather than 11932! This has an adverse impact on
- * do_gettimeoffset() -- it stops working! What is also not
- * good is that the interval that our timer function gets called
- * is no longer 10.0002 ms, but 9.9767 ms. To get around this
- * would require using a different timing source. Maybe someone
- * could use the RTC - I know that this can interrupt at frequencies
- * ranging from 8192Hz to 2Hz. If I had the energy, I'd somehow fix
- * it so that at startup, the timer code in sched.c would select
- * using either the RTC or the 8253 timer. The decision would be
- * based on whether there was any other device around that needed
- * to trample on the 8253. I'd set up the RTC to interrupt at 1024 Hz,
- * and then do some jiggery to have a version of do_timer that
- * advanced the clock by 1/1024 s. Every time that reached over 1/100
- * of a second, then do all the old code. If the time was kept correct
- * then do_gettimeoffset could just return 0 - there is no low order
- * divider that can be accessed.
- *
- * Ideally, you would be able to use the RTC for the speaker driver,
- * but it appears that the speaker driver really needs interrupt more
- * often than every 120 us or so.
- *
- * Anyway, this needs more thought.... pjsg (1993-08-28)
- *
- * If you are really that interested, you should be reading
- * comp.protocols.time.ntp!
- */
-
-static unsigned long get_offset_pit(void)
-{
- int count;
- unsigned long flags;
- static unsigned long jiffies_p = 0;
-
- /*
- * cache volatile jiffies temporarily; we have xtime_lock.
- */
- unsigned long jiffies_t;
-
- spin_lock_irqsave(&i8253_lock, flags);
- /* timer count may underflow right here */
- outb_p(0x00, PIT_MODE); /* latch the count ASAP */
-
- count = inb_p(PIT_CH0); /* read the latched count */
-
- /*
- * We do this guaranteed double memory access instead of a _p
- * postfix in the previous port access. Wheee, hackady hack
- */
- jiffies_t = jiffies;
-
- count |= inb_p(PIT_CH0) << 8;
-
- /* VIA686a test code... reset the latch if count > max + 1 */
- if (count > LATCH) {
- outb_p(0x34, PIT_MODE);
- outb_p(LATCH & 0xff, PIT_CH0);
- outb(LATCH >> 8, PIT_CH0);
- count = LATCH - 1;
- }
-
- /*
- * avoiding timer inconsistencies (they are rare, but they happen)...
- * there are two kinds of problems that must be avoided here:
- * 1. the timer counter underflows
- * 2. hardware problem with the timer, not giving us continuous time,
- * the counter does small "jumps" upwards on some Pentium systems,
- * (see c't 95/10 page 335 for Neptun bug.)
- */
-
- if( jiffies_t == jiffies_p ) {
- if( count > count_p ) {
- /* the nutcase */
- count = do_timer_overflow(count);
- }
- } else
- jiffies_p = jiffies_t;
-
- count_p = count;
-
- spin_unlock_irqrestore(&i8253_lock, flags);
-
- count = ((LATCH-1) - count) * TICK_SIZE;
- count = (count + LATCH/2) / LATCH;
-
- return count;
-}
-
-
-/* tsc timer_opts struct */
-struct timer_opts timer_pit = {
- .name = "pit",
- .mark_offset = mark_offset_pit,
- .get_offset = get_offset_pit,
- .monotonic_clock = monotonic_clock_pit,
- .delay = delay_pit,
-};
-
-struct init_timer_opts __initdata timer_pit_init = {
- .init = init_pit,
- .opts = &timer_pit,
-};
-
-void setup_pit_timer(void)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
- outb_p(0x34,PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
- udelay(10);
- outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
- udelay(10);
- outb(LATCH >> 8 , PIT_CH0); /* MSB */
- spin_unlock_irqrestore(&i8253_lock, flags);
-}