linux/arch/arm/common/time-acorn.c
Linus Torvalds 0cd61b68c3 Initial blind fixup for arm for irq changes
Untested, but this should fix up the bulk of the totally mechanical
issues, and should make the actual detail fixing easier.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-06 10:59:54 -07:00

97 lines
2.1 KiB
C

/*
* linux/arch/arm/common/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=Jun-2004 DS Moved to arch/arm/common b/c shared w/CLPS7500
*/
#include <linux/timex.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/hardware/ioc.h>
#include <asm/mach/time.h>
unsigned long ioc_timer_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);
}
static irqreturn_t
ioc_timer_interrupt(int irq, void *dev_id)
{
write_seqlock(&xtime_lock);
timer_tick();
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
static struct irqaction ioc_timer_irq = {
.name = "timer",
.flags = IRQF_DISABLED,
.handler = ioc_timer_interrupt
};
/*
* Set up timer interrupt.
*/
static void __init ioc_timer_init(void)
{
ioctime_init();
setup_irq(IRQ_TIMER, &ioc_timer_irq);
}
struct sys_timer ioc_timer = {
.init = ioc_timer_init,
.offset = ioc_timer_gettimeoffset,
};