You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
110 lines
2.5 KiB
110 lines
2.5 KiB
20 years ago
|
/*
|
||
|
|
* arch/arm/mach-iop3xx/iop321-time.c
|
||
|
|
*
|
||
|
|
* Timer code for IOP321 based systems
|
||
|
|
*
|
||
|
|
* Author: Deepak Saxena <dsaxena@mvista.com>
|
||
|
|
*
|
||
|
|
* Copyright 2002-2003 MontaVista Software Inc.
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify it
|
||
|
|
* under the terms of the GNU General Public License as published by the
|
||
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
||
|
|
* option) any later version.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/interrupt.h>
|
||
|
|
#include <linux/time.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <linux/timex.h>
|
||
|
|
|
||
|
|
#include <asm/hardware.h>
|
||
|
|
#include <asm/io.h>
|
||
|
|
#include <asm/irq.h>
|
||
|
|
#include <asm/uaccess.h>
|
||
|
|
#include <asm/mach-types.h>
|
||
|
|
#include <asm/mach/irq.h>
|
||
|
|
#include <asm/mach/time.h>
|
||
|
|
|
||
|
|
#define IOP321_TIME_SYNC 0
|
||
|
|
|
||
|
|
static inline unsigned long get_elapsed(void)
|
||
|
|
{
|
||
|
|
return LATCH - *IOP321_TU_TCR0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static unsigned long iop321_gettimeoffset(void)
|
||
|
|
{
|
||
|
|
unsigned long elapsed, usec;
|
||
|
|
u32 tisr1, tisr2;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* If an interrupt was pending before we read the timer,
|
||
|
|
* we've already wrapped. Factor this into the time.
|
||
|
|
* If an interrupt was pending after we read the timer,
|
||
|
|
* it may have wrapped between checking the interrupt
|
||
|
|
* status and reading the timer. Re-read the timer to
|
||
|
|
* be sure its value is after the wrap.
|
||
|
|
*/
|
||
|
|
|
||
|
|
asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr1));
|
||
|
|
elapsed = get_elapsed();
|
||
|
|
asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr2));
|
||
|
|
|
||
|
|
if(tisr1 & 1)
|
||
|
|
elapsed += LATCH;
|
||
|
|
else if (tisr2 & 1)
|
||
|
|
elapsed = LATCH + get_elapsed();
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Now convert them to usec.
|
||
|
|
*/
|
||
|
|
usec = (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH;
|
||
|
|
|
||
|
|
return usec;
|
||
|
|
}
|
||
|
|
|
||
|
|
static irqreturn_t
|
||
|
|
iop321_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
|
||
|
|
{
|
||
|
|
u32 tisr;
|
||
|
|
|
||
|
|
write_seqlock(&xtime_lock);
|
||
|
|
|
||
|
|
asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr));
|
||
|
|
tisr |= 1;
|
||
|
|
asm volatile("mcr p6, 0, %0, c6, c1, 0" : : "r" (tisr));
|
||
|
|
|
||
|
|
timer_tick(regs);
|
||
|
|
|
||
|
|
write_sequnlock(&xtime_lock);
|
||
|
|
|
||
|
|
return IRQ_HANDLED;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct irqaction iop321_timer_irq = {
|
||
|
|
.name = "IOP321 Timer Tick",
|
||
|
|
.handler = iop321_timer_interrupt,
|
||
|
|
.flags = SA_INTERRUPT
|
||
|
|
};
|
||
|
|
|
||
|
|
static void __init iop321_timer_init(void)
|
||
|
|
{
|
||
|
|
u32 timer_ctl;
|
||
|
|
|
||
|
|
setup_irq(IRQ_IOP321_TIMER0, &iop321_timer_irq);
|
||
|
|
|
||
|
|
timer_ctl = IOP321_TMR_EN | IOP321_TMR_PRIVILEGED | IOP321_TMR_RELOAD |
|
||
|
|
IOP321_TMR_RATIO_1_1;
|
||
|
|
|
||
|
|
asm volatile("mcr p6, 0, %0, c4, c1, 0" : : "r" (LATCH));
|
||
|
|
|
||
|
|
asm volatile("mcr p6, 0, %0, c0, c1, 0" : : "r" (timer_ctl));
|
||
|
|
}
|
||
|
|
|
||
|
|
struct sys_timer iop321_timer = {
|
||
|
|
.init = &iop321_timer_init,
|
||
|
|
.offset = iop321_gettimeoffset,
|
||
|
|
};
|