blob: 1a23f0dcd4b89cee7e8b6b3afedbaeb80aab9ed3 [file] [log] [blame]
/*
* linux/arch/arm/mach-clps711x/time.c
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/timex.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/leds.h>
#include <asm/io.h>
#include <asm/hardware/clps7111.h>
#include <asm/mach/time.h>
/*
* gettimeoffset() returns time since last timer tick, in usecs.
*
* 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy.
* 'tick' is usecs per jiffy.
*/
static unsigned long clps711x_gettimeoffset(void)
{
unsigned long hwticks;
hwticks = LATCH - (clps_readl(TC2D) & 0xffff); /* since last underflow */
return (hwticks * (tick_nsec / 1000)) / LATCH;
}
/*
* IRQ handler for the timer
*/
static irqreturn_t
p720t_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
write_seqlock(&xtime_lock);
timer_tick(regs);
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
static struct irqaction clps711x_timer_irq = {
.name = "CLPS711x Timer Tick",
.flags = SA_INTERRUPT | SA_TIMER,
.handler = p720t_timer_interrupt,
};
static void __init clps711x_timer_init(void)
{
struct timespec tv;
unsigned int syscon;
syscon = clps_readl(SYSCON1);
syscon |= SYSCON1_TC2S | SYSCON1_TC2M;
clps_writel(syscon, SYSCON1);
clps_writel(LATCH-1, TC2D); /* 512kHz / 100Hz - 1 */
setup_irq(IRQ_TC2OI, &clps711x_timer_irq);
tv.tv_nsec = 0;
tv.tv_sec = clps_readl(RTCDR);
do_settimeofday(&tv);
}
struct sys_timer clps711x_timer = {
.init = clps711x_timer_init,
.offset = clps711x_gettimeoffset,
};