mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 10:56:40 +00:00
4ff859fe1d
The clockevents code was being told that the footbridge clock event
device ticks at 16x the rate which it actually does. This leads to
timekeeping problems since it allows the clocksource to wrap before
the kernel notices. Fix this by using the correct clock.
Fixes: 4e8d76373c ("ARM: footbridge: convert to clockevents/clocksource")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: <stable@vger.kernel.org>
108 lines
2.3 KiB
C
108 lines
2.3 KiB
C
/*
|
|
* linux/arch/arm/mach-footbridge/dc21285-timer.c
|
|
*
|
|
* Copyright (C) 1998 Russell King.
|
|
* Copyright (C) 1998 Phil Blundell
|
|
*/
|
|
#include <linux/clockchips.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/init.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/irq.h>
|
|
|
|
#include <asm/irq.h>
|
|
|
|
#include <asm/hardware/dec21285.h>
|
|
#include <asm/mach/time.h>
|
|
#include <asm/system_info.h>
|
|
|
|
#include "common.h"
|
|
|
|
static cycle_t cksrc_dc21285_read(struct clocksource *cs)
|
|
{
|
|
return cs->mask - *CSR_TIMER2_VALUE;
|
|
}
|
|
|
|
static int cksrc_dc21285_enable(struct clocksource *cs)
|
|
{
|
|
*CSR_TIMER2_LOAD = cs->mask;
|
|
*CSR_TIMER2_CLR = 0;
|
|
*CSR_TIMER2_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16;
|
|
return 0;
|
|
}
|
|
|
|
static void cksrc_dc21285_disable(struct clocksource *cs)
|
|
{
|
|
*CSR_TIMER2_CNTL = 0;
|
|
}
|
|
|
|
static struct clocksource cksrc_dc21285 = {
|
|
.name = "dc21285_timer2",
|
|
.rating = 200,
|
|
.read = cksrc_dc21285_read,
|
|
.enable = cksrc_dc21285_enable,
|
|
.disable = cksrc_dc21285_disable,
|
|
.mask = CLOCKSOURCE_MASK(24),
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
};
|
|
|
|
static void ckevt_dc21285_set_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *c)
|
|
{
|
|
switch (mode) {
|
|
case CLOCK_EVT_MODE_RESUME:
|
|
case CLOCK_EVT_MODE_PERIODIC:
|
|
*CSR_TIMER1_CLR = 0;
|
|
*CSR_TIMER1_LOAD = (mem_fclk_21285 + 8 * HZ) / (16 * HZ);
|
|
*CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD |
|
|
TIMER_CNTL_DIV16;
|
|
break;
|
|
|
|
default:
|
|
*CSR_TIMER1_CNTL = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
static struct clock_event_device ckevt_dc21285 = {
|
|
.name = "dc21285_timer1",
|
|
.features = CLOCK_EVT_FEAT_PERIODIC,
|
|
.rating = 200,
|
|
.irq = IRQ_TIMER1,
|
|
.set_mode = ckevt_dc21285_set_mode,
|
|
};
|
|
|
|
static irqreturn_t timer1_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct clock_event_device *ce = dev_id;
|
|
|
|
*CSR_TIMER1_CLR = 0;
|
|
|
|
ce->event_handler(ce);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct irqaction footbridge_timer_irq = {
|
|
.name = "dc21285_timer1",
|
|
.handler = timer1_interrupt,
|
|
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
|
|
.dev_id = &ckevt_dc21285,
|
|
};
|
|
|
|
/*
|
|
* Set up timer interrupt.
|
|
*/
|
|
void __init footbridge_timer_init(void)
|
|
{
|
|
struct clock_event_device *ce = &ckevt_dc21285;
|
|
unsigned rate = DIV_ROUND_CLOSEST(mem_fclk_21285, 16);
|
|
|
|
clocksource_register_hz(&cksrc_dc21285, rate);
|
|
|
|
setup_irq(ce->irq, &footbridge_timer_irq);
|
|
|
|
ce->cpumask = cpumask_of(smp_processor_id());
|
|
clockevents_config_and_register(ce, rate, 0x4, 0xffffff);
|
|
}
|