linux-sg2042/arch/mips/kernel/cevt-gt641xx.c

143 lines
3.6 KiB
C

/*
* GT641xx clockevent routines.
*
* Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* 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.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <asm/gt64120.h>
#include <asm/time.h>
#include <irq.h>
static DEFINE_SPINLOCK(gt641xx_timer_lock);
static unsigned int gt641xx_base_clock;
void gt641xx_set_base_clock(unsigned int clock)
{
gt641xx_base_clock = clock;
}
int gt641xx_timer0_state(void)
{
if (GT_READ(GT_TC0_OFS))
return 0;
GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
GT_WRITE(GT_TC_CONTROL_OFS, GT_TC_CONTROL_ENTC0_MSK);
return 1;
}
static int gt641xx_timer0_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
u32 ctrl;
spin_lock(&gt641xx_timer_lock);
ctrl = GT_READ(GT_TC_CONTROL_OFS);
ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
ctrl |= GT_TC_CONTROL_ENTC0_MSK;
GT_WRITE(GT_TC0_OFS, delta);
GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
spin_unlock(&gt641xx_timer_lock);
return 0;
}
static void gt641xx_timer0_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
u32 ctrl;
spin_lock(&gt641xx_timer_lock);
ctrl = GT_READ(GT_TC_CONTROL_OFS);
ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
ctrl |= GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK;
break;
case CLOCK_EVT_MODE_ONESHOT:
ctrl |= GT_TC_CONTROL_ENTC0_MSK;
break;
default:
break;
}
GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
spin_unlock(&gt641xx_timer_lock);
}
static void gt641xx_timer0_event_handler(struct clock_event_device *dev)
{
}
static struct clock_event_device gt641xx_timer0_clockevent = {
.name = "gt641xx-timer0",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.cpumask = CPU_MASK_CPU0,
.irq = GT641XX_TIMER0_IRQ,
.set_next_event = gt641xx_timer0_set_next_event,
.set_mode = gt641xx_timer0_set_mode,
.event_handler = gt641xx_timer0_event_handler,
};
static irqreturn_t gt641xx_timer0_interrupt(int irq, void *dev_id)
{
struct clock_event_device *cd = &gt641xx_timer0_clockevent;
cd->event_handler(cd);
return IRQ_HANDLED;
}
static struct irqaction gt641xx_timer0_irqaction = {
.handler = gt641xx_timer0_interrupt,
.flags = IRQF_DISABLED | IRQF_PERCPU,
.name = "gt641xx_timer0",
};
static int __init gt641xx_timer0_clockevent_init(void)
{
struct clock_event_device *cd;
if (!gt641xx_base_clock)
return 0;
GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
cd = &gt641xx_timer0_clockevent;
cd->rating = 200 + gt641xx_base_clock / 10000000;
clockevent_set_clock(cd, gt641xx_base_clock);
cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
clockevents_register_device(&gt641xx_timer0_clockevent);
return setup_irq(GT641XX_TIMER0_IRQ, &gt641xx_timer0_irqaction);
}
arch_initcall(gt641xx_timer0_clockevent_init);