140 lines
3 KiB
C
140 lines
3 KiB
C
/*
|
|
* DS1287 clockevent driver
|
|
*
|
|
* Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org>
|
|
*
|
|
* 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/mc146818rtc.h>
|
|
#include <linux/irq.h>
|
|
|
|
#include <asm/time.h>
|
|
|
|
int ds1287_timer_state(void)
|
|
{
|
|
return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
|
|
}
|
|
|
|
int ds1287_set_base_clock(unsigned int hz)
|
|
{
|
|
u8 rate;
|
|
|
|
switch (hz) {
|
|
case 128:
|
|
rate = 0x9;
|
|
break;
|
|
case 256:
|
|
rate = 0x8;
|
|
break;
|
|
case 1024:
|
|
rate = 0x6;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ds1287_set_next_event(unsigned long delta,
|
|
struct clock_event_device *evt)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int ds1287_shutdown(struct clock_event_device *evt)
|
|
{
|
|
u8 val;
|
|
|
|
spin_lock(&rtc_lock);
|
|
|
|
val = CMOS_READ(RTC_REG_B);
|
|
val &= ~RTC_PIE;
|
|
CMOS_WRITE(val, RTC_REG_B);
|
|
|
|
spin_unlock(&rtc_lock);
|
|
return 0;
|
|
}
|
|
|
|
static int ds1287_set_periodic(struct clock_event_device *evt)
|
|
{
|
|
u8 val;
|
|
|
|
spin_lock(&rtc_lock);
|
|
|
|
val = CMOS_READ(RTC_REG_B);
|
|
val |= RTC_PIE;
|
|
CMOS_WRITE(val, RTC_REG_B);
|
|
|
|
spin_unlock(&rtc_lock);
|
|
return 0;
|
|
}
|
|
|
|
static void ds1287_event_handler(struct clock_event_device *dev)
|
|
{
|
|
}
|
|
|
|
static struct clock_event_device ds1287_clockevent = {
|
|
.name = "ds1287",
|
|
.features = CLOCK_EVT_FEAT_PERIODIC,
|
|
.set_next_event = ds1287_set_next_event,
|
|
.set_state_shutdown = ds1287_shutdown,
|
|
.set_state_periodic = ds1287_set_periodic,
|
|
.tick_resume = ds1287_shutdown,
|
|
.event_handler = ds1287_event_handler,
|
|
};
|
|
|
|
static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct clock_event_device *cd = &ds1287_clockevent;
|
|
|
|
/* Ack the RTC interrupt. */
|
|
CMOS_READ(RTC_REG_C);
|
|
|
|
cd->event_handler(cd);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct irqaction ds1287_irqaction = {
|
|
.handler = ds1287_interrupt,
|
|
.flags = IRQF_PERCPU | IRQF_TIMER,
|
|
.name = "ds1287",
|
|
};
|
|
|
|
int __init ds1287_clockevent_init(int irq)
|
|
{
|
|
struct clock_event_device *cd;
|
|
|
|
cd = &ds1287_clockevent;
|
|
cd->rating = 100;
|
|
cd->irq = irq;
|
|
clockevent_set_clock(cd, 32768);
|
|
cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
|
|
cd->max_delta_ticks = 0x7fffffff;
|
|
cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
|
|
cd->min_delta_ticks = 0x300;
|
|
cd->cpumask = cpumask_of(0);
|
|
|
|
clockevents_register_device(&ds1287_clockevent);
|
|
|
|
return setup_irq(irq, &ds1287_irqaction);
|
|
}
|