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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* DS1287 clockevent driver
*
* Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org>
*/
#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;
}
int __init ds1287_clockevent_init(int irq)
{
unsigned long flags = IRQF_PERCPU | IRQF_TIMER;
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 request_irq(irq, ds1287_interrupt, flags, "ds1287", NULL);
}
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