1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  DS1287 clockevent driver
  4 *
  5 *  Copyright (C) 2008	Yoichi Yuasa <yuasa@linux-mips.org>
  6 */
  7#include <linux/clockchips.h>
  8#include <linux/init.h>
  9#include <linux/interrupt.h>
 10#include <linux/mc146818rtc.h>
 11#include <linux/irq.h>
 12
 13#include <asm/time.h>
 14
 15int ds1287_timer_state(void)
 16{
 17	return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
 18}
 19
 20int ds1287_set_base_clock(unsigned int hz)
 21{
 22	u8 rate;
 23
 24	switch (hz) {
 25	case 128:
 26		rate = 0x9;
 27		break;
 28	case 256:
 29		rate = 0x8;
 30		break;
 31	case 1024:
 32		rate = 0x6;
 33		break;
 34	default:
 35		return -EINVAL;
 36	}
 37
 38	CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
 39
 40	return 0;
 41}
 42
 43static int ds1287_set_next_event(unsigned long delta,
 44				 struct clock_event_device *evt)
 45{
 46	return -EINVAL;
 47}
 48
 49static int ds1287_shutdown(struct clock_event_device *evt)
 50{
 51	u8 val;
 52
 53	spin_lock(&rtc_lock);
 54
 55	val = CMOS_READ(RTC_REG_B);
 56	val &= ~RTC_PIE;
 57	CMOS_WRITE(val, RTC_REG_B);
 58
 59	spin_unlock(&rtc_lock);
 60	return 0;
 61}
 62
 63static int ds1287_set_periodic(struct clock_event_device *evt)
 64{
 65	u8 val;
 66
 67	spin_lock(&rtc_lock);
 68
 69	val = CMOS_READ(RTC_REG_B);
 70	val |= RTC_PIE;
 71	CMOS_WRITE(val, RTC_REG_B);
 72
 73	spin_unlock(&rtc_lock);
 74	return 0;
 75}
 76
 77static void ds1287_event_handler(struct clock_event_device *dev)
 78{
 79}
 80
 81static struct clock_event_device ds1287_clockevent = {
 82	.name			= "ds1287",
 83	.features		= CLOCK_EVT_FEAT_PERIODIC,
 84	.set_next_event		= ds1287_set_next_event,
 85	.set_state_shutdown	= ds1287_shutdown,
 86	.set_state_periodic	= ds1287_set_periodic,
 87	.tick_resume		= ds1287_shutdown,
 88	.event_handler		= ds1287_event_handler,
 89};
 90
 91static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
 92{
 93	struct clock_event_device *cd = &ds1287_clockevent;
 94
 95	/* Ack the RTC interrupt. */
 96	CMOS_READ(RTC_REG_C);
 97
 98	cd->event_handler(cd);
 99
100	return IRQ_HANDLED;
101}
102
103int __init ds1287_clockevent_init(int irq)
104{
105	unsigned long flags = IRQF_PERCPU | IRQF_TIMER;
106	struct clock_event_device *cd;
107
108	cd = &ds1287_clockevent;
109	cd->rating = 100;
110	cd->irq = irq;
111	clockevent_set_clock(cd, 32768);
112	cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
113	cd->max_delta_ticks = 0x7fffffff;
114	cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
115	cd->min_delta_ticks = 0x300;
116	cd->cpumask = cpumask_of(0);
117
118	clockevents_register_device(&ds1287_clockevent);
119
120	return request_irq(irq, ds1287_interrupt, flags, "ds1287", NULL);
121}

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  DS1287 clockevent driver
  4 *
  5 *  Copyright (C) 2008	Yoichi Yuasa <yuasa@linux-mips.org>
  6 */
  7#include <linux/clockchips.h>
  8#include <linux/init.h>
  9#include <linux/interrupt.h>
 10#include <linux/mc146818rtc.h>
 11#include <linux/irq.h>
 12
 13#include <asm/time.h>
 14
 15int ds1287_timer_state(void)
 16{
 17	return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
 18}
 19
 20int ds1287_set_base_clock(unsigned int hz)
 21{
 22	u8 rate;
 23
 24	switch (hz) {
 25	case 128:
 26		rate = 0x9;
 27		break;
 28	case 256:
 29		rate = 0x8;
 30		break;
 31	case 1024:
 32		rate = 0x6;
 33		break;
 34	default:
 35		return -EINVAL;
 36	}
 37
 38	CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
 39
 40	return 0;
 41}
 42
 43static int ds1287_set_next_event(unsigned long delta,
 44				 struct clock_event_device *evt)
 45{
 46	return -EINVAL;
 47}
 48
 49static int ds1287_shutdown(struct clock_event_device *evt)
 50{
 51	u8 val;
 52
 53	spin_lock(&rtc_lock);
 54
 55	val = CMOS_READ(RTC_REG_B);
 56	val &= ~RTC_PIE;
 57	CMOS_WRITE(val, RTC_REG_B);
 58
 59	spin_unlock(&rtc_lock);
 60	return 0;
 61}
 62
 63static int ds1287_set_periodic(struct clock_event_device *evt)
 64{
 65	u8 val;
 66
 67	spin_lock(&rtc_lock);
 68
 69	val = CMOS_READ(RTC_REG_B);
 70	val |= RTC_PIE;
 71	CMOS_WRITE(val, RTC_REG_B);
 72
 73	spin_unlock(&rtc_lock);
 74	return 0;
 75}
 76
 77static void ds1287_event_handler(struct clock_event_device *dev)
 78{
 79}
 80
 81static struct clock_event_device ds1287_clockevent = {
 82	.name			= "ds1287",
 83	.features		= CLOCK_EVT_FEAT_PERIODIC,
 84	.set_next_event		= ds1287_set_next_event,
 85	.set_state_shutdown	= ds1287_shutdown,
 86	.set_state_periodic	= ds1287_set_periodic,
 87	.tick_resume		= ds1287_shutdown,
 88	.event_handler		= ds1287_event_handler,
 89};
 90
 91static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
 92{
 93	struct clock_event_device *cd = &ds1287_clockevent;
 94
 95	/* Ack the RTC interrupt. */
 96	CMOS_READ(RTC_REG_C);
 97
 98	cd->event_handler(cd);
 99
100	return IRQ_HANDLED;
101}
102
103int __init ds1287_clockevent_init(int irq)
104{
105	unsigned long flags = IRQF_PERCPU | IRQF_TIMER;
106	struct clock_event_device *cd;
107
108	cd = &ds1287_clockevent;
109	cd->rating = 100;
110	cd->irq = irq;
111	clockevent_set_clock(cd, 32768);
112	cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
113	cd->max_delta_ticks = 0x7fffffff;
114	cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
115	cd->min_delta_ticks = 0x300;
116	cd->cpumask = cpumask_of(0);
117
118	clockevents_register_device(&ds1287_clockevent);
119
120	return request_irq(irq, ds1287_interrupt, flags, "ds1287", NULL);
121}