[mirror_ubuntu-focal-kernel.git] / arch / mips / kernel / cevt-ds1287.c

// 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;
}

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);
}
Commit	Line	Data
16216333	1	// SPDX-License-Identifier: GPL-2.0-or-later
6457d9fc YY	2	/*
	3	* DS1287 clockevent driver
	4	*
70342287	5	* Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org>
6457d9fc YY	6	*/
	7	#include <linux/clockchips.h>
	8	#include <linux/init.h>
	9	#include <linux/interrupt.h>
	10	#include <linux/mc146818rtc.h>
ca4d3e67	11	#include <linux/irq.h>
6457d9fc YY	12
	13	#include <asm/time.h>
	14
	15	int ds1287_timer_state(void)
	16	{
	17	return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
	18	}
	19
	20	int 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
	43	static int ds1287_set_next_event(unsigned long delta,
	44	struct clock_event_device *evt)
	45	{
	46	return -EINVAL;
	47	}
	48
9f95618f	49	static int ds1287_shutdown(struct clock_event_device *evt)
6457d9fc YY	50	{
	51	u8 val;
	52
	53	spin_lock(&rtc_lock);
	54
	55	val = CMOS_READ(RTC_REG_B);
9f95618f VK	56	val &= ~RTC_PIE;
9f95618f VK	57	CMOS_WRITE(val, RTC_REG_B);
6457d9fc	58
9f95618f VK	59	spin_unlock(&rtc_lock);
	60	return 0;
	61	}
6457d9fc	62
9f95618f VK	63	static 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;
6457d9fc YY	71	CMOS_WRITE(val, RTC_REG_B);
	72
	73	spin_unlock(&rtc_lock);
9f95618f	74	return 0;
6457d9fc YY	75	}
	76
	77	static void ds1287_event_handler(struct clock_event_device *dev)
	78	{
	79	}
	80
	81	static struct clock_event_device ds1287_clockevent = {
9f95618f VK	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,
6457d9fc YY	89	};
	90
	91	static 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
	103	static struct irqaction ds1287_irqaction = {
	104	.handler = ds1287_interrupt,
8b5690f8	105	.flags = IRQF_PERCPU \| IRQF_TIMER,
6457d9fc YY	106	.name = "ds1287",
	107	};
	108
	109	int __init ds1287_clockevent_init(int irq)
	110	{
	111	struct clock_event_device *cd;
	112
	113	cd = &ds1287_clockevent;
	114	cd->rating = 100;
	115	cd->irq = irq;
	116	clockevent_set_clock(cd, 32768);
	117	cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
e4db9253	118	cd->max_delta_ticks = 0x7fffffff;
6457d9fc	119	cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
e4db9253	120	cd->min_delta_ticks = 0x300;
320ab2b0	121	cd->cpumask = cpumask_of(0);
6457d9fc YY	122
	123	clockevents_register_device(&ds1287_clockevent);
	124
	125	return setup_irq(irq, &ds1287_irqaction);
	126	}