[deliverable/linux.git] / arch / mips / kernel / cevt-ds1287.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->min_delta_ns = clockevent_delta2ns(0x300, cd);
	cd->cpumask = cpumask_of(0);

	clockevents_register_device(&ds1287_clockevent);

	return setup_irq(irq, &ds1287_irqaction);
}
Commit	Line	Data
6457d9fc YY	1	/*
	2	* DS1287 clockevent driver
	3	*
70342287	4	* Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org>
6457d9fc YY	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20	#include <linux/clockchips.h>
	21	#include <linux/init.h>
	22	#include <linux/interrupt.h>
	23	#include <linux/mc146818rtc.h>
ca4d3e67	24	#include <linux/irq.h>
6457d9fc YY	25
	26	#include <asm/time.h>
	27
	28	int ds1287_timer_state(void)
	29	{
	30	return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
	31	}
	32
	33	int ds1287_set_base_clock(unsigned int hz)
	34	{
	35	u8 rate;
	36
	37	switch (hz) {
	38	case 128:
	39	rate = 0x9;
	40	break;
	41	case 256:
	42	rate = 0x8;
	43	break;
	44	case 1024:
	45	rate = 0x6;
	46	break;
	47	default:
	48	return -EINVAL;
	49	}
	50
	51	CMOS_WRITE(RTC_REF_CLCK_32KHZ \| rate, RTC_REG_A);
	52
	53	return 0;
	54	}
	55
	56	static int ds1287_set_next_event(unsigned long delta,
	57	struct clock_event_device *evt)
	58	{
	59	return -EINVAL;
	60	}
	61
9f95618f	62	static int ds1287_shutdown(struct clock_event_device *evt)
6457d9fc YY	63	{
	64	u8 val;
	65
	66	spin_lock(&rtc_lock);
	67
	68	val = CMOS_READ(RTC_REG_B);
9f95618f VK	69	val &= ~RTC_PIE;
9f95618f VK	70	CMOS_WRITE(val, RTC_REG_B);
6457d9fc	71
9f95618f VK	72	spin_unlock(&rtc_lock);
	73	return 0;
	74	}
6457d9fc	75
9f95618f VK	76	static int ds1287_set_periodic(struct clock_event_device *evt)
	77	{
	78	u8 val;
	79
	80	spin_lock(&rtc_lock);
	81
	82	val = CMOS_READ(RTC_REG_B);
	83	val \|= RTC_PIE;
6457d9fc YY	84	CMOS_WRITE(val, RTC_REG_B);
	85
	86	spin_unlock(&rtc_lock);
9f95618f	87	return 0;
6457d9fc YY	88	}
	89
	90	static void ds1287_event_handler(struct clock_event_device *dev)
	91	{
	92	}
	93
	94	static struct clock_event_device ds1287_clockevent = {
9f95618f VK	95	.name = "ds1287",
	96	.features = CLOCK_EVT_FEAT_PERIODIC,
	97	.set_next_event = ds1287_set_next_event,
	98	.set_state_shutdown = ds1287_shutdown,
	99	.set_state_periodic = ds1287_set_periodic,
	100	.tick_resume = ds1287_shutdown,
	101	.event_handler = ds1287_event_handler,
6457d9fc YY	102	};
	103
	104	static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
	105	{
	106	struct clock_event_device *cd = &ds1287_clockevent;
	107
	108	/* Ack the RTC interrupt. */
	109	CMOS_READ(RTC_REG_C);
	110
	111	cd->event_handler(cd);
	112
	113	return IRQ_HANDLED;
	114	}
	115
	116	static struct irqaction ds1287_irqaction = {
	117	.handler = ds1287_interrupt,
8b5690f8	118	.flags = IRQF_PERCPU \| IRQF_TIMER,
6457d9fc YY	119	.name = "ds1287",
	120	};
	121
	122	int __init ds1287_clockevent_init(int irq)
	123	{
	124	struct clock_event_device *cd;
	125
	126	cd = &ds1287_clockevent;
	127	cd->rating = 100;
	128	cd->irq = irq;
	129	clockevent_set_clock(cd, 32768);
	130	cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
	131	cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
320ab2b0	132	cd->cpumask = cpumask_of(0);
6457d9fc YY	133
	134	clockevents_register_device(&ds1287_clockevent);
	135
	136	return setup_irq(irq, &ds1287_irqaction);
	137	}