[linux-2.6-block.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 <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 void ds1287_set_mode(enum clock_event_mode mode,
			    struct clock_event_device *evt)
{
	u8 val;

	spin_lock(&rtc_lock);

	val = CMOS_READ(RTC_REG_B);

	switch (mode) {
	case CLOCK_EVT_MODE_PERIODIC:
		val |= RTC_PIE;
		break;
	default:
		val &= ~RTC_PIE;
		break;
	}

	CMOS_WRITE(val, RTC_REG_B);

	spin_unlock(&rtc_lock);
}

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_mode	= ds1287_set_mode,
	.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_DISABLED | 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	*
ada8e951	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>
	24
	25	#include <asm/time.h>
	26
	27	int ds1287_timer_state(void)
	28	{
	29	return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
	30	}
	31
	32	int ds1287_set_base_clock(unsigned int hz)
	33	{
	34	u8 rate;
	35
	36	switch (hz) {
	37	case 128:
	38	rate = 0x9;
	39	break;
	40	case 256:
	41	rate = 0x8;
	42	break;
	43	case 1024:
	44	rate = 0x6;
	45	break;
	46	default:
	47	return -EINVAL;
	48	}
	49
	50	CMOS_WRITE(RTC_REF_CLCK_32KHZ \| rate, RTC_REG_A);
	51
	52	return 0;
	53	}
	54
	55	static int ds1287_set_next_event(unsigned long delta,
	56	struct clock_event_device *evt)
	57	{
	58	return -EINVAL;
	59	}
	60
	61	static void ds1287_set_mode(enum clock_event_mode mode,
	62	struct clock_event_device *evt)
	63	{
	64	u8 val;
	65
	66	spin_lock(&rtc_lock);
	67
	68	val = CMOS_READ(RTC_REG_B);
69
70	switch (mode) {
71	case CLOCK_EVT_MODE_PERIODIC:
72	val \|= RTC_PIE;
73	break;
74	default:
75	val &= ~RTC_PIE;
76	break;
77	}
78
79	CMOS_WRITE(val, RTC_REG_B);
80
81	spin_unlock(&rtc_lock);
82	}
83
84	static void ds1287_event_handler(struct clock_event_device *dev)
85	{
86	}
87
88	static struct clock_event_device ds1287_clockevent = {
89	.name = "ds1287",
90	.features = CLOCK_EVT_FEAT_PERIODIC,
6457d9fc YY	91	.set_next_event = ds1287_set_next_event,
	92	.set_mode = ds1287_set_mode,
	93	.event_handler = ds1287_event_handler,
	94	};
	95
	96	static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
	97	{
	98	struct clock_event_device *cd = &ds1287_clockevent;
	99
	100	/* Ack the RTC interrupt. */
	101	CMOS_READ(RTC_REG_C);
	102
	103	cd->event_handler(cd);
	104
	105	return IRQ_HANDLED;
	106	}
	107
	108	static struct irqaction ds1287_irqaction = {
	109	.handler = ds1287_interrupt,
c49e38c1	110	.flags = IRQF_DISABLED \| IRQF_PERCPU \| IRQF_TIMER,
6457d9fc YY	111	.name = "ds1287",
	112	};
	113
	114	int __init ds1287_clockevent_init(int irq)
	115	{
	116	struct clock_event_device *cd;
	117
	118	cd = &ds1287_clockevent;
	119	cd->rating = 100;
	120	cd->irq = irq;
	121	clockevent_set_clock(cd, 32768);
	122	cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
	123	cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
320ab2b0	124	cd->cpumask = cpumask_of(0);
6457d9fc YY	125
	126	clockevents_register_device(&ds1287_clockevent);
	127
	128	return setup_irq(irq, &ds1287_irqaction);
	129	}