[linux.git] / drivers / rtc / rtc-omap.c

/*
 * TI OMAP1 Real Time Clock interface for Linux
 *
 * Copyright (C) 2003 MontaVista Software, Inc.
 * Author: George G. Davis <[email protected]> or <[email protected]>
 *
 * Copyright (C) 2006 David Brownell (new RTC framework)
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/platform_device.h>

#include <asm/io.h>


/* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
 * with century-range alarm matching, driven by the 32kHz clock.
 *
 * The main user-visible ways it differs from PC RTCs are by omitting
 * "don't care" alarm fields and sub-second periodic IRQs, and having
 * an autoadjust mechanism to calibrate to the true oscillator rate.
 *
 * Board-specific wiring options include using split power mode with
 * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
 * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
 * low power modes).  See the BOARD-SPECIFIC CUSTOMIZATION comment.
 */

#define OMAP_RTC_BASE			0xfffb4800

/* RTC registers */
#define OMAP_RTC_SECONDS_REG		0x00
#define OMAP_RTC_MINUTES_REG		0x04
#define OMAP_RTC_HOURS_REG		0x08
#define OMAP_RTC_DAYS_REG		0x0C
#define OMAP_RTC_MONTHS_REG		0x10
#define OMAP_RTC_YEARS_REG		0x14
#define OMAP_RTC_WEEKS_REG		0x18

#define OMAP_RTC_ALARM_SECONDS_REG	0x20
#define OMAP_RTC_ALARM_MINUTES_REG	0x24
#define OMAP_RTC_ALARM_HOURS_REG	0x28
#define OMAP_RTC_ALARM_DAYS_REG		0x2c
#define OMAP_RTC_ALARM_MONTHS_REG	0x30
#define OMAP_RTC_ALARM_YEARS_REG	0x34

#define OMAP_RTC_CTRL_REG		0x40
#define OMAP_RTC_STATUS_REG		0x44
#define OMAP_RTC_INTERRUPTS_REG		0x48

#define OMAP_RTC_COMP_LSB_REG		0x4c
#define OMAP_RTC_COMP_MSB_REG		0x50
#define OMAP_RTC_OSC_REG		0x54

/* OMAP_RTC_CTRL_REG bit fields: */
#define OMAP_RTC_CTRL_SPLIT		(1<<7)
#define OMAP_RTC_CTRL_DISABLE		(1<<6)
#define OMAP_RTC_CTRL_SET_32_COUNTER	(1<<5)
#define OMAP_RTC_CTRL_TEST		(1<<4)
#define OMAP_RTC_CTRL_MODE_12_24	(1<<3)
#define OMAP_RTC_CTRL_AUTO_COMP		(1<<2)
#define OMAP_RTC_CTRL_ROUND_30S		(1<<1)
#define OMAP_RTC_CTRL_STOP		(1<<0)

/* OMAP_RTC_STATUS_REG bit fields: */
#define OMAP_RTC_STATUS_POWER_UP        (1<<7)
#define OMAP_RTC_STATUS_ALARM           (1<<6)
#define OMAP_RTC_STATUS_1D_EVENT        (1<<5)
#define OMAP_RTC_STATUS_1H_EVENT        (1<<4)
#define OMAP_RTC_STATUS_1M_EVENT        (1<<3)
#define OMAP_RTC_STATUS_1S_EVENT        (1<<2)
#define OMAP_RTC_STATUS_RUN             (1<<1)
#define OMAP_RTC_STATUS_BUSY            (1<<0)

/* OMAP_RTC_INTERRUPTS_REG bit fields: */
#define OMAP_RTC_INTERRUPTS_IT_ALARM    (1<<3)
#define OMAP_RTC_INTERRUPTS_IT_TIMER    (1<<2)


#define rtc_read(addr)		omap_readb(OMAP_RTC_BASE + (addr))
#define rtc_write(val, addr)	omap_writeb(val, OMAP_RTC_BASE + (addr))


/* we rely on the rtc framework to handle locking (rtc->ops_lock),
 * so the only other requirement is that register accesses which
 * require BUSY to be clear are made with IRQs locally disabled
 */
static void rtc_wait_not_busy(void)
{
	int	count = 0;
	u8	status;

	/* BUSY may stay active for 1/32768 second (~30 usec) */
	for (count = 0; count < 50; count++) {
		status = rtc_read(OMAP_RTC_STATUS_REG);
		if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
			break;
		udelay(1);
	}
	/* now we have ~15 usec to read/write various registers */
}

static irqreturn_t rtc_irq(int irq, void *rtc)
{
	unsigned long		events = 0;
	u8			irq_data;

	irq_data = rtc_read(OMAP_RTC_STATUS_REG);

	/* alarm irq? */
	if (irq_data & OMAP_RTC_STATUS_ALARM) {
		rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
		events |= RTC_IRQF | RTC_AF;
	}

	/* 1/sec periodic/update irq? */
	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
		events |= RTC_IRQF | RTC_UF;

	rtc_update_irq(rtc, 1, events);

	return IRQ_HANDLED;
}

#ifdef	CONFIG_RTC_INTF_DEV

static int
omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
	u8 reg;

	switch (cmd) {
	case RTC_AIE_OFF:
	case RTC_AIE_ON:
	case RTC_UIE_OFF:
	case RTC_UIE_ON:
		break;
	default:
		return -ENOIOCTLCMD;
	}

	local_irq_disable();
	rtc_wait_not_busy();
	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	switch (cmd) {
	/* AIE = Alarm Interrupt Enable */
	case RTC_AIE_OFF:
		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
		break;
	case RTC_AIE_ON:
		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
		break;
	/* UIE = Update Interrupt Enable (1/second) */
	case RTC_UIE_OFF:
		reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER;
		break;
	case RTC_UIE_ON:
		reg |= OMAP_RTC_INTERRUPTS_IT_TIMER;
		break;
	}
	rtc_wait_not_busy();
	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	local_irq_enable();

	return 0;
}

#else
#define	omap_rtc_ioctl	NULL
#endif

/* this hardware doesn't support "don't care" alarm fields */
static int tm2bcd(struct rtc_time *tm)
{
	if (rtc_valid_tm(tm) != 0)
		return -EINVAL;

	tm->tm_sec = bin2bcd(tm->tm_sec);
	tm->tm_min = bin2bcd(tm->tm_min);
	tm->tm_hour = bin2bcd(tm->tm_hour);
	tm->tm_mday = bin2bcd(tm->tm_mday);

	tm->tm_mon = bin2bcd(tm->tm_mon + 1);

	/* epoch == 1900 */
	if (tm->tm_year < 100 || tm->tm_year > 199)
		return -EINVAL;
	tm->tm_year = bin2bcd(tm->tm_year - 100);

	return 0;
}

static void bcd2tm(struct rtc_time *tm)
{
	tm->tm_sec = bcd2bin(tm->tm_sec);
	tm->tm_min = bcd2bin(tm->tm_min);
	tm->tm_hour = bcd2bin(tm->tm_hour);
	tm->tm_mday = bcd2bin(tm->tm_mday);
	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
	/* epoch == 1900 */
	tm->tm_year = bcd2bin(tm->tm_year) + 100;
}


static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	/* we don't report wday/yday/isdst ... */
	local_irq_disable();
	rtc_wait_not_busy();

	tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
	tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
	tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
	tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
	tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
	tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);

	local_irq_enable();

	bcd2tm(tm);
	return 0;
}

static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	if (tm2bcd(tm) < 0)
		return -EINVAL;
	local_irq_disable();
	rtc_wait_not_busy();

	rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
	rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
	rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
	rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
	rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
	rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);

	local_irq_enable();

	return 0;
}

static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	local_irq_disable();
	rtc_wait_not_busy();

	alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
	alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
	alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
	alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
	alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
	alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);

	local_irq_enable();

	bcd2tm(&alm->time);
	alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
			& OMAP_RTC_INTERRUPTS_IT_ALARM);

	return 0;
}

static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	u8 reg;

	if (tm2bcd(&alm->time) < 0)
		return -EINVAL;

	local_irq_disable();
	rtc_wait_not_busy();

	rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
	rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
	rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
	rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
	rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
	rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);

	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	if (alm->enabled)
		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
	else
		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);

	local_irq_enable();

	return 0;
}

static struct rtc_class_ops omap_rtc_ops = {
	.ioctl		= omap_rtc_ioctl,
	.read_time	= omap_rtc_read_time,
	.set_time	= omap_rtc_set_time,
	.read_alarm	= omap_rtc_read_alarm,
	.set_alarm	= omap_rtc_set_alarm,
};

static int omap_rtc_alarm;
static int omap_rtc_timer;

static int __init omap_rtc_probe(struct platform_device *pdev)
{
	struct resource		*res, *mem;
	struct rtc_device	*rtc;
	u8			reg, new_ctrl;

	omap_rtc_timer = platform_get_irq(pdev, 0);
	if (omap_rtc_timer <= 0) {
		pr_debug("%s: no update irq?\n", pdev->name);
		return -ENOENT;
	}

	omap_rtc_alarm = platform_get_irq(pdev, 1);
	if (omap_rtc_alarm <= 0) {
		pr_debug("%s: no alarm irq?\n", pdev->name);
		return -ENOENT;
	}

	/* NOTE:  using static mapping for RTC registers */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res && res->start != OMAP_RTC_BASE) {
		pr_debug("%s: RTC registers at %08x, expected %08x\n",
			pdev->name, (unsigned) res->start, OMAP_RTC_BASE);
		return -ENOENT;
	}

	if (res)
		mem = request_mem_region(res->start,
				res->end - res->start + 1,
				pdev->name);
	else
		mem = NULL;
	if (!mem) {
		pr_debug("%s: RTC registers at %08x are not free\n",
			pdev->name, OMAP_RTC_BASE);
		return -EBUSY;
	}

	rtc = rtc_device_register(pdev->name, &pdev->dev,
			&omap_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc)) {
		pr_debug("%s: can't register RTC device, err %ld\n",
			pdev->name, PTR_ERR(rtc));
		goto fail;
	}
	platform_set_drvdata(pdev, rtc);
	dev_set_drvdata(&rtc->dev, mem);

	/* clear pending irqs, and set 1/second periodic,
	 * which we'll use instead of update irqs
	 */
	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);

	/* clear old status */
	reg = rtc_read(OMAP_RTC_STATUS_REG);
	if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
		pr_info("%s: RTC power up reset detected\n",
			pdev->name);
		rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
	}
	if (reg & (u8) OMAP_RTC_STATUS_ALARM)
		rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);

	/* handle periodic and alarm irqs */
	if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED,
			rtc->dev.bus_id, rtc)) {
		pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
			pdev->name, omap_rtc_timer);
		goto fail0;
	}
	if (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
			rtc->dev.bus_id, rtc)) {
		pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
			pdev->name, omap_rtc_alarm);
		goto fail1;
	}

	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
	reg = rtc_read(OMAP_RTC_CTRL_REG);
	if (reg & (u8) OMAP_RTC_CTRL_STOP)
		pr_info("%s: already running\n", pdev->name);

	/* force to 24 hour mode */
	new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP);
	new_ctrl |= OMAP_RTC_CTRL_STOP;

	/* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
	 *
	 *  - Boards wired so that RTC_WAKE_INT does something, and muxed
	 *    right (W13_1610_RTC_WAKE_INT is the default after chip reset),
	 *    should initialize the device wakeup flag appropriately.
	 *
	 *  - Boards wired so RTC_ON_nOFF is used as the reset signal,
	 *    rather than nPWRON_RESET, should forcibly enable split
	 *    power mode.  (Some chip errata report that RTC_CTRL_SPLIT
	 *    is write-only, and always reads as zero...)
	 */
	device_init_wakeup(&pdev->dev, 0);

	if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
		pr_info("%s: split power mode\n", pdev->name);

	if (reg != new_ctrl)
		rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);

	return 0;

fail1:
	free_irq(omap_rtc_timer, NULL);
fail0:
	rtc_device_unregister(rtc);
fail:
	release_resource(mem);
	return -EIO;
}

static int __exit omap_rtc_remove(struct platform_device *pdev)
{
	struct rtc_device	*rtc = platform_get_drvdata(pdev);;

	device_init_wakeup(&pdev->dev, 0);

	/* leave rtc running, but disable irqs */
	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);

	free_irq(omap_rtc_timer, rtc);
	free_irq(omap_rtc_alarm, rtc);

	release_resource(dev_get_drvdata(&rtc->dev));
	rtc_device_unregister(rtc);
	return 0;
}

#ifdef CONFIG_PM

static u8 irqstat;

static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
{
	irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);

	/* FIXME the RTC alarm is not currently acting as a wakeup event
	 * source, and in fact this enable() call is just saving a flag
	 * that's never used...
	 */
	if (device_may_wakeup(&pdev->dev))
		enable_irq_wake(omap_rtc_alarm);
	else
		rtc_write(0, OMAP_RTC_INTERRUPTS_REG);

	return 0;
}

static int omap_rtc_resume(struct platform_device *pdev)
{
	if (device_may_wakeup(&pdev->dev))
		disable_irq_wake(omap_rtc_alarm);
	else
		rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
	return 0;
}

#else
#define omap_rtc_suspend NULL
#define omap_rtc_resume  NULL
#endif

static void omap_rtc_shutdown(struct platform_device *pdev)
{
	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
}

MODULE_ALIAS("platform:omap_rtc");
static struct platform_driver omap_rtc_driver = {
	.remove		= __exit_p(omap_rtc_remove),
	.suspend	= omap_rtc_suspend,
	.resume		= omap_rtc_resume,
	.shutdown	= omap_rtc_shutdown,
	.driver		= {
		.name	= "omap_rtc",
		.owner	= THIS_MODULE,
	},
};

static int __init rtc_init(void)
{
	return platform_driver_probe(&omap_rtc_driver, omap_rtc_probe);
}
module_init(rtc_init);

static void __exit rtc_exit(void)
{
	platform_driver_unregister(&omap_rtc_driver);
}
module_exit(rtc_exit);

MODULE_AUTHOR("George G. Davis (and others)");
MODULE_LICENSE("GPL");
Commit	Line	Data
db68b189 DB	1	/*
	2	* TI OMAP1 Real Time Clock interface for Linux
	3	*
	4	* Copyright (C) 2003 MontaVista Software, Inc.
	5	* Author: George G. Davis <[email protected]> or <[email protected]>
	6	*
	7	* Copyright (C) 2006 David Brownell (new RTC framework)
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
	14
	15	#include <linux/kernel.h>
	16	#include <linux/init.h>
	17	#include <linux/module.h>
	18	#include <linux/ioport.h>
	19	#include <linux/delay.h>
	20	#include <linux/rtc.h>
	21	#include <linux/bcd.h>
	22	#include <linux/platform_device.h>
	23
	24	#include <asm/io.h>
db68b189 DB	25
	26
	27	/* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
	28	* with century-range alarm matching, driven by the 32kHz clock.
	29	*
	30	* The main user-visible ways it differs from PC RTCs are by omitting
	31	* "don't care" alarm fields and sub-second periodic IRQs, and having
	32	* an autoadjust mechanism to calibrate to the true oscillator rate.
	33	*
	34	* Board-specific wiring options include using split power mode with
	35	* RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
	36	* and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
	37	* low power modes). See the BOARD-SPECIFIC CUSTOMIZATION comment.
	38	*/
	39
	40	#define OMAP_RTC_BASE 0xfffb4800
	41
	42	/* RTC registers */
	43	#define OMAP_RTC_SECONDS_REG 0x00
	44	#define OMAP_RTC_MINUTES_REG 0x04
	45	#define OMAP_RTC_HOURS_REG 0x08
	46	#define OMAP_RTC_DAYS_REG 0x0C
	47	#define OMAP_RTC_MONTHS_REG 0x10
	48	#define OMAP_RTC_YEARS_REG 0x14
	49	#define OMAP_RTC_WEEKS_REG 0x18
	50
	51	#define OMAP_RTC_ALARM_SECONDS_REG 0x20
	52	#define OMAP_RTC_ALARM_MINUTES_REG 0x24
	53	#define OMAP_RTC_ALARM_HOURS_REG 0x28
	54	#define OMAP_RTC_ALARM_DAYS_REG 0x2c
	55	#define OMAP_RTC_ALARM_MONTHS_REG 0x30
	56	#define OMAP_RTC_ALARM_YEARS_REG 0x34
	57
	58	#define OMAP_RTC_CTRL_REG 0x40
	59	#define OMAP_RTC_STATUS_REG 0x44
	60	#define OMAP_RTC_INTERRUPTS_REG 0x48
	61
	62	#define OMAP_RTC_COMP_LSB_REG 0x4c
	63	#define OMAP_RTC_COMP_MSB_REG 0x50
	64	#define OMAP_RTC_OSC_REG 0x54
	65
	66	/* OMAP_RTC_CTRL_REG bit fields: */
	67	#define OMAP_RTC_CTRL_SPLIT (1<<7)
	68	#define OMAP_RTC_CTRL_DISABLE (1<<6)
	69	#define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5)
	70	#define OMAP_RTC_CTRL_TEST (1<<4)
	71	#define OMAP_RTC_CTRL_MODE_12_24 (1<<3)
	72	#define OMAP_RTC_CTRL_AUTO_COMP (1<<2)
	73	#define OMAP_RTC_CTRL_ROUND_30S (1<<1)
	74	#define OMAP_RTC_CTRL_STOP (1<<0)
	75
	76	/* OMAP_RTC_STATUS_REG bit fields: */
	77	#define OMAP_RTC_STATUS_POWER_UP (1<<7)
	78	#define OMAP_RTC_STATUS_ALARM (1<<6)
	79	#define OMAP_RTC_STATUS_1D_EVENT (1<<5)
	80	#define OMAP_RTC_STATUS_1H_EVENT (1<<4)
	81	#define OMAP_RTC_STATUS_1M_EVENT (1<<3)
	82	#define OMAP_RTC_STATUS_1S_EVENT (1<<2)
	83	#define OMAP_RTC_STATUS_RUN (1<<1)
	84	#define OMAP_RTC_STATUS_BUSY (1<<0)
	85
	86	/* OMAP_RTC_INTERRUPTS_REG bit fields: */
	87	#define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3)
	88	#define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2)
89
90
91	#define rtc_read(addr) omap_readb(OMAP_RTC_BASE + (addr))
92	#define rtc_write(val, addr) omap_writeb(val, OMAP_RTC_BASE + (addr))
93
94
db68b189 DB	95	/* we rely on the rtc framework to handle locking (rtc->ops_lock),
	96	* so the only other requirement is that register accesses which
	97	* require BUSY to be clear are made with IRQs locally disabled
	98	*/
	99	static void rtc_wait_not_busy(void)
	100	{
	101	int count = 0;
	102	u8 status;
	103
	104	/* BUSY may stay active for 1/32768 second (~30 usec) */
	105	for (count = 0; count < 50; count++) {
	106	status = rtc_read(OMAP_RTC_STATUS_REG);
	107	if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
	108	break;
	109	udelay(1);
	110	}
	111	/* now we have ~15 usec to read/write various registers */
	112	}
	113
ab6a2d70	114	static irqreturn_t rtc_irq(int irq, void *rtc)
db68b189 DB	115	{
	116	unsigned long events = 0;
	117	u8 irq_data;
	118
	119	irq_data = rtc_read(OMAP_RTC_STATUS_REG);
	120
	121	/* alarm irq? */
	122	if (irq_data & OMAP_RTC_STATUS_ALARM) {
	123	rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
	124	events \|= RTC_IRQF \| RTC_AF;
	125	}
	126
	127	/* 1/sec periodic/update irq? */
	128	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
	129	events \|= RTC_IRQF \| RTC_UF;
	130
ab6a2d70	131	rtc_update_irq(rtc, 1, events);
db68b189 DB	132
	133	return IRQ_HANDLED;
	134	}
	135
	136	#ifdef CONFIG_RTC_INTF_DEV
	137
	138	static int
	139	omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
	140	{
	141	u8 reg;
	142
	143	switch (cmd) {
	144	case RTC_AIE_OFF:
	145	case RTC_AIE_ON:
	146	case RTC_UIE_OFF:
	147	case RTC_UIE_ON:
	148	break;
	149	default:
	150	return -ENOIOCTLCMD;
	151	}
	152
	153	local_irq_disable();
	154	rtc_wait_not_busy();
	155	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	156	switch (cmd) {
	157	/* AIE = Alarm Interrupt Enable */
	158	case RTC_AIE_OFF:
	159	reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	160	break;
	161	case RTC_AIE_ON:
	162	reg \|= OMAP_RTC_INTERRUPTS_IT_ALARM;
	163	break;
	164	/* UIE = Update Interrupt Enable (1/second) */
	165	case RTC_UIE_OFF:
	166	reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER;
	167	break;
	168	case RTC_UIE_ON:
	169	reg \|= OMAP_RTC_INTERRUPTS_IT_TIMER;
	170	break;
	171	}
	172	rtc_wait_not_busy();
	173	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	174	local_irq_enable();
	175
	176	return 0;
	177	}
	178
	179	#else
	180	#define omap_rtc_ioctl NULL
	181	#endif
	182
	183	/* this hardware doesn't support "don't care" alarm fields */
	184	static int tm2bcd(struct rtc_time *tm)
	185	{
	186	if (rtc_valid_tm(tm) != 0)
	187	return -EINVAL;
	188
fe20ba70 AB	189	tm->tm_sec = bin2bcd(tm->tm_sec);
	190	tm->tm_min = bin2bcd(tm->tm_min);
	191	tm->tm_hour = bin2bcd(tm->tm_hour);
	192	tm->tm_mday = bin2bcd(tm->tm_mday);
db68b189	193
fe20ba70	194	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
db68b189 DB	195
	196	/* epoch == 1900 */
	197	if (tm->tm_year < 100 \|\| tm->tm_year > 199)
	198	return -EINVAL;
fe20ba70	199	tm->tm_year = bin2bcd(tm->tm_year - 100);
db68b189 DB	200
	201	return 0;
	202	}
	203
	204	static void bcd2tm(struct rtc_time *tm)
	205	{
fe20ba70 AB	206	tm->tm_sec = bcd2bin(tm->tm_sec);
	207	tm->tm_min = bcd2bin(tm->tm_min);
	208	tm->tm_hour = bcd2bin(tm->tm_hour);
	209	tm->tm_mday = bcd2bin(tm->tm_mday);
	210	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
db68b189	211	/* epoch == 1900 */
fe20ba70	212	tm->tm_year = bcd2bin(tm->tm_year) + 100;
db68b189 DB	213	}
	214
	215
	216	static int omap_rtc_read_time(struct device dev, struct rtc_time tm)
	217	{
	218	/* we don't report wday/yday/isdst ... */
	219	local_irq_disable();
	220	rtc_wait_not_busy();
	221
	222	tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
	223	tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
	224	tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
	225	tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
	226	tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
	227	tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
	228
	229	local_irq_enable();
	230
	231	bcd2tm(tm);
	232	return 0;
	233	}
	234
	235	static int omap_rtc_set_time(struct device dev, struct rtc_time tm)
	236	{
	237	if (tm2bcd(tm) < 0)
	238	return -EINVAL;
	239	local_irq_disable();
	240	rtc_wait_not_busy();
	241
	242	rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
	243	rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
	244	rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
	245	rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
	246	rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
	247	rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
	248
	249	local_irq_enable();
	250
	251	return 0;
	252	}
	253
	254	static int omap_rtc_read_alarm(struct device dev, struct rtc_wkalrm alm)
	255	{
	256	local_irq_disable();
	257	rtc_wait_not_busy();
	258
	259	alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
	260	alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
	261	alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
	262	alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
	263	alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
	264	alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
	265
	266	local_irq_enable();
	267
	268	bcd2tm(&alm->time);
a2db8dfc	269	alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
db68b189	270	& OMAP_RTC_INTERRUPTS_IT_ALARM);
db68b189 DB	271
	272	return 0;
	273	}
	274
	275	static int omap_rtc_set_alarm(struct device dev, struct rtc_wkalrm alm)
	276	{
	277	u8 reg;
	278
db68b189 DB	279	if (tm2bcd(&alm->time) < 0)
	280	return -EINVAL;
	281
	282	local_irq_disable();
	283	rtc_wait_not_busy();
	284
	285	rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
	286	rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
	287	rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
	288	rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
	289	rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
	290	rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
	291
	292	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	293	if (alm->enabled)
	294	reg \|= OMAP_RTC_INTERRUPTS_IT_ALARM;
	295	else
	296	reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	297	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	298
	299	local_irq_enable();
	300
	301	return 0;
	302	}
	303
	304	static struct rtc_class_ops omap_rtc_ops = {
	305	.ioctl = omap_rtc_ioctl,
	306	.read_time = omap_rtc_read_time,
	307	.set_time = omap_rtc_set_time,
	308	.read_alarm = omap_rtc_read_alarm,
	309	.set_alarm = omap_rtc_set_alarm,
	310	};
	311
	312	static int omap_rtc_alarm;
	313	static int omap_rtc_timer;
	314
71fc8224	315	static int __init omap_rtc_probe(struct platform_device *pdev)
db68b189 DB	316	{
	317	struct resource res, mem;
	318	struct rtc_device *rtc;
	319	u8 reg, new_ctrl;
	320
	321	omap_rtc_timer = platform_get_irq(pdev, 0);
	322	if (omap_rtc_timer <= 0) {
	323	pr_debug("%s: no update irq?\n", pdev->name);
	324	return -ENOENT;
	325	}
	326
	327	omap_rtc_alarm = platform_get_irq(pdev, 1);
	328	if (omap_rtc_alarm <= 0) {
	329	pr_debug("%s: no alarm irq?\n", pdev->name);
	330	return -ENOENT;
	331	}
	332
	333	/* NOTE: using static mapping for RTC registers */
	334	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	335	if (res && res->start != OMAP_RTC_BASE) {
	336	pr_debug("%s: RTC registers at %08x, expected %08x\n",
	337	pdev->name, (unsigned) res->start, OMAP_RTC_BASE);
	338	return -ENOENT;
	339	}
	340
	341	if (res)
	342	mem = request_mem_region(res->start,
	343	res->end - res->start + 1,
	344	pdev->name);
	345	else
	346	mem = NULL;
	347	if (!mem) {
	348	pr_debug("%s: RTC registers at %08x are not free\n",
	349	pdev->name, OMAP_RTC_BASE);
	350	return -EBUSY;
	351	}
	352
	353	rtc = rtc_device_register(pdev->name, &pdev->dev,
	354	&omap_rtc_ops, THIS_MODULE);
	355	if (IS_ERR(rtc)) {
	356	pr_debug("%s: can't register RTC device, err %ld\n",
	357	pdev->name, PTR_ERR(rtc));
	358	goto fail;
	359	}
	360	platform_set_drvdata(pdev, rtc);
558a40f7	361	dev_set_drvdata(&rtc->dev, mem);
db68b189 DB	362
	363	/* clear pending irqs, and set 1/second periodic,
	364	* which we'll use instead of update irqs
	365	*/
	366	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	367
	368	/* clear old status */
	369	reg = rtc_read(OMAP_RTC_STATUS_REG);
	370	if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
	371	pr_info("%s: RTC power up reset detected\n",
	372	pdev->name);
	373	rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
	374	}
	375	if (reg & (u8) OMAP_RTC_STATUS_ALARM)
	376	rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
	377
	378	/* handle periodic and alarm irqs */
38515e90	379	if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED,
cd966209	380	rtc->dev.bus_id, rtc)) {
db68b189 DB	381	pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
	382	pdev->name, omap_rtc_timer);
	383	goto fail0;
	384	}
38515e90	385	if (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
cd966209	386	rtc->dev.bus_id, rtc)) {
db68b189 DB	387	pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
	388	pdev->name, omap_rtc_alarm);
	389	goto fail1;
	390	}
	391
	392	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
	393	reg = rtc_read(OMAP_RTC_CTRL_REG);
	394	if (reg & (u8) OMAP_RTC_CTRL_STOP)
	395	pr_info("%s: already running\n", pdev->name);
	396
	397	/* force to 24 hour mode */
	398	new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT\|OMAP_RTC_CTRL_AUTO_COMP);
	399	new_ctrl \|= OMAP_RTC_CTRL_STOP;
	400
	401	/* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
	402	*
	403	* - Boards wired so that RTC_WAKE_INT does something, and muxed
	404	* right (W13_1610_RTC_WAKE_INT is the default after chip reset),
	405	* should initialize the device wakeup flag appropriately.
	406	*
	407	* - Boards wired so RTC_ON_nOFF is used as the reset signal,
	408	* rather than nPWRON_RESET, should forcibly enable split
	409	* power mode. (Some chip errata report that RTC_CTRL_SPLIT
	410	* is write-only, and always reads as zero...)
	411	*/
	412	device_init_wakeup(&pdev->dev, 0);
	413
	414	if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
	415	pr_info("%s: split power mode\n", pdev->name);
	416
	417	if (reg != new_ctrl)
	418	rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
	419
	420	return 0;
	421
	422	fail1:
	423	free_irq(omap_rtc_timer, NULL);
	424	fail0:
	425	rtc_device_unregister(rtc);
	426	fail:
	427	release_resource(mem);
	428	return -EIO;
	429	}
	430
71fc8224	431	static int __exit omap_rtc_remove(struct platform_device *pdev)
db68b189 DB	432	{
	433	struct rtc_device *rtc = platform_get_drvdata(pdev);;
	434
	435	device_init_wakeup(&pdev->dev, 0);
	436
	437	/* leave rtc running, but disable irqs */
	438	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	439
	440	free_irq(omap_rtc_timer, rtc);
	441	free_irq(omap_rtc_alarm, rtc);
	442
558a40f7	443	release_resource(dev_get_drvdata(&rtc->dev));
db68b189 DB	444	rtc_device_unregister(rtc);
	445	return 0;
	446	}
	447
	448	#ifdef CONFIG_PM
	449
db68b189 DB	450	static u8 irqstat;
	451
	452	static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
	453	{
db68b189 DB	454	irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	455
	456	/* FIXME the RTC alarm is not currently acting as a wakeup event
	457	* source, and in fact this enable() call is just saving a flag
	458	* that's never used...
	459	*/
	460	if (device_may_wakeup(&pdev->dev))
	461	enable_irq_wake(omap_rtc_alarm);
	462	else
	463	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	464
	465	return 0;
	466	}
	467
	468	static int omap_rtc_resume(struct platform_device *pdev)
	469	{
db68b189 DB	470	if (device_may_wakeup(&pdev->dev))
	471	disable_irq_wake(omap_rtc_alarm);
	472	else
	473	rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
	474	return 0;
	475	}
	476
	477	#else
	478	#define omap_rtc_suspend NULL
	479	#define omap_rtc_resume NULL
	480	#endif
	481
	482	static void omap_rtc_shutdown(struct platform_device *pdev)
	483	{
	484	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	485	}
	486
ad28a07b	487	MODULE_ALIAS("platform:omap_rtc");
db68b189	488	static struct platform_driver omap_rtc_driver = {
71fc8224	489	.remove = __exit_p(omap_rtc_remove),
db68b189 DB	490	.suspend = omap_rtc_suspend,
	491	.resume = omap_rtc_resume,
	492	.shutdown = omap_rtc_shutdown,
	493	.driver = {
	494	.name = "omap_rtc",
	495	.owner = THIS_MODULE,
	496	},
	497	};
	498
	499	static int __init rtc_init(void)
	500	{
71fc8224	501	return platform_driver_probe(&omap_rtc_driver, omap_rtc_probe);
db68b189 DB	502	}
	503	module_init(rtc_init);
	504
	505	static void __exit rtc_exit(void)
	506	{
	507	platform_driver_unregister(&omap_rtc_driver);
	508	}
	509	module_exit(rtc_exit);
	510
	511	MODULE_AUTHOR("George G. Davis (and others)");
	512	MODULE_LICENSE("GPL");