[deliverable/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 <gdavis@mvista.com> or <source@mvista.com>
 *
 * 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>
#include <asm/mach/time.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))


/* platform_bus isn't hotpluggable, so for static linkage it'd be safe
 * to get rid of probe() and remove() code ... too bad the driver struct
 * remembers probe(), that's about 25% of the runtime footprint!!
 */
#ifndef	MODULE
#undef	__devexit
#undef	__devexit_p
#define	__devexit	__exit
#define	__devexit_p	__exit_p
#endif


/* 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 __devinit 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 __devexit 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 = {
	.probe		= omap_rtc_probe,
	.remove		= __devexit_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_register(&omap_rtc_driver);
}
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 <gdavis@mvista.com> or <source@mvista.com>
	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>
	25	#include <asm/mach/time.h>
	26
	27
	28	/* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
	29	* with century-range alarm matching, driven by the 32kHz clock.
	30	*
	31	* The main user-visible ways it differs from PC RTCs are by omitting
	32	* "don't care" alarm fields and sub-second periodic IRQs, and having
	33	* an autoadjust mechanism to calibrate to the true oscillator rate.
	34	*
	35	* Board-specific wiring options include using split power mode with
	36	* RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
	37	* and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
	38	* low power modes). See the BOARD-SPECIFIC CUSTOMIZATION comment.
	39	*/
	40
	41	#define OMAP_RTC_BASE 0xfffb4800
	42
	43	/* RTC registers */
	44	#define OMAP_RTC_SECONDS_REG 0x00
	45	#define OMAP_RTC_MINUTES_REG 0x04
	46	#define OMAP_RTC_HOURS_REG 0x08
	47	#define OMAP_RTC_DAYS_REG 0x0C
	48	#define OMAP_RTC_MONTHS_REG 0x10
	49	#define OMAP_RTC_YEARS_REG 0x14
	50	#define OMAP_RTC_WEEKS_REG 0x18
	51
	52	#define OMAP_RTC_ALARM_SECONDS_REG 0x20
	53	#define OMAP_RTC_ALARM_MINUTES_REG 0x24
	54	#define OMAP_RTC_ALARM_HOURS_REG 0x28
	55	#define OMAP_RTC_ALARM_DAYS_REG 0x2c
	56	#define OMAP_RTC_ALARM_MONTHS_REG 0x30
	57	#define OMAP_RTC_ALARM_YEARS_REG 0x34
	58
	59	#define OMAP_RTC_CTRL_REG 0x40
	60	#define OMAP_RTC_STATUS_REG 0x44
	61	#define OMAP_RTC_INTERRUPTS_REG 0x48
	62
	63	#define OMAP_RTC_COMP_LSB_REG 0x4c
	64	#define OMAP_RTC_COMP_MSB_REG 0x50
65	#define OMAP_RTC_OSC_REG 0x54
66
67	/* OMAP_RTC_CTRL_REG bit fields: */
68	#define OMAP_RTC_CTRL_SPLIT (1<<7)
69	#define OMAP_RTC_CTRL_DISABLE (1<<6)
70	#define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5)
71	#define OMAP_RTC_CTRL_TEST (1<<4)
72	#define OMAP_RTC_CTRL_MODE_12_24 (1<<3)
73	#define OMAP_RTC_CTRL_AUTO_COMP (1<<2)
74	#define OMAP_RTC_CTRL_ROUND_30S (1<<1)
75	#define OMAP_RTC_CTRL_STOP (1<<0)
76
77	/* OMAP_RTC_STATUS_REG bit fields: */
78	#define OMAP_RTC_STATUS_POWER_UP (1<<7)
79	#define OMAP_RTC_STATUS_ALARM (1<<6)
80	#define OMAP_RTC_STATUS_1D_EVENT (1<<5)
81	#define OMAP_RTC_STATUS_1H_EVENT (1<<4)
82	#define OMAP_RTC_STATUS_1M_EVENT (1<<3)
83	#define OMAP_RTC_STATUS_1S_EVENT (1<<2)
84	#define OMAP_RTC_STATUS_RUN (1<<1)
85	#define OMAP_RTC_STATUS_BUSY (1<<0)
86
87	/* OMAP_RTC_INTERRUPTS_REG bit fields: */
88	#define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3)
89	#define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2)
90
91
92	#define rtc_read(addr) omap_readb(OMAP_RTC_BASE + (addr))
93	#define rtc_write(val, addr) omap_writeb(val, OMAP_RTC_BASE + (addr))
94
95
96	/* platform_bus isn't hotpluggable, so for static linkage it'd be safe
97	* to get rid of probe() and remove() code ... too bad the driver struct
98	* remembers probe(), that's about 25% of the runtime footprint!!
99	*/
100	#ifndef MODULE
101	#undef __devexit
102	#undef __devexit_p
103	#define __devexit __exit
104	#define __devexit_p __exit_p
105	#endif
106
107
108	/* we rely on the rtc framework to handle locking (rtc->ops_lock),
109	* so the only other requirement is that register accesses which
110	* require BUSY to be clear are made with IRQs locally disabled
111	*/
112	static void rtc_wait_not_busy(void)
113	{
114	int count = 0;
115	u8 status;
116
117	/* BUSY may stay active for 1/32768 second (~30 usec) */
118	for (count = 0; count < 50; count++) {
119	status = rtc_read(OMAP_RTC_STATUS_REG);
120	if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
121	break;
122	udelay(1);
123	}
124	/* now we have ~15 usec to read/write various registers */
125	}
126
ab6a2d70	127	static irqreturn_t rtc_irq(int irq, void *rtc)
db68b189 DB	128	{
	129	unsigned long events = 0;
	130	u8 irq_data;
	131
	132	irq_data = rtc_read(OMAP_RTC_STATUS_REG);
	133
	134	/* alarm irq? */
	135	if (irq_data & OMAP_RTC_STATUS_ALARM) {
	136	rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
	137	events \|= RTC_IRQF \| RTC_AF;
	138	}
	139
	140	/* 1/sec periodic/update irq? */
	141	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
	142	events \|= RTC_IRQF \| RTC_UF;
	143
ab6a2d70	144	rtc_update_irq(rtc, 1, events);
db68b189 DB	145
	146	return IRQ_HANDLED;
	147	}
	148
	149	#ifdef CONFIG_RTC_INTF_DEV
	150
	151	static int
	152	omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
	153	{
	154	u8 reg;
	155
	156	switch (cmd) {
	157	case RTC_AIE_OFF:
	158	case RTC_AIE_ON:
	159	case RTC_UIE_OFF:
	160	case RTC_UIE_ON:
	161	break;
	162	default:
	163	return -ENOIOCTLCMD;
	164	}
	165
	166	local_irq_disable();
	167	rtc_wait_not_busy();
	168	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	169	switch (cmd) {
	170	/* AIE = Alarm Interrupt Enable */
	171	case RTC_AIE_OFF:
	172	reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	173	break;
	174	case RTC_AIE_ON:
	175	reg \|= OMAP_RTC_INTERRUPTS_IT_ALARM;
	176	break;
	177	/* UIE = Update Interrupt Enable (1/second) */
	178	case RTC_UIE_OFF:
	179	reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER;
	180	break;
	181	case RTC_UIE_ON:
	182	reg \|= OMAP_RTC_INTERRUPTS_IT_TIMER;
	183	break;
	184	}
	185	rtc_wait_not_busy();
	186	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	187	local_irq_enable();
	188
	189	return 0;
	190	}
	191
	192	#else
	193	#define omap_rtc_ioctl NULL
	194	#endif
	195
	196	/* this hardware doesn't support "don't care" alarm fields */
	197	static int tm2bcd(struct rtc_time *tm)
	198	{
	199	if (rtc_valid_tm(tm) != 0)
	200	return -EINVAL;
	201
	202	tm->tm_sec = BIN2BCD(tm->tm_sec);
	203	tm->tm_min = BIN2BCD(tm->tm_min);
	204	tm->tm_hour = BIN2BCD(tm->tm_hour);
	205	tm->tm_mday = BIN2BCD(tm->tm_mday);
	206
	207	tm->tm_mon = BIN2BCD(tm->tm_mon + 1);
	208
209	/* epoch == 1900 */
210	if (tm->tm_year < 100 \|\| tm->tm_year > 199)
211	return -EINVAL;
212	tm->tm_year = BIN2BCD(tm->tm_year - 100);
213
214	return 0;
215	}
216
217	static void bcd2tm(struct rtc_time *tm)
218	{
219	tm->tm_sec = BCD2BIN(tm->tm_sec);
220	tm->tm_min = BCD2BIN(tm->tm_min);
221	tm->tm_hour = BCD2BIN(tm->tm_hour);
222	tm->tm_mday = BCD2BIN(tm->tm_mday);
223	tm->tm_mon = BCD2BIN(tm->tm_mon) - 1;
224	/* epoch == 1900 */
225	tm->tm_year = BCD2BIN(tm->tm_year) + 100;
226	}
227
228
229	static int omap_rtc_read_time(struct device dev, struct rtc_time tm)
230	{
231	/* we don't report wday/yday/isdst ... */
232	local_irq_disable();
233	rtc_wait_not_busy();
234
235	tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
236	tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
237	tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
238	tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
239	tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
240	tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
241
242	local_irq_enable();
243
244	bcd2tm(tm);
245	return 0;
246	}
247
248	static int omap_rtc_set_time(struct device dev, struct rtc_time tm)
249	{
250	if (tm2bcd(tm) < 0)
251	return -EINVAL;
252	local_irq_disable();
253	rtc_wait_not_busy();
254
255	rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
256	rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
257	rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
258	rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
259	rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
260	rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
261
262	local_irq_enable();
263
264	return 0;
265	}
266
267	static int omap_rtc_read_alarm(struct device dev, struct rtc_wkalrm alm)
268	{
269	local_irq_disable();
270	rtc_wait_not_busy();
271
272	alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
273	alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
274	alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
275	alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
276	alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
277	alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
278
279	local_irq_enable();
280
281	bcd2tm(&alm->time);
a2db8dfc	282	alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
db68b189	283	& OMAP_RTC_INTERRUPTS_IT_ALARM);
db68b189 DB	284
	285	return 0;
	286	}
	287
	288	static int omap_rtc_set_alarm(struct device dev, struct rtc_wkalrm alm)
	289	{
	290	u8 reg;
	291
db68b189 DB	292	if (tm2bcd(&alm->time) < 0)
	293	return -EINVAL;
	294
	295	local_irq_disable();
	296	rtc_wait_not_busy();
	297
	298	rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
	299	rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
	300	rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
	301	rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
	302	rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
	303	rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
	304
	305	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	306	if (alm->enabled)
	307	reg \|= OMAP_RTC_INTERRUPTS_IT_ALARM;
	308	else
	309	reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	310	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	311
	312	local_irq_enable();
	313
	314	return 0;
	315	}
	316
	317	static struct rtc_class_ops omap_rtc_ops = {
	318	.ioctl = omap_rtc_ioctl,
	319	.read_time = omap_rtc_read_time,
	320	.set_time = omap_rtc_set_time,
	321	.read_alarm = omap_rtc_read_alarm,
	322	.set_alarm = omap_rtc_set_alarm,
	323	};
	324
	325	static int omap_rtc_alarm;
	326	static int omap_rtc_timer;
	327
	328	static int __devinit omap_rtc_probe(struct platform_device *pdev)
	329	{
	330	struct resource res, mem;
	331	struct rtc_device *rtc;
	332	u8 reg, new_ctrl;
	333
	334	omap_rtc_timer = platform_get_irq(pdev, 0);
	335	if (omap_rtc_timer <= 0) {
	336	pr_debug("%s: no update irq?\n", pdev->name);
	337	return -ENOENT;
	338	}
	339
	340	omap_rtc_alarm = platform_get_irq(pdev, 1);
	341	if (omap_rtc_alarm <= 0) {
	342	pr_debug("%s: no alarm irq?\n", pdev->name);
	343	return -ENOENT;
	344	}
	345
	346	/* NOTE: using static mapping for RTC registers */
	347	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	348	if (res && res->start != OMAP_RTC_BASE) {
	349	pr_debug("%s: RTC registers at %08x, expected %08x\n",
	350	pdev->name, (unsigned) res->start, OMAP_RTC_BASE);
	351	return -ENOENT;
	352	}
	353
	354	if (res)
	355	mem = request_mem_region(res->start,
356	res->end - res->start + 1,
357	pdev->name);
358	else
359	mem = NULL;
360	if (!mem) {
361	pr_debug("%s: RTC registers at %08x are not free\n",
362	pdev->name, OMAP_RTC_BASE);
363	return -EBUSY;
364	}
365
366	rtc = rtc_device_register(pdev->name, &pdev->dev,
367	&omap_rtc_ops, THIS_MODULE);
368	if (IS_ERR(rtc)) {
369	pr_debug("%s: can't register RTC device, err %ld\n",
370	pdev->name, PTR_ERR(rtc));
371	goto fail;
372	}
373	platform_set_drvdata(pdev, rtc);
558a40f7	374	dev_set_drvdata(&rtc->dev, mem);
db68b189 DB	375
	376	/* clear pending irqs, and set 1/second periodic,
	377	* which we'll use instead of update irqs
	378	*/
	379	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	380
	381	/* clear old status */
	382	reg = rtc_read(OMAP_RTC_STATUS_REG);
	383	if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
	384	pr_info("%s: RTC power up reset detected\n",
	385	pdev->name);
	386	rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
	387	}
	388	if (reg & (u8) OMAP_RTC_STATUS_ALARM)
	389	rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
	390
	391	/* handle periodic and alarm irqs */
38515e90	392	if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED,
cd966209	393	rtc->dev.bus_id, rtc)) {
db68b189 DB	394	pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
	395	pdev->name, omap_rtc_timer);
	396	goto fail0;
	397	}
38515e90	398	if (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
cd966209	399	rtc->dev.bus_id, rtc)) {
db68b189 DB	400	pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
	401	pdev->name, omap_rtc_alarm);
	402	goto fail1;
	403	}
	404
	405	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
	406	reg = rtc_read(OMAP_RTC_CTRL_REG);
	407	if (reg & (u8) OMAP_RTC_CTRL_STOP)
	408	pr_info("%s: already running\n", pdev->name);
	409
	410	/* force to 24 hour mode */
	411	new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT\|OMAP_RTC_CTRL_AUTO_COMP);
	412	new_ctrl \|= OMAP_RTC_CTRL_STOP;
	413
	414	/* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
	415	*
	416	* - Boards wired so that RTC_WAKE_INT does something, and muxed
	417	* right (W13_1610_RTC_WAKE_INT is the default after chip reset),
	418	* should initialize the device wakeup flag appropriately.
	419	*
	420	* - Boards wired so RTC_ON_nOFF is used as the reset signal,
	421	* rather than nPWRON_RESET, should forcibly enable split
	422	* power mode. (Some chip errata report that RTC_CTRL_SPLIT
	423	* is write-only, and always reads as zero...)
	424	*/
	425	device_init_wakeup(&pdev->dev, 0);
	426
	427	if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
	428	pr_info("%s: split power mode\n", pdev->name);
	429
	430	if (reg != new_ctrl)
	431	rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
	432
	433	return 0;
	434
	435	fail1:
	436	free_irq(omap_rtc_timer, NULL);
	437	fail0:
	438	rtc_device_unregister(rtc);
	439	fail:
	440	release_resource(mem);
	441	return -EIO;
	442	}
	443
	444	static int __devexit omap_rtc_remove(struct platform_device *pdev)
	445	{
	446	struct rtc_device *rtc = platform_get_drvdata(pdev);;
	447
	448	device_init_wakeup(&pdev->dev, 0);
	449
	450	/* leave rtc running, but disable irqs */
	451	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	452
	453	free_irq(omap_rtc_timer, rtc);
	454	free_irq(omap_rtc_alarm, rtc);
	455
558a40f7	456	release_resource(dev_get_drvdata(&rtc->dev));
db68b189 DB	457	rtc_device_unregister(rtc);
	458	return 0;
	459	}
	460
	461	#ifdef CONFIG_PM
	462
db68b189 DB	463	static u8 irqstat;
	464
	465	static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
	466	{
db68b189 DB	467	irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	468
	469	/* FIXME the RTC alarm is not currently acting as a wakeup event
	470	* source, and in fact this enable() call is just saving a flag
	471	* that's never used...
	472	*/
	473	if (device_may_wakeup(&pdev->dev))
	474	enable_irq_wake(omap_rtc_alarm);
	475	else
	476	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	477
	478	return 0;
	479	}
	480
	481	static int omap_rtc_resume(struct platform_device *pdev)
	482	{
db68b189 DB	483	if (device_may_wakeup(&pdev->dev))
	484	disable_irq_wake(omap_rtc_alarm);
	485	else
	486	rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
	487	return 0;
	488	}
	489
	490	#else
	491	#define omap_rtc_suspend NULL
	492	#define omap_rtc_resume NULL
	493	#endif
	494
	495	static void omap_rtc_shutdown(struct platform_device *pdev)
	496	{
	497	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	498	}
	499
ad28a07b	500	MODULE_ALIAS("platform:omap_rtc");
db68b189 DB	501	static struct platform_driver omap_rtc_driver = {
	502	.probe = omap_rtc_probe,
	503	.remove = __devexit_p(omap_rtc_remove),
	504	.suspend = omap_rtc_suspend,
	505	.resume = omap_rtc_resume,
	506	.shutdown = omap_rtc_shutdown,
	507	.driver = {
	508	.name = "omap_rtc",
	509	.owner = THIS_MODULE,
	510	},
	511	};
	512
	513	static int __init rtc_init(void)
	514	{
	515	return platform_driver_register(&omap_rtc_driver);
	516	}
	517	module_init(rtc_init);
	518
	519	static void __exit rtc_exit(void)
	520	{
	521	platform_driver_unregister(&omap_rtc_driver);
	522	}
	523	module_exit(rtc_exit);
	524
	525	MODULE_AUTHOR("George G. Davis (and others)");
	526	MODULE_LICENSE("GPL");