[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>


/* 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) for OMAP1 boards (OMAP-L138 has this built into
 * the SoC). 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)

static void __iomem	*rtc_base;

#define rtc_read(addr)		__raw_readb(rtc_base + (addr))
#define rtc_write(val, addr)	__raw_writeb(val, 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_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) {
	/* 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

static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	u8 reg;

	local_irq_disable();
	rtc_wait_not_busy();
	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	if (enabled)
		reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
	else
		reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	rtc_wait_not_busy();
	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	local_irq_enable();

	return 0;
}

/* 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,
	.alarm_irq_enable = omap_rtc_alarm_irq_enable,
};

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;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		pr_debug("%s: RTC resource data missing\n", pdev->name);
		return -ENOENT;
	}

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

	rtc_base = ioremap(res->start, resource_size(res));
	if (!rtc_base) {
		pr_debug("%s: RTC registers can't be mapped\n", pdev->name);
		goto fail;
	}

	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 fail0;
	}
	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,
			dev_name(&rtc->dev), rtc)) {
		pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
			pdev->name, omap_rtc_timer);
		goto fail1;
	}
	if ((omap_rtc_timer != omap_rtc_alarm) &&
		(request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
			dev_name(&rtc->dev), rtc))) {
		pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
			pdev->name, omap_rtc_alarm);
		goto fail2;
	}

	/* 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:
	 *
	 *  - Device wake-up capability setting should come through chip
	 *    init logic. OMAP1 boards should initialize the "wakeup capable"
	 *    flag in the platform device if the board is wired right for
	 *    being woken up by RTC alarm. For OMAP-L138, this capability
	 *    is built into the SoC by the "Deep Sleep" capability.
	 *
	 *  - 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...)
	 */

	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;

fail2:
	free_irq(omap_rtc_timer, NULL);
fail1:
	rtc_device_unregister(rtc);
fail0:
	iounmap(rtc_base);
fail:
	release_mem_region(mem->start, resource_size(mem));
	return -EIO;
}

static int __exit omap_rtc_remove(struct platform_device *pdev)
{
	struct rtc_device	*rtc = platform_get_drvdata(pdev);
	struct resource		*mem = dev_get_drvdata(&rtc->dev);

	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);

	if (omap_rtc_timer != omap_rtc_alarm)
		free_irq(omap_rtc_alarm, rtc);

	rtc_device_unregister(rtc);
	iounmap(rtc_base);
	release_mem_region(mem->start, resource_size(mem));
	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 <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>
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
fa5b0782 SN	37	* low power modes) for OMAP1 boards (OMAP-L138 has this built into
fa5b0782 SN	38	* the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment.
db68b189 DB	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
8cfde8c1	91	static void __iomem *rtc_base;
db68b189	92
8cfde8c1 MG	93	#define rtc_read(addr) __raw_readb(rtc_base + (addr))
8cfde8c1 MG	94	#define rtc_write(val, addr) __raw_writeb(val, rtc_base + (addr))
db68b189 DB	95
db68b189 DB	96
db68b189 DB	97	/* we rely on the rtc framework to handle locking (rtc->ops_lock),
	98	* so the only other requirement is that register accesses which
	99	* require BUSY to be clear are made with IRQs locally disabled
	100	*/
	101	static void rtc_wait_not_busy(void)
	102	{
	103	int count = 0;
	104	u8 status;
	105
	106	/* BUSY may stay active for 1/32768 second (~30 usec) */
	107	for (count = 0; count < 50; count++) {
	108	status = rtc_read(OMAP_RTC_STATUS_REG);
	109	if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
	110	break;
	111	udelay(1);
	112	}
	113	/* now we have ~15 usec to read/write various registers */
	114	}
	115
ab6a2d70	116	static irqreturn_t rtc_irq(int irq, void *rtc)
db68b189 DB	117	{
	118	unsigned long events = 0;
	119	u8 irq_data;
	120
	121	irq_data = rtc_read(OMAP_RTC_STATUS_REG);
	122
	123	/* alarm irq? */
	124	if (irq_data & OMAP_RTC_STATUS_ALARM) {
	125	rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
	126	events \|= RTC_IRQF \| RTC_AF;
	127	}
	128
	129	/* 1/sec periodic/update irq? */
	130	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
	131	events \|= RTC_IRQF \| RTC_UF;
	132
ab6a2d70	133	rtc_update_irq(rtc, 1, events);
db68b189 DB	134
	135	return IRQ_HANDLED;
	136	}
	137
	138	#ifdef CONFIG_RTC_INTF_DEV
	139
	140	static int
	141	omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
	142	{
	143	u8 reg;
	144
	145	switch (cmd) {
db68b189 DB	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) {
db68b189 DB	157	/* UIE = Update Interrupt Enable (1/second) */
	158	case RTC_UIE_OFF:
	159	reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER;
	160	break;
	161	case RTC_UIE_ON:
	162	reg \|= OMAP_RTC_INTERRUPTS_IT_TIMER;
	163	break;
	164	}
	165	rtc_wait_not_busy();
	166	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	167	local_irq_enable();
	168
	169	return 0;
	170	}
	171
	172	#else
	173	#define omap_rtc_ioctl NULL
	174	#endif
	175
16380c15 JS	176	static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
	177	{
	178	u8 reg;
	179
	180	local_irq_disable();
	181	rtc_wait_not_busy();
	182	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	183	if (enabled)
	184	reg \|= OMAP_RTC_INTERRUPTS_IT_ALARM;
	185	else
	186	reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	187	rtc_wait_not_busy();
	188	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	189	local_irq_enable();
	190
	191	return 0;
	192	}
	193
db68b189 DB	194	/* this hardware doesn't support "don't care" alarm fields */
	195	static int tm2bcd(struct rtc_time *tm)
	196	{
	197	if (rtc_valid_tm(tm) != 0)
	198	return -EINVAL;
	199
fe20ba70 AB	200	tm->tm_sec = bin2bcd(tm->tm_sec);
	201	tm->tm_min = bin2bcd(tm->tm_min);
	202	tm->tm_hour = bin2bcd(tm->tm_hour);
	203	tm->tm_mday = bin2bcd(tm->tm_mday);
db68b189	204
fe20ba70	205	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
db68b189 DB	206
	207	/* epoch == 1900 */
	208	if (tm->tm_year < 100 \|\| tm->tm_year > 199)
	209	return -EINVAL;
fe20ba70	210	tm->tm_year = bin2bcd(tm->tm_year - 100);
db68b189 DB	211
	212	return 0;
	213	}
	214
	215	static void bcd2tm(struct rtc_time *tm)
	216	{
fe20ba70 AB	217	tm->tm_sec = bcd2bin(tm->tm_sec);
	218	tm->tm_min = bcd2bin(tm->tm_min);
	219	tm->tm_hour = bcd2bin(tm->tm_hour);
	220	tm->tm_mday = bcd2bin(tm->tm_mday);
	221	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
db68b189	222	/* epoch == 1900 */
fe20ba70	223	tm->tm_year = bcd2bin(tm->tm_year) + 100;
db68b189 DB	224	}
	225
	226
	227	static int omap_rtc_read_time(struct device dev, struct rtc_time tm)
	228	{
	229	/* we don't report wday/yday/isdst ... */
	230	local_irq_disable();
	231	rtc_wait_not_busy();
	232
	233	tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
	234	tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
	235	tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
	236	tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
	237	tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
	238	tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
	239
	240	local_irq_enable();
	241
	242	bcd2tm(tm);
	243	return 0;
	244	}
	245
	246	static int omap_rtc_set_time(struct device dev, struct rtc_time tm)
	247	{
	248	if (tm2bcd(tm) < 0)
	249	return -EINVAL;
	250	local_irq_disable();
	251	rtc_wait_not_busy();
	252
	253	rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
	254	rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
	255	rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
	256	rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
	257	rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
	258	rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
	259
	260	local_irq_enable();
	261
	262	return 0;
	263	}
	264
	265	static int omap_rtc_read_alarm(struct device dev, struct rtc_wkalrm alm)
	266	{
	267	local_irq_disable();
	268	rtc_wait_not_busy();
	269
	270	alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
	271	alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
	272	alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
	273	alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
	274	alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
	275	alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
	276
	277	local_irq_enable();
	278
	279	bcd2tm(&alm->time);
a2db8dfc	280	alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
db68b189	281	& OMAP_RTC_INTERRUPTS_IT_ALARM);
db68b189 DB	282
	283	return 0;
	284	}
	285
	286	static int omap_rtc_set_alarm(struct device dev, struct rtc_wkalrm alm)
	287	{
	288	u8 reg;
	289
db68b189 DB	290	if (tm2bcd(&alm->time) < 0)
	291	return -EINVAL;
	292
	293	local_irq_disable();
	294	rtc_wait_not_busy();
	295
	296	rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
	297	rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
	298	rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
	299	rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
	300	rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
	301	rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
	302
	303	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	304	if (alm->enabled)
	305	reg \|= OMAP_RTC_INTERRUPTS_IT_ALARM;
	306	else
	307	reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	308	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	309
	310	local_irq_enable();
	311
	312	return 0;
	313	}
	314
	315	static struct rtc_class_ops omap_rtc_ops = {
	316	.ioctl = omap_rtc_ioctl,
	317	.read_time = omap_rtc_read_time,
	318	.set_time = omap_rtc_set_time,
	319	.read_alarm = omap_rtc_read_alarm,
	320	.set_alarm = omap_rtc_set_alarm,
16380c15	321	.alarm_irq_enable = omap_rtc_alarm_irq_enable,
db68b189 DB	322	};
	323
	324	static int omap_rtc_alarm;
	325	static int omap_rtc_timer;
	326
71fc8224	327	static int __init omap_rtc_probe(struct platform_device *pdev)
db68b189 DB	328	{
	329	struct resource res, mem;
	330	struct rtc_device *rtc;
	331	u8 reg, new_ctrl;
	332
	333	omap_rtc_timer = platform_get_irq(pdev, 0);
	334	if (omap_rtc_timer <= 0) {
	335	pr_debug("%s: no update irq?\n", pdev->name);
	336	return -ENOENT;
	337	}
	338
	339	omap_rtc_alarm = platform_get_irq(pdev, 1);
	340	if (omap_rtc_alarm <= 0) {
	341	pr_debug("%s: no alarm irq?\n", pdev->name);
	342	return -ENOENT;
	343	}
	344
db68b189	345	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
8cfde8c1 MG	346	if (!res) {
8cfde8c1 MG	347	pr_debug("%s: RTC resource data missing\n", pdev->name);
db68b189 DB	348	return -ENOENT;
	349	}
	350
8cfde8c1	351	mem = request_mem_region(res->start, resource_size(res), pdev->name);
db68b189 DB	352	if (!mem) {
db68b189 DB	353	pr_debug("%s: RTC registers at %08x are not free\n",
8cfde8c1	354	pdev->name, res->start);
db68b189 DB	355	return -EBUSY;
	356	}
	357
8cfde8c1 MG	358	rtc_base = ioremap(res->start, resource_size(res));
	359	if (!rtc_base) {
	360	pr_debug("%s: RTC registers can't be mapped\n", pdev->name);
	361	goto fail;
	362	}
	363
db68b189 DB	364	rtc = rtc_device_register(pdev->name, &pdev->dev,
	365	&omap_rtc_ops, THIS_MODULE);
	366	if (IS_ERR(rtc)) {
	367	pr_debug("%s: can't register RTC device, err %ld\n",
	368	pdev->name, PTR_ERR(rtc));
8cfde8c1	369	goto fail0;
db68b189 DB	370	}
db68b189 DB	371	platform_set_drvdata(pdev, rtc);
558a40f7	372	dev_set_drvdata(&rtc->dev, mem);
db68b189 DB	373
	374	/* clear pending irqs, and set 1/second periodic,
	375	* which we'll use instead of update irqs
	376	*/
	377	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	378
	379	/* clear old status */
	380	reg = rtc_read(OMAP_RTC_STATUS_REG);
	381	if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
	382	pr_info("%s: RTC power up reset detected\n",
	383	pdev->name);
	384	rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
	385	}
	386	if (reg & (u8) OMAP_RTC_STATUS_ALARM)
	387	rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
	388
	389	/* handle periodic and alarm irqs */
38515e90	390	if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED,
744bcb13	391	dev_name(&rtc->dev), rtc)) {
db68b189 DB	392	pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
db68b189 DB	393	pdev->name, omap_rtc_timer);
8cfde8c1	394	goto fail1;
db68b189	395	}
8cfde8c1 MG	396	if ((omap_rtc_timer != omap_rtc_alarm) &&
	397	(request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
	398	dev_name(&rtc->dev), rtc))) {
db68b189 DB	399	pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
db68b189 DB	400	pdev->name, omap_rtc_alarm);
8cfde8c1	401	goto fail2;
db68b189 DB	402	}
	403
	404	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
	405	reg = rtc_read(OMAP_RTC_CTRL_REG);
	406	if (reg & (u8) OMAP_RTC_CTRL_STOP)
	407	pr_info("%s: already running\n", pdev->name);
	408
	409	/* force to 24 hour mode */
	410	new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT\|OMAP_RTC_CTRL_AUTO_COMP);
	411	new_ctrl \|= OMAP_RTC_CTRL_STOP;
	412
	413	/* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
	414	*
fa5b0782 SN	415	* - Device wake-up capability setting should come through chip
	416	* init logic. OMAP1 boards should initialize the "wakeup capable"
	417	* flag in the platform device if the board is wired right for
	418	* being woken up by RTC alarm. For OMAP-L138, this capability
	419	* is built into the SoC by the "Deep Sleep" capability.
db68b189 DB	420	*
	421	* - Boards wired so RTC_ON_nOFF is used as the reset signal,
	422	* rather than nPWRON_RESET, should forcibly enable split
	423	* power mode. (Some chip errata report that RTC_CTRL_SPLIT
	424	* is write-only, and always reads as zero...)
	425	*/
db68b189 DB	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
8cfde8c1	435	fail2:
db68b189	436	free_irq(omap_rtc_timer, NULL);
8cfde8c1	437	fail1:
db68b189	438	rtc_device_unregister(rtc);
8cfde8c1 MG	439	fail0:
8cfde8c1 MG	440	iounmap(rtc_base);
db68b189	441	fail:
19412ce9	442	release_mem_region(mem->start, resource_size(mem));
db68b189 DB	443	return -EIO;
	444	}
	445
71fc8224	446	static int __exit omap_rtc_remove(struct platform_device *pdev)
db68b189	447	{
a419aef8	448	struct rtc_device *rtc = platform_get_drvdata(pdev);
19412ce9	449	struct resource *mem = dev_get_drvdata(&rtc->dev);
db68b189 DB	450
	451	device_init_wakeup(&pdev->dev, 0);
	452
	453	/* leave rtc running, but disable irqs */
	454	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	455
	456	free_irq(omap_rtc_timer, rtc);
8cfde8c1 MG	457
	458	if (omap_rtc_timer != omap_rtc_alarm)
	459	free_irq(omap_rtc_alarm, rtc);
db68b189	460
db68b189	461	rtc_device_unregister(rtc);
19412ce9 AL	462	iounmap(rtc_base);
19412ce9 AL	463	release_mem_region(mem->start, resource_size(mem));
db68b189 DB	464	return 0;
	465	}
	466
	467	#ifdef CONFIG_PM
	468
db68b189 DB	469	static u8 irqstat;
	470
	471	static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
	472	{
db68b189 DB	473	irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	474
	475	/* FIXME the RTC alarm is not currently acting as a wakeup event
	476	* source, and in fact this enable() call is just saving a flag
	477	* that's never used...
	478	*/
	479	if (device_may_wakeup(&pdev->dev))
	480	enable_irq_wake(omap_rtc_alarm);
	481	else
	482	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	483
	484	return 0;
	485	}
	486
	487	static int omap_rtc_resume(struct platform_device *pdev)
	488	{
db68b189 DB	489	if (device_may_wakeup(&pdev->dev))
	490	disable_irq_wake(omap_rtc_alarm);
	491	else
	492	rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
	493	return 0;
	494	}
	495
	496	#else
	497	#define omap_rtc_suspend NULL
	498	#define omap_rtc_resume NULL
	499	#endif
	500
	501	static void omap_rtc_shutdown(struct platform_device *pdev)
	502	{
	503	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	504	}
	505
ad28a07b	506	MODULE_ALIAS("platform:omap_rtc");
db68b189	507	static struct platform_driver omap_rtc_driver = {
71fc8224	508	.remove = __exit_p(omap_rtc_remove),
db68b189 DB	509	.suspend = omap_rtc_suspend,
	510	.resume = omap_rtc_resume,
	511	.shutdown = omap_rtc_shutdown,
	512	.driver = {
	513	.name = "omap_rtc",
	514	.owner = THIS_MODULE,
	515	},
	516	};
	517
	518	static int __init rtc_init(void)
	519	{
71fc8224	520	return platform_driver_probe(&omap_rtc_driver, omap_rtc_probe);
db68b189 DB	521	}
	522	module_init(rtc_init);
	523
	524	static void __exit rtc_exit(void)
	525	{
	526	platform_driver_unregister(&omap_rtc_driver);
	527	}
	528	module_exit(rtc_exit);
	529
	530	MODULE_AUTHOR("George G. Davis (and others)");
	531	MODULE_LICENSE("GPL");