[linux-block.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	DRIVER_NAME			"omap_rtc"

#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

#define OMAP_RTC_KICK0_REG		0x6c
#define OMAP_RTC_KICK1_REG		0x70

/* 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)

/* OMAP_RTC_KICKER values */
#define	KICK0_VALUE			0x83e70b13
#define	KICK1_VALUE			0x95a4f1e0

#define	OMAP_RTC_HAS_KICKER		0x1

static void __iomem	*rtc_base;

#define rtc_read(addr)		readb(rtc_base + (addr))
#define rtc_write(val, addr)	writeb(val, rtc_base + (addr))

#define rtc_writel(val, addr)	writel(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;
}

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 = {
	.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 struct platform_device_id omap_rtc_devtype[] = {
	{
		.name	= DRIVER_NAME,
	}, {
		.name	= "da830-rtc",
		.driver_data = OMAP_RTC_HAS_KICKER,
	},
	{},
};
MODULE_DEVICE_TABLE(platform, omap_rtc_devtype);

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

	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;
	}

	id_entry = platform_get_device_id(pdev);
	if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER)) {
		rtc_writel(KICK0_VALUE, OMAP_RTC_KICK0_REG);
		rtc_writel(KICK1_VALUE, OMAP_RTC_KICK1_REG);
	}

	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, 0,
			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, 0,
			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, rtc);
fail1:
	rtc_device_unregister(rtc);
fail0:
	if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER))
		rtc_writel(0, OMAP_RTC_KICK0_REG);
	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);
	const struct platform_device_id *id_entry =
				platform_get_device_id(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);

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

	rtc_device_unregister(rtc);
	if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER))
		rtc_writel(0, OMAP_RTC_KICK0_REG);
	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	= DRIVER_NAME,
		.owner	= THIS_MODULE,
	},
	.id_table	= omap_rtc_devtype,
};

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	*/
db68b189 DB	40
cab1458c AM	41	#define DRIVER_NAME "omap_rtc"
cab1458c AM	42
db68b189 DB	43	#define OMAP_RTC_BASE 0xfffb4800
	44
	45	/* RTC registers */
	46	#define OMAP_RTC_SECONDS_REG 0x00
	47	#define OMAP_RTC_MINUTES_REG 0x04
	48	#define OMAP_RTC_HOURS_REG 0x08
	49	#define OMAP_RTC_DAYS_REG 0x0C
	50	#define OMAP_RTC_MONTHS_REG 0x10
	51	#define OMAP_RTC_YEARS_REG 0x14
	52	#define OMAP_RTC_WEEKS_REG 0x18
	53
	54	#define OMAP_RTC_ALARM_SECONDS_REG 0x20
	55	#define OMAP_RTC_ALARM_MINUTES_REG 0x24
	56	#define OMAP_RTC_ALARM_HOURS_REG 0x28
	57	#define OMAP_RTC_ALARM_DAYS_REG 0x2c
	58	#define OMAP_RTC_ALARM_MONTHS_REG 0x30
	59	#define OMAP_RTC_ALARM_YEARS_REG 0x34
	60
	61	#define OMAP_RTC_CTRL_REG 0x40
	62	#define OMAP_RTC_STATUS_REG 0x44
	63	#define OMAP_RTC_INTERRUPTS_REG 0x48
	64
	65	#define OMAP_RTC_COMP_LSB_REG 0x4c
	66	#define OMAP_RTC_COMP_MSB_REG 0x50
	67	#define OMAP_RTC_OSC_REG 0x54
	68
cab1458c AM	69	#define OMAP_RTC_KICK0_REG 0x6c
	70	#define OMAP_RTC_KICK1_REG 0x70
	71
db68b189 DB	72	/* OMAP_RTC_CTRL_REG bit fields: */
	73	#define OMAP_RTC_CTRL_SPLIT (1<<7)
	74	#define OMAP_RTC_CTRL_DISABLE (1<<6)
	75	#define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5)
	76	#define OMAP_RTC_CTRL_TEST (1<<4)
	77	#define OMAP_RTC_CTRL_MODE_12_24 (1<<3)
	78	#define OMAP_RTC_CTRL_AUTO_COMP (1<<2)
	79	#define OMAP_RTC_CTRL_ROUND_30S (1<<1)
	80	#define OMAP_RTC_CTRL_STOP (1<<0)
	81
	82	/* OMAP_RTC_STATUS_REG bit fields: */
	83	#define OMAP_RTC_STATUS_POWER_UP (1<<7)
	84	#define OMAP_RTC_STATUS_ALARM (1<<6)
	85	#define OMAP_RTC_STATUS_1D_EVENT (1<<5)
	86	#define OMAP_RTC_STATUS_1H_EVENT (1<<4)
	87	#define OMAP_RTC_STATUS_1M_EVENT (1<<3)
	88	#define OMAP_RTC_STATUS_1S_EVENT (1<<2)
	89	#define OMAP_RTC_STATUS_RUN (1<<1)
	90	#define OMAP_RTC_STATUS_BUSY (1<<0)
	91
	92	/* OMAP_RTC_INTERRUPTS_REG bit fields: */
	93	#define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3)
	94	#define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2)
	95
cab1458c AM	96	/* OMAP_RTC_KICKER values */
	97	#define KICK0_VALUE 0x83e70b13
	98	#define KICK1_VALUE 0x95a4f1e0
	99
	100	#define OMAP_RTC_HAS_KICKER 0x1
	101
8cfde8c1	102	static void __iomem *rtc_base;
db68b189	103
cab1458c AM	104	#define rtc_read(addr) readb(rtc_base + (addr))
	105	#define rtc_write(val, addr) writeb(val, rtc_base + (addr))
	106
	107	#define rtc_writel(val, addr) writel(val, rtc_base + (addr))
db68b189 DB	108
db68b189 DB	109
db68b189 DB	110	/* we rely on the rtc framework to handle locking (rtc->ops_lock),
	111	* so the only other requirement is that register accesses which
	112	* require BUSY to be clear are made with IRQs locally disabled
	113	*/
	114	static void rtc_wait_not_busy(void)
	115	{
	116	int count = 0;
	117	u8 status;
	118
	119	/* BUSY may stay active for 1/32768 second (~30 usec) */
	120	for (count = 0; count < 50; count++) {
	121	status = rtc_read(OMAP_RTC_STATUS_REG);
	122	if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
	123	break;
	124	udelay(1);
	125	}
	126	/* now we have ~15 usec to read/write various registers */
	127	}
	128
ab6a2d70	129	static irqreturn_t rtc_irq(int irq, void *rtc)
db68b189 DB	130	{
	131	unsigned long events = 0;
	132	u8 irq_data;
	133
	134	irq_data = rtc_read(OMAP_RTC_STATUS_REG);
	135
	136	/* alarm irq? */
	137	if (irq_data & OMAP_RTC_STATUS_ALARM) {
	138	rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
	139	events \|= RTC_IRQF \| RTC_AF;
	140	}
	141
	142	/* 1/sec periodic/update irq? */
	143	if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
	144	events \|= RTC_IRQF \| RTC_UF;
	145
ab6a2d70	146	rtc_update_irq(rtc, 1, events);
db68b189 DB	147
	148	return IRQ_HANDLED;
	149	}
	150
16380c15 JS	151	static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
	152	{
	153	u8 reg;
	154
	155	local_irq_disable();
	156	rtc_wait_not_busy();
	157	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	158	if (enabled)
	159	reg \|= OMAP_RTC_INTERRUPTS_IT_ALARM;
	160	else
	161	reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	162	rtc_wait_not_busy();
	163	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	164	local_irq_enable();
	165
	166	return 0;
	167	}
	168
db68b189 DB	169	/* this hardware doesn't support "don't care" alarm fields */
	170	static int tm2bcd(struct rtc_time *tm)
	171	{
	172	if (rtc_valid_tm(tm) != 0)
	173	return -EINVAL;
	174
fe20ba70 AB	175	tm->tm_sec = bin2bcd(tm->tm_sec);
	176	tm->tm_min = bin2bcd(tm->tm_min);
	177	tm->tm_hour = bin2bcd(tm->tm_hour);
	178	tm->tm_mday = bin2bcd(tm->tm_mday);
db68b189	179
fe20ba70	180	tm->tm_mon = bin2bcd(tm->tm_mon + 1);
db68b189 DB	181
	182	/* epoch == 1900 */
	183	if (tm->tm_year < 100 \|\| tm->tm_year > 199)
	184	return -EINVAL;
fe20ba70	185	tm->tm_year = bin2bcd(tm->tm_year - 100);
db68b189 DB	186
	187	return 0;
	188	}
	189
	190	static void bcd2tm(struct rtc_time *tm)
	191	{
fe20ba70 AB	192	tm->tm_sec = bcd2bin(tm->tm_sec);
	193	tm->tm_min = bcd2bin(tm->tm_min);
	194	tm->tm_hour = bcd2bin(tm->tm_hour);
	195	tm->tm_mday = bcd2bin(tm->tm_mday);
	196	tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
db68b189	197	/* epoch == 1900 */
fe20ba70	198	tm->tm_year = bcd2bin(tm->tm_year) + 100;
db68b189 DB	199	}
	200
	201
	202	static int omap_rtc_read_time(struct device dev, struct rtc_time tm)
	203	{
	204	/* we don't report wday/yday/isdst ... */
	205	local_irq_disable();
	206	rtc_wait_not_busy();
	207
	208	tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
	209	tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
	210	tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
	211	tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
	212	tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
	213	tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
	214
	215	local_irq_enable();
	216
	217	bcd2tm(tm);
	218	return 0;
	219	}
	220
	221	static int omap_rtc_set_time(struct device dev, struct rtc_time tm)
	222	{
	223	if (tm2bcd(tm) < 0)
	224	return -EINVAL;
	225	local_irq_disable();
	226	rtc_wait_not_busy();
	227
	228	rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
	229	rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
	230	rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
	231	rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
	232	rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
	233	rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
	234
	235	local_irq_enable();
	236
	237	return 0;
	238	}
	239
	240	static int omap_rtc_read_alarm(struct device dev, struct rtc_wkalrm alm)
	241	{
	242	local_irq_disable();
	243	rtc_wait_not_busy();
	244
	245	alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
	246	alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
	247	alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
	248	alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
	249	alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
	250	alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
	251
	252	local_irq_enable();
	253
	254	bcd2tm(&alm->time);
a2db8dfc	255	alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
db68b189	256	& OMAP_RTC_INTERRUPTS_IT_ALARM);
db68b189 DB	257
	258	return 0;
	259	}
	260
	261	static int omap_rtc_set_alarm(struct device dev, struct rtc_wkalrm alm)
	262	{
	263	u8 reg;
	264
db68b189 DB	265	if (tm2bcd(&alm->time) < 0)
	266	return -EINVAL;
	267
	268	local_irq_disable();
	269	rtc_wait_not_busy();
	270
	271	rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
	272	rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
	273	rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
	274	rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
	275	rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
	276	rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
	277
	278	reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	279	if (alm->enabled)
	280	reg \|= OMAP_RTC_INTERRUPTS_IT_ALARM;
	281	else
	282	reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
	283	rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
	284
	285	local_irq_enable();
	286
	287	return 0;
	288	}
	289
	290	static struct rtc_class_ops omap_rtc_ops = {
db68b189 DB	291	.read_time = omap_rtc_read_time,
	292	.set_time = omap_rtc_set_time,
	293	.read_alarm = omap_rtc_read_alarm,
	294	.set_alarm = omap_rtc_set_alarm,
16380c15	295	.alarm_irq_enable = omap_rtc_alarm_irq_enable,
db68b189 DB	296	};
	297
	298	static int omap_rtc_alarm;
	299	static int omap_rtc_timer;
	300
cab1458c AM	301	static struct platform_device_id omap_rtc_devtype[] = {
	302	{
	303	.name = DRIVER_NAME,
	304	}, {
	305	.name = "da830-rtc",
	306	.driver_data = OMAP_RTC_HAS_KICKER,
	307	},
	308	{},
	309	};
	310	MODULE_DEVICE_TABLE(platform, omap_rtc_devtype);
	311
71fc8224	312	static int __init omap_rtc_probe(struct platform_device *pdev)
db68b189 DB	313	{
	314	struct resource res, mem;
	315	struct rtc_device *rtc;
	316	u8 reg, new_ctrl;
cab1458c	317	const struct platform_device_id *id_entry;
db68b189 DB	318
	319	omap_rtc_timer = platform_get_irq(pdev, 0);
	320	if (omap_rtc_timer <= 0) {
	321	pr_debug("%s: no update irq?\n", pdev->name);
	322	return -ENOENT;
	323	}
	324
	325	omap_rtc_alarm = platform_get_irq(pdev, 1);
	326	if (omap_rtc_alarm <= 0) {
	327	pr_debug("%s: no alarm irq?\n", pdev->name);
	328	return -ENOENT;
	329	}
	330
db68b189	331	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
8cfde8c1 MG	332	if (!res) {
8cfde8c1 MG	333	pr_debug("%s: RTC resource data missing\n", pdev->name);
db68b189 DB	334	return -ENOENT;
	335	}
	336
8cfde8c1	337	mem = request_mem_region(res->start, resource_size(res), pdev->name);
db68b189 DB	338	if (!mem) {
db68b189 DB	339	pr_debug("%s: RTC registers at %08x are not free\n",
8cfde8c1	340	pdev->name, res->start);
db68b189 DB	341	return -EBUSY;
	342	}
	343
8cfde8c1 MG	344	rtc_base = ioremap(res->start, resource_size(res));
	345	if (!rtc_base) {
	346	pr_debug("%s: RTC registers can't be mapped\n", pdev->name);
	347	goto fail;
	348	}
	349
cab1458c AM	350	id_entry = platform_get_device_id(pdev);
	351	if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER)) {
	352	rtc_writel(KICK0_VALUE, OMAP_RTC_KICK0_REG);
	353	rtc_writel(KICK1_VALUE, OMAP_RTC_KICK1_REG);
	354	}
	355
db68b189 DB	356	rtc = rtc_device_register(pdev->name, &pdev->dev,
	357	&omap_rtc_ops, THIS_MODULE);
	358	if (IS_ERR(rtc)) {
	359	pr_debug("%s: can't register RTC device, err %ld\n",
	360	pdev->name, PTR_ERR(rtc));
8cfde8c1	361	goto fail0;
db68b189 DB	362	}
db68b189 DB	363	platform_set_drvdata(pdev, rtc);
558a40f7	364	dev_set_drvdata(&rtc->dev, mem);
db68b189 DB	365
	366	/* clear pending irqs, and set 1/second periodic,
	367	* which we'll use instead of update irqs
	368	*/
	369	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	370
	371	/* clear old status */
	372	reg = rtc_read(OMAP_RTC_STATUS_REG);
	373	if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
	374	pr_info("%s: RTC power up reset detected\n",
	375	pdev->name);
	376	rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
	377	}
	378	if (reg & (u8) OMAP_RTC_STATUS_ALARM)
	379	rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
	380
	381	/* handle periodic and alarm irqs */
2f6e5f94	382	if (request_irq(omap_rtc_timer, rtc_irq, 0,
744bcb13	383	dev_name(&rtc->dev), rtc)) {
db68b189 DB	384	pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
db68b189 DB	385	pdev->name, omap_rtc_timer);
8cfde8c1	386	goto fail1;
db68b189	387	}
8cfde8c1	388	if ((omap_rtc_timer != omap_rtc_alarm) &&
2f6e5f94	389	(request_irq(omap_rtc_alarm, rtc_irq, 0,
8cfde8c1	390	dev_name(&rtc->dev), rtc))) {
db68b189 DB	391	pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
db68b189 DB	392	pdev->name, omap_rtc_alarm);
8cfde8c1	393	goto fail2;
db68b189 DB	394	}
	395
	396	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
	397	reg = rtc_read(OMAP_RTC_CTRL_REG);
	398	if (reg & (u8) OMAP_RTC_CTRL_STOP)
	399	pr_info("%s: already running\n", pdev->name);
	400
	401	/* force to 24 hour mode */
12b3e038	402	new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT\|OMAP_RTC_CTRL_AUTO_COMP);
db68b189 DB	403	new_ctrl \|= OMAP_RTC_CTRL_STOP;
	404
	405	/* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
	406	*
fa5b0782 SN	407	* - Device wake-up capability setting should come through chip
	408	* init logic. OMAP1 boards should initialize the "wakeup capable"
	409	* flag in the platform device if the board is wired right for
	410	* being woken up by RTC alarm. For OMAP-L138, this capability
	411	* is built into the SoC by the "Deep Sleep" capability.
db68b189 DB	412	*
	413	* - Boards wired so RTC_ON_nOFF is used as the reset signal,
	414	* rather than nPWRON_RESET, should forcibly enable split
	415	* power mode. (Some chip errata report that RTC_CTRL_SPLIT
	416	* is write-only, and always reads as zero...)
	417	*/
db68b189 DB	418
	419	if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
	420	pr_info("%s: split power mode\n", pdev->name);
	421
	422	if (reg != new_ctrl)
	423	rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
	424
	425	return 0;
	426
8cfde8c1	427	fail2:
2dd93c4f	428	free_irq(omap_rtc_timer, rtc);
8cfde8c1	429	fail1:
db68b189	430	rtc_device_unregister(rtc);
8cfde8c1	431	fail0:
cab1458c AM	432	if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER))
cab1458c AM	433	rtc_writel(0, OMAP_RTC_KICK0_REG);
8cfde8c1	434	iounmap(rtc_base);
db68b189	435	fail:
19412ce9	436	release_mem_region(mem->start, resource_size(mem));
db68b189 DB	437	return -EIO;
	438	}
	439
71fc8224	440	static int __exit omap_rtc_remove(struct platform_device *pdev)
db68b189	441	{
a419aef8	442	struct rtc_device *rtc = platform_get_drvdata(pdev);
19412ce9	443	struct resource *mem = dev_get_drvdata(&rtc->dev);
cab1458c AM	444	const struct platform_device_id *id_entry =
cab1458c AM	445	platform_get_device_id(pdev);
db68b189 DB	446
	447	device_init_wakeup(&pdev->dev, 0);
	448
	449	/* leave rtc running, but disable irqs */
	450	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	451
	452	free_irq(omap_rtc_timer, rtc);
8cfde8c1 MG	453
	454	if (omap_rtc_timer != omap_rtc_alarm)
	455	free_irq(omap_rtc_alarm, rtc);
db68b189	456
db68b189	457	rtc_device_unregister(rtc);
cab1458c AM	458	if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER))
cab1458c AM	459	rtc_writel(0, OMAP_RTC_KICK0_REG);
19412ce9 AL	460	iounmap(rtc_base);
19412ce9 AL	461	release_mem_region(mem->start, resource_size(mem));
db68b189 DB	462	return 0;
	463	}
	464
	465	#ifdef CONFIG_PM
	466
db68b189 DB	467	static u8 irqstat;
	468
	469	static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
	470	{
db68b189 DB	471	irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
	472
	473	/* FIXME the RTC alarm is not currently acting as a wakeup event
	474	* source, and in fact this enable() call is just saving a flag
	475	* that's never used...
	476	*/
	477	if (device_may_wakeup(&pdev->dev))
	478	enable_irq_wake(omap_rtc_alarm);
	479	else
	480	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	481
	482	return 0;
	483	}
	484
	485	static int omap_rtc_resume(struct platform_device *pdev)
	486	{
db68b189 DB	487	if (device_may_wakeup(&pdev->dev))
	488	disable_irq_wake(omap_rtc_alarm);
	489	else
	490	rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
	491	return 0;
	492	}
	493
	494	#else
	495	#define omap_rtc_suspend NULL
	496	#define omap_rtc_resume NULL
	497	#endif
	498
	499	static void omap_rtc_shutdown(struct platform_device *pdev)
	500	{
	501	rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
	502	}
	503
ad28a07b	504	MODULE_ALIAS("platform:omap_rtc");
db68b189	505	static struct platform_driver omap_rtc_driver = {
71fc8224	506	.remove = __exit_p(omap_rtc_remove),
db68b189 DB	507	.suspend = omap_rtc_suspend,
	508	.resume = omap_rtc_resume,
	509	.shutdown = omap_rtc_shutdown,
	510	.driver = {
cab1458c	511	.name = DRIVER_NAME,
db68b189 DB	512	.owner = THIS_MODULE,
db68b189 DB	513	},
cab1458c	514	.id_table = omap_rtc_devtype,
db68b189 DB	515	};
	516
	517	static int __init rtc_init(void)
	518	{
71fc8224	519	return platform_driver_probe(&omap_rtc_driver, omap_rtc_probe);
db68b189 DB	520	}
	521	module_init(rtc_init);
	522
	523	static void __exit rtc_exit(void)
	524	{
	525	platform_driver_unregister(&omap_rtc_driver);
	526	}
	527	module_exit(rtc_exit);
	528
	529	MODULE_AUTHOR("George G. Davis (and others)");
	530	MODULE_LICENSE("GPL");