openwrt-owl/target/linux/coldfire/patches/027-Add-RTC-driver-support-on-MCF5441x-platform.patch

From 6462d09dad154b69ea6180c0acb2d009627ff1be Mon Sep 17 00:00:00 2001
From: Alison Wang <b18965@freescale.com>
Date: Thu, 4 Aug 2011 09:59:46 +0800
Subject: [PATCH 27/52] Add RTC driver support on MCF5441x platform

Support on-chip robust-RTC module on MCF5441x platform.

Signed-off-by: Alison Wang <b18965@freescale.com>
---
 drivers/rtc/Kconfig      |    9 +
 drivers/rtc/Makefile     |    1 +
 drivers/rtc/rtc-m5441x.c |  638 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 648 insertions(+), 0 deletions(-)
 create mode 100644 drivers/rtc/rtc-m5441x.c

--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -928,6 +928,15 @@ config RTC_MCF
 
 	  If you build it as a module it will be call mcf-rtc.
 
+config RTC_M5441X
+        tristate "Freescale Coldfire M5441X platform Real Time Clock"
+        depends on COLDFIRE
+        help
+          If you say yes here you will get support for the on-chip Coldfire
+	  Real-Time Clock for mcf5441x platform.
+
+	  If you build it as a module it will be call rtc-m5441x.
+
 config RTC_DRV_PS3
 	tristate "PS3 RTC"
 	depends on PPC_PS3
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -103,3 +103,4 @@ obj-$(CONFIG_RTC_DRV_WM831X)	+= rtc-wm83
 obj-$(CONFIG_RTC_DRV_WM8350)	+= rtc-wm8350.o
 obj-$(CONFIG_RTC_DRV_X1205)	+= rtc-x1205.o
 obj-$(CONFIG_RTC_MCF)           += rtc-mcf.o
+obj-$(CONFIG_RTC_M5441X)	+= rtc-m5441x.o
--- /dev/null
+++ b/drivers/rtc/rtc-m5441x.c
@@ -0,0 +1,638 @@
+/*
+ * Copyright (C) 2010-2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * Lanttor.Guo@freescale.com
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/*
+ * Implementation based on rtc-mcf.c
+ */
+
+/*
+ * RTC Real Time Clock (RTC) Driver
+ *
+ * @file rtc-m5441x.c
+ * @brief Real Time Clock interface
+ *
+ * This file contains Real Time Clock interface for Linux.
+ *
+ */
+#include <linux/rtc.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/uaccess.h>
+#include <asm/mcfsim.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#ifdef readw
+#undef readw
+#endif
+
+#ifdef writew
+#undef writew
+#endif
+
+#define readw(addr)      in_be16(addr)
+#define writew(val, addr) out_be16((addr), (val))
+
+
+#define PIT_ALL_ON (MCF_RTC_ISR_2HZ | MCF_RTC_ISR_SAM0 | MCF_RTC_ISR_SAM1 | \
+		     MCF_RTC_ISR_SAM2 | MCF_RTC_ISR_SAM3 | MCF_RTC_ISR_SAM4 | \
+		     MCF_RTC_ISR_SAM5 | MCF_RTC_ISR_SAM6 | MCF_RTC_ISR_SAM7)
+
+#define MAX_PIE_NUM     9
+#define MAX_PIE_FREQ    512
+const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = {
+	{2,   MCF_RTC_ISR_2HZ},
+	{4,   MCF_RTC_ISR_SAM0},
+	{8,   MCF_RTC_ISR_SAM1},
+	{16,  MCF_RTC_ISR_SAM2},
+	{32,  MCF_RTC_ISR_SAM3},
+	{64,  MCF_RTC_ISR_SAM4},
+	{128, MCF_RTC_ISR_SAM5},
+	{256, MCF_RTC_ISR_SAM6},
+	{MAX_PIE_FREQ, MCF_RTC_ISR_SAM7},
+};
+
+/* Those are the bits from a classic RTC we want to mimic */
+#define RTC_IRQF                0x80	/* any of the following 3 is active */
+#define RTC_PF                  0x40	/* Periodic interrupt */
+#define RTC_AF                  0x20	/* Alarm interrupt */
+#define RTC_UF                  0x10	/* Update interrupt for 1Hz RTC */
+
+#define MCF_RTC_TIME            0
+#define MCF_RTC_ALARM           1
+
+struct rtc_plat_data {
+	struct rtc_device *rtc;
+	int irq;
+	unsigned int irqen;
+	int alrm_sec;
+	int alrm_min;
+	int alrm_hour;
+	int alrm_mday;
+};
+
+static const int year_cal_basic = 2112;
+
+#define RTC_VERSION		"0.1"
+
+static u32 rtc_freq = 2;	/* minimun value for PIE */
+static unsigned long rtc_status;
+
+static struct rtc_time g_rtc_alarm = {
+	.tm_year = 0,
+	.tm_mon = 0,
+	.tm_mday = 0,
+	.tm_hour = 0,
+	.tm_mon = 0,
+	.tm_sec = 0,
+};
+
+static DEFINE_SPINLOCK(rtc_lock);
+
+
+/*
+ * This funciton is used to disable RTC register write protection
+ */
+static void disable_register_write_protection(void)
+{
+	if (readw(MCF_RTC_SR) & MCF_RTC_SR_WPE) {
+		writew(0x0000, MCF_RTC_CR);
+		writew(0x0001, MCF_RTC_CR);
+		writew(0x0003, MCF_RTC_CR);
+		writew(0x0002, MCF_RTC_CR);
+	}
+
+}
+
+/*
+ * This function is used to obtain the RTC time or the alarm value in
+ * second.
+ *
+ * @param  time_alarm   use MCF_RTC_TIME for RTC time value;
+ *			    MCF_RTC_ALARM for alarm value
+ *
+ * @return The RTC time or alarm time in second.
+ */
+static u32 get_alarm_or_time(struct device *dev, int time_alarm,
+			struct rtc_time *tm)
+{
+	dev_dbg(dev, "debug function %s()!\n", __func__);
+
+	if (time_alarm == MCF_RTC_TIME) {
+		/*check register information */
+		dev_dbg(dev, "RTC_YEARMON:0x%x,RTC_DAYS:0x%x,RTC_HOURMIN:0x%x,"
+			"RTC_SECONDS:0x%x\n", readw(MCF_RTC_YEARMON),
+			readw(MCF_RTC_DAYS), readw(MCF_RTC_HOURMIN),
+			readw(MCF_RTC_SECONDS));
+
+		/* get year */
+		tm->tm_year = year_cal_basic +
+			(char)(MCF_RTC_YEARMON_YEAR_RD(readw(MCF_RTC_YEARMON)));
+		/* get month */
+		tm->tm_mon =
+			MCF_RTC_YEARMON_MON_RD(readw(MCF_RTC_YEARMON)) - 1;
+		/* get month day */
+		tm->tm_mday = MCF_RTC_DAYS_DAY_RD(readw(MCF_RTC_DAYS));
+		/* get year day */
+		tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon,
+				tm->tm_year);
+		/* year minus 1900 */
+		tm->tm_year = tm->tm_year - 1900;
+		/* get week day */
+		tm->tm_wday = MCF_RTC_DAYS_DAYWEEK_RD(readw(MCF_RTC_DAYS));
+		/* get hours */
+		tm->tm_hour =
+			MCF_RTC_HOURMIN_HOURS_RD(readw(MCF_RTC_HOURMIN));
+		/* get minutes */
+		tm->tm_min =
+			MCF_RTC_HOURMIN_MINUTES_RD(readw(MCF_RTC_HOURMIN));
+		/* get seconds */
+		tm->tm_sec =
+			MCF_RTC_SECONDS_SECONDS_RD(readw(MCF_RTC_SECONDS));
+		/* no day saving time */
+		tm->tm_isdst = -1;
+
+		/* check rtc_tm fileds information */
+		dev_dbg(dev, "RTC TIME --> year:%d,yday:%d,mon:%d,mday:%d,"
+			"wday:%d,hour:%d,min:%d,sec:%d\n", tm->tm_year,
+			tm->tm_yday, tm->tm_mon, tm->tm_mday, tm->tm_wday,
+			tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	} else if (time_alarm == MCF_RTC_ALARM) {
+		tm->tm_year = year_cal_basic +
+			(char)MCF_RTC_YEARMON_YEAR_RD
+			(readw(MCF_RTC_ALRM_YRMON));
+		tm->tm_mon =
+			MCF_RTC_YEARMON_MON_RD(readw(MCF_RTC_ALRM_YRMON)) - 1;
+		tm->tm_mday = MCF_RTC_DAYS_DAY_RD(readw(MCF_RTC_ALRM_DAYS));
+		tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon,
+			tm->tm_year);
+		tm->tm_year = tm->tm_year - 1900;
+		tm->tm_wday =
+			MCF_RTC_DAYS_DAYWEEK_RD(readw(MCF_RTC_ALRM_DAYS));
+		tm->tm_hour =
+			MCF_RTC_HOURMIN_HOURS_RD(readw(MCF_RTC_ALRM_HM));
+		tm->tm_min =
+			MCF_RTC_HOURMIN_MINUTES_RD(readw(MCF_RTC_ALRM_HM));
+		tm->tm_sec =
+			MCF_RTC_SECONDS_SECONDS_RD(readw(MCF_RTC_ALRM_SEC));
+		tm->tm_isdst = -1;
+
+		/* debug information */
+		dev_dbg(dev, "RTC ALARM --> year:%d,yday:%d,mon:%d,mday:%d,"
+			"wday:%d,hour:%d,min:%d,sec:%d\n", tm->tm_year,
+			tm->tm_yday, tm->tm_mon, tm->tm_mday, tm->tm_wday,
+			tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	} else {
+		panic("wrong value for time_alarm=%d\n", time_alarm);
+	}
+
+	return 0;
+}
+
+/*
+ * This function sets the RTC alarm value or the time value.
+ *
+ * @param  time_alarm	the new alarm value to be updated in the RTC
+ * @param  time	use MCF_RTC_TIME for RTC time value;
+ *			MCF_RTC_ALARM for alarm value
+ */
+static void set_alarm_or_time(struct device *dev, int time_alarm,
+			struct rtc_time *tm)
+{
+	char year;
+
+	dev_dbg(dev, "debug function %s()!\n", __func__);
+
+	/* wirte enable setting */
+	disable_register_write_protection();
+
+	if (time_alarm == MCF_RTC_TIME) {
+		/* check rtc_time fields information */
+		dev_dbg(dev, "RTC TIME --> year:%d,yday:%d,mon:%d,mday:%d,"
+			"wday:%d,hour:%d,min:%d,sec:%d\n", tm->tm_year,
+			tm->tm_yday, tm->tm_mon, tm->tm_mday, tm->tm_wday,
+			tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+		year = ((tm->tm_year + 1900) - year_cal_basic);
+		/* write RTC_YEARMON register */
+		writew((year << 8) | (tm->tm_mon + 1), MCF_RTC_YEARMON);
+
+		/* write RTC_DAYS register */
+		writew(MCF_RTC_DAYS_DAYWEEK_SET(tm->tm_wday) |
+			MCF_RTC_DAYS_DAY_SET(tm->tm_mday), MCF_RTC_DAYS);
+
+		/* write RTC_HOURMIN register */
+		writew(MCF_RTC_HOURMIN_HOURS_SET(tm->tm_hour) |
+			MCF_RTC_HOURMIN_MINUTES_SET(tm->tm_min),
+			MCF_RTC_HOURMIN);
+
+		/* write RTC_SECONDS register */
+		writew(MCF_RTC_SECONDS_SECONDS_SET
+			(tm->tm_sec), MCF_RTC_SECONDS);
+
+		/* debug information */
+		dev_dbg(dev, "RTC_YEARMON:0x%x, RTC_DAYS:0x%x, "
+			"RTC_HOURMIN:0x%x, RTC_SECONDS:0x%x\n",
+			readw(MCF_RTC_YEARMON), readw(MCF_RTC_DAYS),
+			readw(MCF_RTC_HOURMIN), readw(MCF_RTC_SECONDS));
+	} else if (time_alarm == MCF_RTC_ALARM) {
+
+		year = ((tm->tm_year + 1900) - year_cal_basic);
+		/* write RTC_YEARMON register */
+		writew((year << 8) | (tm->tm_mon + 1), MCF_RTC_ALRM_YRMON);
+
+		/* write RTC_DAYS register */
+		writew(MCF_RTC_DAYS_DAYWEEK_SET(tm->tm_wday) |
+			MCF_RTC_DAYS_DAY_SET(tm->tm_mday), MCF_RTC_ALRM_DAYS);
+
+		/* write RTC_HOURMIN register */
+		writew(MCF_RTC_HOURMIN_HOURS_SET(tm->tm_hour) |
+			MCF_RTC_HOURMIN_MINUTES_SET(tm->tm_min),
+			MCF_RTC_ALRM_HM);
+
+		/* write RTC_SECONDS register */
+		writew(MCF_RTC_SECONDS_SECONDS_SET
+			(tm->tm_sec), MCF_RTC_ALRM_SEC);
+
+		/* debug information */
+		dev_dbg(dev, "ALRM_YRMON:0x%x,ALRM_DAYS:0x%x,ALRM_HM:0x%x,"
+			"ALRM_SEC:0x%x\n", readw(MCF_RTC_ALRM_YRMON),
+			readw(MCF_RTC_ALRM_DAYS), readw(MCF_RTC_ALRM_HM),
+			readw(MCF_RTC_ALRM_SEC));
+	} else {
+		panic("wrong value for time_alarm=%d\n", time_alarm);
+	}
+}
+
+/*!
+ * This function updates the RTC alarm registers and then clears all the
+ * interrupt status bits.
+ *
+ * @param  alrm         the new alarm value to be updated in the RTC
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
+{
+	/* clear all the interrupt status bits */
+	disable_register_write_protection();
+
+	writew(readw(MCF_RTC_ISR), MCF_RTC_ISR);
+
+	set_alarm_or_time(dev, MCF_RTC_ALARM, alrm);
+
+	return 0;
+}
+
+/*!
+ * This function is the RTC interrupt service routine.
+ *
+ * @param  irq          RTC IRQ number
+ * @param  dev_id       device ID which is not used
+ *
+ * @return IRQ_HANDLED as defined in the include/linux/interrupt.h file.
+ */
+static irqreturn_t mcf_rtc_interrupt(int irq, void *dev_id)
+{
+	struct platform_device *pdev = dev_id;
+	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+	u16 status = 0;
+	u32 events = 0;
+
+	spin_lock(&rtc_lock);
+
+	/* clear interrupt sources */
+	status = readw(MCF_RTC_ISR) & readw(MCF_RTC_IER);
+
+	disable_register_write_protection();
+
+	writew(status, MCF_RTC_ISR);
+
+	/* clear alarm interrupt if it has occurred */
+	if (status & MCF_RTC_ISR_ALM)
+		status &= ~MCF_RTC_ISR_ALM;
+
+	/* update irq data & counter */
+	if (status & MCF_RTC_ISR_ALM)
+		events |= (RTC_AF | RTC_IRQF);
+	if (status & MCF_RTC_ISR_1HZ)
+		events |= (RTC_UF | RTC_IRQF);
+	if (status & PIT_ALL_ON)
+		events |= (RTC_PF | RTC_IRQF);
+
+	if ((status & MCF_RTC_ISR_ALM) && rtc_valid_tm(&g_rtc_alarm))
+		rtc_update_alarm(&pdev->dev, &g_rtc_alarm);
+
+	spin_unlock(&rtc_lock);
+	rtc_update_irq(pdata->rtc, 1, events);
+	return IRQ_HANDLED;
+}
+
+/*!
+ * clear all interrupts and release the IRQ
+ */
+static void mcf_rtc_release(struct device *dev)
+{
+	spin_lock_irq(&rtc_lock);
+
+	disable_register_write_protection();
+
+	writew(0, MCF_RTC_IER);			/* Disable all rtc interrupts */
+	writew(readw(MCF_RTC_ISR), MCF_RTC_ISR);
+	spin_unlock_irq(&rtc_lock);
+	rtc_status = 0;
+}
+
+/*!
+ * This function is used to support some ioctl calls directly.
+ * Other ioctl calls are supported indirectly through the
+ * arm/common/rtctime.c file.
+ *
+ * @param  cmd          ioctl command as defined in include/linux/rtc.h
+ * @param  arg          value for the ioctl command
+ *
+ * @return  0 if successful or negative value otherwise.
+ */
+static int mcf_rtc_ioctl(struct device *dev, unsigned int cmd,
+			 unsigned long arg)
+{
+	int i;
+
+	disable_register_write_protection();
+
+	switch (cmd) {
+	case RTC_PIE_OFF:
+		writew((readw(MCF_RTC_IER) & ~PIT_ALL_ON), MCF_RTC_IER);
+		return 0;
+	case RTC_IRQP_SET:
+		if (arg < 2 || arg > MAX_PIE_FREQ || (arg % 2) != 0)
+			return -EINVAL;	/* Also make sure a power of 2Hz */
+		if ((arg > 64) && (!capable(CAP_SYS_RESOURCE)))
+			return -EACCES;
+		rtc_freq = arg;
+		return 0;
+	case RTC_IRQP_READ:
+		return put_user(rtc_freq, (u32 *) arg);
+	case RTC_PIE_ON:
+		for (i = 0; i < MAX_PIE_NUM; i++) {
+			if (PIE_BIT_DEF[i][0] == rtc_freq)
+				break;
+		}
+		if (i == MAX_PIE_NUM)
+			return -EACCES;
+		spin_lock_irq(&rtc_lock);
+		writew((readw(MCF_RTC_IER) | PIE_BIT_DEF[i][1]), MCF_RTC_IER);
+		spin_unlock_irq(&rtc_lock);
+		return 0;
+	case RTC_AIE_OFF:
+		spin_lock_irq(&rtc_lock);
+		writew((readw(MCF_RTC_IER) & ~MCF_RTC_ISR_ALM), MCF_RTC_IER);
+		spin_unlock_irq(&rtc_lock);
+		return 0;
+
+	case RTC_AIE_ON:
+		spin_lock_irq(&rtc_lock);
+		writew((readw(MCF_RTC_IER) | MCF_RTC_ISR_ALM), MCF_RTC_IER);
+		spin_unlock_irq(&rtc_lock);
+		return 0;
+
+	case RTC_UIE_OFF:	/* UIE is for the 1Hz interrupt */
+		spin_lock_irq(&rtc_lock);
+		writew((readw(MCF_RTC_IER) & ~MCF_RTC_ISR_1HZ), MCF_RTC_IER);
+		spin_unlock_irq(&rtc_lock);
+		return 0;
+
+	case RTC_UIE_ON:
+		spin_lock_irq(&rtc_lock);
+		writew((readw(MCF_RTC_IER) | MCF_RTC_ISR_1HZ), MCF_RTC_IER);
+		spin_unlock_irq(&rtc_lock);
+		return 0;
+	}
+	return -ENOIOCTLCMD;
+}
+
+/*!
+ * This function reads the current RTC time into tm in Gregorian date.
+ *
+ * @param  tm           contains the RTC time value upon return
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mcf_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	do {
+		get_alarm_or_time(dev, MCF_RTC_TIME, tm);
+	} while (0);
+
+	return 0;
+}
+
+/*!
+ * This function sets the internal RTC time based on tm in Gregorian date.
+ *
+ * @param  tm           the time value to be set in the RTC
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mcf_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	do {
+		set_alarm_or_time(dev, MCF_RTC_TIME, tm);
+	} while (0);
+
+	return 0;
+}
+
+/*!
+ * This function reads the current alarm value into the passed in \b alrm
+ * argument. It updates the \b alrm's pending field value based on the whether
+ * an alarm interrupt occurs or not.
+ *
+ * @param  alrm         contains the RTC alarm value upon return
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mcf_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	do {
+		get_alarm_or_time(dev, MCF_RTC_ALARM, &alrm->time);
+	} while (0);
+
+	alrm->pending = ((readw(MCF_RTC_ISR) & MCF_RTC_ISR_ALM) != 0) ? 1 : 0;
+
+	return 0;
+}
+
+/*!
+ * This function sets the RTC alarm based on passed in alrm.
+ *
+ * @param  alrm         the alarm value to be set in the RTC
+ *
+ * @return  0 if successful; non-zero otherwise.
+ */
+static int mcf_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	int ret;
+
+	spin_lock_irq(&rtc_lock);
+
+	disable_register_write_protection();
+
+	if (rtc_valid_tm(&alrm->time)) {
+		if (alrm->time.tm_sec > 59 ||
+		    alrm->time.tm_hour > 23 || alrm->time.tm_min > 59) {
+			ret = -EINVAL;
+			goto out;
+		}
+		ret = rtc_update_alarm(dev, &alrm->time);
+	} else {
+		ret = rtc_valid_tm(&alrm->time);
+		if (ret)
+			goto out;
+		ret = rtc_update_alarm(dev, &alrm->time);
+	}
+
+	if (ret == 0) {
+		memcpy(&g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
+
+		if (alrm->enabled) {
+			writew((readw(MCF_RTC_IER) | MCF_RTC_ISR_ALM),
+				MCF_RTC_IER);
+		} else {
+			writew((readw(MCF_RTC_IER) & ~MCF_RTC_ISR_ALM),
+				MCF_RTC_IER);
+		}
+	}
+out:
+	spin_unlock_irq(&rtc_lock);
+
+	return ret;
+}
+
+/*!
+ * The RTC driver structure
+ */
+static struct rtc_class_ops mcf_rtc_ops = {
+	.ioctl = mcf_rtc_ioctl,
+	.read_time = mcf_rtc_read_time,
+	.set_time = mcf_rtc_set_time,
+	.read_alarm = mcf_rtc_read_alarm,
+	.set_alarm = mcf_rtc_set_alarm,
+};
+
+static int __devinit mcf_rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+	struct rtc_plat_data *pdata = NULL;
+	u32 ret = 0;
+
+	disable_register_write_protection();
+	/* Clear interrupt before request irq */
+	writew(0x0100, MCF_RTC_CR);
+	writew(0x0001, MCF_RTC_IER);
+
+	if (!(readw(MCF_RTC_CFG_DATA) & MCF_RTC_CFG_DATA_OSCEN))
+		writew(MCF_RTC_CFG_DATA_OSCEN, MCF_RTC_CFG_DATA);
+
+	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+
+	pdata->irq = MCFINT_VECBASE + MCFINT_RTC;
+	if (request_irq(pdata->irq, mcf_rtc_interrupt, IRQF_DISABLED,
+			pdev->name, pdev) < 0) {
+		dev_warn(&pdev->dev, "interrupt not available.\n");
+		pdata->irq = -1;
+	}
+
+	if (test_and_set_bit(1, &rtc_status))
+		return -EBUSY;
+
+	rtc = rtc_device_register(pdev->name, &pdev->dev, &mcf_rtc_ops,
+				THIS_MODULE);
+	if (IS_ERR(rtc)) {
+		ret = PTR_ERR(rtc);
+		if (pdata->irq >= 0)
+			free_irq(pdata->irq, pdev);
+		kfree(pdata);
+		return ret;
+	}
+	pdata->rtc = rtc;
+	platform_set_drvdata(pdev, pdata);
+
+	dev_dbg(&pdev->dev, "RTC_CR:0x%x, RTC_SR:0x%x\n", readw(MCF_RTC_CR),
+		readw(MCF_RTC_SR));
+
+	printk(KERN_INFO "Real Time Clock Driver v%s\n", RTC_VERSION);
+	return ret;
+}
+
+static int __devexit mcf_rtc_remove(struct platform_device *pdev)
+{
+	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+
+	rtc_device_unregister(pdata->rtc);
+	if (pdata->irq >= 0)
+		free_irq(pdata->irq, pdev);
+	kfree(pdata);
+	mcf_rtc_release(NULL);
+	return 0;
+}
+
+/*!
+ * Contains pointers to the power management callback functions.
+ */
+MODULE_ALIAS("rtc-m5441x");
+static struct platform_driver mcf_rtc_driver = {
+	.driver	= {
+		   .name = "rtc-m5441x",
+		   .owner = THIS_MODULE,
+		   },
+	.probe	= mcf_rtc_probe,
+	.remove	= __devexit_p(mcf_rtc_remove),
+};
+
+/*!
+ * This function creates the /proc/driver/rtc file and registers the device RTC
+ * in the /dev/misc directory. It also reads the RTC value from external source
+ * and setup the internal RTC properly.
+ *
+ * @return  -1 if RTC is failed to initialize; 0 is successful.
+ */
+static int __init mcf_rtc_init(void)
+{
+	return platform_driver_register(&mcf_rtc_driver);
+}
+
+/*!
+ * This function removes the /proc/driver/rtc file and un-registers the
+ * device RTC from the /dev/misc directory.
+ */
+static void __exit mcf_rtc_exit(void)
+{
+	platform_driver_unregister(&mcf_rtc_driver);
+
+}
+
+module_init(mcf_rtc_init);
+module_exit(mcf_rtc_exit);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("Real Time Clock Driver (MCF)");
+MODULE_LICENSE("GPL V2");