drivers/rtc/rtc-tps6586x.c - linux - Git at Google

 /*
  * rtc-tps6586x.c: RTC driver for TI PMIC TPS6586X
  *
  * Copyright (c) 2012, NVIDIA Corporation.
  *
  * Author: Laxman Dewangan <ldewangan@nvidia.com>
  *
  * 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 version 2.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
  * whether express or implied; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  * 02111-1307, USA
  */

 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/mfd/tps6586x.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/rtc.h>
 #include <linux/slab.h>

 #define RTC_CTRL			0xc0
 #define POR_RESET_N			BIT(7)
 #define OSC_SRC_SEL			BIT(6)
 #define RTC_ENABLE			BIT(5)	/* enables alarm */
 #define RTC_BUF_ENABLE			BIT(4)	/* 32 KHz buffer enable */
 #define PRE_BYPASS			BIT(3)	/* 0=1KHz or 1=32KHz updates */
 #define CL_SEL_MASK			(BIT(2)|BIT(1))
 #define CL_SEL_POS			1
 #define RTC_ALARM1_HI			0xc1
 #define RTC_COUNT4			0xc6

 /* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */
 #define RTC_COUNT4_DUMMYREAD		0xc5

 /*only 14-bits width in second*/
 #define ALM1_VALID_RANGE_IN_SEC		0x3FFF

 #define TPS6586X_RTC_CL_SEL_1_5PF	0x0
 #define TPS6586X_RTC_CL_SEL_6_5PF	0x1
 #define TPS6586X_RTC_CL_SEL_7_5PF	0x2
 #define TPS6586X_RTC_CL_SEL_12_5PF	0x3

 struct tps6586x_rtc {
 	struct device		*dev;
 	struct rtc_device	*rtc;
 	int			irq;
 	bool			irq_en;
 	unsigned long long	epoch_start;
 };

 static inline struct device *to_tps6586x_dev(struct device *dev)
 {
 	return dev->parent;
 }

 static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
 	struct device *tps_dev = to_tps6586x_dev(dev);
 	unsigned long long ticks = 0;
 	unsigned long seconds;
 	u8 buff[6];
 	int ret;
 	int i;

 	ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff);
 	if (ret < 0) {
 		dev_err(dev, "read counter failed with err %d\n", ret);
 		return ret;
 	}

 	for (i = 1; i < sizeof(buff); i++) {
 		ticks <<= 8;
 		ticks |= buff[i];
 	}

 	seconds = ticks >> 10;
 	seconds += rtc->epoch_start;
 	rtc_time_to_tm(seconds, tm);
 	return 0;
 }

 static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
 	struct device *tps_dev = to_tps6586x_dev(dev);
 	unsigned long long ticks;
 	unsigned long seconds;
 	u8 buff[5];
 	int ret;

 	rtc_tm_to_time(tm, &seconds);
 	if (seconds < rtc->epoch_start) {
 		dev_err(dev, "requested time unsupported\n");
 		return -EINVAL;
 	}
 	seconds -= rtc->epoch_start;

 	ticks = (unsigned long long)seconds << 10;
 	buff[0] = (ticks >> 32) & 0xff;
 	buff[1] = (ticks >> 24) & 0xff;
 	buff[2] = (ticks >> 16) & 0xff;
 	buff[3] = (ticks >> 8) & 0xff;
 	buff[4] = ticks & 0xff;

 	/* Disable RTC before changing time */
 	ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
 	if (ret < 0) {
 		dev_err(dev, "failed to clear RTC_ENABLE\n");
 		return ret;
 	}

 	ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff);
 	if (ret < 0) {
 		dev_err(dev, "failed to program new time\n");
 		return ret;
 	}

 	/* Enable RTC */
 	ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
 	if (ret < 0) {
 		dev_err(dev, "failed to set RTC_ENABLE\n");
 		return ret;
 	}
 	return 0;
 }

 static int tps6586x_rtc_alarm_irq_enable(struct device *dev,
 			 unsigned int enabled)
 {
 	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

 	if (enabled && !rtc->irq_en) {
 		enable_irq(rtc->irq);
 		rtc->irq_en = true;
 	} else if (!enabled && rtc->irq_en)  {
 		disable_irq(rtc->irq);
 		rtc->irq_en = false;
 	}
 	return 0;
 }

 static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
 	struct device *tps_dev = to_tps6586x_dev(dev);
 	unsigned long seconds;
 	unsigned long ticks;
 	unsigned long rtc_current_time;
 	unsigned long long rticks = 0;
 	u8 buff[3];
 	u8 rbuff[6];
 	int ret;
 	int i;

 	rtc_tm_to_time(&alrm->time, &seconds);

 	if (alrm->enabled && (seconds < rtc->epoch_start)) {
 		dev_err(dev, "can't set alarm to requested time\n");
 		return -EINVAL;
 	}

 	ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled);
 	if (ret < 0) {
 		dev_err(dev, "can't set alarm irq, err %d\n", ret);
 		return ret;
 	}

 	seconds -= rtc->epoch_start;
 	ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD,
 			sizeof(rbuff), rbuff);
 	if (ret < 0) {
 		dev_err(dev, "read counter failed with err %d\n", ret);
 		return ret;
 	}

 	for (i = 1; i < sizeof(rbuff); i++) {
 		rticks <<= 8;
 		rticks |= rbuff[i];
 	}

 	rtc_current_time = rticks >> 10;
 	if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC)
 		seconds = rtc_current_time - 1;

 	ticks = (unsigned long long)seconds << 10;
 	buff[0] = (ticks >> 16) & 0xff;
 	buff[1] = (ticks >> 8) & 0xff;
 	buff[2] = ticks & 0xff;

 	ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
 	if (ret)
 		dev_err(dev, "programming alarm failed with err %d\n", ret);

 	return ret;
 }

 static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
 	struct device *tps_dev = to_tps6586x_dev(dev);
 	unsigned long ticks;
 	unsigned long seconds;
 	u8 buff[3];
 	int ret;

 	ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
 	if (ret) {
 		dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret);
 		return ret;
 	}

 	ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2];
 	seconds = ticks >> 10;
 	seconds += rtc->epoch_start;

 	rtc_time_to_tm(seconds, &alrm->time);
 	return 0;
 }

 static const struct rtc_class_ops tps6586x_rtc_ops = {
 	.read_time	= tps6586x_rtc_read_time,
 	.set_time	= tps6586x_rtc_set_time,
 	.set_alarm	= tps6586x_rtc_set_alarm,
 	.read_alarm	= tps6586x_rtc_read_alarm,
 	.alarm_irq_enable = tps6586x_rtc_alarm_irq_enable,
 };

 static irqreturn_t tps6586x_rtc_irq(int irq, void *data)
 {
 	struct tps6586x_rtc *rtc = data;

 	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
 	return IRQ_HANDLED;
 }

 static int tps6586x_rtc_probe(struct platform_device *pdev)
 {
 	struct device *tps_dev = to_tps6586x_dev(&pdev->dev);
 	struct tps6586x_rtc *rtc;
 	int ret;

 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
 	if (!rtc)
 		return -ENOMEM;

 	rtc->dev = &pdev->dev;
 	rtc->irq = platform_get_irq(pdev, 0);

 	/* Set epoch start as 00:00:00:01:01:2009 */
 	rtc->epoch_start = mktime(2009, 1, 1, 0, 0, 0);

 	/* 1 kHz tick mode, enable tick counting */
 	ret = tps6586x_update(tps_dev, RTC_CTRL,
 		RTC_ENABLE | OSC_SRC_SEL |
 		((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK),
 		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "unable to start counter\n");
 		return ret;
 	}

 	device_init_wakeup(&pdev->dev, 1);

 	platform_set_drvdata(pdev, rtc);
 	rtc->rtc = devm_rtc_device_register(&pdev->dev, dev_name(&pdev->dev),
 				       &tps6586x_rtc_ops, THIS_MODULE);
 	if (IS_ERR(rtc->rtc)) {
 		ret = PTR_ERR(rtc->rtc);
 		dev_err(&pdev->dev, "RTC device register: ret %d\n", ret);
 		goto fail_rtc_register;
 	}

 	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
 				tps6586x_rtc_irq,
 				IRQF_ONESHOT,
 				dev_name(&pdev->dev), rtc);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n",
 				rtc->irq, ret);
 		goto fail_rtc_register;
 	}
 	disable_irq(rtc->irq);
 	return 0;

 fail_rtc_register:
 	tps6586x_update(tps_dev, RTC_CTRL, 0,
 		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
 	return ret;
 };

 static int tps6586x_rtc_remove(struct platform_device *pdev)
 {
 	struct device *tps_dev = to_tps6586x_dev(&pdev->dev);

 	tps6586x_update(tps_dev, RTC_CTRL, 0,
 		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int tps6586x_rtc_suspend(struct device *dev)
 {
 	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

 	if (device_may_wakeup(dev))
 		enable_irq_wake(rtc->irq);
 	return 0;
 }

 static int tps6586x_rtc_resume(struct device *dev)
 {
 	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

 	if (device_may_wakeup(dev))
 		disable_irq_wake(rtc->irq);
 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_rtc_suspend,
 			tps6586x_rtc_resume);

 static struct platform_driver tps6586x_rtc_driver = {
 	.driver	= {
 		.name	= "tps6586x-rtc",
 		.pm	= &tps6586x_pm_ops,
 	},
 	.probe	= tps6586x_rtc_probe,
 	.remove	= tps6586x_rtc_remove,
 };
 module_platform_driver(tps6586x_rtc_driver);

 MODULE_ALIAS("platform:tps6586x-rtc");
 MODULE_DESCRIPTION("TI TPS6586x RTC driver");
 MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>");
 MODULE_LICENSE("GPL v2");
	/*
	* rtc-tps6586x.c: RTC driver for TI PMIC TPS6586X
	*
	* Copyright (c) 2012, NVIDIA Corporation.
	*
	* Author: Laxman Dewangan <ldewangan@nvidia.com>
	*
	* 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 version 2.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
	* whether express or implied; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	* 02111-1307, USA
	*/

	#include <linux/device.h>
	#include <linux/err.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/mfd/tps6586x.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <linux/rtc.h>
	#include <linux/slab.h>

	#define RTC_CTRL 0xc0
	#define POR_RESET_N BIT(7)
	#define OSC_SRC_SEL BIT(6)
	#define RTC_ENABLE BIT(5) /* enables alarm */
	#define RTC_BUF_ENABLE BIT(4) /* 32 KHz buffer enable */
	#define PRE_BYPASS BIT(3) /* 0=1KHz or 1=32KHz updates */
	#define CL_SEL_MASK (BIT(2)\|BIT(1))
	#define CL_SEL_POS 1
	#define RTC_ALARM1_HI 0xc1
	#define RTC_COUNT4 0xc6

	/* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */
	#define RTC_COUNT4_DUMMYREAD 0xc5

	/only 14-bits width in second/
	#define ALM1_VALID_RANGE_IN_SEC 0x3FFF

	#define TPS6586X_RTC_CL_SEL_1_5PF 0x0
	#define TPS6586X_RTC_CL_SEL_6_5PF 0x1
	#define TPS6586X_RTC_CL_SEL_7_5PF 0x2
	#define TPS6586X_RTC_CL_SEL_12_5PF 0x3

	struct tps6586x_rtc {
	struct device *dev;
	struct rtc_device *rtc;
	int irq;
	bool irq_en;
	unsigned long long epoch_start;
	};

	static inline struct device to_tps6586x_dev(struct device dev)
	{
	return dev->parent;
	}

	static int tps6586x_rtc_read_time(struct device dev, struct rtc_time tm)
	{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
	struct device *tps_dev = to_tps6586x_dev(dev);
	unsigned long long ticks = 0;
	unsigned long seconds;
	u8 buff[6];
	int ret;
	int i;

	ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff);
	if (ret < 0) {
	dev_err(dev, "read counter failed with err %d\n", ret);
	return ret;
	}

	for (i = 1; i < sizeof(buff); i++) {
	ticks <<= 8;
	ticks \|= buff[i];
	}

	seconds = ticks >> 10;
	seconds += rtc->epoch_start;
	rtc_time_to_tm(seconds, tm);
	return 0;
	}

	static int tps6586x_rtc_set_time(struct device dev, struct rtc_time tm)
	{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
	struct device *tps_dev = to_tps6586x_dev(dev);
	unsigned long long ticks;
	unsigned long seconds;
	u8 buff[5];
	int ret;

	rtc_tm_to_time(tm, &seconds);
	if (seconds < rtc->epoch_start) {
	dev_err(dev, "requested time unsupported\n");
	return -EINVAL;
	}
	seconds -= rtc->epoch_start;

	ticks = (unsigned long long)seconds << 10;
	buff[0] = (ticks >> 32) & 0xff;
	buff[1] = (ticks >> 24) & 0xff;
	buff[2] = (ticks >> 16) & 0xff;
	buff[3] = (ticks >> 8) & 0xff;
	buff[4] = ticks & 0xff;

	/* Disable RTC before changing time */
	ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
	if (ret < 0) {
	dev_err(dev, "failed to clear RTC_ENABLE\n");
	return ret;
	}

	ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff);
	if (ret < 0) {
	dev_err(dev, "failed to program new time\n");
	return ret;
	}

	/* Enable RTC */
	ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
	if (ret < 0) {
	dev_err(dev, "failed to set RTC_ENABLE\n");
	return ret;
	}
	return 0;
	}

	static int tps6586x_rtc_alarm_irq_enable(struct device *dev,
	unsigned int enabled)
	{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

	if (enabled && !rtc->irq_en) {
	enable_irq(rtc->irq);
	rtc->irq_en = true;
	} else if (!enabled && rtc->irq_en) {
	disable_irq(rtc->irq);
	rtc->irq_en = false;
	}
	return 0;
	}

	static int tps6586x_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
	struct device *tps_dev = to_tps6586x_dev(dev);
	unsigned long seconds;
	unsigned long ticks;
	unsigned long rtc_current_time;
	unsigned long long rticks = 0;
	u8 buff[3];
	u8 rbuff[6];
	int ret;
	int i;

	rtc_tm_to_time(&alrm->time, &seconds);

	if (alrm->enabled && (seconds < rtc->epoch_start)) {
	dev_err(dev, "can't set alarm to requested time\n");
	return -EINVAL;
	}

	ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled);
	if (ret < 0) {
	dev_err(dev, "can't set alarm irq, err %d\n", ret);
	return ret;
	}

	seconds -= rtc->epoch_start;
	ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD,
	sizeof(rbuff), rbuff);
	if (ret < 0) {
	dev_err(dev, "read counter failed with err %d\n", ret);
	return ret;
	}

	for (i = 1; i < sizeof(rbuff); i++) {
	rticks <<= 8;
	rticks \|= rbuff[i];
	}

	rtc_current_time = rticks >> 10;
	if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC)
	seconds = rtc_current_time - 1;

	ticks = (unsigned long long)seconds << 10;
	buff[0] = (ticks >> 16) & 0xff;
	buff[1] = (ticks >> 8) & 0xff;
	buff[2] = ticks & 0xff;

	ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
	if (ret)
	dev_err(dev, "programming alarm failed with err %d\n", ret);

	return ret;
	}

	static int tps6586x_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
	struct device *tps_dev = to_tps6586x_dev(dev);
	unsigned long ticks;
	unsigned long seconds;
	u8 buff[3];
	int ret;

	ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
	if (ret) {
	dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret);
	return ret;
	}

	ticks = (buff[0] << 16) \| (buff[1] << 8) \| buff[2];
	seconds = ticks >> 10;
	seconds += rtc->epoch_start;

	rtc_time_to_tm(seconds, &alrm->time);
	return 0;
	}

	static const struct rtc_class_ops tps6586x_rtc_ops = {
	.read_time = tps6586x_rtc_read_time,
	.set_time = tps6586x_rtc_set_time,
	.set_alarm = tps6586x_rtc_set_alarm,
	.read_alarm = tps6586x_rtc_read_alarm,
	.alarm_irq_enable = tps6586x_rtc_alarm_irq_enable,
	};

	static irqreturn_t tps6586x_rtc_irq(int irq, void *data)
	{
	struct tps6586x_rtc *rtc = data;

	rtc_update_irq(rtc->rtc, 1, RTC_IRQF \| RTC_AF);
	return IRQ_HANDLED;
	}

	static int tps6586x_rtc_probe(struct platform_device *pdev)
	{
	struct device *tps_dev = to_tps6586x_dev(&pdev->dev);
	struct tps6586x_rtc *rtc;
	int ret;

	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
	if (!rtc)
	return -ENOMEM;

	rtc->dev = &pdev->dev;
	rtc->irq = platform_get_irq(pdev, 0);

	/* Set epoch start as 00:00:00:01:01:2009 */
	rtc->epoch_start = mktime(2009, 1, 1, 0, 0, 0);

	/* 1 kHz tick mode, enable tick counting */
	ret = tps6586x_update(tps_dev, RTC_CTRL,
	RTC_ENABLE \| OSC_SRC_SEL \|
	((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK),
	RTC_ENABLE \| OSC_SRC_SEL \| PRE_BYPASS \| CL_SEL_MASK);
	if (ret < 0) {
	dev_err(&pdev->dev, "unable to start counter\n");
	return ret;
	}

	device_init_wakeup(&pdev->dev, 1);

	platform_set_drvdata(pdev, rtc);
	rtc->rtc = devm_rtc_device_register(&pdev->dev, dev_name(&pdev->dev),
	&tps6586x_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc->rtc)) {
	ret = PTR_ERR(rtc->rtc);
	dev_err(&pdev->dev, "RTC device register: ret %d\n", ret);
	goto fail_rtc_register;
	}

	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
	tps6586x_rtc_irq,
	IRQF_ONESHOT,
	dev_name(&pdev->dev), rtc);
	if (ret < 0) {
	dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n",
	rtc->irq, ret);
	goto fail_rtc_register;
	}
	disable_irq(rtc->irq);
	return 0;

	fail_rtc_register:
	tps6586x_update(tps_dev, RTC_CTRL, 0,
	RTC_ENABLE \| OSC_SRC_SEL \| PRE_BYPASS \| CL_SEL_MASK);
	return ret;
	};

	static int tps6586x_rtc_remove(struct platform_device *pdev)
	{
	struct device *tps_dev = to_tps6586x_dev(&pdev->dev);

	tps6586x_update(tps_dev, RTC_CTRL, 0,
	RTC_ENABLE \| OSC_SRC_SEL \| PRE_BYPASS \| CL_SEL_MASK);
	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int tps6586x_rtc_suspend(struct device *dev)
	{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
	enable_irq_wake(rtc->irq);
	return 0;
	}

	static int tps6586x_rtc_resume(struct device *dev)
	{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
	disable_irq_wake(rtc->irq);
	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_rtc_suspend,
	tps6586x_rtc_resume);

	static struct platform_driver tps6586x_rtc_driver = {
	.driver = {
	.name = "tps6586x-rtc",
	.pm = &tps6586x_pm_ops,
	},
	.probe = tps6586x_rtc_probe,
	.remove = tps6586x_rtc_remove,
	};
	module_platform_driver(tps6586x_rtc_driver);

	MODULE_ALIAS("platform:tps6586x-rtc");
	MODULE_DESCRIPTION("TI TPS6586x RTC driver");
	MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>");
	MODULE_LICENSE("GPL v2");