| /* | 
 |  * rtc-tps80031.c -- TI TPS80031/TPS80032 RTC driver | 
 |  * | 
 |  * RTC driver for TI TPS80031/TPS80032 Fully Integrated | 
 |  * Power Management with Power Path and Battery Charger | 
 |  * | 
 |  * 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/bcd.h> | 
 | #include <linux/device.h> | 
 | #include <linux/err.h> | 
 | #include <linux/init.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/module.h> | 
 | #include <linux/mfd/tps80031.h> | 
 | #include <linux/platform_device.h> | 
 | #include <linux/pm.h> | 
 | #include <linux/rtc.h> | 
 | #include <linux/slab.h> | 
 |  | 
 | #define ENABLE_ALARM_INT			0x08 | 
 | #define ALARM_INT_STATUS			0x40 | 
 |  | 
 | /** | 
 |  * Setting bit to 1 in STOP_RTC will run the RTC and | 
 |  * setting this bit to 0 will freeze RTC. | 
 |  */ | 
 | #define STOP_RTC				0x1 | 
 |  | 
 | /* Power on reset Values of RTC registers */ | 
 | #define TPS80031_RTC_POR_YEAR			0 | 
 | #define TPS80031_RTC_POR_MONTH			1 | 
 | #define TPS80031_RTC_POR_DAY			1 | 
 |  | 
 | /* Numbers of registers for time and alarms */ | 
 | #define TPS80031_RTC_TIME_NUM_REGS		7 | 
 | #define TPS80031_RTC_ALARM_NUM_REGS		6 | 
 |  | 
 | /** | 
 |  * PMU RTC have only 2 nibbles to store year information, so using an | 
 |  * offset of 100 to set the base year as 2000 for our driver. | 
 |  */ | 
 | #define RTC_YEAR_OFFSET 100 | 
 |  | 
 | struct tps80031_rtc { | 
 | 	struct rtc_device	*rtc; | 
 | 	int			irq; | 
 | }; | 
 |  | 
 | static int tps80031_rtc_read_time(struct device *dev, struct rtc_time *tm) | 
 | { | 
 | 	u8 buff[TPS80031_RTC_TIME_NUM_REGS]; | 
 | 	int ret; | 
 |  | 
 | 	ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1, | 
 | 			TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff); | 
 | 	if (ret < 0) { | 
 | 		dev_err(dev, "reading RTC_SECONDS_REG failed, err = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	tm->tm_sec = bcd2bin(buff[0]); | 
 | 	tm->tm_min = bcd2bin(buff[1]); | 
 | 	tm->tm_hour = bcd2bin(buff[2]); | 
 | 	tm->tm_mday = bcd2bin(buff[3]); | 
 | 	tm->tm_mon = bcd2bin(buff[4]) - 1; | 
 | 	tm->tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET; | 
 | 	tm->tm_wday = bcd2bin(buff[6]); | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int tps80031_rtc_set_time(struct device *dev, struct rtc_time *tm) | 
 | { | 
 | 	u8 buff[7]; | 
 | 	int ret; | 
 |  | 
 | 	buff[0] = bin2bcd(tm->tm_sec); | 
 | 	buff[1] = bin2bcd(tm->tm_min); | 
 | 	buff[2] = bin2bcd(tm->tm_hour); | 
 | 	buff[3] = bin2bcd(tm->tm_mday); | 
 | 	buff[4] = bin2bcd(tm->tm_mon + 1); | 
 | 	buff[5] = bin2bcd(tm->tm_year % RTC_YEAR_OFFSET); | 
 | 	buff[6] = bin2bcd(tm->tm_wday); | 
 |  | 
 | 	/* Stop RTC while updating the RTC time registers */ | 
 | 	ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1, | 
 | 				TPS80031_RTC_CTRL_REG, STOP_RTC); | 
 | 	if (ret < 0) { | 
 | 		dev_err(dev->parent, "Stop RTC failed, err = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1, | 
 | 			TPS80031_SECONDS_REG, | 
 | 			TPS80031_RTC_TIME_NUM_REGS, buff); | 
 | 	if (ret < 0) { | 
 | 		dev_err(dev, "writing RTC_SECONDS_REG failed, err %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1, | 
 | 				TPS80031_RTC_CTRL_REG, STOP_RTC); | 
 | 	if (ret < 0) | 
 | 		dev_err(dev->parent, "Start RTC failed, err = %d\n", ret); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int tps80031_rtc_alarm_irq_enable(struct device *dev, | 
 | 					 unsigned int enable) | 
 | { | 
 | 	int ret; | 
 |  | 
 | 	if (enable) | 
 | 		ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1, | 
 | 				TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT); | 
 | 	else | 
 | 		ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1, | 
 | 				TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT); | 
 | 	if (ret < 0) { | 
 | 		dev_err(dev, "Update on RTC_INT failed, err = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int tps80031_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) | 
 | { | 
 | 	u8 buff[TPS80031_RTC_ALARM_NUM_REGS]; | 
 | 	int ret; | 
 |  | 
 | 	buff[0] = bin2bcd(alrm->time.tm_sec); | 
 | 	buff[1] = bin2bcd(alrm->time.tm_min); | 
 | 	buff[2] = bin2bcd(alrm->time.tm_hour); | 
 | 	buff[3] = bin2bcd(alrm->time.tm_mday); | 
 | 	buff[4] = bin2bcd(alrm->time.tm_mon + 1); | 
 | 	buff[5] = bin2bcd(alrm->time.tm_year % RTC_YEAR_OFFSET); | 
 | 	ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1, | 
 | 			TPS80031_ALARM_SECONDS_REG, | 
 | 			TPS80031_RTC_ALARM_NUM_REGS, buff); | 
 | 	if (ret < 0) { | 
 | 		dev_err(dev, "Writing RTC_ALARM failed, err %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 | 	return tps80031_rtc_alarm_irq_enable(dev, alrm->enabled); | 
 | } | 
 |  | 
 | static int tps80031_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) | 
 | { | 
 | 	u8 buff[6]; | 
 | 	int ret; | 
 |  | 
 | 	ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1, | 
 | 			TPS80031_ALARM_SECONDS_REG, | 
 | 			TPS80031_RTC_ALARM_NUM_REGS, buff); | 
 | 	if (ret < 0) { | 
 | 		dev_err(dev->parent, | 
 | 			"reading RTC_ALARM failed, err = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	alrm->time.tm_sec = bcd2bin(buff[0]); | 
 | 	alrm->time.tm_min = bcd2bin(buff[1]); | 
 | 	alrm->time.tm_hour = bcd2bin(buff[2]); | 
 | 	alrm->time.tm_mday = bcd2bin(buff[3]); | 
 | 	alrm->time.tm_mon = bcd2bin(buff[4]) - 1; | 
 | 	alrm->time.tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET; | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int clear_alarm_int_status(struct device *dev, struct tps80031_rtc *rtc) | 
 | { | 
 | 	int ret; | 
 | 	u8 buf; | 
 |  | 
 | 	/** | 
 | 	 * As per datasheet, A dummy read of this  RTC_STATUS_REG register | 
 | 	 * is necessary before each I2C read in order to update the status | 
 | 	 * register value. | 
 | 	 */ | 
 | 	ret = tps80031_read(dev->parent, TPS80031_SLAVE_ID1, | 
 | 				TPS80031_RTC_STATUS_REG, &buf); | 
 | 	if (ret < 0) { | 
 | 		dev_err(dev, "reading RTC_STATUS failed. err = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	/* clear Alarm status bits.*/ | 
 | 	ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1, | 
 | 			TPS80031_RTC_STATUS_REG, ALARM_INT_STATUS); | 
 | 	if (ret < 0) { | 
 | 		dev_err(dev, "clear Alarm INT failed, err = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 | 	return 0; | 
 | } | 
 |  | 
 | static irqreturn_t tps80031_rtc_irq(int irq, void *data) | 
 | { | 
 | 	struct device *dev = data; | 
 | 	struct tps80031_rtc *rtc = dev_get_drvdata(dev); | 
 | 	int ret; | 
 |  | 
 | 	ret = clear_alarm_int_status(dev, rtc); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); | 
 | 	return IRQ_HANDLED; | 
 | } | 
 |  | 
 | static const struct rtc_class_ops tps80031_rtc_ops = { | 
 | 	.read_time = tps80031_rtc_read_time, | 
 | 	.set_time = tps80031_rtc_set_time, | 
 | 	.set_alarm = tps80031_rtc_set_alarm, | 
 | 	.read_alarm = tps80031_rtc_read_alarm, | 
 | 	.alarm_irq_enable = tps80031_rtc_alarm_irq_enable, | 
 | }; | 
 |  | 
 | static int tps80031_rtc_probe(struct platform_device *pdev) | 
 | { | 
 | 	struct tps80031_rtc *rtc; | 
 | 	struct rtc_time tm; | 
 | 	int ret; | 
 |  | 
 | 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); | 
 | 	if (!rtc) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	rtc->irq = platform_get_irq(pdev, 0); | 
 | 	platform_set_drvdata(pdev, rtc); | 
 |  | 
 | 	/* Start RTC */ | 
 | 	ret = tps80031_set_bits(pdev->dev.parent, TPS80031_SLAVE_ID1, | 
 | 			TPS80031_RTC_CTRL_REG, STOP_RTC); | 
 | 	if (ret < 0) { | 
 | 		dev_err(&pdev->dev, "failed to start RTC. err = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	/* If RTC have POR values, set time 01:01:2000 */ | 
 | 	tps80031_rtc_read_time(&pdev->dev, &tm); | 
 | 	if ((tm.tm_year == RTC_YEAR_OFFSET + TPS80031_RTC_POR_YEAR) && | 
 | 		(tm.tm_mon == (TPS80031_RTC_POR_MONTH - 1)) && | 
 | 		(tm.tm_mday == TPS80031_RTC_POR_DAY)) { | 
 | 		tm.tm_year = 2000; | 
 | 		tm.tm_mday = 1; | 
 | 		tm.tm_mon = 1; | 
 | 		ret = tps80031_rtc_set_time(&pdev->dev, &tm); | 
 | 		if (ret < 0) { | 
 | 			dev_err(&pdev->dev, | 
 | 				"RTC set time failed, err = %d\n", ret); | 
 | 			return ret; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	/* Clear alarm intretupt status if it is there */ | 
 | 	ret = clear_alarm_int_status(&pdev->dev, rtc); | 
 | 	if (ret < 0) { | 
 | 		dev_err(&pdev->dev, "Clear alarm int failed, err = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, | 
 | 			       &tps80031_rtc_ops, THIS_MODULE); | 
 | 	if (IS_ERR(rtc->rtc)) { | 
 | 		ret = PTR_ERR(rtc->rtc); | 
 | 		dev_err(&pdev->dev, "RTC registration failed, err %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, | 
 | 			tps80031_rtc_irq, | 
 | 			IRQF_ONESHOT, | 
 | 			dev_name(&pdev->dev), rtc); | 
 | 	if (ret < 0) { | 
 | 		dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n", | 
 | 			 rtc->irq, ret); | 
 | 		return ret; | 
 | 	} | 
 | 	device_set_wakeup_capable(&pdev->dev, 1); | 
 | 	return 0; | 
 | } | 
 |  | 
 | #ifdef CONFIG_PM_SLEEP | 
 | static int tps80031_rtc_suspend(struct device *dev) | 
 | { | 
 | 	struct tps80031_rtc *rtc = dev_get_drvdata(dev); | 
 |  | 
 | 	if (device_may_wakeup(dev)) | 
 | 		enable_irq_wake(rtc->irq); | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int tps80031_rtc_resume(struct device *dev) | 
 | { | 
 | 	struct tps80031_rtc *rtc = dev_get_drvdata(dev); | 
 |  | 
 | 	if (device_may_wakeup(dev)) | 
 | 		disable_irq_wake(rtc->irq); | 
 | 	return 0; | 
 | }; | 
 | #endif | 
 |  | 
 | static SIMPLE_DEV_PM_OPS(tps80031_pm_ops, tps80031_rtc_suspend, | 
 | 			tps80031_rtc_resume); | 
 |  | 
 | static struct platform_driver tps80031_rtc_driver = { | 
 | 	.driver	= { | 
 | 		.name	= "tps80031-rtc", | 
 | 		.pm	= &tps80031_pm_ops, | 
 | 	}, | 
 | 	.probe	= tps80031_rtc_probe, | 
 | }; | 
 |  | 
 | module_platform_driver(tps80031_rtc_driver); | 
 |  | 
 | MODULE_ALIAS("platform:tps80031-rtc"); | 
 | MODULE_DESCRIPTION("TI TPS80031/TPS80032 RTC driver"); | 
 | MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); | 
 | MODULE_LICENSE("GPL v2"); |