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Commit 0942a71e authored by Rajeev Kumar's avatar Rajeev Kumar Committed by Linus Torvalds
Browse files

rtc: add support for spear rtc 



Signed-off-by: default avatarRajeev Kumar <rajeev-dlh.kumar@st.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@st.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c258f9a0

drivers/rtc/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -682,6 +682,14 @@ config RTC_DRV_WM8350 
	  This driver can also be built as a module. If so, the module

	  will be called "rtc-wm8350".



config RTC_DRV_SPEAR

	tristate "SPEAR ST RTC"

	depends on PLAT_SPEAR

	default y

	help

	 If you say Y here you will get support for the RTC found on

	 spear



config RTC_DRV_PCF50633

	depends on MFD_PCF50633

	tristate "NXP PCF50633 RTC"

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -91,6 +91,7 @@ obj-$(CONFIG_RTC_DRV_S35390A) += rtc-s35390a.o 
obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o

obj-$(CONFIG_RTC_DRV_SA1100)	+= rtc-sa1100.o

obj-$(CONFIG_RTC_DRV_SH)	+= rtc-sh.o

obj-$(CONFIG_RTC_DRV_SPEAR)	+= rtc-spear.o

obj-$(CONFIG_RTC_DRV_STARFIRE)	+= rtc-starfire.o

obj-$(CONFIG_RTC_DRV_STK17TA8)	+= rtc-stk17ta8.o

obj-$(CONFIG_RTC_DRV_STMP)	+= rtc-stmp3xxx.o

drivers/rtc/rtc-spear.c

0 → 100644
+534 −0
Original line number Diff line number Diff line 
/*

 * drivers/rtc/rtc-spear.c

 *

 * Copyright (C) 2010 ST Microelectronics

 * Rajeev Kumar<rajeev-dlh.kumar@st.com>

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */



#include <linux/bcd.h>

#include <linux/clk.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/irq.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/rtc.h>

#include <linux/slab.h>

#include <linux/spinlock.h>



/* RTC registers */

#define TIME_REG		0x00

#define DATE_REG		0x04

#define ALARM_TIME_REG		0x08

#define ALARM_DATE_REG		0x0C

#define CTRL_REG		0x10

#define STATUS_REG		0x14



/* TIME_REG & ALARM_TIME_REG */

#define SECONDS_UNITS		(0xf<<0)	/* seconds units position */

#define SECONDS_TENS		(0x7<<4)	/* seconds tens position */

#define MINUTES_UNITS		(0xf<<8)	/* minutes units position */

#define MINUTES_TENS		(0x7<<12)	/* minutes tens position */

#define HOURS_UNITS		(0xf<<16)	/* hours units position */

#define HOURS_TENS		(0x3<<20)	/* hours tens position */



/* DATE_REG & ALARM_DATE_REG */

#define DAYS_UNITS		(0xf<<0)	/* days units position */

#define DAYS_TENS		(0x3<<4)	/* days tens position */

#define MONTHS_UNITS		(0xf<<8)	/* months units position */

#define MONTHS_TENS		(0x1<<12)	/* months tens position */

#define YEARS_UNITS		(0xf<<16)	/* years units position */

#define YEARS_TENS		(0xf<<20)	/* years tens position */

#define YEARS_HUNDREDS		(0xf<<24)	/* years hundereds position */

#define YEARS_MILLENIUMS	(0xf<<28)	/* years millenium position */



/* MASK SHIFT TIME_REG & ALARM_TIME_REG*/

#define SECOND_SHIFT		0x00		/* seconds units */

#define MINUTE_SHIFT		0x08		/* minutes units position */

#define HOUR_SHIFT		0x10		/* hours units position */

#define MDAY_SHIFT		0x00		/* Month day shift */

#define MONTH_SHIFT		0x08		/* Month shift */

#define YEAR_SHIFT		0x10		/* Year shift */



#define SECOND_MASK		0x7F

#define MIN_MASK		0x7F

#define HOUR_MASK		0x3F

#define DAY_MASK		0x3F

#define MONTH_MASK		0x7F

#define YEAR_MASK		0xFFFF



/* date reg equal to time reg, for debug only */

#define TIME_BYP		(1<<9)

#define INT_ENABLE		(1<<31)		/* interrupt enable */



/* STATUS_REG */

#define CLK_UNCONNECTED		(1<<0)

#define PEND_WR_TIME		(1<<2)

#define PEND_WR_DATE		(1<<3)

#define LOST_WR_TIME		(1<<4)

#define LOST_WR_DATE		(1<<5)

#define RTC_INT_MASK		(1<<31)

#define STATUS_BUSY		(PEND_WR_TIME | PEND_WR_DATE)

#define STATUS_FAIL		(LOST_WR_TIME | LOST_WR_DATE)



struct spear_rtc_config {

	struct clk *clk;

	spinlock_t lock;

	void __iomem *ioaddr;

};



static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config)

{

	unsigned int val;

	unsigned long flags;



	spin_lock_irqsave(&config->lock, flags);

	val = readl(config->ioaddr + STATUS_REG);

	val |= RTC_INT_MASK;

	writel(val, config->ioaddr + STATUS_REG);

	spin_unlock_irqrestore(&config->lock, flags);

}



static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config)

{

	unsigned int val;



	val = readl(config->ioaddr + CTRL_REG);

	if (!(val & INT_ENABLE)) {

		spear_rtc_clear_interrupt(config);

		val |= INT_ENABLE;

		writel(val, config->ioaddr + CTRL_REG);

	}

}



static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config)

{

	unsigned int val;



	val = readl(config->ioaddr + CTRL_REG);

	if (val & INT_ENABLE) {

		val &= ~INT_ENABLE;

		writel(val, config->ioaddr + CTRL_REG);

	}

}



static inline int is_write_complete(struct spear_rtc_config *config)

{

	int ret = 0;

	unsigned long flags;



	spin_lock_irqsave(&config->lock, flags);

	if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL)

		ret = -EIO;

	spin_unlock_irqrestore(&config->lock, flags);



	return ret;

}



static void rtc_wait_not_busy(struct spear_rtc_config *config)

{

	int status, count = 0;

	unsigned long flags;



	/* Assuming BUSY may stay active for 80 msec) */

	for (count = 0; count < 80; count++) {

		spin_lock_irqsave(&config->lock, flags);

		status = readl(config->ioaddr + STATUS_REG);

		spin_unlock_irqrestore(&config->lock, flags);

		if ((status & STATUS_BUSY) == 0)

			break;

		/* check status busy, after each msec */

		msleep(1);

	}

}



static irqreturn_t spear_rtc_irq(int irq, void *dev_id)

{

	struct rtc_device *rtc = (struct rtc_device *)dev_id;

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);

	unsigned long flags, events = 0;

	unsigned int irq_data;



	spin_lock_irqsave(&config->lock, flags);

	irq_data = readl(config->ioaddr + STATUS_REG);

	spin_unlock_irqrestore(&config->lock, flags);



	if ((irq_data & RTC_INT_MASK)) {

		spear_rtc_clear_interrupt(config);

		events = RTC_IRQF | RTC_AF;

		rtc_update_irq(rtc, 1, events);

		return IRQ_HANDLED;

	} else

		return IRQ_NONE;



}



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);

	tm->tm_year = bin2bcd(tm->tm_year);



	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);

}



/*

 * spear_rtc_read_time - set the time

 * @dev: rtc device in use

 * @tm: holds date and time

 *

 * This function read time and date. On success it will return 0

 * otherwise -ve error is returned.

 */

static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct rtc_device *rtc = platform_get_drvdata(pdev);

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);

	unsigned int time, date;



	/* we don't report wday/yday/isdst ... */

	rtc_wait_not_busy(config);



	time = readl(config->ioaddr + TIME_REG);

	date = readl(config->ioaddr + DATE_REG);

	tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;

	tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;

	tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;

	tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;

	tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;

	tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;



	bcd2tm(tm);

	return 0;

}



/*

 * spear_rtc_set_time - set the time

 * @dev: rtc device in use

 * @tm: holds date and time

 *

 * This function set time and date. On success it will return 0

 * otherwise -ve error is returned.

 */

static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct rtc_device *rtc = platform_get_drvdata(pdev);

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);

	unsigned int time, date, err = 0;



	if (tm2bcd(tm) < 0)

		return -EINVAL;



	rtc_wait_not_busy(config);

	time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) |

		(tm->tm_hour << HOUR_SHIFT);

	date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) |

		(tm->tm_year << YEAR_SHIFT);

	writel(time, config->ioaddr + TIME_REG);

	writel(date, config->ioaddr + DATE_REG);

	err = is_write_complete(config);

	if (err < 0)

		return err;



	return 0;

}



/*

 * spear_rtc_read_alarm - read the alarm time

 * @dev: rtc device in use

 * @alm: holds alarm date and time

 *

 * This function read alarm time and date. On success it will return 0

 * otherwise -ve error is returned.

 */

static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct rtc_device *rtc = platform_get_drvdata(pdev);

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);

	unsigned int time, date;



	rtc_wait_not_busy(config);



	time = readl(config->ioaddr + ALARM_TIME_REG);

	date = readl(config->ioaddr + ALARM_DATE_REG);

	alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;

	alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;

	alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;

	alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;

	alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;

	alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;



	bcd2tm(&alm->time);

	alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE;



	return 0;

}



/*

 * spear_rtc_set_alarm - set the alarm time

 * @dev: rtc device in use

 * @alm: holds alarm date and time

 *

 * This function set alarm time and date. On success it will return 0

 * otherwise -ve error is returned.

 */

static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct rtc_device *rtc = platform_get_drvdata(pdev);

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);

	unsigned int time, date, err = 0;



	if (tm2bcd(&alm->time) < 0)

		return -EINVAL;



	rtc_wait_not_busy(config);



	time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min <<

			MINUTE_SHIFT) |	(alm->time.tm_hour << HOUR_SHIFT);

	date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon <<

			MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT);



	writel(time, config->ioaddr + ALARM_TIME_REG);

	writel(date, config->ioaddr + ALARM_DATE_REG);

	err = is_write_complete(config);

	if (err < 0)

		return err;



	if (alm->enabled)

		spear_rtc_enable_interrupt(config);

	else

		spear_rtc_disable_interrupt(config);



	return 0;

}

static struct rtc_class_ops spear_rtc_ops = {

	.read_time = spear_rtc_read_time,

	.set_time = spear_rtc_set_time,

	.read_alarm = spear_rtc_read_alarm,

	.set_alarm = spear_rtc_set_alarm,

};



static int __devinit spear_rtc_probe(struct platform_device *pdev)

{

	struct resource *res;

	struct rtc_device *rtc;

	struct spear_rtc_config *config;

	unsigned int status = 0;

	int irq;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!res) {

		dev_err(&pdev->dev, "no resource defined\n");

		return -EBUSY;

	}

	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {

		dev_err(&pdev->dev, "rtc region already claimed\n");

		return -EBUSY;

	}



	config = kzalloc(sizeof(*config), GFP_KERNEL);

	if (!config) {

		dev_err(&pdev->dev, "out of memory\n");

		status = -ENOMEM;

		goto err_release_region;

	}



	config->clk = clk_get(&pdev->dev, NULL);

	if (IS_ERR(config->clk)) {

		status = PTR_ERR(config->clk);

		goto err_kfree;

	}



	status = clk_enable(config->clk);

	if (status < 0)

		goto err_clk_put;



	config->ioaddr = ioremap(res->start, resource_size(res));

	if (!config->ioaddr) {

		dev_err(&pdev->dev, "ioremap fail\n");

		status = -ENOMEM;

		goto err_disable_clock;

	}



	spin_lock_init(&config->lock);



	rtc = rtc_device_register(pdev->name, &pdev->dev, &spear_rtc_ops,

			THIS_MODULE);

	if (IS_ERR(rtc)) {

		dev_err(&pdev->dev, "can't register RTC device, err %ld\n",

				PTR_ERR(rtc));

		status = PTR_ERR(rtc);

		goto err_iounmap;

	}



	platform_set_drvdata(pdev, rtc);

	dev_set_drvdata(&rtc->dev, config);



	/* alarm irqs */

	irq = platform_get_irq(pdev, 0);

	if (irq < 0) {

		dev_err(&pdev->dev, "no update irq?\n");

		status = irq;

		goto err_clear_platdata;

	}



	status = request_irq(irq, spear_rtc_irq, 0, pdev->name, rtc);

	if (status) {

		dev_err(&pdev->dev, "Alarm interrupt IRQ%d already \

				claimed\n", irq);

		goto err_clear_platdata;

	}



	if (!device_can_wakeup(&pdev->dev))

		device_init_wakeup(&pdev->dev, 1);



	return 0;



err_clear_platdata:

	platform_set_drvdata(pdev, NULL);

	dev_set_drvdata(&rtc->dev, NULL);

	rtc_device_unregister(rtc);

err_iounmap:

	iounmap(config->ioaddr);

err_disable_clock:

	clk_disable(config->clk);

err_clk_put:

	clk_put(config->clk);

err_kfree:

	kfree(config);

err_release_region:

	release_mem_region(res->start, resource_size(res));



	return status;

}



static int __devexit spear_rtc_remove(struct platform_device *pdev)

{

	struct rtc_device *rtc = platform_get_drvdata(pdev);

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);

	int irq;

	struct resource *res;



	/* leave rtc running, but disable irqs */

	spear_rtc_disable_interrupt(config);

	device_init_wakeup(&pdev->dev, 0);

	irq = platform_get_irq(pdev, 0);

	if (irq)

		free_irq(irq, pdev);

	clk_disable(config->clk);

	clk_put(config->clk);

	iounmap(config->ioaddr);

	kfree(config);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (res)

		release_mem_region(res->start, resource_size(res));

	platform_set_drvdata(pdev, NULL);

	dev_set_drvdata(&rtc->dev, NULL);

	rtc_device_unregister(rtc);



	return 0;

}



#ifdef CONFIG_PM



static int spear_rtc_suspend(struct platform_device *pdev, pm_message_t state)

{

	struct rtc_device *rtc = platform_get_drvdata(pdev);

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);

	int irq;



	irq = platform_get_irq(pdev, 0);

	if (device_may_wakeup(&pdev->dev))

		enable_irq_wake(irq);

	else {

		spear_rtc_disable_interrupt(config);

		clk_disable(config->clk);

	}



	return 0;

}



static int spear_rtc_resume(struct platform_device *pdev)

{

	struct rtc_device *rtc = platform_get_drvdata(pdev);

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);

	int irq;



	irq = platform_get_irq(pdev, 0);



	if (device_may_wakeup(&pdev->dev))

		disable_irq_wake(irq);

	else {

		clk_enable(config->clk);

		spear_rtc_enable_interrupt(config);

	}



	return 0;

}



#else

#define spear_rtc_suspend	NULL

#define spear_rtc_resume	NULL

#endif



static void spear_rtc_shutdown(struct platform_device *pdev)

{

	struct rtc_device *rtc = platform_get_drvdata(pdev);

	struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev);



	spear_rtc_disable_interrupt(config);

	clk_disable(config->clk);

}



static struct platform_driver spear_rtc_driver = {

	.probe = spear_rtc_probe,

	.remove = __devexit_p(spear_rtc_remove),

	.suspend = spear_rtc_suspend,

	.resume = spear_rtc_resume,

	.shutdown = spear_rtc_shutdown,

	.driver = {

		.name = "rtc-spear",

	},

};



static int __init rtc_init(void)

{

	return platform_driver_register(&spear_rtc_driver);

}

module_init(rtc_init);



static void __exit rtc_exit(void)

{

	platform_driver_unregister(&spear_rtc_driver);

}

module_exit(rtc_exit);



MODULE_ALIAS("platform:rtc-spear");

MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");

MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");

MODULE_LICENSE("GPL");