drivers/rtc/rtc-ds1302.c - kernel/msm-4.19 - Gitiles

 /*
  * Dallas DS1302 RTC Support
  *
  *  Copyright (C) 2002  David McCullough
  *  Copyright (C) 2003 - 2007  Paul Mundt
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License version 2.  See the file "COPYING" in the main directory of
  * this archive for more details.
  */
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/time.h>
 #include <linux/rtc.h>
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/bcd.h>
 #include <asm/rtc.h>

 #define DRV_NAME	"rtc-ds1302"
 #define DRV_VERSION	"0.1.0"

 #define	RTC_CMD_READ	0x81		/* Read command */
 #define	RTC_CMD_WRITE	0x80		/* Write command */

 #define RTC_ADDR_RAM0	0x20		/* Address of RAM0 */
 #define RTC_ADDR_TCR	0x08		/* Address of trickle charge register */
 #define	RTC_ADDR_YEAR	0x06		/* Address of year register */
 #define	RTC_ADDR_DAY	0x05		/* Address of day of week register */
 #define	RTC_ADDR_MON	0x04		/* Address of month register */
 #define	RTC_ADDR_DATE	0x03		/* Address of day of month register */
 #define	RTC_ADDR_HOUR	0x02		/* Address of hour register */
 #define	RTC_ADDR_MIN	0x01		/* Address of minute register */
 #define	RTC_ADDR_SEC	0x00		/* Address of second register */

 #define	RTC_RESET	0x1000
 #define	RTC_IODATA	0x0800
 #define	RTC_SCLK	0x0400

 #ifdef CONFIG_SH_SECUREEDGE5410
 #include <mach/snapgear.h>
 #define set_dp(x)	SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
 #define get_dp()	SECUREEDGE_READ_IOPORT()
 #else
 #error "Add support for your platform"
 #endif

 struct ds1302_rtc {
 	struct rtc_device *rtc_dev;
 	spinlock_t lock;
 };

 static void ds1302_sendbits(unsigned int val)
 {
 	int i;

 	for (i = 8; (i); i--, val >>= 1) {
 		set_dp((get_dp() & ~RTC_IODATA) | ((val & 0x1) ?
 			RTC_IODATA : 0));
 		set_dp(get_dp() | RTC_SCLK);	/* clock high */
 		set_dp(get_dp() & ~RTC_SCLK);	/* clock low */
 	}
 }

 static unsigned int ds1302_recvbits(void)
 {
 	unsigned int val;
 	int i;

 	for (i = 0, val = 0; (i < 8); i++) {
 		val |= (((get_dp() & RTC_IODATA) ? 1 : 0) << i);
 		set_dp(get_dp() | RTC_SCLK);	/* clock high */
 		set_dp(get_dp() & ~RTC_SCLK);	/* clock low */
 	}

 	return val;
 }

 static unsigned int ds1302_readbyte(unsigned int addr)
 {
 	unsigned int val;

 	set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));

 	set_dp(get_dp() | RTC_RESET);
 	ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_READ);
 	val = ds1302_recvbits();
 	set_dp(get_dp() & ~RTC_RESET);

 	return val;
 }

 static void ds1302_writebyte(unsigned int addr, unsigned int val)
 {
 	set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));
 	set_dp(get_dp() | RTC_RESET);
 	ds1302_sendbits(((addr & 0x3f) << 1) | RTC_CMD_WRITE);
 	ds1302_sendbits(val);
 	set_dp(get_dp() & ~RTC_RESET);
 }

 static int ds1302_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct ds1302_rtc *rtc = dev_get_drvdata(dev);

 	spin_lock_irq(&rtc->lock);

 	tm->tm_sec	= BCD2BIN(ds1302_readbyte(RTC_ADDR_SEC));
 	tm->tm_min	= BCD2BIN(ds1302_readbyte(RTC_ADDR_MIN));
 	tm->tm_hour	= BCD2BIN(ds1302_readbyte(RTC_ADDR_HOUR));
 	tm->tm_wday	= BCD2BIN(ds1302_readbyte(RTC_ADDR_DAY));
 	tm->tm_mday	= BCD2BIN(ds1302_readbyte(RTC_ADDR_DATE));
 	tm->tm_mon	= BCD2BIN(ds1302_readbyte(RTC_ADDR_MON)) - 1;
 	tm->tm_year	= BCD2BIN(ds1302_readbyte(RTC_ADDR_YEAR));

 	if (tm->tm_year < 70)
 		tm->tm_year += 100;

 	spin_unlock_irq(&rtc->lock);

 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 		"mday=%d, mon=%d, year=%d, wday=%d\n",
 		__func__,
 		tm->tm_sec, tm->tm_min, tm->tm_hour,
 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);

 	if (rtc_valid_tm(tm) < 0)
 		dev_err(dev, "invalid date\n");

 	return 0;
 }

 static int ds1302_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct ds1302_rtc *rtc = dev_get_drvdata(dev);

 	spin_lock_irq(&rtc->lock);

 	/* Stop RTC */
 	ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) | 0x80);

 	ds1302_writebyte(RTC_ADDR_SEC, BIN2BCD(tm->tm_sec));
 	ds1302_writebyte(RTC_ADDR_MIN, BIN2BCD(tm->tm_min));
 	ds1302_writebyte(RTC_ADDR_HOUR, BIN2BCD(tm->tm_hour));
 	ds1302_writebyte(RTC_ADDR_DAY, BIN2BCD(tm->tm_wday));
 	ds1302_writebyte(RTC_ADDR_DATE, BIN2BCD(tm->tm_mday));
 	ds1302_writebyte(RTC_ADDR_MON, BIN2BCD(tm->tm_mon + 1));
 	ds1302_writebyte(RTC_ADDR_YEAR, BIN2BCD(tm->tm_year % 100));

 	/* Start RTC */
 	ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);

 	spin_unlock_irq(&rtc->lock);

 	return 0;
 }

 static int ds1302_rtc_ioctl(struct device *dev, unsigned int cmd,
 			    unsigned long arg)
 {
 	switch (cmd) {
 #ifdef RTC_SET_CHARGE
 	case RTC_SET_CHARGE:
 	{
 		struct ds1302_rtc *rtc = dev_get_drvdata(dev);
 		int tcs_val;

 		if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int)))
 			return -EFAULT;

 		spin_lock_irq(&rtc->lock);
 		ds1302_writebyte(RTC_ADDR_TCR, (0xa0 | tcs_val * 0xf));
 		spin_unlock_irq(&rtc->lock);
 		return 0;
 	}
 #endif
 	}

 	return -ENOIOCTLCMD;
 }

 static struct rtc_class_ops ds1302_rtc_ops = {
 	.read_time	= ds1302_rtc_read_time,
 	.set_time	= ds1302_rtc_set_time,
 	.ioctl		= ds1302_rtc_ioctl,
 };

 static int __devinit ds1302_rtc_probe(struct platform_device *pdev)
 {
 	struct ds1302_rtc *rtc;
 	int ret;

 	/* Reset */
 	set_dp(get_dp() & ~(RTC_RESET | RTC_IODATA | RTC_SCLK));

 	/* Write a magic value to the DS1302 RAM, and see if it sticks. */
 	ds1302_writebyte(RTC_ADDR_RAM0, 0x42);
 	if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42)
 		return -ENODEV;

 	rtc = kzalloc(sizeof(struct ds1302_rtc), GFP_KERNEL);
 	if (unlikely(!rtc))
 		return -ENOMEM;

 	spin_lock_init(&rtc->lock);
 	rtc->rtc_dev = rtc_device_register("ds1302", &pdev->dev,
 					   &ds1302_rtc_ops, THIS_MODULE);
 	if (IS_ERR(rtc->rtc_dev)) {
 		ret = PTR_ERR(rtc->rtc_dev);
 		goto out;
 	}

 	platform_set_drvdata(pdev, rtc);

 	return 0;
 out:
 	kfree(rtc);
 	return ret;
 }

 static int __devexit ds1302_rtc_remove(struct platform_device *pdev)
 {
 	struct ds1302_rtc *rtc = platform_get_drvdata(pdev);

 	if (likely(rtc->rtc_dev))
 		rtc_device_unregister(rtc->rtc_dev);

 	platform_set_drvdata(pdev, NULL);

 	kfree(rtc);

 	return 0;
 }

 static struct platform_driver ds1302_platform_driver = {
 	.driver		= {
 		.name	= DRV_NAME,
 		.owner	= THIS_MODULE,
 	},
 	.probe		= ds1302_rtc_probe,
 	.remove		= __devexit_p(ds1302_rtc_remove),
 };

 static int __init ds1302_rtc_init(void)
 {
 	return platform_driver_register(&ds1302_platform_driver);
 }

 static void __exit ds1302_rtc_exit(void)
 {
 	platform_driver_unregister(&ds1302_platform_driver);
 }

 module_init(ds1302_rtc_init);
 module_exit(ds1302_rtc_exit);

 MODULE_DESCRIPTION("Dallas DS1302 RTC driver");
 MODULE_VERSION(DRV_VERSION);
 MODULE_AUTHOR("Paul Mundt, David McCullough");
 MODULE_LICENSE("GPL v2");
	/*
	* Dallas DS1302 RTC Support
	*
	* Copyright (C) 2002 David McCullough
	* Copyright (C) 2003 - 2007 Paul Mundt
	*
	* This file is subject to the terms and conditions of the GNU General Public
	* License version 2. See the file "COPYING" in the main directory of
	* this archive for more details.
	*/
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/platform_device.h>
	#include <linux/time.h>
	#include <linux/rtc.h>
	#include <linux/spinlock.h>
	#include <linux/io.h>
	#include <linux/bcd.h>
	#include <asm/rtc.h>

	#define DRV_NAME "rtc-ds1302"
	#define DRV_VERSION "0.1.0"

	#define RTC_CMD_READ 0x81 /* Read command */
	#define RTC_CMD_WRITE 0x80 /* Write command */

	#define RTC_ADDR_RAM0 0x20 /* Address of RAM0 */
	#define RTC_ADDR_TCR 0x08 /* Address of trickle charge register */
	#define RTC_ADDR_YEAR 0x06 /* Address of year register */
	#define RTC_ADDR_DAY 0x05 /* Address of day of week register */
	#define RTC_ADDR_MON 0x04 /* Address of month register */
	#define RTC_ADDR_DATE 0x03 /* Address of day of month register */
	#define RTC_ADDR_HOUR 0x02 /* Address of hour register */
	#define RTC_ADDR_MIN 0x01 /* Address of minute register */
	#define RTC_ADDR_SEC 0x00 /* Address of second register */

	#define RTC_RESET 0x1000
	#define RTC_IODATA 0x0800
	#define RTC_SCLK 0x0400

	#ifdef CONFIG_SH_SECUREEDGE5410
	#include <mach/snapgear.h>
	#define set_dp(x) SECUREEDGE_WRITE_IOPORT(x, 0x1c00)
	#define get_dp() SECUREEDGE_READ_IOPORT()
	#else
	#error "Add support for your platform"
	#endif

	struct ds1302_rtc {
	struct rtc_device *rtc_dev;
	spinlock_t lock;
	};

	static void ds1302_sendbits(unsigned int val)
	{
	int i;

	for (i = 8; (i); i--, val >>= 1) {
	set_dp((get_dp() & ~RTC_IODATA) \| ((val & 0x1) ?
	RTC_IODATA : 0));
	set_dp(get_dp() \| RTC_SCLK); /* clock high */
	set_dp(get_dp() & ~RTC_SCLK); /* clock low */
	}
	}

	static unsigned int ds1302_recvbits(void)
	{
	unsigned int val;
	int i;

	for (i = 0, val = 0; (i < 8); i++) {
	val \|= (((get_dp() & RTC_IODATA) ? 1 : 0) << i);
	set_dp(get_dp() \| RTC_SCLK); /* clock high */
	set_dp(get_dp() & ~RTC_SCLK); /* clock low */
	}

	return val;
	}

	static unsigned int ds1302_readbyte(unsigned int addr)
	{
	unsigned int val;

	set_dp(get_dp() & ~(RTC_RESET \| RTC_IODATA \| RTC_SCLK));

	set_dp(get_dp() \| RTC_RESET);
	ds1302_sendbits(((addr & 0x3f) << 1) \| RTC_CMD_READ);
	val = ds1302_recvbits();
	set_dp(get_dp() & ~RTC_RESET);

	return val;
	}

	static void ds1302_writebyte(unsigned int addr, unsigned int val)
	{
	set_dp(get_dp() & ~(RTC_RESET \| RTC_IODATA \| RTC_SCLK));
	set_dp(get_dp() \| RTC_RESET);
	ds1302_sendbits(((addr & 0x3f) << 1) \| RTC_CMD_WRITE);
	ds1302_sendbits(val);
	set_dp(get_dp() & ~RTC_RESET);
	}

	static int ds1302_rtc_read_time(struct device dev, struct rtc_time tm)
	{
	struct ds1302_rtc *rtc = dev_get_drvdata(dev);

	spin_lock_irq(&rtc->lock);

	tm->tm_sec = BCD2BIN(ds1302_readbyte(RTC_ADDR_SEC));
	tm->tm_min = BCD2BIN(ds1302_readbyte(RTC_ADDR_MIN));
	tm->tm_hour = BCD2BIN(ds1302_readbyte(RTC_ADDR_HOUR));
	tm->tm_wday = BCD2BIN(ds1302_readbyte(RTC_ADDR_DAY));
	tm->tm_mday = BCD2BIN(ds1302_readbyte(RTC_ADDR_DATE));
	tm->tm_mon = BCD2BIN(ds1302_readbyte(RTC_ADDR_MON)) - 1;
	tm->tm_year = BCD2BIN(ds1302_readbyte(RTC_ADDR_YEAR));

	if (tm->tm_year < 70)
	tm->tm_year += 100;

	spin_unlock_irq(&rtc->lock);

	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	"mday=%d, mon=%d, year=%d, wday=%d\n",
	__func__,
	tm->tm_sec, tm->tm_min, tm->tm_hour,
	tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);

	if (rtc_valid_tm(tm) < 0)
	dev_err(dev, "invalid date\n");

	return 0;
	}

	static int ds1302_rtc_set_time(struct device dev, struct rtc_time tm)
	{
	struct ds1302_rtc *rtc = dev_get_drvdata(dev);

	spin_lock_irq(&rtc->lock);

	/* Stop RTC */
	ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) \| 0x80);

	ds1302_writebyte(RTC_ADDR_SEC, BIN2BCD(tm->tm_sec));
	ds1302_writebyte(RTC_ADDR_MIN, BIN2BCD(tm->tm_min));
	ds1302_writebyte(RTC_ADDR_HOUR, BIN2BCD(tm->tm_hour));
	ds1302_writebyte(RTC_ADDR_DAY, BIN2BCD(tm->tm_wday));
	ds1302_writebyte(RTC_ADDR_DATE, BIN2BCD(tm->tm_mday));
	ds1302_writebyte(RTC_ADDR_MON, BIN2BCD(tm->tm_mon + 1));
	ds1302_writebyte(RTC_ADDR_YEAR, BIN2BCD(tm->tm_year % 100));

	/* Start RTC */
	ds1302_writebyte(RTC_ADDR_SEC, ds1302_readbyte(RTC_ADDR_SEC) & ~0x80);

	spin_unlock_irq(&rtc->lock);

	return 0;
	}

	static int ds1302_rtc_ioctl(struct device *dev, unsigned int cmd,
	unsigned long arg)
	{
	switch (cmd) {
	#ifdef RTC_SET_CHARGE
	case RTC_SET_CHARGE:
	{
	struct ds1302_rtc *rtc = dev_get_drvdata(dev);
	int tcs_val;

	if (copy_from_user(&tcs_val, (int __user *)arg, sizeof(int)))
	return -EFAULT;

	spin_lock_irq(&rtc->lock);
	ds1302_writebyte(RTC_ADDR_TCR, (0xa0 \| tcs_val * 0xf));
	spin_unlock_irq(&rtc->lock);
	return 0;
	}
	#endif
	}

	return -ENOIOCTLCMD;
	}

	static struct rtc_class_ops ds1302_rtc_ops = {
	.read_time = ds1302_rtc_read_time,
	.set_time = ds1302_rtc_set_time,
	.ioctl = ds1302_rtc_ioctl,
	};

	static int __devinit ds1302_rtc_probe(struct platform_device *pdev)
	{
	struct ds1302_rtc *rtc;
	int ret;

	/* Reset */
	set_dp(get_dp() & ~(RTC_RESET \| RTC_IODATA \| RTC_SCLK));

	/* Write a magic value to the DS1302 RAM, and see if it sticks. */
	ds1302_writebyte(RTC_ADDR_RAM0, 0x42);
	if (ds1302_readbyte(RTC_ADDR_RAM0) != 0x42)
	return -ENODEV;

	rtc = kzalloc(sizeof(struct ds1302_rtc), GFP_KERNEL);
	if (unlikely(!rtc))
	return -ENOMEM;

	spin_lock_init(&rtc->lock);
	rtc->rtc_dev = rtc_device_register("ds1302", &pdev->dev,
	&ds1302_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc->rtc_dev)) {
	ret = PTR_ERR(rtc->rtc_dev);
	goto out;
	}

	platform_set_drvdata(pdev, rtc);

	return 0;
	out:
	kfree(rtc);
	return ret;
	}

	static int __devexit ds1302_rtc_remove(struct platform_device *pdev)
	{
	struct ds1302_rtc *rtc = platform_get_drvdata(pdev);

	if (likely(rtc->rtc_dev))
	rtc_device_unregister(rtc->rtc_dev);

	platform_set_drvdata(pdev, NULL);

	kfree(rtc);

	return 0;
	}

	static struct platform_driver ds1302_platform_driver = {
	.driver = {
	.name = DRV_NAME,
	.owner = THIS_MODULE,
	},
	.probe = ds1302_rtc_probe,
	.remove = __devexit_p(ds1302_rtc_remove),
	};

	static int __init ds1302_rtc_init(void)
	{
	return platform_driver_register(&ds1302_platform_driver);
	}

	static void __exit ds1302_rtc_exit(void)
	{
	platform_driver_unregister(&ds1302_platform_driver);
	}

	module_init(ds1302_rtc_init);
	module_exit(ds1302_rtc_exit);

	MODULE_DESCRIPTION("Dallas DS1302 RTC driver");
	MODULE_VERSION(DRV_VERSION);
	MODULE_AUTHOR("Paul Mundt, David McCullough");
	MODULE_LICENSE("GPL v2");